Hoffa fracture of the femoral condyle Injury mechanism, classification, diagnosis, and treatment

Background: Hoffa fractures are coronal-plane fractures of the femoral condyle, which are rarer than sagittal-plane condylar fractures. This study aimed to systematically review the clinical knowledge base of Hoffa fractures to facilitate the diagnosis and management of such injuries. Methods: We searched Medline, Embase, Cochrane Library, Google Scholar, China National Knowledge Infrastructure, and China Biology Medicine disc, using the terms "Hoffa fracture" and "coronal fracture of femoral condyle." Results: One hundred five articles on Hoffa fractures were reviewed, and the clinical knowledge base was summarized. High-energy trauma is a common cause of a Hoffa fracture, although low-energy trauma and iatrogenic injury can also lead to these fractures. Commonly used classifications include the Letenneur classification, a computed tomography (CT) classification, the AO classification, and modified AO classification. Radiography can reveal fracture lines. If radiographic findings are negative in questionable cases, CT and magnetic resonance imaging (MRI) should be performed. Nondisplaced fractures can be managed conservatively; however, they involve a high risk of redisplacement. Open reduction and internal fixation are preferred. For young patients with good compliance, simple medial or lateral condylar fractures can be treated via a medial or lateral parapatellar approach. After fracture exposure, headless compression screws can be inserted perpendicularly to the fracture line from posterior to anterior. For bicondylar fractures, a median parapatellar incision can be used. For complex fractures in patients with osteoporosis or a high body mass index, cannulated screws with antigliding plate fixation should be used. Conclusion: Here, we summarized the injury mechanism, diagnosis, classification, and treatment options of Hoffa fractures.