Bilateral Tibial Tubercle Avulsion Fractures in Children - Clinical Results of a Rare Fracture.

BACKGROUND: Tibial tubercle avulsion fractures are rare, they represent less than 1% of all physeal fractures. Compared to monolateral tibial tubercle avulsion fractures, bilateral occurrence is even rarer. The purpose of this study is to report about the so far largest group of bilateral avulsion fractures and to compare them to unilateral fractures as well as to current literature.

METHOD: All patients who suffered from bilateral tibial tubercle fractures between January 2009 and March 2019 were included. All medical records and radiographs were reviewed and a clinical follow-up was performed. The examined criteria were age, gender, mechanism of injury, classification, risk factors, complications, management and outcomes. Clinical outcome was measured using the well established Tegner activity scale and Lysholm-Gillquist score. The same criteria were analyzed in a literature review of bilateral tibial tubercle fractures to compare our results to available literature.

RESULTS: We found four children with bilateral tibial tubercle avulsion fractures. All patients were male with a mean age of 14.5 ± 0.7 years (13 - 15). Mean follow-up examination was 13.6 ± 6.5 months (8 - 29) after surgery. The avulsions occurred during jumping activities in all cases. All children could no longer stand or move because of sudden pain in the knee. We found type IV fractures in three cases, type III fractures in four cases and one type V fracture according to the Ogden classification. All children were treated by open or closed reduction and stabilization with screws or K-wires. Follow-up showed complete fracture healing without complications in all patients. There were no changes in Tegner activity scale and Lysholm-Gillquist Score and knee function comparable to prior to the accident was achieved in all cases.

CONCLUSION: Good clinical results without restrictions regarding function of the knee joint can be achieved by direct operative treatment of bilateral tibial avulsion fractures. A reduction in sporting activity has not to be expected. There were no differences between bilateral or unilateral tibial tubercle avulsion fractures.