eMedicine Specialties > Sports Medicine > Wrist and Hand

Phalangeal Fractures

Author: Jay E Bowen, DO, Assistant Professor, Clinical Coordinator Sports Medicine Fellowship, Department of Physical Medicine and Rehabilitation, Kessler Rehabilitation Corporation
Coauthor(s): Gerard A Malanga, MD, Founder and Director, New Jersey Sports Medicine Institute; Director of Pain Management, Overlook Hospital; Director of Sports Medicine, Sports Medicine Fellowship Director, Mountainside Hospital; Clinical Chief, Rehabilitation Medicine and Electrodiagnosis, St Michael's Medical Center; Medical Director, Consultant, Horizon Healthcare Worker's Compensation Services, Blue Cross and Blue Shield Worker's Compensation; Elena Napolitano, MD, Staff Physician, Department of Physical Medicine and Rehabilitation, University of Medicine and Dentistry of New Jersey; Alice Tzeng, MD, Resident, Resident, Department of Physical Medicine and Rehabilitation, University of Medicine and Dentistry of New Jersey
Contributor Information and Disclosures

Updated: Jan 23, 2009

Introduction

Background

Hand injuries are very common in all sports, especially in ball-playing athletes. Most athletic hand injuries are closed hand injuries and include ligamentous injuries, fractures and fracture-dislocations, tendon injuries, and neurovascular problems. There is increasing recognition that fractures and dislocations of the hand can result in long-term pain and disability if they are not recognized and treated early.^1,2,3,4

Extra-articular fractures of the distal phalanx are common and are associated with significant soft-tissue injury. Most distal phalangeal fractures are crush injuries from a perpendicular force. They can be associated with significant debility, usually in the form of soft-tissue loss, nail bed injury, or posttraumatic neuromas. Intra-articular fractures of the distal phalanx can result from avulsion of either the extensor tendon, also known as mallet fractures, or of the flexor digitorum profundus, also known as jersey fractures. These can be associated with either small dorsal fragments or larger articular fragments with volar subluxation of the volar fragment. Conservative management is usually the standard of treatment.

Fractures of the proximal phalanx are more common than fractures of the middle phalanges. Dorsal or palmar angulation may occur with these fractures, depending on their location. Nondisplaced fractures are usually stable and are treated with closed reduction and fixation.^2,5 If significant comminution or segmental bone loss is present, these unstable fractures may require either internal or external fixation.

The proximal interphalangeal (PIP) joint is particularly vulnerable to injury as either an ligamentous or intra-articular fracture, with or without subluxation or dislocation. Middle phalangeal articular fractures at the PIP joint include dorsal lip fractures, palmar lip fractures, and central articular disruptions or pilon fractures. Avulsion and impaction sheer are 2 fracture mechanisms.

Middle phalanx palmar lip fractures are the most common form of osseous injury associated with PIP joint fracture-dislocations. Dorsal fracture-dislocation of the PIP joint is reported to occur in 9 of every 100,000 people each year. Many of these injuries are frequently ignored or treated inappropriately. As a result, there can be permanent swelling, pain, and variable degrees of stiffness, angulation, and degenerative changes.

Hand fractures in the athlete are treated with adequate alignment, immobilization, and then motion. In general, intra-articular fractures must be reduced anatomically. Reduction requires early recognition of the exact location of the fracture and having a complete understanding of the muscle pull on the fragments, then minimizing the deforming force.

For excellent patient education resources, visit eMedicine's Breaks, Fractures, and Dislocations Center. Also, see eMedicine's patient education articles Broken Finger, Broken Hand, and Wrist Injury.

Functional Anatomy

The phalanges do not contain muscle bellies, and motor function is accomplished only by the flexor and extensor tendons. An overview of the muscles and tendons of the hand is necessary. The thenar muscles consist of 3 intrinsic muscles including the abductor pollicis brevis (which abducts the thumb), the flexor pollicis brevis (which flexes the proximal phalanx of the thumb), and the opponens pollicis (which produces opposition of the thumb).

All 3 intrinsic thenar muscles are supplied by the recurrent branch of the median nerve. The adductor pollicis adducts the thumb and is supplied by the deep branch of the ulnar nerve. The hypothenar muscles are also supplied by the deep branch of the ulnar nerve.

The abductor digiti minimi abducts the fifth digit and flexes its proximal phalanx. The flexor digiti minimi is deeper and also flexes the proximal phalanx of the fifth digit. The opponens digiti minimi, as its name implies, opposes the fifth digit.

The lumbricals are 4 muscles that arise from the tendons of flexor digitorum profundus. Their tendons insert into the radial side of each of the proximal phalanges of the fingers and into the dorsal hood. They flex the metacarpophalangeal joints and extend the interphalangeal joints. The first and second lumbricals are supplied by the median nerve, and the third and fourth lumbricals are supplied by the ulnar nerve.

The palmar and dorsal interossei arise from the metacarpals. The palmar interossei insert into the proximal phalanx and the expansion of the extensor digitorum communis. The palmar interossei are adductor muscles. Dorsal interossei are abductors and insert into the proximal phalanges and the dorsal digital hood. The interosseous muscles are all supplied by the deep branch of the ulnar nerve.

