Osteolytic changes accompanying degradation of absorbable fracture fixation implants.

We analysed the radiographs of 67 patients with displaced malleolar fractures treated by open reduction and internal fixation using absorbable polyglycolide rods. Seventeen patients developed a discharging inflammatory foreign-body reaction, a complication unique to these fixation devices. In 34 patients ovoid osteolytic foci, usually 5 to 10 mm in diameter, appeared within the implant channels six to 12 weeks after the operation. The same lesion occurred in 14 of the 17 patients who developed a foreign-body reaction, whereas only 20 out of the 50 patients with an uneventful course showed osteolytic areas (p less than 0.01). In patients with a foreign-body reaction the osteolytic foci tended to occur in the deepest parts of the implant channels. However, after one year the normal structure of the bone was restored.