Valgus knee deformity due to nonunion of lateral Hoffa fracture: A case report

Hoffa fractures are rare intra-articular injuries, and nonunion of Hoffa fractures is rarer. We report the case of an adult male with a nonunion of a Hoffa fracture by open reduction and internal fixation in which the lateral meniscus tear was treated by an arthroscopic surgery. A healthy 38-year-old man who had a history of untreated trauma to the left knee in a motorcycle accident 11 years ago presented to our hospital with the complaint of chronic left knee pain for 5 years. The patient had an obvious valgus knee with 0°–140° of motion, and radiographs revealed the nonunion of the left lateral Hoffa fracture (Letenneur type-III). Routine arthroscopic evaluation and a lateral meniscus posterior tear repair using all inside device were performed. The knee joint was exposed using a lateral para patella approach. The fracture was fixed with three 4.5-mm headless screws and distal femoral locking plates. Mobilization was started from the first operative day. Full weight bearing was allowed 8 weeks postoperatively. At the 1-year follow up, the X-ray showed healing of the nonunion site with no displacement of the Hoffa fracture. The knee range of motion, lower limb alignment, and clinical outcome were also improved. Nonunion of the Hoffa fracture should be treated by an internal fixation despite the chronicity.