Growth Plate Fractures (Physeal Fractures) 

Updated: Dec 13, 2021
Author: Steven I Rabin, MD, FAAOS; Chief Editor: Jeffrey D Thomson, MD 

Overview

Practice Essentials

Growth plate (physeal) fractures may be defined as disruptions in the cartilaginous physis of long bones that may or may not involve epiphyseal or metaphyseal bone.[1]

Injuries to the physes are more likely to occur in an active pediatric population than sprains or ligament injuries are, in part because the ligaments and joint capsules have greater structural strength and integrity than the growth plates do.[2]  These ligamentous structures are two to five times stronger than the growth plates at either end of a long bone and therefore are less often injured in children sustaining excessive external loads to the joints. Injuries that might injure the ligaments in adults will more often injure the physes in the skeletally immature.[2, 3, 4, 5]

Growth plate injuries can usually be distinguished from sprains on clinical examination, where the growth plate injury is tender over the bone and the sprain is tender over the joint itself. When there is doubt, the injury should usually be considered a physeal or growth plate injury because of the potential for serious long-term complications (including growth arrest or deformity) with an occult physeal injury. However, Boutis et al did demonstrate, at least in the ankle, that with negative radiographs, magnetic resonance imaging (MRI) consistently demonstrates sprains instead of growth plate injuries.[6]

This article discusses some of the important orthopedic history relative to the physes, the relevant anatomy, the most commonly used classification system, and some details of physeal fractures in specific areas of the body. It is essential to keep in mind that with growth plate fractures, as with real estate, the most important datum is location, and timing is the key to treatment.

Furthermore, it must be clearly understood that children are not merely smaller versions of adults. There are specific considerations in treating childhood fractures that differ from those appropriate in treating adult fractures, often including different surgical approaches and technical concerns, different alignment goals, different fixation devices, and different follow-up intervals. What is unacceptable in an adult might be acceptable in a child.

Children are likely to develop growth plate injuries when subjected to similar trauma at joints where adults tend to tear their ligaments. The growth plate is the weakest part of the bone.[3, 4]  It is two to five times weaker than the surrounding connective tissue (tendons and ligaments).[7, 5]

Participation in sports increases the risk of growth plate injury.[8]  Injuries to the growth plates in young athletes has been increasing over the past 70 years.[7]  With more than 30 million childen involved in organized sports in the United States alone, these injuries likely will continue to increase.[3, 4]  This increased prevalence of growth plate injury may be due to year-round training, early sports specialization, starting at younger ages, and a decreased emphasis on free play.[7]  Additionally, there has been an increase in repetitive loading without adequate rest, resulting in overuse pathology.[7]

There are two types of growth plates: the epiphyses, which are at the ends of bones and provide longitudinal growth, and the apophyses, which are at the points of muscle attachments.[7]

The treating provider needs to know which fractures are likely to remodel (usually those with angulation in the plane of joint motion) and which are unlikely to remodel (eg, fractures with rotational deformity, joint incongruity, or physeal stepoff, as well as those occurring in patients near skeletal maturity). Surgical approaches may also be different in children as compared with adults; percutaneous Kirschner wire (K-wire) fixation may be stable enough, and prevention of iatrogenic injury to the physis is of significant importance. 

When growth deformity is possible, the treating provider must predict the degree of expected remodeling, and this requires an understanding of the specific fracture. Assessment of bone age using the Greulich-Pyle atlas and charts can give an estimate of remaining growth. Fractures in the metaphysis, closer to the growth plate, remodel more reliably than those in the diaphysis do. If inadequate remodeling is predicted, then corrective surgery is usually required. 

If surgery is required, it is best to initiate treatment promptly, before healing begins and fracture surfaces smooth off or Z-deformities develop with partial continued growth. If a chronic deformity has developed, correction with epiphysiodesis is commonly preferred to the more invasive osteotomy.

In general, the limited access and small bones encountered in pediatric procedures make surgical treatment more technically challenging in children than similar operations in adults would be.

See Common Pediatric Sports and Recreational Injuries, a Critical Images slideshow, to help recognize some of the more common injuries and conditions associated with pediatric recreational activities 

Anatomy

Technically, two growth plates may be considered to exist in immature long bones: the horizontal growth plate (physis) and the spherical growth plate (which enables epiphyseal growth). For the purposes of this article, the horizontal growth plate is addressed.

There are two types of growth plates: the epiphyses, which are at the ends of bones and provide longitudinal growth, and the apophyses, which are at the points of muscle attachments.[7, 9]

The horizontal growth plate is easily seen on radiographs of most growing long bones as a horizontal radiolucent region near the end of the bone. It may also be referred to as the cartilaginous growth plate, physis, or epiphyseal plate. The epiphysis is not the cartilaginous growth plate—epiphysis and growth plate are not synonyms—but, rather, the bone of the secondary ossification center.

Zones of physis

The physis is an organized system of tissue located at the ends of long bones, consisting of an arrangement of chondrocytes surrounded by a matrix consisting of proteoglycan aggregates. The chondrocytes of the physis are divided into a system of zones based on different stages of maturation in the endochondral sequence of ossification and their function, as follows.

Reserve/resting zone

The reserve/resting zone is immediately adjacent to the epiphysis and consists of irregularly scattered chondrocytes with low rates of proliferation. This layer supplies developing cartilage cells and stores necessary materials (eg, lipids, glycogen, and proteoglycan aggregates) for later growth, and injury to this layer results in cessation of growth.

Proliferative zone

In this zone, chondrocytes are flattened and stacked upon each other in well-defined columns. These cells produce necessary matrix and are responsible for longitudinal growth of the bone via active cell division.

Hypertrophic zone

In the hypertrophic zone, adjacent to the metaphysis (which is further subdivided into maturation, degeneration, and provisional calcification zones), cells increase in size, accumulate calcium within their mitochondria, and deteriorate. The ultimate result is cell death, which releases calcium from matrix vesicles, impregnating the matrix with calcium salt (a process necessary for invasion of metaphyseal blood vessels, ingrowth of chondroclasts and osteblasts, destruction of cartilage cells, and bone formation along the walls of the calcified cartilage matrix).

No active growth occurs in this layer. Columns of cells extending toward the metaphysis are at various stages of maturation. This is the weakest portion of the physis and is commonly a site of fracture or alteration (eg, widening, as in rickets)

Metaphysis

The metaphysis, adjacent to the physis, is composed of primary and secondary spongiosa layers. Primary spongiosa is mineralized to form woven bone and is subsequently remodeled to form secondary spongiosa. Branches of the metaphyseal and nutrient arteries enter the secondary spongiosa and form closed capillary loops in the primary spongiosa.

Periphery of physis

The periphery of the physis consists of the following two elements:

  • Groove of Ranvier
  • Perichondrial ring (of Lacroix)

The groove of Ranvier is a wedge-shaped zone of cells contiguous with the epiphysis at the periphery. It supplies chondrocytes to the periphery of the physis, enabling lateral growth or increased width of the physis. Langenskiöld proposed that cells from the reserve zone migrate into the region of the groove of Ranvier.[10]  The perichondrial ring is a dense fibrous ring that surrounds the physis and is critical to the overall stability of the growth plate. The perichondrial ring's stabilizing effect may be lost in pathologic conditions such as slipped capital femoral epiphysis (SCFE).

Pathophysiology

Growth plate (physeal) fractures are typically believed to occur through the zone of provisional calcification but may traverse several zones, depending on the type of external load application. For instance, with application of compression-type loads, the histologic zone of failure is typically the provisional calcification portion of the hypertrophic zone. Shear forces may also cause failure in the hypertrophic zone. Tension forces lead to failure of the proliferative zone.

Growth plate injury can also be iatrogrenic. A common concern is repair of the anterior cruciate ligament (ACL) in the skeletally immature. Wall et al reported an "all-epiphyseal" ACL reconstruction to avoid transfixation or drilling across active open growth plates.[11] Although there were no growth arrests, three patients had knee overgrowth, with two requiring further surgery. The ACL reconstructions had excellent functional outcomes despite high rates of complications (48%) and secondary procedures (37%). The incidence of graft failure was similar to that seen with other ACL techniques.

Growth plate injuries can be divided into two broad categories: (1) primary epiphyseal injuries that are usually due to acute trauma and (2) apophyseal injuries that are usually due to overuse.[7] Apophyses are located at the sites where tendons attach to bone. The tendons do not grow as fast as the bone, causing tension at the apophysis, especially during periods of rapid growth. The imbalance results in inflammation and potentially acute avulsion.

Apophyseal injuries are especially common in children involved in running, pivoting, throwing, kicking, and jumping sports.[7]  Such injuries can be acute or chronic. Acute avulsions occur from a violent muscle contraction transmitted across the apophysis. There is sudden onset of pain, swelling, and weakness, and radiographs confirm the infjury. Chronic apophyseal avulsions are due to repetitive traction across the muscle-tendon-bone-cartilage complex, where the cartilage of the apophysis is the "weakest link."[4]

Examples of overuse apophyseal injuries include Osgood-Schlatter disease, Sever disease (calcaneal apophysitis), and Sindig-Larsen-Johannsson syndrome; these involve chronic apophysitis/inflammation at apophyses—specifically, the patellar tendon insertion at the tibial tuberosity apophysis, the Achilles tendon at the vertical calcaneal apophysis, and the patellar tendon at the inferior pole of the patella, respectively.[3]  Little League elbow is an overuse injury of the medial epicondylar apophysis (the attachment for the forearm flexing and pronating muscles).[4]

Factors that increase the risk of overuse injury include anatomic misalignment; prior injury; poor conditioning; growth spurts; improper training methods; poor technique; improper surfaces for practice or competition; excessive pressure to perform from peers, coaches, and parents; inappropriate equipment; and unreported injuries.[5] Growth plate injuries are especially common during periods of rapid bone growth.[7, 5]

Classification of Epiphyseal Injuries

Growth plate injuries were first classified by Poland in 1898; his four-part classification system progressed from a simple epiphyseal separation to an epiphyseal separation in which it is split in two. Many other classification systems followed, including a system suggested by Petersen in 1994. This system was constructed on the basis of a population-based epidemiologic study and was arranged to progress from the physis least involved to the injury that posed the greatest threat to the physis.

Of the various classification systems used throughout the world, the Salter-Harris (SH) classification, initially proposed in 1963 by Robert Salter and W Robert Harris of Toronto,[12, 13]  is generally preferred and is the accepted standard in North America to facilitate communication among healthcare professionals.[14, 15, 4] The Salter-Harris system categorized the various fracture patterns into five types (subsequently expanded to six) as follows.

