Fibular nonunion after closed rotational ankle fracture

Historically, the standard of care for minimally or nondisplaced, closed, distal fibula fractures has been short-term immobilization and progressive weightbearing. The vast majority of such patients are expected to heal with excellent functional outcome after such treatment. There exists a subpopulation of patients sustaining these fibular fractures who develop symptomatic incomplete union or nonunion despite appropriate management, and later require operative intervention to eliminate pain.

A retrospective review of 17 referred patients with rotational fibular fractures between August 1999 and July 2003 identified six persistently symptomatic distal fibular fractures after an adequate trial of conservative treatment. Due to their persistent localized pain and difficulty with ambulation, five patients underwent operative treatment of the nonunion with autologous bone grafting with plate and screw osteosynthesis. The sixth patient has refused operative intervention despite persistent symptoms.

All six of these patients were identified as low risk for nonunion. Two fibular nonunions were found to be complete and four were partial nonunions. One hundred percent of these patients presented with a chief complaint of pain, had reproducible tenderness with palpation directly at the fracture site, and exhibited a persistent antalgic gait pattern. Four of six patients who underwent surgery noticed complete resolution of their pain and return of their normal gait within an average of 2.3 months postoperatively, with an average follow-up of 19.5 months (range, 2-53 months).

Distal fibula nonunion appears to be a relatively common cause of persistent lateral ankle symptoms in patients who do not enjoy a satisfactory recovery after appropriate conservative treatment. The authors believe that the persistent lateral pain in such patients results from micromotion strain at the incomplete fracture union site. Surgical stabilization of fibular nonunion seems to be a reliable means of resolving these symptoms when conservative measures fail.