[Fixation of displaced fifth metatarsal shaft and neck fractures].

OBJECTIVE

Open reduction and internal fixation of grossly dislocated fifth metatarsal shaft and neck fractures aims at restoration of the anatomical structure of the forefoot. The goal is to restore length, axis, rotation and joint position, while observing the metatarsal index (Maestro curve).

INDICATIONS

Grossly dislocated and/or open shaft/neck fractures of the fifth metatarsal; combined fractures of the forefoot involving the fifth metatarsal.

CONTRAINDICATIONS

Lack of consent to surgery. Overall critical (life-threatening) general condition preventing surgery to the extremities. Contaminated or infected soft tissues.

SURGICAL TECHNIQUE

Depending on the planned method of fixation, open reduction is usually conducted via a lateral approach centrally above the easily palpable metatarsal V shaft. The incision lies above the glabrous skin of the sole. For markedly shortened and multifragment subcapital and shaft fractures of the fifth metatarsal, open reduction and plate fixation is the method of choice. Interlocking plates with a screw diameter of 2.0-2.4 mm are preferred to avoid later soft tissue irritation. Anatomic reconstruction is carried out under longitudinal traction at the fifth toe using small reduction clamps and, if necessary, temporary K‑wire fixation. If the fragments are large enough, one or more interfragmentary lag screws can be used for fracture compression. A straight or condylar plate is used for internal fixation. Long spiral fifth metatarsal shaft fractures may alternatively be fixed with screws. In the case of transverse or subcapital fractures, percutaneous antegrade or retrograde medullary wiring with two Kirschner wires should be considered.

POSTOPERATIVE MANAGEMENT

Following surgical treatment, rest and elevation of the injured leg, and local cooling are indicated. Subsequently, mobilization with partial weight bearing (20 kg) in foot orthosis or cast shoe for 6 weeks.

RESULTS

Even grossly displaced fractures of the fifth metatarsal shaft have a good to excellent prognosis following surgical treatment with high union rates and rare complications. Undisplaced and mildly displaced fractures can be successfully managed nonoperatively with 6 weeks of weight bearing as tolerated in a stable orthosis or cast shoes.