Salter-Harris type I

An SH I fracture typically traverses through the hypertrophic zone of the cartilaginous physis, splitting it and separating the epiphysis from the metaphysis. When these fractures are nondisplaced, they may not be readily evident on radiographs because of the lack of bony involvement. In many instances, only mild-to-moderate soft-tissue swelling is noted radiographically.

Clinical findings may be more impressive than imaging (see the first image below); however, subsequent radiographs may demonstrate physeal widening or new bone growth along physeal margins, indicating the presence of a healing fracture (see the second image below). In general, the prognosis for this type of fracture is excellent. Usually, only closed reduction is necessary for displaced fractures; however, open reduction and internal fixation (ORIF) may be necessary if a stable satisfactory reduction cannot be maintained.

Growth plate (physeal) fractures. Clinical appeara Growth plate (physeal) fractures. Clinical appearance of knee of patient with minimally displaced Salter-Harris I fracture of distal femur. Impressive swelling was noted adjacent to joint, but no evidence of intra-articular swelling was present. Patient was markedly tender to palpation about distal femoral physis.
Growth plate (physeal) fractures. Anteroposterior Growth plate (physeal) fractures. Anteroposterior radiograph of knee of patient in previous image. Note subtle physeal widening, confirming diagnosis of Salter-Harris I fracture of distal femur.

Salter-Harris type II

An SH II fracture splits partially through the physis and includes a variably sized triangular bone fragment of metaphysis (see the image below). This fragment is often referred to as the Thurstan Holland fragment in honor of the British radiologist Charles Thurstan Holland, who drew attention to its existence in 1929.

Growth plate (physeal) fractures. Anteroposterior Growth plate (physeal) fractures. Anteroposterior ankle radiograph demonstrates impressively displaced Salter-Harris II fracture of distal tibial epiphysis (along with comminuted fracture of distal fibular diaphysis).

Periosteum on the side of the Thurstan Holland fragment often remains intact, thus facilitating reduction. This particular fracture pattern occurs in an estimated 75% of all physeal fractures, and it is the most common physeal fracture. The image below illustrates an SH II fracture of the distal femur.

Growth plate (physeal) fractures. Displaced Salter Growth plate (physeal) fractures. Displaced Salter-Harris II fracture of distal femur. Large Thurstan Holland (metaphyseal) fragment may serve as important fixation point for either Steinmann pin or lag screw.

Salter-Harris type III

A SH III fracture pattern combines physeal injury with an articular discontinuity. This fracture partially involves the physis and then extends through the epiphysis into the joint. It has the potential to disrupt the joint surface. This injury is less common and often requires ORIF to ensure proper anatomic realignment of both the physis and the joint surface. .

The image below depicts a common SH III fracture of the distal tibia, a Tillaux fracture, on computed tomography (CT).

Growth plate (physeal) fractures. Multiple compute Growth plate (physeal) fractures. Multiple computed tomography (CT) scans depict displaced Salter-Harris III fracture of distal anterolateral tibial epiphysis (ie, Tillaux fracture).

Salter-Harris type IV

An SH IV fracture runs obliquely through the metaphysis, traverses the physis and epiphysis, and enters the joint. The Thurstan Holland sign (ie, a Thurstan Holland fragment) is also seen with this fracture pattern. The image below illustrates such a fracture of the proximal tibia.

Growth plate (physeal) fractures. Displaced Salter Growth plate (physeal) fractures. Displaced Salter-Harris IV fracture of proximal tibia. Lateral portion of epiphysis (with Thurstan Holland fragment) and medial portion of epiphysis are independently displaced (ie, each is free-floating fragment).

Salter-Harris type V

An SH V lesion involves compression or crush injuries to the physis and is often impossible to diagnose definitively at the time of injury. Knowledge of the injury mechanism simply makes one more or less suspicious of this injury. No fracture lines are evident on initial radiographs, but they may be associated with diaphyseal or metaphyseal fractures. (See the images below.)

Growth plate (physeal) fractures. Salter-Harris V Growth plate (physeal) fractures. Salter-Harris V fracture pattern must be strongly suspected whenever mechanism of injury includes significant compressive forces. This is initial injury radiograph of child's ankle that was subjected to significant compressive and inversion forces. It demonstrates minimally displaced fractures of tibia and fibula with apparent maintenance of distal tibial physeal architecture.
Growth plate (physeal) fractures. Follow-up radiog Growth plate (physeal) fractures. Follow-up radiograph of ankle of child in preceding image. This radiograph depicts growth arrest secondary to Salter-Harris V nature of the injury. Note markedly asymmetric Park-Harris growth recovery line, indicating that lateral portion of growth plate continues to function and medial portion does not.

SH V fractures are generally very rare; however, family members should be warned of the potential disturbance in growth and should be made aware that if growth disturbance occurs, treatment is still available (depending on the child's age and remaining growth potential).

Salter-Harris type VI

An additional classification of physeal fractures that was not considered in the original SH classification but is now occasionally included is SH VI, which describes an injury to the peripheral portion of the physis and may result in a peripheral bony bridge formation that may produce considerable angular deformity by tethering the intact physis.[16]  (See the images below.)

Growth plate (physeal) fractures. Mortise radiogra Growth plate (physeal) fractures. Mortise radiograph demonstrating somewhat subtle physeal injury to distal tibia. Salter-Harris VI pattern may be suspected on basis of history and physical examination. In this case, radiograph indicates that it is quite likely that small portion of peripheral medial physis (as well as small amount of adjacent epiphyseal and metaphyseal bone) has been avulsed.
Growth plate (physeal) fractures. Clinical photogr Growth plate (physeal) fractures. Clinical photograph of patient above with displaced Salter-Harris II fracture of distal femur. Mechanism of injury and physical examination findings are consistent with Salter-Harris VI physeal injury pattern. Some may also refer to this injury type as Kessel fracture.

This injury was suggested by Lipmann Kessel, who described it as follows: "A rare injury of growth plate results from damage to the periosteum or perichondral ring ... following burns or a blow to the surface of the limb, for example a run over injury."[17]

Epidemiology

Mann and Rajmaira collected data on 2650 long bone fractures, 30% of which involved the physes.[18] Neer and Horowitz evaluated 2500 fractures to the physes (growth plate) and determined that the distal radius was the most frequent site of injury (44%), followed by the distal humerus (13%), distal fibula, distal tibia, distal ulna, proximal humerus, distal femur, proximal tibia, and proximal fibula.[19]

According to a 1972 retrospective analysis of 330 acute physeal (growth plate) injuries seen over the course of 20 years, males were affected more than twice as often as females. Females were most frequently affected at a younger age than males (11-12 years vs 12-14 years). These findings correspond with the growth spurts (when the physes are weakest) of the respective sexes and with males' increased willingness to engage in high-risk activities. Within this population, upper-extremity injuries were more frequent than lower-extremity injuries overall.

Prognosis

Prognosis depends on the severity of physeal damage, the skeletal age of the patient, the treatment, and the site of the fracture.

For chronic overuse apophyseal injuries (such as occur in Osgood-Schlatter disease, for example), earlier treatment improves prognosis.[7] The prognosis is good in most athletes with appropriate treatment.[4]

The severity of physeal damage is categorized according to the SH classification (see Classification of Epiphyseal Injuries). Type I injury (separation through the physis) has the best prognosis, whereas type V injury (a crush injury to the physis) and type VI injury have worse prognoses.[4]

Pediatric patients who are still growing have the potential to remodel or restore angulation with continued growth, especially in the plane of joint motion. (Intra-articular stepoffs and rotational deformities do not remodel.) The closer the patient is to skeletal maturity, the less likely it is that full correction of the deformity will occur.

The site of the fracture also influences remodeling. The undulating nature of the distal femur physis makes any displacement of the epiphysis relative to the metaphysis more difficult to reduce anatomically and more prone to the development of bone bars crossing the physis and tethering growth, resulting in angulation and shortening. Distal femur physeal fractures have a 40% complication rate. The proximal femur physis is intra-articular, with potential disruption of the vascular supply also increasing the risk of complications after physeal injury. The proximal tibia has a tendency to angulate with growth as well, even with an anatomic reduction.

 

Presentation

History

Patients with acute growth plate fracture typically complain of what seems to be localized joint pain, often following a traumatic event (eg, fall or collision). Swelling near a joint with focal tenderness over the physis is usually present (see the image below). Lower-extremity injuries present as an inability to bear weight on the injured side; upper-extremity injuries present with complaints of impaired function and reduced range of motion (ROM), quite similar to ligamentous injury. 

Growth plate (physeal) fractures. Clinical appeara Growth plate (physeal) fractures. Clinical appearance of knee of patient with minimally displaced Salter-Harris I fracture of distal femur. Impressive swelling was noted adjacent to joint, but no evidence of intra-articular swelling was present. Patient was markedly tender to palpation about distal femoral physis.

Most acute injuries to the growth plates are from a fall. It is essential to obtain a history of sports involvement, in that 33% of acute injuries occur during sports. Hockey, football, and baseball are the activities most often involved; biking, skiing, and snowboarding are the next most common activities causing acute growth plate injury.[4]  Little League shoulder, gymnast wrist, Little League elbow, Osgood-Schlatter disease, Sever disease, and Sinding-Larsen-Johansson disease are examples of physeal injuries commonly associated with sports that involve overuse at specific apophyses.[3]  

Physical Examination

The main differential in a pediatric patient who has pain and swelling at the distal end of a long bone with normal radiographs is a sprain. If the patient has tenderness specifically directly over the bone/growth plate, the injury is most likely a Salter-Harris (SH) type I physeal injury. If the tenderness is more over the ligaments, then the injury could be a sprain. Because the ligaments are five times stronger than the physis, most "sprains" in children are actually SH I growth plate injuries.

Ligamentous laxity tests of the joints of the injured side may elicit pain and positive findings similar to those indicative of joint injury. (An SH III or SH IV fracture of the distal femur is the classic example.) Positive joint laxity test findings must not be dismissed as only involving the related joint tissues.

 

DDx

Diagnostic Considerations

A high index of suspicion is required to diagnose many growth plate injuries. If initial images are normal but clinical examination reveals tenderness over a physis, additional images including oblique images, comparison views of the opposite side, computed tomography (CT), or magnetic resonance imaging (MRI) may be indicated.  Misdiagnosis of a physeal injury as a sprain can result in long-term complications from growth deformity including growth arrest and arthritis.

