Management of mucoid degeneration of the anterior cruciate ligament: a systematic review

PURPOSE: The purpose of this study was to investigate the outcomes of management of mucoid degeneration of the anterior cruciate ligament (MDACL) by performing a systematic review of methods of treatment that have been reported. METHODS: A systematic literature search in the databases MEDLINE, Embase, Google Scholar, Cochrane, ISI web of science and Scopus was performed through July 2020 by three independent reviewers. The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and registered in the PROSPERO database (CRD42018087782). Quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS) criteria. RESULTS: A total of nine studies were eligible for review. All nine studies assessed the outcome of arthroscopic debridement of MDACL. A total of 313 knees in 292 patients were included. The mean follow up ranged from 13 to 72 months. There was strong association between MDACL and chondral lesions (82%) and between MDACL and meniscal tears (69%). The rate of simultaneous meniscectomy ranged from 13 to 44%. Postoperative pain relief ranged from 53.8 to 95%. There was an improvement in postoperative range of motion and outcome scores (Lysholm and International Knee Documentation Committee scores and the Knee Injury and Osteoarthritis Outcome Score). Postoperative Lachman test was positive in 40% of patients, and 6% of patients had symptomatic instability. The mean MINORS score was 9.5 out of 16 (4-12). CONCLUSIONS: Arthroscopic debridement of the anterior cruciate ligament (ACL) results in satisfactory pain relief and improvement in knee outcome scores. Postoperative ACL laxity is common after arthroscopic ACL debridement, however, symptomatic instability is not. The need for delayed ACL reconstruction should be discussed preoperatively, especially if complete resection of the ACL is to be performed. LEVEL OF EVIDENCE: IV.