Practice Essentials
Phalangeal fractures are common injuries that can occur at the proximal, middle, or distal phalanx. [1] They may significantly affect hand function. [2] Even subtle injuries, such as a simple finger jam, can lead to decreased motion and a poor outcome if not diagnosed and treated promptly. This is especially true with injuries to the proximal interphalangeal (PIP) joint.
Historically, closed treatment has been the therapeutic mainstay for phalangeal fractures. Fractures of the phalanges, if unstable or irreducible, necessitate fixation secure enough to allow early motion in order to prevent adhesion formation. Percutaneous pinning allowed the conversion of more unstable fracture patterns to stable configurations capable of tolerating early motion. Subsequently, minifragment screws and plates were developed to assist in the management of complex phalangeal fractures.
For patient education resources, see the First Aid and Injuries Center, as well as Broken Finger and Broken Hand.
Anatomy
There are few places in the body where function and anatomy are as closely intertwined as they are in the finger. (See Hand Anatomy.) Injuries and subsequent scar formation can upset the delicate balance that normally exists, particularly at the PIP joint and the extensor apparatus. Anatomic considerations are based on the level of injury.
Distal phalanx
The terminal extensions of the flexor and extensor tendons insert into the base of the distal phalanx. These tendons can rupture at their insertion or can avulse a fragment of bone. Tuft fractures are commonly associated with injury to the overlying nail bed.
Distal interphalangeal joint
The head of the middle phalanx consists of two condyles that articulate with the base of the distal phalanx to form the distal interphalangeal (DIP) joint. With an axial load, one or both of the condyles may fracture. A closely adherent volar plate provides significant stability. Radial and ulnar collateral ligaments provide resistance to stresses in the coronal plane.
Middle phalanx
Sublimis tendons insert along a broad expanse on the volar aspect of the proximal half of the phalanx. The profundus tendon is held tightly in the flexor sheath by the important A4 pulley at the midportion of the phalanx. The middle phalanx region also contains additional cruciate pulleys (C2 and C3), which are located proximal and distal to the A4 pulley, respectively.
On the extensor side, the central slip inserts into the base of the middle phalanx. The lateral bands join over the distal portion of this phalanx to form the terminal extensor tendon. The two lateral bands are held together by the triangular ligament, which prevents volar subluxation of the lateral bands.
Proximal interphalangeal joint
The anatomy of the PIP joint is similar to that of the DIP joint. The volar plate covers a broad expanse over the joint and is the main stabilizer to joint dislocation. The collateral ligaments are larger at the PIP joint and consist of proper and accessory components.
Proximal phalanx
Sublimis and profundus tendons run together in the flexor sheath (zone 2) at this level. The A2 flexor pulley covers most of the proximal half of the phalanx; the C1 pulley is located more distally. The extensor digitorum communis (EDC) tendon runs the length of the phalanx and is stabilized by oblique and transverse fibers of the intrinsic apparatus. The lateral bands run from a lateral and volar position at the proximal aspect of the phalanx to a more dorsolateral position at the level of the PIP joint.
Pathophysiology
The stability of phalangeal fractures is dependent on the following factors:
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Location
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Fracture orientation
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Degree of initial displacement
Distal tuft fractures usually are stable, despite comminution. Unicondylar and bicondylar fractures involving the interphalangeal (IP) joints are inherently unstable. Displaced fractures involving the diaphyses of the proximal and middle phalanges also are unstable secondary to the pull of the intrinsics and flexor tendons. Fractures with an intact periosteal sleeve and no initial displacement usually are stable.
Etiology
Fractures and dislocations of the phalanges occur from a variety of mechanisms. In younger patients, these injuries are more likely to be sports-related. Older patients are likely to be injured by machinery or by falls. Crush injuries are common at the distal phalanx, whereas the PIP joint is usually damaged by an axial blow to the finger. [3]
Epidemiology
Because many injuries to the phalanges go unreported, defining the true incidence has been difficult. Fractures of the phalanges certainly are among the most common in the entire skeleton and may account for as many as 10% of all fractures. [3]
In a retrospective study (N = 245) addressing the epidemiology and characteristics of pediatric hand injuries requiring emergency surgery, Dizin et al found that 69% of injuries occurred at home, 11% at school, and 4% at a sports center. [4] The majority of the injuries involved the dorsal aspect, and the fingers were more often affected than the hand. The single most common lesion, occurring in 36% of cases, was a crush injury of a distal phalanx. Fracture/dislocations accounted for 12% of cases.
A study of 21,341 finger fractures from the Swedish Fracture Register found that the most common of these injuries was fracture of the base of the fifth finger, followed by fracture of the distal phalanx of the fourth finger. [5] Open fractures were most common in the distal phalanges (particularly the distal phalanx of the third finger); intra-articular fractures were most common in the middle phalanges. The most frequent cause of a finger fracture was a fall. Mean age at injury was 40 years (men, 38 y; women, 43 y). In adults, 86% of finger fractures in adults were treated nonoperatively; men underwent operative treatment more frequently than women did.
Prognosis
Outcome following phalangeal fractures depends on patient and injury factors, as well as on the expertise of the surgeon. Poorer results have been documented for patients older than 50 years and for those with associated systemic illness. High-energy fractures with comminution and soft-tissue injury also lead to poorer outcomes. Tendon injury, especially extensor tendon injury, in association with fracture, compromises results. Factors that the surgeon can control include selecting the appropriate fixation and ensuring that the period of immobilization does not exceed 3 weeks.
Kootstra et al compared patient-reported outcome measures and complications for three methods of surgical fixation in 159 patients with 159 proximal phalangeal (thumb excluded) fractures: Kirschner wire (K-wire; 44%), lag-screw (26%), and plate (30%). [6] The mean Disabilities of the Arm, Shoulder, and Hand (DASH) score was 5.0, and and the mean Patient-Rated Wrist/Hand Evaluation (PRWHE) score was 8.2. The fixation methods did not differ with regard to functional outcomes, though unplanned reoperation was more common in the plate group. K-wire fixation was found to be associated with better esthetic outcomes than open reduction with internal fixation (ORIF) was.
In a retrospective study (N = 46) examining proximal phalangeal fractures treated by means of percutaneous antegrade pinning, Ederer et al compared functional outcomes after early active postoperative motion (n = 28) with those after after 6 weeks of splint immobilization (n = 18). [7] The two groups did not differ significantly with respect to complication rate, number of revisions required, finger motion, or grip strength. However, the early active motion group was able to return to work earlier (2.5 vs 9.0 wk) and had a better DASH score (1.7 vs 2.5).
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Phalangeal fractures. Acute dorsal proximal interphalangeal joint (PIPJ) fracture-dislocation. Image courtesy of Mark Baratz, MD.
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Phalangeal fractures. Treatment with dorsal blocking splint. Image courtesy of Mark Baratz, MD.
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Phalangeal fractures. Custom figure-of-eight splint used once motion is begun. Image courtesy of Mark Baratz, MD.
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Phalangeal fractures. Complex unstable fracture of the proximal phalanx. Image courtesy of Mark Baratz, MD.
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Phalangeal fractures. Treatment with multiple minifragment screws plus Kirschner wires (K-wires). Image courtesy of Mark Baratz, MD.
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Phalangeal fractures. Acute dorsal proximal interphalangeal joint (PIPJ) fracture-dislocation. A concentric reduction could not be maintained in a dorsal blocking splint. Image courtesy of Mark Baratz, MD.
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Phalangeal fractures. Treatment with a dorsal blocking percutaneous pin. Image courtesy of Mark Baratz, MD.
