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Comparable Midterm Survival After Medial Meniscus Root Repair for High and Low Intraoperative Outerbridge
Camila Grandberg1, Abigail N Boduch1, Robert E Bilodeau1
1Department of Orthopaedic Surgery, UPMC Freddie Fu Sports Medicine Center, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
Background:
While medial meniscus posterior root repairs (MMPRRs) have been shown to reverse harmful biomechanical effects of medial meniscus posterior root tears, it is questionable whether meaningful improvement occurs in patients with advanced chondral loss.
Purpose/Hypothesis:
The objectives of this study were to compare midterm survival of MMPRR and to determine patient-reported outcomes (PROs) after MMPRR based on intraoperative Outerbridge grades (0-2 vs 3 and 4). It was hypothesized that patients undergoing MMPRR with Outerbridge grades 3 and 4 would have a decreased rate of MMPRR survival and inferior PROs compared to patients with Outerbridge grades 0 to 2.
Study Design:
Cohort study; Level of evidence, 3.
Methods:
Consecutive patients who underwent primary isolated MMPRR performed at a single institution between July 2003 and November 2022 with a minimum follow-up of 1 year were included and categorized according to medial compartment Outerbridge grade (0-2 or 3 and 4) based on diagnostic arthroscopy. Failure was defined as reoperation of the index knee. PROs collected included International Knee Documentation Committee (IKDC), visual analog scale (VAS) for pain, and Marx activity scale scores, which were compared to the previously established minimal clinically important difference (MCID) and/or clinically meaningful change. A minimum follow-up of 2 years was used for PRO analyses. Data were collected through electronic medical records and/or prospectively distributed surveys. A post hoc power analysis was performed, yielding a post hoc power of >0.99.
Results:
A total of 170 patients were included (74 in the Outerbridge grade 0-2 group and 96 in the Outerbridge grade 3 and 4 group). The mean follow-up time was 5 years. There were no significant descriptive differences between groups. The median survival was 11 years, and there were no significant differences between groups in the survival analysis. There was 80% survival at 8 years overall, with 80% survival at 8 years and 7 years for Outerbridge grades 0 to 2 and grades 3 and 4, respectively. The failure rate was 17.6%, with no significant differences between groups, and the mean time to reoperation was 5.3 years. The mean postoperative IKDC score was 64.1 ± 23.0. The mean IKDC change was 27.6 ± 29.7, reaching the MCID of 10.17, with no significant differences between groups. The VAS score decreased from 6.1 ± 2.2 preoperatively to 3.0 ± 3.0 postoperatively, with no significant differences between groups.
Conclusion:
Midterm survival and clinical outcomes after MMPRR were comparable between patients with intraoperative Outerbridge grades 0 to 2 and grades 3 and 4, with no significant differences in failure rate or survival. The overall median survival was 11 years, with an 80% survival rate at 8 years. The change in IKDC score exceeded the MCID in both groups. These findings indicate that MMPRR is durable and effective and intraoperative Outerbridge classification grades should not dissuade orthopaedic surgeons from performing MMPRR.
