Examining the Efficacy of Medial Meniscus Posterior Root Repair: A Meta-analysis and Systematic Review of Biomechanical and Clinical Outcomes

Abstract

Background: Medial meniscus posterior root (MMPR) injuries accelerate the progression of osteoarthritis. While partial meniscectomy was once considered the gold standard for treatment, meniscus root repair has become increasingly utilized with reported improvements in clinical and biomechanical outcomes. Purpose: To perform a systematic review of biomechanical outcomes and a meta–analysis of clinical and radiographic outcomes after MMPR repair. Study Design: Meta-analysis and systematic review; Level of evidence, 4. Methods: The PubMed, Embase, and Cochrane databases were queried in August 2021 for studies reporting biomechanical, clinical, and radiographic outcomes after MMPR repair. Biomechanical studies were assessed for main results and conclusions. Data including study characteristics, cohort demographics, and outcomes were extracted. Included clinical studies were analyzed with a random–effects meta-analysis of proportions for binary outcomes or continuous outcomes for mean differences between preoperative and postoperative time points. Subgroup analysis for studies reporting repair outcomes with concomitant high tibial osteotomy (HTO) was performed where appropriate. Results: A total of 13 biomechanical studies were identified and reported an overall improvement in mean and peak contact pressures after MMPR repair. There were 24 clinical studies, consisting of 876 patients (877 knees), identified, with 3 studies (106 knees) reporting outcomes with concomitant HTO. The mean patient age was 57.1 years (range, 23-74 years), with a mean follow–up of 27.7 months (range, 2-64 months). Overall, clinical outcomes (Lysholm, Hospital for Special Surgery, International Knee Documentation Committee, visual analog scale for pain, Tegner, and Knee injury and Osteoarthritis Outcome Score scores) were noted to improve postoperatively compared with preoperatively, with improved Lysholm scores in patients undergoing concomitant HTO versus MMPR repair alone. Meniscal extrusion was not significantly improved after MMPR repair compared with preoperative measurements. The progression in Kellgren-Lawrence grades from grade 0 to grades 1 to 3 occurred in 5.9% (21/354) of patients after repair, with no patients progressing from grades 1 to 3 to grade 4. Conclusion: MMPR repair generally improved biomechanical outcomes and led to improved patient–reported outcomes with greater improvements noted in patients undergoing concomitant HTO. Repair did not significantly improve meniscal extrusion, while only 5.9% of patients were noted to progress to low–grade osteoarthritis. The high level of heterogeneity in the included biomechanical and clinical investigations emphasizes the need for more well–designed studies that evaluate outcomes after MMPR repair.

Medial Meniscal Extrusion in Patients With Medial Meniscus Root Tears: A Systematic Review and Meta-analysis

“…However, there are studies that have shown that meniscus root repair does not significantly decrease postoperative MME 6,24,46 or OA progression. 8 A recent meta-analysis found that 33.5% of patients treated via meniscal repair underwent conversion to total knee arthroplasty within 10 years.…”

“…9 A recent cadaveric biomechanical study found that the utilization of an anatomic transtibial pull-out root repair with centralization suture techniques achieved better restoration of the contact mechanics of the knee and meniscal extrusion when compared with nonanatomic repairs. 13 However, there are studies that have shown that meniscus root repair does not significantly decrease postoperative MME 6,24,46 or OA progression. 8 A recent metaanalysis found that 33.5% of patients treated via meniscal repair underwent conversion to total knee arthroplasty within 10 years.…”

Medial meniscal lesions increase antero‐posterior laxity in knees with anterior cruciate ligament injury

“…This is a key aspect, since meniscal tears represent one of the most common injuries in orthopaedics, with a mean annual incidence of 60−70 per 100.000 [23], and since patients undergoing ACL reconstruction have been reported to have a meniscus tear incidence from 55% up to nearly 80% [24][25][26][27][28]. Meniscal lesions should therefore be carefully considered when performing ACL reconstruction surgery to restore knee stability [29][30][31][32]. In fact, while meniscectomy can increase the femoro-tibial contact stress and anterior tibial translation in ACL-deficient knees, meniscal repair showed to increase anteromedial knee laxity [8,33].…”

Medial Meniscus Posterior Root Tears Lead to Changes in Joint Contact Mechanics at Low Flexion Angles During Simulated Gait

“…Nonetheless, despite broad clinical evidence suggesting favorable outcomes, multiple studies have documented the persistence and/or progression of medial meniscal extrusion on magnetic resonance imaging after meniscus root repair. 25 Advancements in surgical techniques, such as application of a centralization meniscal suture, 7,23,29 aim to further reduce medial meniscal extrusion, improve rates of meniscal healing, and prevent progression of osteoarthritis.…”