As the tendons of the long flexor and extensor muscles reach the hand, the flexor tendons must first pass deep to the flexor retinaculum and the extensor tendons must pass under the extensor retinaculum. Flexor tendons on the palmar side are anchored to the phalanges by fibrous flexor sheaths to prevent "bow-stringing." Synovial sheaths prevent friction from occurring between fibrous flexor sheaths and the tendons. Synovial sheaths are present on the dorsum of the hand deep to the extensor retinaculum. They extend from a point proximal to the retinaculum to a point in the proximal one third of the dorsum of the hand.

Anatomy of the distal interphalangeal (DIP) joint includes the insertion of the extensor tendon on the distal phalanx.

Sport-Specific Biomechanics

The PIP joint is the most commonly injured area in the hand. There is both anatomic and functional complexity to this joint, which consists of the articulation of the proximal end of the middle phalanx and the distal end of the proximal phalanx. It is a hinge joint with range of motion from 0 º to 120 º in the extension-flexion plane, with the bulk of static and dynamic stability provided by the surrounding ligaments and tendons.

The capsule surrounding the articular surface is composed of the volar plate, thick collateral ligaments, and the extensor tendon dorsally, which divides into 3 slips as it passes over the proximal phalanx. The central slip of the extensor tendon passes directly over the joint and inserts on the dorsal base of the middle phalanx. The lateral bands of the extensor tendon combine distally with the tendons of the intrinsic hand muscles (the retinacular ligaments) to form the extensor tendon that attach to the distal phalanx.

The thick ulnar and radial collateral ligaments of the PIP joint combine with the volar plate to provide lateral stability. The volar plate, a thick fibrocartilaginous structure, forms a sturdy attachment to the middle phalanx where it becomes continuous with the articular cartilage. This limits extension of the PIP joint beyond 0 º.

Proximally, the volar plate forms a thin continuous attachment with the synovial reflection. The lateral margins remain thick strong ligaments. This results in a cul-de-sac between the proximal half of the volar plate and the head of the proximal phalanx, which allows the base of the middle phalanx to glide along the articular surface of the proximal phalanx as the finger flexes. Thus, the volar plate becomes both a static stabilizer limiting hyperextension beyond 0 º and a dynamic stabilizer that influences the position of the flexor tendons at initiation of PIP joint flexion.

