An adolescent female at chronological age of 13 years and 10 months presented with acute right knee pain after hyperextending her knee while playing basketball. She felt a "pop" during the hyperextension and had been unable to bear weight after injury. On physical examination, she had lateral joint line pain without ligamentous laxity. There was limited knee range of motion, and a moderate joint effusion was present.
Presenting radiographs of the right knee were normal (Figure 10). MRI of the right knee showed pivot-shift bone marrow contusion pattern in the lateral compartment and root ligament avulsion of the lateral meniscus posterior horn (Figure 11). A 5 mm FOPE zone was also present in the central portion of the distal femur physis (Figure 12). The distal femur physis was still open.
She underwent 2 months of conservative management without relief in symptoms. The patient subsequently had knee arthroscopy for repair of the lateral meniscus posterior horn root ligament. The right knee pain and joint effusion resolved after surgery with return of normal range of motion by 3 months after meniscal repair. The patient has not returned for additional follow-up.