Malunion of Hand Fracture Treatment & Management
- Author: Palaniappan Lakshmanan, MBBS, MS, AFRCS, FRCS(Tr&Orth); Chief Editor: Harris Gellman, MD more...
The hand is a highly complex structure that requires integrated function of extrinsic and intrinsic motor units across a complex and limited bony and articular framework. The hand also functions as a sensory organ and an organ of communication. All these factors should be considered before reconstruction is undertaken.
The goals of treatment are to restore disordered function and, occasionally, to correct cosmetic deformity. Accordingly, the malunion should be carefully studied with an eye to understanding the original deforming forces. Important principles in the management of malunions include the following:
Rotational deformities are most disabling yet frequently not appreciated; a 10° rotational malunion results in a 2-cm overlap at the fingertip; alignment should always be checked with the fingers flexed in the palm
An appropriate form of osteotomy and subsequent fixation must be tailored to each individual deformity; familiarity with osteotomy techniques and alternative forms of fixation affords flexibility in treating deformities
The soft tissues must be inspected carefully for scarring, adhesions, and contractures; careful protection of delicate structures by judicious tenolysis and arthrolysis may be needed at the time of osteotomy
Appropriate, functional, postoperative rehabilitation is a must for good results; otherwise, even the best surgery produces suboptimal results.
A carefully planned osteotomy is necessary and must be executed with the least possible further damage to soft tissues. Techniques of osteotomy must be tailored to the biomechanical requirements for proper realignment of the malunited fracture.
Seo et al described an osteotomy technique for correcting malunion of the proximal phalanx that is minimally invasive and is performed under local anesthesia. They reported that among the advantages that this technique offers is that it permits active flexion and extension, which leads to more accurate reduction and earlier recovery.
Malunion of phalangeal fractures
Clinically significant malrotation results in functional impairment and usually necessitates osteotomy through the phalanx or the metacarpal. (See the images below.)
Phalangeal osteotomy corrects the malunion at its site of origin, allows simultaneous correction of angular deformities, and permits concomitant soft-tissue procedures such as tenolysis or capsulotomy. Phalangeal osteotomies can be either step-cut or transverse, which are performed with a power saw. Step-cut osteotomies are fixed with either small AO (Arbeitsgemeinschaft für Osteosynthese [Association for the Study of Osteosynthesis]) screws or Kirschner wires (K-wires); transverse osteotomies can be held with a plate or with K-wires.
Metacarpal-base osteotomies for malrotation correction can achieve up to 18-19° of correction in the index, long, and ring fingers, and up to 20-30° in the small fingers.
Volar angulation of 25-35° results in fixed flexion deformity of the proximal interphalangeal (PIP) joint. This requires correction by means of either closed- or open-wedge osteotomy and fixation with K-pins. The open wedge requires a bone graft to fill the gap, whereas the closed wedge may result in shortening of the finger.
Lateral angulation of phalangeal fractures is corrected in the same manner as volar angulation—that is, by performing osteotomies with a power saw.
Shortening due to a comminuted fracture that is allowed to heal in a collapsed fashion or that occurs after a long spiral fracture can be corrected with an appropriately fashioned intercalary graft insertion. When a spiral fracture of the phalanx heals in a shortened position with a distal spike on the proximal fragment, blocking flexion of the digit, careful removal of the spike may be all that is required.
Unreduced condylar fractures extending into the joint require corrective osteotomy, arthrodesis, or arthroplasty.
Malunion of metacarpal fractures
Dorsal angulation usually occurs in the second or third metacarpal and is bothersome, both cosmetically and functionally, as it weakens the grip of the hand (see the images below). Correction is achieved with closed- or open-wedge osteotomies or fixation with K-wires or AO plates.
The closed wedge is preferred over the open wedge for two reasons. First, healing of only one surface is required, unlike the open wedge, in which healing of two surfaces is required. Second, the intrinsics can accommodate some shortening with a closed wedge, whereas with an open wedge, lengthening of the bone occurs. Such lengthening may aggravate the intrinsic tightness, especially when posttraumatic intrinsic muscle contracture has occurred.
Rotational malunion results from overlapping of the affected finger over the adjacent finger. Cosmetic deformity is often marked, and grip is impaired. Correction is achieved through a metacarpal-base osteotomy. During the operation, a longitudinal mark is made on the metaphysis with an osteotome prior to the osteotomy. Then, the osteotomy is performed with a power saw perpendicular to the mark. The rotation is corrected and fixed with several K-wires or AO plates.
Intra-articular metacarpal malunions are difficult to correct with osteotomies. However, correction can be achieved by maintaining reduction with screws and plates or with screws and cancellous bone grafts.
Malunion in carpal bones
The scaphoid is the usual site for carpal malunion. Malunion of other carpal bones is rare. Malunion of the scaphoid is best prevented. If malunion of the scaphoid is detected soon after union, corrective osteotomy can be considered. Late malunion of the scaphoid is best managed symptomatically. Finally, scaphoid cheilectomy or radial styloidectomy can be considered if symptoms persist.
