Less is more: lag screw only fixation of lateral malleolar fractures

Displaced fractures of the lateral malleolus are typically treated with plate osteosynthesis with or without the use of lag screws, and immobilisation in a plaster cast for up to 6 weeks. Fixation through a smaller incision with less metal, such as lag screw only fixation, would theoretically lead to decreased infection rates and less irritation caused by hardware. The purpose of this study was to evaluate the benefits and success of lag screw only fixation of the lateral malleolus in non-comminuted oblique fractures of the lateral malleolus. A total of 25 patients who had non-comminuted unstable oblique fractures of their lateral malleolus that had been surgically fixed with lag screws only were retrospectively evaluated. All patients were younger than 60 years of age. Evaluation of the success of fixation, complications, resultant mobility and patient satisfaction was based on information gathered from chart reviews, X-ray findings and a standardised questionnaire based on the AOFAS Foot and Ankle Outcomes Questionnaire. These results were compared to an age-matched group of 25 consecutive patients treated with plate osteosynthesis. Of the 25 patients fixed with lag screws, nine had an unstable fracture of the lateral malleolus only, ten were bimalleolar fractures and six were trimalleolar. Eighteen patients were treated with two lag screws, and seven were treated with three lag screws. The bi- and trimalleolar fractures were treated with standard partially threaded cancellous screws. None of the lag screw-only group lost reduction. There were no documented wound infections in the lag screw group as compared to three deep infections in the plate group. Lag screw-only patients reported no palpable hardware as compared to 50% of the plate group. AOFAS scores at a mean of 12 months post-operative were similar in both groups. Lag screw only fixation of the lateral malleolus is a safe and effective method that has a number of advantages over plate osteosynthesis, in particular less soft tissue dissection, less prominent, symptomatic and palpable hardware and a reduced requirement for secondary surgical removal.