An example is provided by the case of a child with knee pain and tenderness over the physis in whom routine anteroposterior (AP) and lateral imaging do not show the fracture (see the first image below). An inexpensive oblique x-ray easily reveals the Salter-Harris (SH) type III fracture of the distal femur (see the second image below).

Growth plate (physeal) fractures. Anteroposterior Growth plate (physeal) fractures. Anteroposterior and lateral views of distal femur Salter-Harris III fracture where fracture is not well seen.
Growth plate (physeal) fractures. Oblique view of Growth plate (physeal) fractures. Oblique view of distal femur reveals Salter-Harris III fracture of distal femur.

Another example is provided by the case of a patient with ankle pain in whom plain radiographs do not show the Tillaux fracture of the distal tibia (see the first image below) but a CT scan clearly reveals the pathology (see the second image below).

Growth plate (physeal) fractures. Tillaux fracture Growth plate (physeal) fractures. Tillaux fracture of distal tibia epiphysis that is not well seen on anteroposterior radiograph.
Growth plate (physeal) fractures. Tillaux fracture Growth plate (physeal) fractures. Tillaux fracture that was not well seen on plain radiographs is now relatively easy to see on axial CT image.

Differential Diagnoses

 

Workup

Plain Radiography

Many acute physeal injuries are not clearly visible on plain radiographs, because of the cartilaginous-osseous nature and irregular contours of the physes.[20]

Plain radiographs may depict physeal widening as the only sign of displacement. In order to help delineate the injury, two views perpendicular to each other (usually anteroposterior [AP] and lateral) are necessary. Oblique images may also better define a fracture. An example is shown below, in which a Salter-Harris (SH) type III fracture is not well seen on the usual AP and lateral images (see the first image below) but is well seen on the oblique image (see the second image below).

Growth plate (physeal) fractures. Anteroposterior Growth plate (physeal) fractures. Anteroposterior and lateral views of distal femur Salter-Harris III fracture where fracture is not well seen.
Growth plate (physeal) fractures. Oblique view of Growth plate (physeal) fractures. Oblique view of distal femur reveals Salter-Harris III fracture of distal femur.

Another example is shown below, in which a radial head fracture is not well seen on the usual AP and lateral images (see the first image below) but is well seen on the oblique image (see the second image below).

Growth plate (physeal) fractures. Radial head frac Growth plate (physeal) fractures. Radial head fracture in child that is difficult to see on standard anteroposterior and lateral images.
Growth plate (physeal) fractures. Radial head frac Growth plate (physeal) fractures. Radial head fracture in child that was difficult to see on anteroposterior and lateral images is now well seen on oblique view.

Occasionally, comparison views of the opposite extremity may be helpful. Comparison views can help establish occult separation of the physis, as in an SH I injury. 

Radiographic stress views (varus and valgus) may be indicated in certain patients. They are not recommended in all instances, because stress maneuvers may cause further physeal damage. However, stress radiographs may be necessary in order to accurately diagnose physeal plate injury. Stress views may prove particularly useful for demonstrating separation between the epiphysis and the metaphysis in injuries around the knee and elbow.[21]

Overuse injury to the physes often appears as widening of the physis on plain radiographs.[22]  Additional changes with chronic stress to apophyses include fragmentation and irregular ossification (typically seen in Osgood-Schlatter disease, for example). 

Other Imaging Modalities

Computed tomography

Computed tomography (CT) is at times necessary to delineate fragmentation and orientation of severely comminuted epiphyseal and metaphyseal fractures.[23]  CT is indicated for cases where the patient has tenderness over the physis but plain radiographs are normal or for preoperative planning to aid the surgeon in reduction or fixation. (See the images below.)  Advanced imaging modalities (including CT and magnetic resonance imaging [MRI]) show greater average displacement than plain radiographs do.[24]

Growth plate (physeal) fractures. Tillaux fracture Growth plate (physeal) fractures. Tillaux fracture of distal tibia epiphysis that is not well seen on anteroposterior radiograph.
Growth plate (physeal) fractures. Tillaux fracture Growth plate (physeal) fractures. Tillaux fracture that was not well seen on plain radiographs is now relatively easy to see on axial CT image.

Bone scanning

Bone scans are not particularly helpful, because the physes are normally relatively active on nuclear scans.

Magnetic resonance imaging

MRI has proved to be the most accurate evaluation tool for the fracture anatomy when performed in the acute phase of injury (initial 10 days). MRI can depict altered arrest lines and transphyseal bridging abnormalities before they are evident on plain radiographs.[25]

 

Treatment

Approach Considerations

Salter-Harris (SH) I and SH II growth plate (physeal) injuries usually can be managed adequately with closed manipulative reduction. Upon reduction, these injuries are typically stable, and casting suffices. At times, periosteal flaps or other local tissue may interpose into the fracture site and inhibit complete reduction. This complication may necessitate surgical extraction of the tissues to enable satisfactory or anatomic reduction.[14, 26]

SH III and SH IV injuries represent disruption of the physis and the epiphysis, as well as intra-articular fracture. Intra-articular discontinuity can lead to early degenerative arthritis, and physeal discontinuity can disturb longitudinal growth. According to Bright,[26]  proper management of SH III and SH IV injuries requires anatomic reduction and internal fixation to restore anatomic alignment of the joint surfaces and proper alignment of juxtaposing physeal surfaces. In many cases, nondisplaced fracture fragments have migrated subsequent to cast immobilization only.

SH V and SH VI injuries often result in partial or complete growth arrest (physeal bar formation). As a result, physeal bar resection may be required, or other surgical procedures may be necessary to prevent or correct deformity.[15]

Absolute contraindications for reduction of displaced growth plate fractures are few. They amount to the unusual situations in which the risks of sedation or general anesthesia are believed to dramatically outweigh the potential benefits of growth plate fracture reduction.

Relative contraindications for growth plate fracture reduction would be SH I or II fractures with clinically insignificant displacement. Also, fractures with greater displacement that present late (>1 week after injury) should not be manipulated. In such cases, the risks of the additional force that would have to be exerted on the growth plate must be weighed against the likelihood of spontaneous remodeling of the fracture over time or performing an osteotomy later after growth has ceased.

Nonoperative Therapy

Closed reduction, casting, and splinting

Very commonly, growth plate (physeal) fractures can be treated nonoperatively. Factors that affect treatment decisions include the following:

  • Severity of the injury
  • Anatomic location of the injury
  • Classification of the fracture
  • Plane of the deformity
  • Patient age
  • Growth potential of the involved physis

Most SH I and II injuries can be treated with closed reduction and casting or splinting and then reexamination in 7-10 days to evaluate maintenance of the reduction.

Some sites, such as the proximal humerus and clavicle, have excellent potential to heal and remodel even with severe-appearing deformity.

As an illustrative example of proximal humerus remodeling, a 7-year-old boy presented with a deformed proximal humerus fracture (see the first image below). The fracture healed with abundant callus but with deformity (see the second image below). Excellent remodeling was already seen at 2-year follow-up (see the third image below).

Growth plate (physeal) fractures. Angulated proxim Growth plate (physeal) fractures. Angulated proximal humerus fracture in child (anteroposterior and Y views).
Growth plate (physeal) fractures. Healed proximal Growth plate (physeal) fractures. Healed proximal humerus with abundant callus and angulation in child.
Growth plate (physeal) fractures. Remodeling of pr Growth plate (physeal) fractures. Remodeling of proximal humerus fracture in child.

Closed reductions through manipulation and traction must be performed carefully, with the patient (and the involved musculature) as relaxed as possible in order to avoid unnecessary wrestling of the bony components that may lead to grating of the physis on sharp metaphyseal bone fragments and potential iatrogenic damage to the physis. In an uncooperative patient (or one with significant pain or muscle spasm), reduction under anesthesia is preferred.

Less-than-satisfactory reductions are preferred to repeated attempts at reduction that may damage the germinal layer of cells within the physis. To avoid physeal damage, efforts at reduction should focus more on traction and less on forceful manipulation of the bone fragments.

Disruption of the physis may warrant restoration of its congruency to ensure proper joint mechanics. Angular deformities may occur as a consequence of malreduction or partial growth arrest. The location and direction of the deformity must be considered in planning treatment. In general, greater angular deformity can be tolerated in the upper extremity than in the lower extremity, more valgus deformity can be tolerated than varus, and more flexion deformity can be tolerated than extension. Rotation is not well tolerated, especially in the lower extremity.

More proximal deformities of the lower extremity are better compensated for than distal deformities (with ankle deformities least well compensated of all). Spontaneous correction of angular deformities is greatest when the asymmetry is in the plane of flexion or extension (ie, the plane of joint motion), with function often returning to normal unless the fracture occurs near the end of growth.

The age of the patient at the time of injury is of paramount importance in helping predict clinical outcomes because more correction can be anticipated in younger patients. Thus, growth arrest in 14- to 15-year-old girls or 17- to 18-year-old boys is of little consequence in terms of limb length, given the limited growth potential, but can be very important in terms of malunion. Younger children with full growth potential can correct more deformity, but a growth arrest leading to shortening can be more devastating.

Acute apophyseal avulsions can usually be treated nonoperatively. Chronic apophyseal avulsions are also treated nonoperatively with reduction of repetitive stress and physical therapy to decrease underlying biomechanical problems.[4]

Tissue engineering

Most of the research into cartilage regeneration has focused on articular cartilage, but some of this research may be applicable to growth plate cartilage as well. At present, no reliable means of regeneration exists. Cartilage cannot regenerate itself, partly because of its low cellularity and lack of vascular supply. In addition, chondrocytes in articular cartilage are well differentiated, and multipotent progenitor cells are relatively few. Thus, cartilage can heal the margins of damage but does not form a scar to join the defect edges together.

Many tissue-engineering strategies have been developed (eg, implantation of chondrogenic cells at various developmental stages into the defect site, implantation of cartilage itself [osteochondral autograft/mosaic arthroplasty], cartilage transplantation, and allogenic grafts). Periosteal and perichondrial tissue grafts have been considered for their stockpile of multipotent osteochondral progenitor cells. Scaffolding to provide a substrate for chondroprogenitor cell attachment and migration across cartilaginous defects has been studied as well.

These techniques have had variable success. Tissue scaffolding has proved effective at overcoming some deficiencies in tissue engineering. Collagen, a natural tissue, and poly-lactide-co-glycolide (PLGA), a polymer that elicits small acute immune responses, have shown promise as cartilage repair scaffolds. Chitin has been determined to be effective as a scaffolding for attaching and carrying stem cells for the repair of growth plate defects.

