Tibial tuberosity fractures in adolescents: is a posterior metaphyseal fracture component a predictor of complications?

BACKGROUND: Tibial tuberosity fractures have been described as uncommon injuries, but their frequency appears to be increasing. Because of the relatively few cases reported in the literature, little is known regarding risk factors for complications. In a large group of adolescents with tibial tuberosity fractures, we noted more frequent complications in patients who had posterior metaphyseal fractures in addition to tibial tuberosity avulsion fractures. The purpose of this study was to examine the outcomes associated with this fracture pattern and compare them with tibial tuberosity fractures without the posterior component.

METHODS: All patients who had closed or open reduction and internal fixation of a tibial tuberosity fracture between January 2003 and December 2010 were identified. All radiographs and medical records were reviewed.

RESULTS: Fifty-three tibial tuberosity fractures had radiographs available for review; 15 (28%) fractures had a posterior component identified by either radiograph or computed tomography scan. Four of these combined injuries had an adverse event: 1 patient had compartment syndrome affecting all 4 compartments and 3 patients had refractures after closed reduction and casting. None of the 38 tibial tuberosity fractures without a posterior metaphyseal component had these complications. All patients had complete fracture healing and had returned to full activity at last follow-up.

CONCLUSIONS: In this study, a posterior metaphyseal fracture associated with a tibial tuberosity fracture was a marker for potential complications. If radiographs suggest that a fracture line extends through the posterior metaphysis, computed tomography imaging is recommended to confirm the fracture pattern. Open reduction and internal fixation that includes both the anterior and posterior fragments is recommended for all fractures with these combined components, including nondisplaced fractures, because of an increased risk of refracture.

LEVEL OF EVIDENCE: Level IV (case study).