Indications for retrograde intramedullary screw fixation of the distal fibula: a retrospective cohort series.

INTRODUCTION: Ankle fractures are a common orthopaedic injury that often require surgical fixation. Because the comorbid population in the United States continues to survive longer, it has become routine to treat comorbid patients with unstable ankle fractures. The literature has identified comorbidities known to increase the risk of ankle fracture complications to include age 55 years or older, body mass index >29.9, polytrauma, open fractures, diabetes mellitus, smoking, peripheral neuropathy, and alcohol use.

METHODS: We retrospectively reviewed 37 patients who received retrograde intramedullary screw fixation of the distal fibula, all of whom had preexisting conditions known to increase the rate of postoperative complications.

RESULTS: Thirty-seven patients were included in this study, of whom 36 (97.3%) went on to union. Six of 37 patients (16.2%) had complications although only one (2.7%) was due to inadequate fixation. The average time to weight-bearing as tolerated was 57.2 days (15-115 days). Two patients (5.4%) had symptomatic instrumentation requiring removal after union. Two patients (5.4%) had delayed union of the distal fibula, which responded to the use of a bone stimulator. One patient (2.7%) developed a nonunion which led to chronic subluxation of the ankle joint. One patient (2.7%) had a minor medial ankle wound complication that was treated with oral antibiotics and local wound care.

CONCLUSIONS: Retrograde intramedullary screw fixation of the distal fibula is a viable alternative to plate and screw fixation in patients with unstable ankle fractures who have known risk factors for increased complications. However, not all distal fibula fractures are amenable to this fixation method.

LEVEL OF EVIDENCE: Level III retrospective cohort study.