Fixation of ankle arthrodesis in a national orthopaedic hospital in Nigeria.

Internal fixation is currently preferred for ankle arthrodesis. There are, however, situations in which external fixation is a safer choice. This is a five-year retrospective study of ankle arthrodesis to assess the choice, technique and outcome of fixation methods used. Case notes and radiographs of patients with complete records who had ankle arthrodesis between January 1st, 2004 and December 31st 2008 were reviewed. Twenty ankle arthrodeses in 20 patients were reviewed. External fixation, commonly with Charnley's device, was used in 95% of the arthrodeses. Initial alignment was lost in 62.5% of arthrodeses with Charnley's device without immediate short leg cast support. One tibiotalar arthrodesis done with a single screw had subtalarjoint penetration. Fusion and complication rates were 90% and 45% respectively. Foot and ankle oedema and pin-tract infection were the commonest complications. External fixation was more commonly used than internal fixation because most of the patients had altered bone anatomy, wounds, active infection, or osteopenia. Charnley's device was the most commonly used external fixator and incorporating it in a short leg cast immediately after operation might improve its rotatory stability. The use of image intensifier is recommended for the placement of two crossed tibiotalar screws to avoid subtalar penetration.