Operatively treated type IV tibial tubercle apophyseal fractures

BACKGROUND:: Displaced tibial tubercle apophyseal fractures in children and adolescents are typically treated with closed reduction or open reduction with anterior to posterior screw fixation. Since the original classification by Watson-Jones and Ogden, an important variant with a posterior metaphyseal fracture line (type IV) was later described. However, there has been a lack of information regarding type IV tibial tubercle apophyseal fractures and its implications for surgical fixation. METHODS:: Twenty-four type IV tibial tubercle fractures in 23 children and adolescents were reviewed. Operative reports and clinic records were used to identify the patient demographics, fracture type, and clinical results. Available imaging was also used to characterize these fractures. Minimum follow-up was 2 years. RESULTS:: Type IV fractures accounted for 18.5% (24/130) of all tibial tubercle apophyseal fractures. Three type IV fractures were identified that had an additional epiphyseal split. These were categorized as type IV-B, whereas the rest were considered type IV-A. There were 19 males and 4 females (average age, 14.8 y; range, 11.8 to 16 y). The most common mechanism was an eccentric quadriceps contraction during basketball. Three patients were initially treated with closed reduction and casting and were noted to have loss of reduction. All patients were treated definitively with open reduction and internal fixation or percutaneous screw placement. In addition to AP compression screws, 4 patients required supplemental plate fixation to stabilize the proximal tibia. Major complications included 1 compartment syndrome and 1 large DVT. All fractures healed and there were no growth disturbances. CONCLUSIONS:: Type IV tibial tubercle apophyseal fractures are an important variant that requires careful assessment to ensure adequate stabilization of the proximal tibia when surgery is warranted. LEVEL OF EVIDENCE:: IV (prognostic case series).