Ogden Type IV Tibial Tuberosity Fractures in Healthy Adolescents: Preoperative Magnetic Resonance Imaging and 2-Year Clinical Follow-up Study

BACKGROUND: Ogden type IV tibial tuberosity fractures, defined as a type of fracture with posterior–inferior metaphyseal extension (Salter-Harris type II variant), are uncommon but challenging pediatric fractures. The purpose of this study was to investigate the clinical and radiological presentation and associated surgical outcomes. METHODS: Ten previously healthy patients who had been surgically treated at the authors’ institution between 2015 and 2018 with at least 2 years of postoperative follow-up were included. Demographic, clinical, and radiological characteristics and treatment/follow-up data were investigated. RESULTS: All included patients were male. All injuries resulted from jump-landings. Unacceptable remaining angular deformity after closed reduction, particularly increased posterior tibial slope angle, was the leading cause of surgery. All preoperative magnetic resonance images (MRIs) showed entrapped periosteum on the anteromedial side of the proximal tibial physis. Surgical removal of the entrapped periosteum achieved successful reduction. Metaphyseal fracture angles between the fracture plane of the metaphyseal beak and the posterior tibial condyle on the axial image of MRI were relatively constant, with an average of 24.3° ± 6.0°. Mean bone age at the time of trauma was older than mean chronological age (16.4 ± 1.0 years vs. 14.6 ± 1.1 years, respectively; p = 0.005). All patients reached skeletal maturity within 2 postoperative years, with little posttraumatic residual height growth (mean, 1.6 ± 0.7 cm from injury to skeletal maturity). At final follow-up, no patients showed significant angular deformity, tibial length discrepancy, or functional deficit. CONCLUSIONS: In healthy adolescents, Ogden type IV tibial tuberosity fractures typically occur by jump-landing injuries, when they have little residual growth remaining. Therefore, accurate fracture reduction was required because of limited remodeling potential. Patients with unacceptable reduction should be investigated for entrapped periosteum on the anteromedial side of the physis because it was the primary obstacle in achieving adequate reduction.