Dynamic Sonographic Visualization of an Occult Posterior Lateral Meniscocapsular Separation: A Case Report

Abstract

Meniscocapsular separation describes detachment of the meniscus from the knee joint capsule. Diagnosis is challenging with conventional examination and imaging methods. We report a case of an 18-year-old female softball catcher with unrevealing magnetic resonance imaging despite continued left knee locking and discomfort with deep squatting. Meniscocapsular separation was revealed only on dynamic sonographic examination, where knee flexion revealed a 3.1-mm gap that developed between the capsule and peripheral meniscus. Arthroscopy confirmed the sonographic findings, and repair resulted in complete resolution of symptoms. This case highlights the utility of dynamic diagnostic sonography in a rare case of posterior lateral meniscocapsular separation. LEVEL OF EVIDENCE: V.

Arthroscopic Diagnosis of Occult Posterolateral Meniscocapsular Separations: Another Hidden Lesion

“…To our knowledge there is only a single case report involving a patient with an isolated lateral MCS, which was diagnosed via ultrasound scanning after a negative MRI result. 9 Much of the literature regarding medial MCS focuses on younger athletes sustaining a twisting injury; however, our patients were middle aged with varied mechanisms of injury. 16,18 All 6 of our patients presented with lateral knee pain and locking symptoms that persisted despite months to years of conservative therapy.…”

“…To our knowledge there is only a single case report involving a patient with an isolated lateral MCS, which was diagnosed via ultrasound scanning after a negative MRI result. 9 …”

“…However, there is only 1 case report in the literature describing an isolated MCS involving the lateral meniscus. 9 A single case report of a lateral MCS has been described in the setting of a rare anatomic aberration known as a double-layered lateral meniscus. 10 The authors describe improvement of clinical symptoms after resection of the upper accessory meniscus and repair of the MCS.…”

Sonographic Diagnosis of Medial Meniscocapsular Separation of the Knee

“…1,[3][4][5][6][7] However, there is only one published sonographic case of posterior lateral MCS, and one case using arthroscopy combined with sonography for the diagnosis and treatment of MCS. 8,9 The current presentation describes two cases of medial MCS with an attempt to explore the sonographic diagnostic criteria of medial MCS. To help understand this report, a review of the anatomy of the medial capsuloligamentous complex is provided.…”