Type VII Tibial Tubercle Fractures are Different from Osgood Schlatter Syndrome and Tibial Tubercle Physeal Fractures

INTRODUCTION: Children and adolescents are prone to both overuse and acute injuries at the tibial tubercle. The most common overuse injury is Osgood Schlatter Syndrome (OSS,) and the most common acute severe injury is tibial tubercle avulsion fracture (TTF). Here we present evidence for a Type VII, all-epiphyseal, tibial tubercle fracture (VIITF) that is different from OSS and TTF. METHODS: This IRB–approved study involved patients that were treated and registered at a tertiary care pediatric hospital from 2014 to 2020. We compared the clinical information, the radiographs, the treatments, and the outcomes of 15 patients with VIITF to 19 patients with OSS and to 14 patients with TTF. RESULTS: All VIITF patients had a sudden onset of pain associated with a specific sports-related injury, and all had lateral radiographs showing a chip-like ossific fragment displaced from the secondary center but with no involvement of the physis. All of the OSS patients had an insidious onset of symptoms with no specific injury, and none had radiographs showing a chip-like fragment. All the TTF patients had a sudden onset of pain after an acute injury. Eleven of the 15 VIITF patients (73%) have formed retro-patellar tendon ossicles, and 7 of those patients (46%) have undergone surgery. All but one of the OSS patients have resolved, and all with non-operative management. All the TTF patients have resolved, and all except those with Ogden type IA fractures, had undergone urgent surgery. CONCLUSIONS: We accepted our hypothesis. VIITF is different from OSS and TTF and can be differentiated on the basis of clinical and radiographic data. CLINICAL RELEVANCE: Most patients with OSS resolve with non-operative management, and TTF patients usually require urgent surgery. Children with VIITF do not need urgent surgery but do need to be followed because some can form painful retro-patellar tendon ossicles, have focal anterior knee pain, and may need surgery to resolve their symptoms. Level of Evidence: Level III: Case Control Study.