Inferior sleeve fracture of the patella.

Patella sleeve fracture is a rare fracture that only occurs in children. Diagnosis is difficult both clinically and radiologically. A high-riding patella and hemarthrosis are important signs when diagnosing this fracture. We report a case of an 11-year-old boy who suffered from patella sleeve fracture without visible bony fragments on a lateral radiograph. Open reduction with transosseous tunneling and patellotibial cerclage wiring for anastomosis protection was performed. Early weight bearing was achieved together with a satisfactory range of knee motion. Premature anterior physeal arrest was noted because of insertion of cerclage wire in the open physis. However, no genu recurvatum was present 2 years after the initial operation. An awareness of sleeve fracture, together with its characteristic clinical and radiological features, is important to avoid misdiagnosis and treatment delay. If the cerclage wire technique is used, care should be taken not to disturb the proximal tibial apophysis.