Common processes involving the extensor mechanism of the knee only in children
Sinding-Larsen-Johansson and patellar sleeve avulsion fracture are two similar injuries in the pediatric population involving the origin of the patellar tendon. Sinding-Larsen-Johansson is similar to Osgood-Schlatter disease with repetitive injury on the inferior pole of the patella. Patellar sleeve avulsion fracture is a result of sudden force as the knee extends and avulses the bone off of the inferior pole of the patella.
