Adolescent Symptomatic Medial Meniscal Ossicle Treatment and Probable Etiology.

Meniscal ossicles are rare, especially in children and adolescents. The clinical exam is often benign, but intra-articular calcification can be evident on radiographs. MRI is beneficial for differentiating between potential diagnoses. Management is usually conservative, with arthroscopy reserved for symptomatic cases that fail conservative treatment. The etiology is unknown, but several theories exist. This case report describes a 16-year-old female athlete who presented with catching in her left knee and occasional pain when jumping hurdles. Radiographs were suggestive of a bony ossicle in the posterior aspect of her medial compartment. Conservative treatment provided little relief. MRI identified an intrameniscal ossicle and a posterior root tear of the medial meniscus. During arthroscopy, compression of the ossicle between the femur and tibia was visualized when the knee was positioned in terminal knee flexion and external rotation. Surgical treatment consisted of partial medial meniscectomy with excision of the ossicle and meniscal repair. The athlete gradually returned to full activity and sports. Although the exact etiology is unknown, trauma is the most likely cause. The patient's young age and absence of calcification on prior radiographs negate degenerative and congenital causes, respectively. Meniscal ossicles in adolescents are rare but need to be considered when intra-articular calcification is present on radiographs.