Arthroscopic Meniscal Repair during Revision ACLR: Low Failure Rates Reported at 6-Year Follow-Up

In a study presented at the AAOS 2024 Annual Meeting, the overall rate of meniscal repair failure after 6-year follow-up was 16 percent in a cohort of patients from the Multicenter ACL Revision Study (MARS) who underwent concurrent revision anterior cruciate ligament (ACL) reconstruction (ACLR) and arthroscopic meniscal repair.

Jacob Fox, MD, a resident in the Department of Orthopaedic Surgery at Vanderbilt University Medical Center, told AAOS Now Daily Editions that the MARS group “was developed to study revision ACL surgery due to knowledge gaps in the literature. Revision ACLR consistently demonstrates higher risk of failure compared to primary reconstructions, and there is minimal level 1 or prospective evidence regarding mid- to long-term outcome.”

Dr. Fox added, “Our study was conducted because there have been no prior studies in the literature to date documenting meniscal repair outcomes and failure rates in the setting of ACL revision with greater than 5 years of follow-up.” Therefore, Dr. Fox and fellow MARS colleagues used the prospectively collected data to report the incidence of meniscal repair failure 6 years after concurrent revision ACLR.

A total of 238 repairs that occurred between 2006 and 2011 were included in the analysis, of which 173 were medial repairs and 65 were lateral repairs. Seventy-six percent of repairs were performed with an all-inside technique. Follow-up was obtained on most patients (77 percent) and was conducted via phone and email to determine whether subsequent surgery was required in either knee since the index revision ACLR. If further surgery was necessary, operative reports were obtained to confirm the pathologic condition and type of surgery when possible.

Of the 31 reported meniscal repair failures, medial tears underwent reoperation for failure at a significantly higher rate when compared with lateral tears (20 percent versus 5.7 percent; P = 0.01). The mean time to failure was shorter in medial repairs (1.7 years) than lateral repairs (1.8 years). Table 1 shows baseline characteristics between meniscal failures and non-failures.

The study also examined patient-reported outcomes, specifically the Knee Injury and Osteoarthritis Outcome Score (KOOS). “One surprising data point was that pain in the meniscal failure group (89 points on the KOOS pain scale, on a scale from 0 to 100, where 100 depicts no pain) did not differ from the non-failure group (92 points) at 6-year follow-up,” Dr. Fox noted. “We expected that pain would have been significantly higher in the meniscal failure cohort, but our study did not show this.”

Dr. Fox acknowledged limitations within the study’s design. “One perceived weakness of this study is that the large number of contributors from different study site locations could lead to varied assessment and identification of chondral and meniscal pathology. To combat this weakness, we had meetings prior to launching the MARS study to educate the involved surgeons and try and create consistency in diagnosis and surgical approach,” he explained. Another limitation was that defining failure solely as “reoperation” may potentially underestimate the actual number of failures. “However,” Dr. Fox noted, “it is not financially practical or safe for all of the patients in the study to undergo second-look arthroscopy or MRIs following repair. Either approach would be cost-prohibitive in this setting.”

When asked about future areas of exploration, Dr. Fox called for further research into the pain response differences between patients experiencing meniscal failure and those with successful repairs. “It would be important for surgeons to know why patients with meniscal failure have similar pain levels to patients with intact repairs,” he said. He also pointed toward further collection of patient-reported outcome measures and examination of the factors predisposing medial-sided repairs to increased failure rate.

One clinical takeaway that Dr. Fox highlighted was a higher and quicker rate of failure in medial meniscus repairs. “This can be taken into consideration with preoperative planning and assessing the possibility of successful meniscal repair.” He further emphasized the low failure rate in the MARS cohort. Regarding the significance of this finding, Dr. Fox said that it “demonstrates to orthopaedic surgeons that arthroscopic meniscal repair is safe and effective even in the setting of complex revision ACLR.”

Dr. Fox’s coauthors of “Meniscal Repair in the Setting of Revision Anterior Cruciate Ligament Reconstruction: 6-Year Follow-Up Results from the MARS Cohort” are Amanda H. Braun, MA; Charles L. Cox, MD, MPH, FAAOS; Christina R. Allen, MD, FAAOS; Daniel E. Cooper, MD, FAAOS; James L. Carey, MD, FAAOS; Kurt P. Spindler, MD, FAAOS; Laura Huston, MS; Rick W. Wright, MD, FAAOS; Robert A. Arciero, MD, FAAOS; and Warren Dunn, MD, MPH, FAAOS.

Cailin Conner is the former associate editor of AAOS Now.