An Intra-tendonous ganglion cyst causing impingement between the anterior cruciate ligament and anterior root of the medial meniscus: a case report

BACKGROUND There are several reports of symptomatic ganglion cysts near the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and lateral and medial meniscus, but symptomatic ganglia arising from the anterior horn of the medial meniscus to the ACL have not been reported. Here we report the arthroscopic resection of a ganglion cyst arising from the anterior horn of the medial meniscus with a meniscal tear to the ACL. CASE PRESENTATION A 43-year-old female presented with a 10-year history of continuous aching pain in the right knee, but without any history of trauma. Clinical examination revealed right-sided knee pain in the medial joint line, exacerbated by end range flexion and extension, a -10°-100° active range of movement, and a -5°-110° passive range of movement。McMurray's, patellar compression, and compression rotation tests were positive. Magnetic resonance imaging (MRI) and arthroscopic examination revealed a cyst related to the ACL and medial meniscus. Histological examination confirmed the cyst to be a ganglion cyst. CONCLUSIONS We present a new type of ganglion cyst, this is the first reported case of an ganglion cyst impinged between the ACL and the medial meniscus. It is hoped that this study will provide a better understanding of the condition and lead to better diagnosis and treatment.