Review Question - QID 217865

This patient has a fifth metacarpal base fracture-dislocation. The best next step in treatment would be a closed reduction and splinting, followed by CT imaging to assess for intra-articular injury.

Metacarpal fractures are the most common hand injury and are divided into fractures of the head, neck, or shaft. Diagnosis is made by orthogonal radiographs of the hand. Treatment is based on which metacarpal is involved, the location of the fracture, and the rotation/angulation of the injury. Metacarpal base fractures that are displaced, comminuted, and impacted are often associated with dorsal subluxation of the metacarpal on the hamate. The mechanism of injury is usually the result of a longitudinally directed force along the axis of the fifth metacarpal.

Kjaer-Petersen et al. reviewed the treatment of 64 intra-articular fractures at the base of the fifth metacarpal. They reported on both nonoperative, percutaneous fixation, open reduction and internal fixation. They concluded that at a median of 4.3 years, 49% had decreased grip power, and several patients had radiographical signs of osteoarthrosis.

Bora et al. reviewed metacarpal base fractures of the small finger. They reported that fractures of the base of the little finger metacarpal without displacement or with minimum ulnar displacement were satisfactorily treated with a molded cast. They concluded that postoperative power grip was improved when fractures of the carpometacarpal joint with ulnar and proximal displacement were corrected.

Figures A-C are the radiographs of the hand demonstrating a fifth metacarpal base fracture-dislocation

Incorrect Answers:
Answer 1: CT imaging may be of value to assess for intra-articular injury but is best performed following a closed reduction and immobilization. CT imaging prior to a reduction will not allow the provider to know the quality of the reduction following immobilization (unless another CT scan is performed).
Answer 3: CRPP is an acceptable treatment modality for this patient. However, an initial closed reduction attempt followed by CT imaging may result in an acceptable reduction without the need for percutaneous fixation.
Answer 4: ORIF may be utilized but a closed reduction and immobilization followed by CT imaging should be performed first. ORIF is indicated in delayed presentations as closed reduction attempts are often unsuccessful.
Answer 5: CMC arthrodesis is likely is not appropriate as an initial treatment option and should be reserved for patients with painful posttraumatic arthritis.