Posterior pilon fractures: a retrospective case series and proposed classification system.

BACKGROUND: Posterior malleolus fractures occur in 7% to 44% of ankle fractures and are associated with worse clinical outcomes. Fractures that involve the posteromedial plafond extending to the medial malleolus have been described previously in small case series. Failure to identify this fracture pattern has led to poor clinical outcomes and persistent talar subluxation. The purpose of this study was to report our outcomes following fixation of this posterior pilon fracture and to describe a novel classification system to help guide operative planning and fixation.

METHODS: Eleven patients were identified following fixation of a posterior pilon fracture over a 4-year span; 7 returned at minimum 1-year follow-up to complete a physical examination, radiographs, and RAND-36 (health-related quality of life score developed at RAND [Research and Development Corporation] as part of the Medical Outcomes Study) and American Orthopaedic Foot & Ankle Society (AOFAS) ankle/hindfoot questionnaires. Patient records were reviewed to evaluate for secondary complications or operative procedures.

RESULTS: Our mean postoperative AOFAS ankle/hindfoot score was 82. Anatomical reduction of the plafond was noted radiographically in 7 of 11 patients, with the remainder demonstrating less than 2 mm of articular incongruity. Five of 7 patients demonstrated ankle and hindfoot range of motion within 5 degrees of the uninvolved extremity. Four complications required operative intervention; 2 patients reported continued pain secondary to development of CRPS.

CONCLUSION: The posterior pilon fracture is a challenging fracture pattern to treat, and it has unique characteristics that require careful attention to operative technique. Our results following fixation of this fracture pattern are comparable with results in the literature. In addition, a novel classification scheme is described to guide recognition and treatment of this fracture pattern.

LEVEL OF EVIDENCE: Level IV, retrospective case series.