Partial resection as a treatment for mucoid degeneration of the anterior cruciate ligament: a case report

Mucoid degeneration of the anterior cruciate ligament (MDACL) is an uncommon degenerative disease. Objective. To present a case of mucoid degeneration of the anterior cruciate ligament diagnosed using Magnetic Resonance Imaging and treated with arthroscopic resection. Methods. In our case report, we examined the medical history of a patient and developed a list of clinical manifestations observed in our case. Magnetic Resonance Imaging is the most efficient approach for differentiating between mucoid degeneration of the anterior cruciate ligament and other knee joint disorders. Results. Our patient presented with a 3-month history of right knee discomfort. The age of the patient was 28 years old. There were no indications of edema or instability, although his knee flexion ranged from 0°–100°. We diagnosed MDACL using MRI and arthroscopic findings. In T2-weighted images, the ACL exhibited an abnormally elevated signal with a mass-like structure of its fibres. In T2-weighted coronal images, the association between the fibres and the aberrant soft tissue was discernible. Based on normal preoperative findings, this case was diagnosed and presented. Magnetic Resonance Imaging revealed a celery-stalk-like appearance of the anterior cruciate ligament suggesting mucoid degeneration of the anterior cruciate ligament, with additional joint effusion. Upon arthroscopy, the anterior cruciate ligament appeared homogenous and hypertrophied with a bulbous lateral portion. The yellow and sclerotic lesions on the lateral portion of the anterior cruciate ligament were excised precisely. Conclusions. In the present case, arthroscopic resection of a degenerating ACL that is causing pain demonstrated good results. In some cases it could lead to subjective progressive laxity after the surgery. The prognosis is dependent on the age of the patient and what other injuries they might have. MDACL should be considered when there is unusual discomfort in the spine and limited flexing. MRI and arthroscopy both pointed to the same diagnosis.