Metatarsal fracture without Lisfranc injury.

Abstract

Metatarsal fractures are frequent, at one-third of all fractures in the foot. The present study reviews the field, addressing 4 questions. Isolated or associated, benign but, in case of crush injury, sometimes severe, prognosis varies and sequelae can be serious. Fatigue fracture is common, often implicating sports activity. It is important to group metatarsal fractures according to the metatarsal or metatarsals involved: first (M1), central (CM) or fifth (M5). Lesion mechanism is a determining factor in management, especially for M5 fatigue fractures. Severity is a matter of associated lesions, particularly in the tarsometatarsal joint and adjacent soft tissue, directly related to trauma kinetics and mechanism. Treatment depends on the site of the fracture, whether it is recent or old, and the severity of the causal trauma. M1 fractures can be managed non-operatively if not displaced; otherwise, internal fixation is recommended. In the CMs and distal M5, non-operative treatment gives excellent results in fractures with little or no displacement, but reduction and internal fixation should be considered for displacement exceeding 3-4 mm or angulation exceeding 10° in whatever plane. In M5, non-operative treatment is indicated for fractures in Lawrence-Botte zones 1 or 2, but particular care is needed for high-level sports players; zone 3 fractures are fatigue fractures, requiring internal fixation. High-energy trauma is associated with skin complications and infection. Surgery is also a risk factor, notably for neurologic complications. Non-union, delayed healing and iterative fracture mainly affect the base of M5, particularly in zone 3. Malunion is associated with poor prognosis due to severe functional disorder in the foot or limb. Post-traumatic osteoarthritis generally follows joint injury at M1 or a CM, or sometimes associated tarsometatarsal joint involvement. LEVEL OF EVIDENCE: V; expert opinion.