Some studies have combined gene therapy and tissue-engineering to regenerate articular cartilage in the hope of applying this approach to epiphyseal cartilage repair. One study used a retroviral vector to introduce human bone morphogenic protein (BMP)-7 complementary DNA into periosteal-derived rabbit mesenchymal stem cells. BMP-7 stimulates synthesis of type II collagen and aggrecan. Grafts containing modified cells consistently showed complete or near-complete articular cartilage regeneration at 8 and 12 weeks; control grafts showed poor regeneration.

The future also holds promise for specific intracellular signaling approaches to posttraumatic disturbances of the growth plate. Leboy et al found that important regulators of physeal chondrocyte hypertrophy include special BMPs: activated cytoplasmic proteins (called Smads) and multifunctional transcription factors (called Runx proteins).[27]

Another potent stimulator of embryonic epiphyseal cartilage is growth differentiation factor (GDF)-5. Buxton et al found that GDF-5 promoted both cell adhesion and proliferation during limb development.[28]

Options for Surgical Therapy

Open reduction and internal fixation or closed reduction and percutaneous fixation

More severe injuries, especially those involving intra-articular fractures, typically require anatomic reduction with open reduction and internal fixation (ORIF) that avoids crossing the physis. Unstable fractures that are suitable for closed reduction will benefit from percutaneous pin fixation to maintain the reduction. Smooth pins should parallel the physis in the epiphysis or metaphysis, avoiding the physis. Oblique application of pins across the physis should be considered only when satisfactory internal fixation is unattainable with transverse fixation. Any internal fixation devices should be easily removable yet adequate for internal fixation.

Special considerations during surgery include avoiding further damage to the growth plate by avoiding periosteal stripping and using smooth pins (screws or threaded pins across the physis should be avoided). The surgeon should also avoid forceful manipulation.  

Physis-sparing techniques must be used in skeletally immature patients.[13]

As an illustrative example, a skeletally immature patient presented with SH type II fracture of the distal femur (see the first image below). An anatomic closed reduction was obtained (see the second image below) and then held with percutaneous pin fixation (see the third image below). The fracture healed uneventfully (see the fourth image below).

Growth plate (physeal) fractures. Displaced Salter Growth plate (physeal) fractures. Displaced Salter-Harris II fracture of distal femur.
Growth plate (physeal) fractures. Anatomic reducti Growth plate (physeal) fractures. Anatomic reduction of previously displaced Salter-Harris II fracture of distal femur.
Growth plate (physeal) fractures. Percutaneous int Growth plate (physeal) fractures. Percutaneous internal fixation of Salter-Harris II fracture of distal femur after anatomic stable closed reduction.
Growth plate (physeal) fractures. Healed Salter-Ha Growth plate (physeal) fractures. Healed Salter-Harris II fracture of distal femur in anatomic position.

SH V fractures are rarely diagnosed acutely, and treatment is often delayed until the formation of a bony bar across the physis is evident. A high level of clinical suspicion is necessary to detect this complication early. In many cases, "early" may mean 6 months or more after the injury. Intra-articular stepoffs will not remodel. Long-term follow-up may be indicated for even benign-appearing fracture patterns.

Growth-plate transplantation

Several experiments have been performed to evaluate the efficacy of interpositioning materials (eg, bone wax, fat, cartilage, silicon rubber, and polymethylmethacrylate [PMMA]) into defects resulting from physeal bar excision. No single material is superior in the prevention of physeal bar reformation. Cartilage may prove ideal, and several possible sources for graft material exist, but each has associated difficulties, including the following:

  • Apophyseal cartilage may lack the growth potential of epiphyseal cartilage
  • Laboratory-procured chondrocyte allograft transplants may take a long time to develop and may not have any real possibility for interhuman transfer, because of the impending immune response
  • In physeal cartilage transfer, difficulties abound in procuring and transferring physes from one site to another

Treatment of Physeal Fractures in Lower Extremity and Hip Joint

Distal femur fractures

Distal femur fractures account for approximately 1-5% of all growth plate (physeal) fractures. The distal femoral physis is the fastest-growing physis in the body and provides 35% of lower-extremity leg length.[24]  This physis closes asymmetrically and is weaker during adolescence, when most SH III physeal injuries occur. Younger patients are more likely to have SH II fractures.[24]  As many as 40% of patients have complications, especially those with high-energy injuries and greater fracture displacement.[29]  

Displacement of the fracture in the sagittal plane may be associated with neurovascular injury in the popliteal fossa and instability on closed reduction. A common mechanism of injury is hyperextension causing anterior displacement of the epiphysis. Physeal fracture displacement in the coronal plane is not associated with other injuries, and the joint may be stable after closed reduction.[30] The irregular undulating shape of the distal femur physis makes perfect reduction difficult, leading to a high incidence of bony bar formation, which can cause premature physeal closure resulting in angular deformity and leg-length discrepancy.[24]

The treating clinician must also search for associated injuries, including anterior cruciate ligament (ACL) tears, which can occur in 8% of patients with intra-articular physeal injuries of the distal femur.[24]

Clinically, the thigh may appear angulated and shortened as compared with the contralateral thigh; and pain, knee effusion, and soft-tissue swelling usually are severe. Hemarthrosis may be more severe in SH III and SH IV fractures, and vascular examinations may reveal diminished or absent distal pulses. Neurologic symptoms also may be evident distally as a consequence of disruption of the posterior tibial and common peroneal nerve distributions. Intra-articular fractures are frequently missed, and advanced imaging may be required for diagnosis.[24]  

Growth plate (physeal) fractures. Anteroposterior Growth plate (physeal) fractures. Anteroposterior and lateral views of distal femur Salter-Harris III fracture where fracture is not well seen.
Growth plate (physeal) fractures. Oblique view of Growth plate (physeal) fractures. Oblique view of distal femur reveals Salter-Harris III fracture of distal femur.

Injuries to the distal femoral physis may result in angular deformities. Certain levels of angulation are acceptable. Posterior angulation up to 20° remodels in children younger than 10 years; however, injuries in adolescent patients do not remodel, and these patients do not tolerate this degree of angulation. Varus and valgus angulation or rotational deformity greater than 5° is not acceptable for the distal femoral physis, because there is no significant coronal plane remodeling.

Treatment of distal femoral physeal fractures varies according to severity of injury. Nondisplaced SH I or SH II fractures, in nonobese young patients in reliable families, can be treated by means of splinting with a hip spica cast.

Any displaced fracture or a fracture in which there is concern about late displacement is best treated with closed reduction under anesthesia, followed by smooth Kirschner wires (K-wires) or Steinmann pins (depending on patient size) for SH I fractures and transverse metaphyseal lag screws (commonly placed percutaneously) for SH II fractures.[31, 32]  If an anatomic closed reduction cannot be obtained, careful open reduction, with care taken to minimize additional damage to the peripheral physis, is necessary.

The images below illustrate an SH II fracture of the distal femur that was treated with closed reduction and percutaneous pin fixation.

Growth plate (physeal) fractures. Displaced Salter Growth plate (physeal) fractures. Displaced Salter-Harris II fracture of distal femur.
Growth plate (physeal) fractures. Percutaneous int Growth plate (physeal) fractures. Percutaneous internal fixation of Salter-Harris II fracture of distal femur after anatomic stable closed reduction.
Growth plate (physeal) fractures. Healed Salter-Ha Growth plate (physeal) fractures. Healed Salter-Harris II fracture of distal femur in anatomic position.

An alternative fixation method that may be employed when the Thurston Holland fragment is small is cross-pinning (see the image below).

Growth plate (physeal) fractures. Anatomic reducti Growth plate (physeal) fractures. Anatomic reduction with percutaneous cross pinning of Salter-Harris II fracture distal femur.

SH III and SH IV injuries usually require anatomic reduction (which cannot be obtained with closed reduction) and are very often unstable. Operative treatment is required because even slight residual displacement can result in formation of a bone bar that causes limb-length discrepancy and angular deformity. An SH III fracture is commonly treated with transverse lag screws across the epiphysis (see the images below).

Growth plate (physeal) fractures. Oblique view of Growth plate (physeal) fractures. Oblique view of distal femur reveals Salter-Harris III fracture of distal femur.
Growth plate (physeal) fractures. Fixation of Salt Growth plate (physeal) fractures. Fixation of Salter-Harris III fracture of distal femur.

Complications of distal femur fractures include growth arrest (partial or complete) with progressive angulation, shortening, or both in 30-80% of patients. Physeal fractures of the distal femur (particularly the common SH I and SH II fracture patterns) have been shown to be associated with an approximately 50% rate of growth disturbance.[33] Leg-length discrepancy and angular deformity are common.[24]

The distal femur is the last physis to fuse and contributes 1 cm per year of femur length. (The distal femur epiphyseal plate contributes 70% of final femur length and 40% of overall lower-extremity length.) The distal physis fuses between 14 and 16 years of age in girls and between 16 and 18 years of age in boys.

Because the incidence of growth arrest is high, even with satisfactory reduction, a lower-extremity limb-length discrepancy of more than 2 cm may develop in one third of patients. Shortening and angulation are related more to the degree of initial displacement than to the accuracy of the reduction. An angulation deformity of more than 5° may develop in one third of patients. A persistent angular deformity in the coronal plane may not correct spontaneously with further growth.

Proximal tibia fractures

Whereas fractures involving the tibia and fibula are the most common lower-extremity pediatric fractures, those involving the proximal tibial physis are among the most uncommon; these injuries account for fewer than 1% of physeal injuries because the proximal tibia growth plate is protected by ligamentous attachments and the fibular head.

When these physeal injuries are fractured, however, they have the highest rate of complications. When posterior displacement occurs, the popliteal artery is vulnerable. At the tibial metaphysis, the artery is just posterior to the popliteus muscle. Moore and Mackenzie found that half of SH I injuries are nondisplaced and are diagnosed by means of stress radiographs.[34]  Apophyseal growth disturbance is rare past the age of 11 years. Genu recurvatum is the most frequent growth deformity, especially in patients younger than 11 years. (See the images below.)

