Metacarpal Fractures

Metacarpal Neck Fractures

Metacarpal neck fractures account for as many as 36% of all fractures of the hand.8 Metacarpals are weakest at the metacarpal neck and are often fractured by a direct blow, torsion, or bending load applied to the digit distally. Most metacarpal neck fractures affect the ring and little fingers. The most famous of these is the Boxer's fracture (although rarely seen in boxers), a fracture of the fifth metacarpal neck. Fractures at this level occur secondary to the instability of the ulnar digits and because the metacarpal head is already in 15 degrees of flexion.

Treatment of these injuries is usually splinting and early range of motion (ROM). If angulation is greater than 50 degrees, closed reduction and casting or operative fixation may be nec-essary.9,10 A prospective study by Lowdon11 found no relationship between residual angulation and the presence of symptoms.

Metacarpal Shaft Fractures

Metacarpal fractures are the most commonly seen hand fractures.12 Due to the low forces involved in athletic activities, com pared to motor vehicle accidents, most fractures are stable. Metacarpals are connected to one another via the transverse intermetacarpal ligament (Fig. 41-2). This is important when there is a fracture of a single metacarpal. Fractures of the middle and ring metacarpals are more stable because there are two transverse intermetacarpal ligaments supporting these bones. Rotational and shortening deformities are more likely to be seen in the index and small finger fractures.

The more distal the fracture is, the greater amount of angu-lation that can be accepted (Fig. 41-3). The ulnar aspect of the hand is more susceptible to fractures due to its greater mobility when compared to the radial aspect of the hand, and for the same reason, more angulation can be tolerated in the ulnar digits. Between 30 and 40 degrees of angulation can be accepted in the ring and small fingers.13 Carpometacarpal motion at the index and long fingers is minimal; therefore, the amount of angulation that is tolerated by these digits is less. The amount of angula-tion that can be accepted in the index and long fingers is 15 degrees.13 Dorsal angulation of these fractures affects the biomechanics of the digit. This angulation weakens the intrinsic muscles, resulting in metacarpal phalangeal joint hyperextension and weakness of the central slip as it extends the PIP joint.

A closed reduction maneuver, as described by Jahss,14 is performed by first disimpacting the fracture by longitudinal traction. The metacarpophalangeal (MCP) and PIP joints are then fully flexed, and a dorsally directed pressure is applied to the proximal phalanx through the flexed PIP joint. The digit should not be immobilized in the Jahss position, but in the safe position (metacarpal phalangeal joints flexed, fingers extended), using an ulnar or radial gutter splint. This allows the extensor

Extra Articular Fractures Metacarpal

Figure 41-2 A spiral fracture of the metacarpal tends to be more unstable in the border digits, where only one side of the metacarpal is supported by a deep intermetacarpal ligament. (From Hastings, Rettig, Strickland: Management of Extra-articular Fractures of the Phalanges and Metacarpals. Philadelphia, Elsevier, 1992.)

Figure 41-2 A spiral fracture of the metacarpal tends to be more unstable in the border digits, where only one side of the metacarpal is supported by a deep intermetacarpal ligament. (From Hastings, Rettig, Strickland: Management of Extra-articular Fractures of the Phalanges and Metacarpals. Philadelphia, Elsevier, 1992.)

Extra Articular Fracture Metacarpal Head

Figure 41-4 Radiograph of a displaced metacarpal fracture.

mechanism to act as a tension band. The splint is continued for 10 to 14 days, and the affected finger is buddy taped to an adjacent finger. It is important to repeat radiographs early in the treatment to prevent any unrecoverable displacement. When treating metacarpal fractures the patient is told to expect that (1) the knuckle contour may be lost permanently, (2) there will be some residual deformity of the digit, (3) if the finger heals in a more flexed position, there is a greater likelihood of refracture with less trauma, and (4) there may be a residual bump on the dorsum of the hand.

