Biodegradable fixation of ankle fractures. A roentgen stereophotogrammetric study of 32 cases.

We performed a prospective randomized study comparing fixation with biodegradable polyglycolic acid (PGA) rods (n 15) or screws (n 17) in 32 selected displaced supination-eversion fractures. Immediate postoperative weight bearing in a walking cast was encouraged. An exact reconstruction of the ankle mortise was achieved in 26/32 ankles. Roentgen stereophotogrammetric analysis (RSA) revealed rather small movements in the ankle mortise during fracture healing. A better stability was achieved by using screws. After 6 months the clinical results did not differ. One case of sinus formation and one with local effusion occurred; both healed without impairing the clinical result. To compare the results with a nondegradable osteosynthesis technique, a reference group of supination-eversion fractures previously operated on with cerclage-wires, staples and pins was used. RSA showed better fracture stability with nondegradable fixation. The clinical results, however, did not differ.