Growth plate (physeal) fractures. Proximal tibia a Growth plate (physeal) fractures. Proximal tibia apophyseal avulsion fracture (anteroposterior, lateral, and oblique images).
Growth plate (physeal) fractures. Proximal tibia a Growth plate (physeal) fractures. Proximal tibia apophysis avulsion as seen on CT.
Growth plate (physeal) fractures. Fixation of prox Growth plate (physeal) fractures. Fixation of proximal tibia apophysis avulsion fracture (healed).

Generally, these fractures occur between 11 and 14 years of age, and more often in boys, but SH I injuries typically occur earlier (average age, 10 years). SH II is the most common type, and one third of these fractures are nondisplaced. SH III injuries are often associated with lateral condyle fractures or medial collateral ligament (MCL) injury. SH IV injuries are often associated with angular deformity. SH V injuries are usually diagnosed retrospectively. Anterior physis closure or tibial tuberosity apophysis closure can cause significant genu recurvatum.

The image below illustrates a procurvatum deformity of the proximal tibia after repair of a proximal tibia apophyseal avulsion.

Growth plate (physeal) fractures. Procurvatum of p Growth plate (physeal) fractures. Procurvatum of proximal tibia after open reduction and internal fixation of proximal tibia apophysis injury.

If the fracture is nondisplaced or an anatomic stable reduction can be obtained with closed manipulation, treatment consists of an above-knee cast for 4 weeks. Generally, treatment of displaced apophyseal fractures requires ORIF.

Complications of these injuries include vascular insufficiency and peroneal nerve palsy, usually transient, and malunion. The proximal tibial physis contributes 0.65 cm of growth per year, resulting in 45% of the length of the tibia and 27% of the length of the lower extremity. The secondary ossification center of the tibial tuberosity apophysis develops at about 7-9 years of age and fuses between 13 and 15 years in girls and between 15 and 19 years old in boys. It is the last portion of the proximal tibial physis to close.

Overuse physeal injuries

Osgood-Schlatter disease and Sever disease represent 18% of pediatric overuse conditions. Osgood-Schlatter disease is a chronic apophysitis at the patella tendon insertion on the tibial tuberosity, usually seen in girls 8-13 years old and in boys 10-15 years old. Sever disease (calcaneal apophysitis) is a chronic apophysitis at the Achilles tendon insertion, usually seen in boys 8-12 years old.[3]

Distal tibia and fibula fractures

Fractures of the distal end of the tibia in children often involve the physis. They are of particular importance because partial growth arrest can occur and result in angular deformity, lower-extremity limb-length discrepancy, incongruity of the joint surface, or a combination of these. Triplane and Tillaux fractures are the two distinct types of distal tibial fractures.[13]

In a triplane fracture classification, two types of fractures exist: two-part and three-part fractures. A two-part fracture is a type of SH IV fracture that primarily occurs when the medial portion of the distal tibial epiphysis is closed.

A three-part fracture is a combination of SH II and SH III fractures that occurs when only the middle portion of the distal tibial epiphysis is closed. It involves fracture of the anterolateral portion of the epiphysis of the distal tibia (similar to Tillaux fracture) and fracture of a large fragment comprising the posterior and medial portions of the tibial epiphysis plus a large metaphyseal fragment of variable size; the fibula also may be fractured. These injuries most commonly occur just before epiphyseal closure and are due to external rotation forces.

The images below illustrate a triplane fracture of the distal tibia.

Growth plate (physeal) fractures. Triplane fractur Growth plate (physeal) fractures. Triplane fracture of distal tibia (anteroposterior and lateral images).
Growth plate (physeal) fractures. Sagittal and axi Growth plate (physeal) fractures. Sagittal and axial CT images of triplane fracture of distal tibia.
Growth plate (physeal) fractures. 3D CT images of Growth plate (physeal) fractures. 3D CT images of triplane fracture of distal tibia are useful for preoperative planning.
Growth plate (physeal) fractures. Healed triplane Growth plate (physeal) fractures. Healed triplane fracture of distal tibia after internal fixation.

Tillaux fractures are SH III fractures involving avulsion of the anterolateral tibial epiphysis. This portion of epiphysis is involved because the physis of the distal tibia closes first in the middle, then in the medial portion, and finally in the lateral portion. This injury occurs in older adolescents (eg, 12-15 years), after the middle and medial parts of the epiphyseal plate have closed but before the lateral part closes. Because it occurs in adolescents with relatively mature growth plates, there is minimal potential for deformity due to growth plate injury.

The images below are from a child with Tillaux fracture of the distal tibia.

Growth plate (physeal) fractures. Tillaux fracture Growth plate (physeal) fractures. Tillaux fracture of distal tibia seen on anteroposterior radiograph.
Growth plate (physeal) fractures. Healed Tillaux f Growth plate (physeal) fractures. Healed Tillaux fracture of distal tibia after internal fixation.

Treatment of displaced SH III and SH IV fractures of the distal tibia requires open reduction. This injury leads to premature physeal closure unless it is anatomically reduced. Development of an angular deformity is possible. Varus deformities, secondary to an osseous bridge formation on the medial aspect of the plate, are the most common complications found with distal tibia growth plate injuries. Limb shortening is the second most common problem associated with these injuries.

Kling et al, evaluating distal tibial physeal fractures that required open reduction, suggested that SH III, SH IV, and perhaps SH II fractures of the distal end of the tibia commonly cause disturbance of growth in the tibia and that closed or open anatomic reduction of the physis may decrease the incidence of these disturbances of growth, including shortening and varus angulation of the ankle.[35]  SH IV fracture of the distal tibia has indeed been associated with premature physeal closure unless it is anatomically reduced, usually with internal fixation.

A high rate of premature physeal closure (PPC) has been reported to occur in SH type I or II fractures of the distal tibia. Rohmiller et al reported a PPC rate of 39.6% in SH type I or II fractures of the distal tibia physis and determined that fracture displacement following reduction was the most important determinant of PPC development.[14]

Barmada et al investigated the incidence and predictors of PPC after distal tibia SH I and II fractures and found that when residual gapping of the physis was greater than 3 mm following reduction, the incidence of PPC was 60%; when the physeal gap was less than 3 mm, there was a 17% incidence of PPC.[36] Upon open reduction of residual gapping, the periosteum was found to be entrapped within the physis, thereby preventing closure of the gap and preventing appropriate recreation of the anatomy.

Russo et al performed a retrospective study of 96 patients presenting with displaced SH II fracture who were initially treated with closed reduction.[37]  Patients with less than 2 mm of postreduction displacement were treated with a nonweightbearing long leg cast (LLC; group 1). Those with 2-4 mm of displacement were treated with either LLC (group 2) or ORIF with removal of any interposed tissue (group 3). Those with more than 4 mm of displacement were treated with ORIF (group 4).

Of the 14 patients in group 1, 29% had a PPC and 7% had to undergo a subsequent procedure (eg, epiphysiodesis or osteotomy).[37]  Of the 33 patients in group 2, 33% had a PPC and 15% had to undergo a subsequent procedure. Of the 11 patients in group 3, 46% had a PPC and 18% had a second procedure. Of the 38 patients in group 4, 55% had a PPC and 23% had a subsequent procedure. No statistically significant differences in the rates of PPC or subsequent surgery were observed between groups.

Distal fibula growth plate fractures may be associated with distal tibia fractures or may occur without an associated tibia fracture. Treatment is nonoperative if the fracture is nondisplaced or if a stable closed reduction can be obtained but may be operative in unstable ankle patterns (with associated syndesmotic injury, a displaced distal tibia fracture, or both).[38]

Medial malleolus fractures have a 38% risk of growth arrest. SH I fracture of the distal fibula is the most common pediatric fracture in the ankle region. It may be difficult to differentiate from a sprain, but when it is not displaced, the treatment is the same: immobilization in a walker boot for 3-4 weeks.[13]

Triradiate cartilage fractures

Traumatic disruptions of the acetabular triradiate cartilage occur infrequently and may be associated with progressive acetabular dysplasia and subluxation of the hip. The volume of cartilage in a child's acetabulum allows a greater capacity for energy absorption than in adults. Thus, in children, fractures of the acetabulum are consistently the result of high-energy trauma. Unfortunately, a younger age at the time of injury is associated with a greater chance of developing acetabular dysplasia. (See the images below.)

Growth plate (physeal) fractures. Triradiate carti Growth plate (physeal) fractures. Triradiate cartilage fracture seen on anteroposterior pelvis x-ray.
Growth plate (physeal) fractures. Triradiate carti Growth plate (physeal) fractures. Triradiate cartilage fracture seen on axial CT.

Disruption of the acetabular triradiate cartilage in patients older than 12 years results in minimal subsequent growth disturbance; however, in younger patients, acetabular growth abnormality is a frequent complication. Growth abnormalities include shallow acetabula and progressive subluxation of the hip.

Triradiate cartilage injuries occurring during adolescence result in fewer growth changes in acetabular morphology and hip joint congruencies. However, in younger children, especially those younger than 10 years, acetabular growth abnormality is a frequent complication of this injury and may result in a shallow acetabulum similar to that seen in patients with developmental dysplasia of the hip (DDH).

By the time patients reach skeletal maturity, disparate growth increases the incongruity of the hip joint and may lead to progressively more severe subluxation of the hip. Acetabular reconstruction may be necessary to correct the gradual subluxation of the femoral head.

Bucholz et al found nine patients with triradiate physeal-cartilage injury who were classified according to the degree of displacement and the probable type of growth-plate disruption.[39]  They determined that two main patterns of injury occurred. The first was a shearing (SH I or II) growth mechanism injury, with central displacement of the distal portion of the acetabulum. This injury pattern seemed to have a favorable prognosis for continued normal acetabular growth, though occasional premature closure of the triradiate physes occurred.

The second injury pattern appeared to be a crushing SH V growth mechanism injury; this type has a poor prognosis, with premature closure of the triradiate physes occurring secondary to the formation of a medial osseous bridge.[39]  Prognosis is dependent on the age of the patient at the time of injury and on the extent of chondro-osseous disruption.

Slipped capital femoral epiphysis

Slipped capital femoral epiphysis (SFCE) is a special case of a progressive overuse growth plate injury.  It should be differentiated from an acute traumatic proximal femur epiphysis SH I fracture.