Clinical

History

• Distal phalangeal fractures
  • Most distal phalangeal fractures are crush injuries from a perpendicular force, as in injuries from a car door or hammer or in sports when a player has a digit stepped on or crushed between the helmets of opposing players. Tuft fractures are often comminuted and are generally stable fractures because of intrinsic splinting of bony fragments by fibrous septae in the fingertips.
  • Physical examination in a person suspected of having a phalangeal fracture starts with inspection, attitude of the injured finger, and localization of any swelling. Neurovascular status should be examined as well as color, capillary refill, and digital temperature. Palpation of the joint over 4 planes (ie, dorsal, volar, medial, lateral) allows assessment of point tenderness over ligamentous origins and insertions, which is suggestive of soft-tissue disruption. Passive range of motion and joint stability should be assessed through dorsal, volar, and lateral stressing. It should not be assumed that lack of full active flexion or extension is merely secondary to joint pain.
  • Fractures at the base of the distal phalanx are usually mallet avulsion fractures and are caused by rupture of the extensor tendon at the DIP joint. These are common injuries in basketball or baseball players.⁶ The mechanism of injury usually results from a direct blow to the tip of the finger that causes forced flexion of the DIP joint.
• Jersey finger
  • Avulsion of the flexor digitorum profundus from its insertion on the volar base of the distal phalanx results in the jersey finger. The mechanism of injury most commonly occurs in football when a player grabs the opponent's jersey. There is forced hyperextension of the DIP joint against an actively contracting flexor tendon. The ring finger is most commonly involved. Pain and swelling of the affected finger occurs, with loss of active flexion of the DIP joint.
  • This injury is often overlooked because on physical examination there is no obvious deformity present and the loss of DIP flexion is either not appreciated or dismissed secondary to pain or soft-tissue swelling. If one suspects flexor tendon avulsion, then gentle active flexion of the DIP joint should be tested specifically. Radiographic findings are often normal but may reveal a small avulsion fracture.
• Middle phalangeal fractures
  • The mechanism of injury of middle phalangeal fractures is usually the result of a blunt or crush force perpendicular to the long axis of the bone. Angulation and rotation are 2 features of instability that must be examined.
  • Visual inspection usually detects dislocations and subluxations but is most valuable in the angulatory or rotary deformities that can accompany subluxation/dislocations. These deformities suggest complications ranging from asymmetric ligament tears to interposed tissues between joint surfaces. Rotational deformities are serious injuries and are detected clinically. Patients should be asked to fully flex the phalanges, and the long axis of the fingers should point to the scaphoid tubercle or the distal radius with the fingers parallel to each other.
  • Dorsal or volar angulation is evaluated radiographically in relation to the insertion of the flexor digitorum superficialis. Fractures distal to the tendon result in volar angulation, and proximal fractures result in dorsal angulation from the resulting muscle pull.
• Proximal phalangeal fractures
  • Proximal phalangeal fractures are relatively common and may result in a great deal of disability. The mechanism of action usually results from a direct perpendicular force, a rotary force, or hyperextension of the finger.
  • The physical examination is the same as that for distal phalangeal fractures (see above).
• Dorsal PIP joint dislocations
  • Dorsal dislocation of the PIP joint is a common injury that occurs secondary to joint hyperextension. The volar plate must be ruptured for dorsal dislocation to occur. This rupture usually occurs at the distal insertion site at the base of the middle phalanx and may involve a tiny avulsion fracture of the base of the middle phalanx.
  • When disruption of the collateral ligaments has also occurred, rotary deformity and lateral stress instability will be apparent. Joint dislocation should be assessed for collateral ligament injury, because any associated collateral ligament problems require orthopedic referral.
• Volar PIP joint dislocations
  • Volar dislocations of the PIP joint are less common than dorsal dislocations and are more difficult to manage than other injuries. A volar dislocation ruptures the extensor mechanism, possibly involving injury of the central slip.
  • Evaluation of the PIP joint injury starts with the history to understand the mechanism and direction of injury, the presence of an initial deformity, and whether a reduction was performed. The physical examination includes thorough inspection and palpation of the area and localization of the tenderness. The examination should also include testing active and passive range of motion, with and without resistance. Tenderness dorsally indicates a central slip injury. This is confirmed if there is pain and inability to extend the PIP joint against resistance. Lateral stressing of the joint assesses integrity of the collateral ligaments and the degree of instability.
• Grading and treatment
  • Instability of the PIP joint is classified as 3 grades, and treatment is based on the grading of the injury. Grading is based on active range of motion and stress testing. When pain interferes with evaluating for these, a local anesthetic block at the metacarpal level should be performed.
    • Grade I injuries are stable through an active range of motion and do not angulate more than 20° greater than the contralateral side on stress testing.
    • Grade II injuries will not deform with active range of motion, but stress testing will show instability, defined as greater than 20° of angulation when compared with the contralateral side. These injuries are due to a complete disruption of one of the major retaining ligaments, which include the radial or ulnar collateral ligaments, the volar plate, or the central extensor slip.
    • Grade III injuries show deformity with active range of motion or the injured fingers are unable to be moved through more than 75% of the range of motion under anesthetic block. This implies complete disruption of greater than 50% of the entire capsule or 2 or more of the major retaining ligaments.
  • Collateral ligament injuries may be the result of a pure angulatory stress or a joint dislocation with the radial collateral ligament as the ligament most frequently injured.
• The most common complication of a volar plate injury or dorsal dislocation is the development of pseudo-boutonniere deformity, which is a persistent PIP joint flexion contracture. Another common problem is detachment of the volar plate, resulting in hyperextension laxity at the PIP joint and a swan-neck deformity. Associated with the swan-neck deformity is the painful snapping of the lateral bands with attempted flexion. Both of these complications can be prevented with appropriate treatment.
• DIP joint dislocations: Dislocations of the DIP joint are uncommon. Such injuries are usually the result of a hyperextension force, and they are frequently open because the skin in this area is both thin and well anchored.
• Boutonniere deformity
  • Disruption of the central slip of the extensor digitorum communis tendon over the PIP joint produces the classic boutonniere deformity. This can be caused by blunt trauma over the dorsal aspect of the finger, with a deep laceration over the PIP joint, or with forced flexion of the joint.
  • Avulsion of the central slip results in a flexion deformity of approximately 15-30° due to unopposed pull of the flexor digitorum superficialis tendon. As a result of loss of extensor tendon function, in addition to localized pain and swelling, the PIP joint cannot be actively extended. One can think of this as the PIP "buttonholing" through the central slip.
  • Prevention of a boutonniere deformity requires a high index of suspicion during the acute stage of the injury. A central slip injury should be suspected in patients who present with pain mainly over the dorsal aspect of the PIP joint.
  • Radiographic findings are rare for the small avulsion fracture at the dorsal base of the middle phalanx. The best indication of central slip damage is inability to extend the PIP joint fully against active resistance. A central slip disruption is present unless proven otherwise when full extension cannot be performed.
  • Immediately after injury, examination will reveal a diffusely swollen PIP joint held in mild flexion. Active extension may be possible with the lateral bands. The diagnosis is made by palpating all 4 quadrants of the joint. This is confirmed if there is pain and inability to extend the PIP joint against resistance. Tenderness dorsally indicates a central slip injury.
  • Boutonniere deformities are graded I through IV.
    • A grade I injury is correctable passively.
    • A grade II injury is the case in which there is a PIP joint flexion contracture of less than 30° that is not passively correctable.
    • Grade III boutonnieres demonstrate a PIP joint flexion contracture greater than 30° and loss of flexion of the distal joint.

Physical

See History.

Causes

See History.

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