Treatment of syndesmotic disruptions of the ankle with bioabsorbable screw fixation

Background: Bioabsorbable implants have restricted indications because of their unique biochemical properties and their inferior biomechanical properties compared with those of conventional metallic implants. The purpose of this prospective study was to assess the efficacy of screws made of polylevolactic acid (PLLA) in the treatment of syndesmotic disruptions associated with ankle fractures and fracture-dislocations. Methods: Thirty-three consecutive patients with a syndesmotic disruption were managed with standard metallic plate-and-screw fixation of the malleolar fracture and with 4.5-mm polylevolactic acid screws, with purchase in four cortices, for fixation of the syndesmosis. Intraoperative radiographs confirmed reduction of the syndesmosis, and all of the patients were managed with a non-weight-bearing plaster splint or brace for six weeks. Clinical and radiographic assessment and functional evaluation with use of the Olerud-Molander scoring system were performed at the time of follow-up. Results: Ten patients were lost to follow-up prior to the twenty-four-month evaluation, leaving twenty-three patients with an average duration of follow-up of thirty-four months (range, twenty-four to forty-three months). All of the malleolar fractures healed in an anatomical position at an average of three months, and no postoperative displacement of the syndesmosis or widening of the medial clear space was detectable on radiographs. No episodes of osteolysis or late inflammation secondary to the hydrolyzed polylactide occurred. Nineteen patients (83%) had an excellent result, and four patients (17%) had a good result. All twenty-three patients returned to their preinjury level of work and activities of daily living. No patient had malunion, nonunion, loss of reduction, or complications attributable to the biomechanical or biochemical properties of the implants. Conclusions: Polylevolactic acid screws are effective in stabilizing disruption of the syndesmosis during healing of unstable ankle fractures. In this small series, the bioabsorbable screw was well tolerated, and there was no need for a second operation to remove it.