Foot fractures

Accessory ossicles in the foot are common in skeletally immature patients and usually fuse with the secondary ossification center at skeletal maturity, but they may persist in adults. The os trigonum and accessory navicular ossicles are seen in about 20% of children and may become symptomatic. Treatment is usually nonoperative, though excision may sometimes be required.[13]

Stubbed great toe/phalanx fractures

The images below illustrate the respective radiographic and clinical appearances of an injury that has been termed the pediatric stubbed great toe. It is a somewhat occult open fracture because the growth plate of the distal phalanx is remarkably close to the nail plate. When a subungual hematoma occurs in conjunction with a growth plate fracture, this does in fact represent an open fracture. Phalangeal fractures are usually SH I or II fractures: when the distal phalanx is involved, there is the potential for nail bed injury.[13]

Growth plate (physeal) fractures. Radiographic evi Growth plate (physeal) fractures. Radiographic evidence of pediatric stubbed great toe.
Growth plate (physeal) fractures. Clinical appeara Growth plate (physeal) fractures. Clinical appearance of pediatric stubbed great toe. Note subungual hematoma, representative of open fracture.

In the great toe (or, at times, the lesser toes), this injury has been termed a Pinckney fracture or Pinckney lesion.[40]  In the hand, such fractures of the terminal phalanx may be called Seymour fractures.[41]

Treatment of Physeal Fractures in Upper Extremity

Proximal humerus fractures

Proximal humerus fractures have a high propensity for remodeling, and severe-appearing deformity can be accepted with the expectation that adequate remodeling will occur in the skeletally immature patient. (See the images below.)  The proximal humerus physis contributes 80% of growth for the upper extremity. The physis fuses between 14 and 17 years in females and between 16 and 18 years in males.[2]

Growth plate (physeal) fractures. Angulated proxim Growth plate (physeal) fractures. Angulated proximal humerus fracture in child (anteroposterior and Y views).
Growth plate (physeal) fractures. Healed proximal Growth plate (physeal) fractures. Healed proximal humerus with abundant callus and angulation in child.
Growth plate (physeal) fractures. Remodeling of pr Growth plate (physeal) fractures. Remodeling of proximal humerus fracture in child.

Elbow fracture

Because ossification rates for the physes at the elbow are highly variable, clinicians should obtain radiographs of the opposite side when evaluating the physes at the elbow.[2]

Supracondylar fractures are the most common type of elbow fracture in children. Long-term follow-up is required.

Radial head fractures can usually be treated in a closed fashion if there is less than 4 mm of translation and less than 30-60º of angulation. Radial head fractures may be difficult to diagnose without adequate radiographic images. (See the images below.)

Growth plate (physeal) fractures. Radial head frac Growth plate (physeal) fractures. Radial head fracture in child that is difficult to see on standard anteroposterior and lateral images.
Growth plate (physeal) fractures. Radial head frac Growth plate (physeal) fractures. Radial head fracture in child that was difficult to see on anteroposterior and lateral images is now well seen on oblique view.

ORIF is often indicated for radial head fractures (see the image below). Closed reduction with percutaneous internal fixation may be possible. With either approach, the surgeon should beware of the posterior interosseous nerve. The radial head should never be excised in children. Even a "dead head" can act as a spacer and allow more normal elbow development.

Growth plate (physeal) fractures. Open reduction a Growth plate (physeal) fractures. Open reduction and internal fixation of radial head fracture in child.

Medial epicondyle avulsion fractures through the apophysis, if stable, can be treated with nonoperative treatment consisting of rest and nonsteroidal anti-inflammatory drugs (NSAIDs). If, however, such fractures are unstable (because of compromise of the ulnar collateral ligament attachment), or if there is intra-articular incarceration, ulnar nerve entrapment, open fracture, or an associated unstable elbow dislocation, then surgical treatment is indicated. Generally, the presence of more than 5 mm of displacement is an indication for surgery.[22]

 Growth plate (physeal) injuries. Medial epicondyl Growth plate (physeal) injuries. Medial epicondyle avulsion fracture in child. Note widening of medial apophysis.

Distal radius and ulna fractures

Physeal injuries of the distal ulna occur much less frequently than those of the distal radius, but the former are associated with a higher incidence of growth arrest because the ulna derives 70-80% of its longitudinal growth from its distal physis. As a result, growth arrest can cause significant ulnar shortening. Some 44% of growth plate injuries involve the distal radius; 90% are type I or II and usually heal well. The physes close at about 18-20 years of age (though significant variation exists). In patients younger than 12 years, the treating provider can accept 20-25º of angulation in the sagittal plane and 10-15º in the coronal plane.

The distal radial physis is the most frequently injured physis in children, usually in those aged 6-10 years. Children typically sustain the injury by falling on an outstretched hand. A great majority of these injuries are SH I and SH II fractures. The distal radial and ulnar physes provide 75-80% of total forearm growth; thus, potential for remodeling and correction of any deformity is excellent.[42]  However, as many as 7% can have significant growth disturbance.[43]

The acceptable amount of residual displacement for distal radial and ulnar fractures is not specifically known; however, 30% physeal displacement heals readily, and 50% displacement may often completely remodel in 1.5 years. Generally, distal radius fractures will remodel at 1º per month (0.9º or 9% per month in the sagittal plane and 0.8º or 11% per month in the coronal plane).[44]  The images below illustrate an SH I fracture with excellent remodeling after 6 months.

Growth plate (physeal) fractures. Salter-Harris I Growth plate (physeal) fractures. Salter-Harris I fracture of distal radius.
Growth plate (physeal) fractures. Healed and remod Growth plate (physeal) fractures. Healed and remodeled Salter-Harris I fracture of distal radius.

Treatment usually consists of either a long arm cast for 3 weeks followed by a short arm cast for 3 weeks or a short arm cast for 4-6 weeks.  Recommendations vary in the literature.

Closed reduction with percutaneous fixation (see the image below) or ORIF is indicated in uncooperative patients, including those with cerebral palsy or head injuries, patients with associated neurovascular injury, patients with ipsilateral supracondylar humerus fracture, and patients close to skeletal maturity in whom adequate remodeling is not expected. Complications of surgery include pin tract infection, extensor tendon rupture over a pin, and radial nerve injury (especially the sensory branch).

Growth plate (physeal) fractures. Closed reduction Growth plate (physeal) fractures. Closed reduction and percutaneous pinning of Salter-Harris II fracture of distal radius.

Lee et al found that significant distal radial growth disturbance occurred in about 7% of physeal fractures[43] ; the rate of distal ulnar growth arrest following physeal fracture (see the image below) is probably at least as high.

Growth plate (physeal) fractures. Growth retardati Growth plate (physeal) fractures. Growth retardation of distal ulna with negative ulnar variance after open reduction and internal fixation of distal radius fracture.

Epiphyseodesis of the distal ulna may be warranted to correct growth retardation of the distal radius with overgrowth of the distal ulna following distal radius fracture (see the images below). (See Complications.)

Growth plate (physeal) fractures. Posttraumatic Ma Growth plate (physeal) fractures. Posttraumatic Madelung deformity with ulna outgrowing radius in skeletally immature child.
Growth plate (physeal) fractures. Posttraumatic Ma Growth plate (physeal) fractures. Posttraumatic Madelung deformity treated with epiphyseodesis of distal ulna to allow radius growth to catch up.
Growth plate (physeal) fractures. Comparison views Growth plate (physeal) fractures. Comparison views of two wrists show almost equal ulnar variance (with correction of previously Madelung deformity by epiphyseodesis).

Physeal Injuries in Athletes

Growth plate (physeal) injuries in athletes constitute a special subset of growth plate injuries in general. About 18% of young athletes develop physeal problems.[5]

In the United States, about 30 million children are involved in organized sports each year. The physis, as the weakest part of the bone, is highly susceptible to injury in young athletes; 15% of all pediatric sports injuries involve the physis.[3] Many physeal injuries sustained by pediatric athletes represent overuse injuries from muscle imbalances. Such injuries might be prevented by placing limits on participation and by providing sport-specific training focusing on flexibility, strengthening, and limitation of repetitive tasks (eg, overhead throwing).

The most effective treatments for overuse physeal injuries are extended periods of active rest and joint immobilization when needed.[3, 8] In a review of the literature, Arnold et al found that 50% of studies recommended 3-5 months with complete cessation of sport-specific activities, whereas 21% recommended activity modification based on symptoms, allowing earlier return to play; the remaining 29% made no specific recommendations.[3]

Intense competition in young athletes can cause both acute and chronic injuries.[2] In sports, neuromuscular fatigue can alter coordination and proprioception, thereby increasing susceptibility to injury.[45] Single-sport specialization also increases abnormal stresses on the musculoskeletal system, resulting in a greater frequency of overuse injury, which frequently involves the physes.[9] Because the developing physes are relatively weak as compared with the ligaments, injuries that might cause ligament damage in adults tend to cause physeal injury in the skeletally immature.[2]  

Treatment of sports-related physeal injury consists of activity modification, anti-inflammatory medication, immobilization in severe cases, and physical therapy.[13, 22]  Most athletes heal with activity modification, improved mechanics, and correction of biomechanical imbalances with physical therapy or exercise programs.[4, 22]

Male and female athletes tend to sustain different injuries, with different mechanisms of injury (see Table 1 below).[46] Because males reach skeletal maturity at an older age than females, athletic physeal injuries occur 75% more often in boys.[5]

Table 1. Physeal Injury Patterns in Male and Female Athletes (Open Table in a new window)

Mechanism and Site of Injury Males Females
Mechanism    
Acute trauma 58.2% 37.5%
Overuse 41.8% 62.5%
Site    
Lower extremity 53.7% 65.8%
Upper extremity 29.8% 15.1%
Spine 8.2% 11.3%

Injury type by anatomic site

The foot and ankle are the most commonly injured sites of the lower extremity in adolescent athletes. Injury patterns differ from those seen in adults because of the presence of growth plates. The os trigonum (a secondary ossification center of the talus) typically appears between the ages of 8 and 10 years in girls and between the ages of 11 and 13 years in boys, then fuses soon after. Acute fracture or repetitive microtrauma can cause pain from impingement. Athletes (including dancers, divers, and soccer players) are prone to activity-related chronic pain from impingement at the os trigonum.

Sever disease (calcaneal apophysitis) is the most common cause of heel pain in children between 8 and 15 years old.[47] The muscles attached to the apophysis can become overly tight as a consequence of different growth rates if repetitive traction forces occur. Sever disease typically occurs in impact sports with excessive running. A young runner may strike the ground more than 600 times for each 1 km of long-distance running. Sever disease occurs in 16% of all pediatric musculoskeletal injuries.[5]

Risk factors for Sever disease include obesity and a high level of physical activity (especially high-impact activity, such as occurs in soccer, cross-country running, track,[47, 5] gymnastics, tennis, or ballet. Physical examination finds tenderness upon squeezing of the heel, and radiographs show sclerosis and fragmentation of the calcaneal apophysis. Treatment consists of rest, ice, stretching, anti-inflammatory meedications, and heel cups.[47]

Osgood-Schlatter disease and Sindig-Larsen-Johannsson syndrome are similar physeal overuse injuries common in sports in the lower extremity.