Optimal site for osteotomy
Whether osteotomy for malunion of metacarpals and phalanges in the hand should be done at the original fracture site or at a separate site is a matter of debate. Correction at the fracture site is generally preferred, in that it addresses the issue at the site of pathology (ie, malunion) and thus can correct the combined deformity (translation, rotation, and angulation). Furthermore, it enables the surgeon to perform tenolysis and capsulolysis at the same time. It especially avoids the zigzag deformity produced by the osteotomy away from the fracture site.
A corrective osteotomy performed at the level of the fracture site is called a focal osteotomy, whereas one performed away from the original fracture site is called an extrafocal osteotomy.
Extrafocal osteotomies do not restore the normal anatomy. However, there are instances where this may be preferred, as in the case of a malunion resulting from a complex or compound fracture that can be treated by a single osteotomy rather than a focal osteotomy. The latter may have to be complex, and the metacarpal or the phalanx may not lend itself to such a complex procedure. Extrafocal osteotomy is also preferred in articular malunions when there is enough joint space or if the articular fragment is too small to be interfered with.
Opening-wedge vs closing-wedge osteotomy
Basically, an osteotomy can be a closing-wedge or an opening-wedge procedure. A closing-wedge osteotomy has the advantage of inherent stability with no additional bone graft; however, it shortens the digit. An opening-wedge procedure may need a structural bone graft, but this is not always the case, as when secure fixation is obtained with a plate and screw, where cancellous bone graft can be used as supplementation.
Securing of osteotomy
As with any other fracture, different options are available, including plaster immobilization, K-wire fixation, plate-and-screw fixation, and external fixator application. An osteotomy can be left alone only if there is inherent stability at the osteotomy site, which can occur with step-cut osteotomies. Basal osteotomies can be held with K-wires. However, plate-and-screw fixation is preferred for rigid fixation and immediate postoperative mobilization to prevent stiffness and adhesions and, thereby, improve function.
Timing of osteotomy
The timing of operative intervention is vital, especially in malaligned fractures proceeding to established malunion. If the fracture malalignment is addressed surgically within 10 weeks, then the fracture site can be exposed, the callus can be removed to recreate the original fracture, and the fracture can be managed with appropriate fixation.
When functional loss is predicted from the amount of malalignment at the time of evaluation, there is little value in waiting to perform the correction. However, in cases with milder deformities, it is better to wait to do a corrective osteotomy until the degree of functional loss can be estimated.
Adequate surgical planning requires adequate preoperative assessment. The patient's neurovascular status should be assessed before any intervention is performed. Intraoperative fluoroscopy or radiography should be used to ensure that adequate fixation is achieved before the patient leaves the operating room. Joint motion should be assessed after fixation so that postoperative expectations can be established.
Most surgery in the hand is undertaken to promote function. Early mobilization is essential to ensure a good outcome. Delaying motion beyond 3 weeks leads to arthrofibrosis and a poor functional outcome. Optimal surgical treatment should allow for adequate postoperative motion, and to achieve a good outcome, patients should be encouraged to move their fingers daily.
Outcome and Prognosis
If treated carefully, with adherence to the principles described, most phalangeal and metacarpal malunions heal without clinically significant complications. Complications may include recurrence of deformity, neurovascular complications, or both.
Some patients may develop stiffness and decreased mobility. Most poor results are documented in elderly patients (>65 years) and in patients with crush injuries or extensive soft-tissue contractures. A combination of these factors increases the risk of compromised results. Proper selection of implants and quick rehabilitation may improve the prognosis.
In a study comparing 218 little-finger metacarpal shaft and neck fractures treated nonoperatively (with no attempt at fracture reduction) with 44 treated operatively with fracture reduction and fixation, severity of palmar angular deformity did not affect the outcome of nonoperatively treated fractures. There were no differences in outcome between operatively treated and nonoperatively treated metacarpal neck fractures; and Disabilities of the Arm, Shoulder, and Hand (DASH) scores and aesthetic outcomes were better for metacarpal shaft fractures treated nonoperatively than for those treated operatively.
Potenza et al reported clinical and radiographic medium-term results for 24 fingers in 20 patients who underwent surgery for posttraumatic malunion of the proximal phalanx. In all cases, corrective osteoclasia or osteotomy was done at the malunion site, followed by miniplate and screw fixation or by screw fixation only. Corrective osteoclasia was performed when malalignment was addressed within 6 weeks after injury. Two patients who had two fractures underwent additional surgery to improve function and range of motion.
Final follow-up occurred at a mean of 24 months after corrective surgery. Good or excellent clinical and radiographic results were obtained for all patients. An improvement in grip strength was demonstrated by all patients. The mean score on the DASH symptom scale was 5 points. The researchers concluded that in situ osteotomy, in conjunction with stabilization by miniplates or screws, is effective for correcting posttraumatic malunions of the proximal phalanges of the fingers.
Future and Controversies
In the future, expanded use of bioabsorbable implants made of polyglycolic acid or poly-L-lactic acid may have advantages over the traditionally used pins, screws, and plates. These bioabsorbable plates will help avoid the need for second procedures to remove implants, which are the main causes of loss of function from iatrogenic causes. Further development of low-profile implants with high tensile strength will allow adequate mobility during postoperative rehabilitation and, thereby, help prevent stiffness.
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