Nondisplaced fractures of the index and long fingers and minimally displaced fractures of the ring and small fingers can usually be treated by external immobilization alone. If crepitus is present, a cast is used for the first 2 weeks. Splinting for a total of 4 to 6 weeks is sufficient to heal most fractures.

Surgery

Various methods can be used to treat failed closed reductions or comminuted fractures in which a closed reduction would not be possible (e.g., intra-articular fractures). Open reduction internal fixation is often necessary if there is entrapment of soft tissues, irreducibility of the fracture, or the fracture is a result of high-energy trauma.15 It is important to rule out any rotational deformity because a slight misalignment at the base is greatly magnified at the tip of the finger. Rotational deformity is an indication for surgery. Dorsal angulation greater than 10 to 15 degrees in the index and long fingers or 30 to 40 degrees in the ring and small fingers or greater than 5 mm of shortening (Fig. 41-4) are other parameters of fractures of metacarpals that call for surgical treatment. Intra-articular extension of a fracture is also generally treated operatively.

Figure 41-3 Effect of fracture level on metacarpal head displacement. (From Hastings, Rettig, Strickland: Management of Extraarticular Fractures of the Phalanges and Metacarpals. Philadelphia, Elsevier, 1992.)

Figure 41-3 Effect of fracture level on metacarpal head displacement. (From Hastings, Rettig, Strickland: Management of Extraarticular Fractures of the Phalanges and Metacarpals. Philadelphia, Elsevier, 1992.)

Closed Reduction Percutaneous PinningMidshaft Metacarpal
Figure 41-5 A, Radiograph of a midshaft metacarpal fracture. B, Radiograph after closed reduction percutaneous pinning of metacarpal fracture.

Many arrangements of Kirschner (K)-wire fixation have been described.16-18 This can consist of crossed K wires, intramedullary wires, or transverse K wires16-18 (Fig. 41-5). The downside of using K wires is that it does not allow for immediate ROM. The use of a single dorsal plate provides the greatest stability and will allow early ROM.19,20 Interfragmentary screws alone may be chosen when the fracture is greater than twice the diameter of the shaft.21 Incisions should not be made directly over the metacarpal in order to minimize adhesions.

The average return to sports is approximately 14 days in football for metacarpal injuries and is independent of nonoperative or operative fixation. This time frame is very sport specific and position dependent. For example, a football lineman will be able to return more quickly than a receiver. However, the receiver will return sooner than a person involved in a racquet sport.

Fractures of the Metacarpal Base

There are certain fractures of the first and fifth metacarpal that deserve to be mentioned. There are essentially two types of intra-articular fractures involving the thumb: a Bennett fracture and a Rolando fracture.

A Bennett fracture involves a portion of the base of the first metacarpal that is displaced by the pull of the abductor pollicis longus tendon (Fig. 41-6). Rolando fractures are more comminuted and affect both sides of the first metacarpal base.

Treatment of both of these fractures consists of operative fixation, either closed reduction and percutaneous fixation22,23 or open reduction and screw fixation.15 With either treatment, return to sports can be as rapid as 1 week, if return to play in a cast is possible. Complete recovery from this type of injury takes 4 to 6 weeks.

A similar fracture is also seen in the fifth metacarpal (Fig. 417). This is the so-called baby Bennett fracture, which becomes displaced by the pull of the extensor carpi ulnaris tendon.24 Treatment and return to play are similar for fractures at the base of the first metacarpal.

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Cure Tennis Elbow Without Surgery

Cure Tennis Elbow Without Surgery

Everything you wanted to know about. How To Cure Tennis Elbow. Are you an athlete who suffers from tennis elbow? Contrary to popular opinion, most people who suffer from tennis elbow do not even play tennis. They get this condition, which is a torn tendon in the elbow, from the strain of using the same motions with the arm, repeatedly. If you have tennis elbow, you understand how the pain can disrupt your day.

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