About 39% of intra-articular distal femur physeal fractures in athletes (SH III or IV) are missed at initial presentation.[24]

In the upper extremity, Little League elbow (medial epicondyle apophysitis) is a traction injury at the medial epicondyle of the humerus at the attachment of the ulnar collateral ligament complex. Acute or chronic injury from valgus force during throwing can destabilize the elbow.[22]  This syndrome is discussed in more detail below under the topic of baseball injuries.

Olecranon apophysitis occurs from chronic forceful contraction of the triceps during the acceleration phase of throwing.[22]

Injury type by sport

Baseball

The overall motion and kinematics of throwing in adolescents are similar to those adults, in whom tremendous shear and rotatory stresses are generated across the shoulder and elbow, especially during pitching.[2, 3] Avulsion fractures of the medial epicondyle are caused by extreme valgus loads with strong muscle contraction during the throwing motion and are especially common as the medial epicondyle physis begins to fuse. Inadequate treatment, or a too-early return to throwing, may lead to nonuion and failure of the physis to fuse, resulting in pain or instability.  Surgical repair of the medial epicondyle is indicated when there is valgus instability or displacement exceeding 5 mm.[2]

The American Academy of Orthopaedic Surgeons (AAOS) has recommended limiting the number of pitches per game to 60-100, with no more than 30-40 in a single practice session, and limiting the number of innings pitched to 4-10 per week. Athletes who throw with a sidearm motion are three times more likely to sustain an injury than overhead throwers; accordingly, sidearm throwing is not recommended.[2] Youth pitchers have a 5% chance of serious throwing injury with 10 years of competitive throwing. Those who pitch more than 100 innings per year have a 3.5 times greater risk of injury.[22]

Little League shoulder is a condition involving epiphysiolysis (separation of the proximal humerus physis) due to repetitive microtrauma from overhead activity. Patients present with diffuse shoulder pain, usually in the dominant shoulder, which is aggravated by throwing motions[2, 3, 4] ; 32% of young pitchers have arm pain while throwing.[3] Risk factors include excessive pitch counts and fatigue. Pitchers throwing breaking pitches (eg, curveballs or sliders) are at higher risk. Little League shoulder is not limited to baseball pitchers but can occur in any athlete who uses repetitive overhead motion.[4]

On examination, patients have tenderness and swelling over the anterolateral shoulder with weak abduction and internal rotation. Radiographs show epiphyseal widening, especially on the anteroposterior (AP) image with the shoulder externally rotated. Radiographs may also show irregularity of the physis and periosteal reaction. (See the image below.)

Growth plate (physeal) injuries. Little League sho Growth plate (physeal) injuries. Little League shoulder. Note irregularity of proximal humeral physis with metaphyseal sclerosis.

Treatment consists of rest followed by gradual return to supervised throwing. The development of Little League shoulder can be prevented though improved technique and limitation of the number of pitches and innings.[2]

The term Little League elbow comprises several abnormalities of the elbow in the skeletally immature athlete, including avulsion fractures of the medial epicondyle, medial epicondyle apophysitis, accelerated medial epicondyle apophyseal growth, and delayed closure of the medial epicondyle growth plate. All of these injuries are the result of repetitive valgus stress and tension overload on the medial side of the elbow.[2, 22] Increased height and weight are risk factors.[3]

Growth plate (physeal) injuries. Little League elb Growth plate (physeal) injuries. Little League elbow. Note widening of medial epicondyle physis.

Patients usually present with medial elbow pain, decreased throwing accuracy, and reduced throwing distance. Patients may have tenderness over the medial epicondyle and occasional flexion contracture.[2, 22] Radiographs may show irregular ossification of the medial epicondylar apophysis, with progression to apophyseal enlargement, separation, and fragmentation.

Treatment consists of rest and gradual return to throwing when symptoms have resolved. Patients should be subject to limitations on the number of pitches thrown and the number of innings pitched and should be taught proper mechanics.[2]

Racquet sports

Athletes playing racquet sports are susceptible to lateral apophysitis due to repetitive wrist extension, which causes repetitive microtrauma to the lateral epicondylar apophysis at the extensor tendon origin. Patients report pain and tenderness at the lateral epicondyle. Although x-ray films may be normal, they may also show widening or fragmentation of the apophysis.

Treatment usually consists of rest, improvement of stroke mechanics, and adjustment of equipment size (especially the grip). Counterforce bracing may also be used to decrease stress at the extensor origin.[2]

Basketball

The proximal tibia physis is most commonly injured during basketball, especially in the setting of uncontrolled high-impact landings. Such injury is also related to taking off from jumps, eccentric muscle contraction with the knee in flexion, and sudden stop-and-go motions.[45]

Football

About 50% of distal femur physeal injuires in athletes occur during football; they are usually the result of a tackle where a valgus force is applied to the lateral aspect of the knee.[24]

Swimming

Physeal injuries seen in swimmers are similar to those seen in overhead baseball throwers.[2]

Soccer

Injury to the fifth metatarsal apophysis is common in soccer. The apophysis of the fifth metatarsal base appears at about 12 years for boys and 10 years for girls and fuses about 2-4 years later. The mechanism of injury is usually twisting of the ankle with a fixed forefoot and is due to traction by the peroneus brevis or the abductor digiti minimi. Patients present with pain and swelling at the base of the fifth metatarsal.

Treatment consists of the use of a hard-soled shoe, walking cast, or boot for 6 weeks, followed by a return to the sport when the patient is pain-free and has normal motion and strength.[13]

Soccer players also have a high incidence of anterior superior iliac spine (ASIS) physeal injuries.[3]

Gymnastics

About 79% of pediatric gymnasts complain of wrist pain during practice or competition.[3] The term gymnast wrist refers to premature closure of the distal radius physis from excess compressive loads during upper-extremity weightbearing in gymnastics. This condition is usually seen in 10- to 14-year-olds, especially during growth spurts. Limited training during growth spurts and gradual progression and variation of training loads may help limit the stress at the distal radius physis and and thus reduce the risk of developing gymnast wrist.[3]

Climbing

Epiphyseal injuries to the fingers (especially the middle and ring fingers) are common in adolescent rock climbers. Patients usually present with pain on the dorsal aspect of the proximal interphalangeal (PIP) joint, which is often mistaken for a sprain.[4]

Conservative treatment is usually successful, but healing takes an average of 7 weeks, with a range of 3-12 months before symptoms resolve.[48]

Running

Distance running is the most common physical activity among girls and the second most common physical activity for boys in the 12- to 15-year-old age group. Long-distance runners who are younger than 15 years have increased vulnerability to overuse injury of their lower-extremity growth plates, but the literature is insufficient to establish mileage limitations or provide other specific recommendations for preventing these injuries.[49]

Complications

Limb-length discrepancy

Growth acceleration is a possible complication of physeal injuries; however, it is uncommon. This complication usually occurs in the first 6-18 months after the initial injury. The rapid healing of the physis enables an increased vascular response that is usually of shorter duration than that for healing of bony fractures. Accelerated growth patterns also may be associated with the use of implants and fixation devices that may stimulate longitudinal growth.The greater growth is rarely significant but does necessitate future assessment by the clinician, possibly until growth ceases.

Complete growth retardation or partial growth arrest may result in progressive limb-length discrepancies. Complete growth arrest is uncommon and depends on when the injury to the physis occurs in relation to the remaining skeletal growth potential. The younger the patient, the greater the potential for problems associated with growth.

If the expected leg-length discrepancy is less than 2.5 cm, the difference can usually be treated nonoperatively, with normal painless gait expected.  If the discrepancy is 2.5-5.0 cm, then treatment usually involves an epiphysiodesis of the longer limb to avoid producing disproportionate limbs if there is enough time for continued growth to correct the difference.

Careful follow-up and monitoring of the growth rate are needed to determine the optimal time for epiphysiodesis. Timing is very important: A procedure done too soon or too late can result in persistent leg-length discrepancy. Tools to estimate the best time for surgery include the growth remaining method of Anderson and Green and the straight-line graph of Moseley. The two methods are essentially equal in accuracy, but the Moseley method is more complicated and requires actual bone lengths over a prolonged period; therefore, it is useful only for young children.

Epiphysiodesis can be accomplished with a surgical staple crossing the growth plate. The advantage of a staple is that growth can resume after removal of the staple (although this is unpredictable).

Another technique is growth plate destruction, accomplished by drilling and grafting the epiphysis, as described by Phemister and later by Anderson and Green. Advantages of growth plate destruction include a lower infection rate and less need for secondary operations as compared with staples, which can loosen or irritate soft tissues and require removal.

With either technique, repeat epiphysiodesis is sometimes required.

The images below show growth retardation of the distal radius relative to the distal ulna (posttraumatic Madelung deformity) after a distal radius SH I fracture, which was treated with epiphysiodesis of the distal ulna.

Growth plate (physeal) fractures. Posttraumatic Ma Growth plate (physeal) fractures. Posttraumatic Madelung deformity treated with epiphyseodesis of distal ulna to allow radius growth to catch up.
Growth plate (physeal) fractures. Comparison views Growth plate (physeal) fractures. Comparison views of two wrists show almost equal ulnar variance (with correction of previously Madelung deformity by epiphyseodesis).

If more than 5 cm of correction is desired, epiphysiodesis usually is not a treatment option, and the clinician may consider lengthening (or shortening) procedures. The images below are of a 14-year-old girl who had a leg-length discrepancy and was near skeletal maturity. She was treated with Ilizarov distraction osteosynthesis.

Growth plate (physeal) fractures. 14-year-old girl Growth plate (physeal) fractures. 14-year-old girl with leg-length discrepancy.
Growth plate (physeal) fractures. Application of I Growth plate (physeal) fractures. Application of Ilizarov external fixator frame with corticotomy for distraction osteogenesis correction of leg-length discrepancy.
Growth plate (physeal) fractures. Ilizarov distrac Growth plate (physeal) fractures. Ilizarov distraction osteogenesis for leg-length discrepancy.
Growth plate (physeal) fractures. Equal leg length Growth plate (physeal) fractures. Equal leg lengths (healing) after Ilizarov distraction osteogenesis.

