Ankle fusion following failed initial treatment of complex ankle fractures in neuropathic diabetics.

BACKGROUND:
Unstable ankle fractures in diabetics with peripheral neuropathy have an increased risk of postoperative complications, often leading to amputation. Primary ankle arthrodesis has been suggested as an alternative when acceptable reduction and mechanical stabilization cannot be obtained.

METHODS:
Over a fourteen year period, thirteen diabetic patients with peripheral neuropathy underwent an attempt at primary ankle arthrodesis following the early post-fracture development of acute neuropathic (Charcot) deformity of the ankle after sustaining a low energy unstable ankle fracture. Eight patients with open wounds and osteomyelitis underwent single stage debridement of the osteomyelitis and primary ankle fusion with an ankle fusion construct circular external fixator. Five patients without evidence of infection underwent primary arthrodesis with a retrograde locked intramedullary nail used for fixation. A successful clinical outcome was achieved with either successful radiographic arthrodesis or stable pseudarthrosis, when community ambulation was achieved with commercially-available therapeutic footwear and a short ankle orthosis.

RESULTS:
Eight of the thirteen patients achieved a successful clinical outcome at a mean follow-up of 48 (range 12-136) months following the initial surgery. Three achieved clinical stability following a second surgery and one following a third. One patient with radiographic nonunion expired due to unrelated causes. One patient underwent transtibial amputation due to persistent infection. Of the five patients with failure of radiographic union, three successfully ambulated in the community with a short ankle orthosis. Postoperative complications included wound and pin-site infection, infected nonunion, chronic wounds, and tibial stress fracture.

CONCLUSION:
In spite of the high risk for complications and initial failure, primary ankle fusion is a reasonable option for diabetic neuropathic patients who develop acute neuropathic arthropathy following ankle fracture.

LEVEL OF EVIDENCE:
Level IV retrospective case series.