Limb malalignment

Premature partial growth arrest is far more common and can appear as peripheral or central closures. These can result in angular deformities and limb-length discrepancies. Premature partial arrests are produced when a bridge of bone (bone bar or bridge) forms, connecting metaphysis to epiphysis and traversing the physis.

This bone bar inhibits growth, and its size and location determine the clinical deformity. For example, if the bar is located medially in the physis of the distal femur, the normal physis continues to grow laterally, producing a varus deformity (genu varum); the opposing location yields a genu valgum deformity.

If adequate growth remains, bar resection may result in correction of the deformity. If inadequate growth remains, osteotomy may be needed for deformity correction.

Investigation into gait analysis for patients with genu valgum deformity has revealed improvements in cosmesis and corrected joint kinematics with hemiphyseal stapling. Anterior bone bars in the distal femoral physis allow normal physeal growth posteriorly but result in a genu recurvatum deformity.

Similarly, central growth arrests result in tented lesions of the physis and epiphysis because of a central osseous tether with the metaphysis, resulting in the characteristic physeal coning. As the physis tries to push the epiphysis away from the metaphysis, the bony bridge hypertrophies in an effort to overcome the increased tension placed on it. Bone tissue under constant tension usually atrophies, but in this instance, a dense reactive cortical bone develops.

Some longitudinal growth may continue in patients with growth retardation, though at a much slower rate; thus, a progressive shortening of the limb occurs. Partial growth arrests may be visible on radiographs as early as 3-4 months after injury or may be delayed as long as 18-24 months. Follow-up checks may be necessary for 1-2 years after injury to monitor physeal healing and growth response.

Articular problems are also a possibility, particularly in physeal fractures that lead to discontinuities of the articular surface (ie, SH III and IV). These lesions can result in intra-articular stepoffs and early degenerative joint disease if they are not properly treated and anatomically reduced. Central growth arrest can promote the physeal tenting phenomena and, ultimately, result in a deformed articular surface.

The images below illustrate a distal tibia physeal malunion resulting in progressive growth deformity.

Growth plate (physeal) fractures. Salter-Harris V Growth plate (physeal) fractures. Salter-Harris V fracture pattern must be strongly suspected whenever mechanism of injury includes significant compressive forces. This is initial injury radiograph of child's ankle that was subjected to significant compressive and inversion forces. It demonstrates minimally displaced fractures of tibia and fibula with apparent maintenance of distal tibial physeal architecture.
Growth plate (physeal) fractures. Follow-up radiog Growth plate (physeal) fractures. Follow-up radiograph of ankle of child in preceding image. This radiograph depicts growth arrest secondary to Salter-Harris V nature of the injury. Note markedly asymmetric Park-Harris growth recovery line, indicating that lateral portion of growth plate continues to function and medial portion does not.

Again, timing is very important. The images below illustrate a proximal tibia apophysis avulsion fracture that developed malunion and was treated too late by means of staple epiphysiodesis. The patient required an osteotomy for correction of the deformity.

Growth plate (physeal) fractures. Procurvatum of p Growth plate (physeal) fractures. Procurvatum of proximal tibia after open reduction and internal fixation of proximal tibia apophysis injury.
Growth plate (physeal) fractures. Epiphyseodesis p Growth plate (physeal) fractures. Epiphyseodesis performed too late to correct procurvatum deformity of proximal tibia.

At 1 year follow-up, the patient had procurvatum of the distal femur with at least partial closure of the distal femoral physis (see the first image below). Workup included bone age studies (including left wrist radiographs and the Greulich-Pyle atlas), which demonstrated that she was near skeletal maturity. Scanograms revealed 42 cm femur length on the right and 41.5 cm femur length on the left (see the second image below).

Growth plate (physeal) fractures. Growth arrest of Growth plate (physeal) fractures. Growth arrest of distal femur at skeletal maturity after Salter-Harris II fracture of distal femur.
Growth plate (physeal) fractures. Scanograms to as Growth plate (physeal) fractures. Scanograms to assess leg lengths after growth plate arrest following Salter-Harris II fracture of distal femur.

It was felt that excellent function could be restored with osteotomy without leg lengthening. The patient was too near skeletal maturity for success to be expected with epiphysiodesis. Osteotomy was successful, restoring position and length (see the image below).

Growth plate (physeal) fractures. Corrective osteo Growth plate (physeal) fractures. Corrective osteotomy after growth arrest deformity following Salter-Harris II fracture of distal femur.

Hardware complications

Hardware crossing the physis should be removed to prevent iatrogenic growth problems. In young children, hardware removal is commonly recommended; continued bone growth can bury hardware, making future removal (if needed) technically challenging. Painful hardware should also be removed. In older patients, hardware that is not causing symptoms can be left in situ.

The images below are from a patient with a healed SH III fracture of the distal femur who had pain from a screw head and washer. The pain resolved after removal of the hardware.

 Growth plate (physeal) fractures. Healed Salter-H Growth plate (physeal) fractures. Healed Salter-Harris III fracture of distal femur with pain over retained hardware (screw head).
Growth plate (physeal) fractures. Resolution of pa Growth plate (physeal) fractures. Resolution of pain after removal of hardware; healed Salter-Harris II fracture of distal femur.

Iatrogenic damage to trochanteric apophysis

Femoral rodding in adolescents carries the risk of closure of the greater trochanteric apophysis, as well as the risk of avascular necrosis of the femoral head.

Arthrofibrosis

Arthrofibrosis following intra-articular physeal injuries (SH III and IV) are not uncommon. For example, 20-30% of patients with distal femur intra-articular physeal injuries may develop loss of knee motion, especially flexion. Postfracture stiffness is less common in patients treated with bracing than those treated with casting; therefore, early mobilization is recommended.[24]

Prevention

In pediatric athletes, the frequency of growth plate injuries can be decreased with appropriate training programs.[8, 7]  Because most athletic injuries are due to chronic overuse, the pathology develops gradually, affording trainers, coaches, and physicians multiple opportunities to intervene and prevent long-term sequelae from developing.[3]

Growth plate injuries tend to occur during periods of rapid growth. Training loads should therefore be reduced during growth spurts, which can be identified by monitoring height measurements every 3 months.[7]

Training programs should limit excessive repetitive movements, using a variety of drills. Limiting pitch counts, for example, may reduce the risk of throwing injuries in baseball pitchers.[7]

Recommendations of the American Academy of Pediatrics for preventing these injuries in youth athletes include the following[8, 7] :

  • The child should take at least 1-2 days off from the sport every week
  • The child should take at least 3 months off from the sport every year (in increments of 1 month); this time can be spent in free play
  • The number of training hours per week should not exceed the child's age or should not exceed 16 regardless of age until skeletal maturity

Long-Term Monitoring

Long-term follow-up is essential for determining whether complications will occur. Management of physeal fractures can thus be divided into two phases. The first phase involves ensuring bone healing, and the second phase involves monitoring growth.

Most growth plate (physeal) injuries should be reevaluated in the short term to ensure maintenance of reduction and proper anatomic relations. Some growth plate fractures are more problematic than others when it comes to the risk of growth arrest. Physeal fractures that are considered to be at increased risk for growth arrest include fractures to the following growth plates:

  • Distal femur [50, 24]
  • Distal tibia [51]
  • Distal radius and ulna
  • Proximal tibia
  • Triradiate cartilage

After initial fracture healing has occurred, physeal fractures require additional follow-up radiographs 6 months after injury, 12 months after injury, or both to assess for growth disturbance. It is reasonable to advise follow-up and educate patient family members as to the potential for growth abnormality, even with fractures that appear very benign; for example, SH V fractures may appear at initial evaluation to be less severe than they actually are. Follow-up is reasonable for a minimum of 12 months or until both the involved physis and the contralateral physis have closed.[24]

The images below are from a child with a minimally displaced SH III distal radius fracture (see the first image below) that was initially treated without surgery. Despite the benign appearance, a central growth arrest of the distal radius developed with posttraumatic arthritis at the scaphoradial articulation and positive ulnar variance as the ulna continued to grow (see the second image below). Ulnar epiphysiodesis and central par resection improved the ulnar variance and the appearance of the scapholunate interval (see the third image below), but posttraumatic arthritis persisted. Conceivably, the outcome might have been improved if the patient had been instructed to follow-up routinely sooner.

Growth plate (physeal) fractures. Minimally displa Growth plate (physeal) fractures. Minimally displaced Salter-Harris III fracture of distal radius.
Growth plate (physeal) fractures. Central deformit Growth plate (physeal) fractures. Central deformity of distal radius with growth retardation and relative lengthening of distal ulna after Salter-Harris III fracture of distal radius.
Growth plate (physeal) fractures. Partial correcti Growth plate (physeal) fractures. Partial correction of deformity (improvement of ulnar variance) after ulnar epiphyseodesis to correct growth retardation of distal radius following Salter-Harris III fracture. Earlier diagnosis and intervention might have improved results.

Growth plate injuries can occur even with diaphyseal fractures or injuries remote from the physes. Therefore, a high index of suspicion must be maintained and appropriate follow-up considered for any fracture in a growing child. It is essential always to be aware of the joint above and below any fracture.

As an illustrative example of growth arrest after remote injury, a 13-year-old skeletally immature boy presented with a midshaft tibia fracture (see the first image below) that was treated with closed reduction and casting and that apparently healed uneventfully (see the second image below). The patient returned 3 years later (at 16 years old) with knee pain and procurvatum deformity (see the third image below). Treatment of the angular deformity was successful after proximal tibia osteotomy (see the fourth and fifth images below).

Growth plate (physeal) fractures. Tibia shaft frac Growth plate (physeal) fractures. Tibia shaft fracture in child.
Growth plate (physeal) fractures. Healed tibia sha Growth plate (physeal) fractures. Healed tibia shaft fracture in child.
Growth plate (physeal) fractures. Comparison radio Growth plate (physeal) fractures. Comparison radiographic views (anteroposterior and lateral, both knees) showing procurvatum deformity of proximal tibia due to growth retardation remote from prior tibial shaft fracture.
Growth plate (physeal) fractures. Opening wedge os Growth plate (physeal) fractures. Opening wedge osteotomy to correct procurvatum deformity of proximal tibia.
Growth plate (physeal) fractures. Healed proximal Growth plate (physeal) fractures. Healed proximal tibia osteotomy.

Although it is impractical to follow all patients until skeletal maturity, at a minimum, the parents should be educated concerning the potential for long-term complications.