Association Between Transtibial Meniscus Root Repair and Rate of Meniscal Healing and Extrusion on Postoperative Magnetic Resonance Imaging: A Prospective Multicenter Study

Background: Prospective studies evaluating second-look imaging of meniscus root repair using a transtibial pull-out technique are limited; therefore, optimal surgical indications and the technique for meniscus root repair remain uncertain. Hypothesis: It was hypothesized that there would be a high rate of healing, improvement in meniscal extrusion, and prevention of articular cartilage degeneration and subchondral bone abnormalities after meniscus root repair. Study Design: Case series; Level of evidence, 4. Methods: Consecutive patients undergoing transtibial root repair were prospectively enrolled at 2 orthopaedic centers between March 2017 and January 2019. Pre- and postoperative magnetic resonance imaging (MRI) scans were reviewed by a musculoskeletal radiologist in a blinded fashion for meniscal healing, quantification of extrusion, articular cartilage grade, subchondral bone changes, and coronary/meniscotibial ligament abnormalities. Given persistent extrusion observed on postoperative MRI scans, an additional 10 patients gave consent and were enrolled for immediate (before weightbearing) postoperative MRI scans. Results: A total of 45 patients (16 male, 29 female; mean ± standard deviation age, 42.3 ± 12.9 years; body mass index, 31.6) were prospectively enrolled in the study; there were 47 meniscus root repairs: 29 medial and 18 lateral (2 with both). Postoperative MRI was obtained at an average of 6.3 months (range, 5.1-8 months); 98% of meniscal repairs had evidence of healing. Mean extrusion increased significantly, from 1.9 ± 1.5 mm preoperatively to 2.6 ± 1.4 mm postoperatively ( P = .03). There was no significant progression of chondromalacia grade, subchondral edema, insufficiency fracture, subchondral cysts, or subchondral collapse. In the additional 10-patient cohort, the mean preoperative extrusion (1.6 ± 1.2 mm) was not significantly different from that immediately postoperatively (2.0 ± 1.0 mm; P = .23). Conclusion: Prospective MRI analysis of transtibial meniscus root repair confirmed a high rate of meniscal healing and no observable progression of cartilage degeneration or subchondral bone abnormalities at the short-term follow-up. However, meniscal extrusion worsened in the first 6 months after surgery. Registration: NCT03037242 ( ClinicalTrials.gov identifier).

Investigating the Chronology of Meniscus Root Tears: Do Medial Meniscus Posterior Root Tears Cause Extrusion or the Other Way Around?

Objectives: Meniscus root tears are increasingly being recognized. Meniscus extrusion has previously been associated with medial root tears; however, the relationship between secondary meniscus restraints, such as the meniscotibial (MT) ligament, extrusion, and root tears has yet to be formally evaluated. The purpose of this study was to better understand the association between MT ligament competence, medial meniscus extrusion, and medial meniscus posterior root tears (MMPRT), as well as to determine the progression of meniscus extrusion over time. Methods: Serial MRI’s from our institution were reviewed for patients who showed evidence of medial meniscus extrusion and MMPRT on at least one of 2+ available MRI’s. All patients were symptomatic at the time of diagnosis. All MRI’s were analyzed independently by two board-certified musculoskeletal radiologists. MT ligament disruption, medial meniscus extrusion, and MMPRT presence was recorded for each MRI. The time between MRI’s, presence of insufficiency fractures, and Outerbridge classification for the medial femur and tibia were also evaluated. Results: 27 knees in 26 patients were included in this study, with a total of 63 MRI’s analyzed (21 knees with 2 MRI’s, 3 with 3 MRI’s, and 3 with 4 MRI’s). All patients demonstrated clear medial meniscus extrusion and meniscotibial ligament disruption prior to the subsequent development of MMPRTs (p < 0.001). Mean extrusion at the time of initial MRI was 3.3 ± 1.1 mm, and increased significantly to 5.5 ± 1.8 mm at the time of first imaging with an identified MMPRT (p < 0.001). The average time between initial MRI and the first identification of MMPRT on a later MRI was 1.7 ± 1.6 years. Conclusions: In a sample of 27 symptomatic knees with serial MRI’s both before and after MMPRT diagnosis, all patients demonstrated MT ligament disruption and associated meniscus extrusion prior to the development of subsequent medial meniscus root tears. These findings suggest that MT ligament disruption and medial meniscus extrusion represent early and predisposing events contributing to MMPRT. Therefore, this provides a possible explanation of why meniscus extrusion is not corrected with medial meniscus root repair.

Medial Meniscus Posterior Root Tear Treatment: A matched cohort comparison of non-operative management, partial meniscectomy and repair

Objectives: Meniscal root disruption results in a loss of hoop strain resistance, increased articular cartilage contact pressure, and acceleration of degenerative changes. There is limited data comparing the outcomes of similarly matched patients with a medial meniscus posterior root tear treated with non-operative management, partial meniscectomy, or repair. The purpose of this study is to compare treatment failure, clinical outcome scores, and radiographic findings for a matched cohort of patients who underwent either non-operative management, partial meniscectomy, or transtibial pull-through repair for a medial meniscus posterior root tear (MMPRT). Our hypothesis is that patients who underwent meniscus root repair will have lower rates of progression to arthroplasty than patients who were treated with non-operative management or partial meniscectomy. Methods: Patients who underwent transtibial medial meniscus posterior horn root repair were matched by meniscus laterality, age, sex and K-L grades to patients treated non-operatively or with a partial meniscectomy. Progression to arthroplasty rates, IKDC and Tegner scores, and radiographic outcomes were analyzed between groups. Results: Forty-five patients were included in this study (15 non-operative, 15 partial meniscectomy, 15 root repair). Progression to arthroplasty demonstrated significant differences among treatment groups at a mean 74 months (non-operative 4/15, partial meniscectomy 9/15, meniscus repair 0/15, p=.0003). The meniscus root repair group had significantly less arthritic progression, as measured by change in K-L grade from pre-op to post-op (non-operative 1.0, partial mensicectomy 1.1, and meniscus repair 0.1, p=.001). Conclusion: Meniscus root repair leads to significantly less arthritis progression and subsequent knee arthroplasty compared to non-operative management and partial meniscectomy in a demographically matched cohort.

Outcomes of Arthroscopic All-Inside Repair Versus Observation in Older Patients With Meniscus Root Tears

Background: Meniscus root tears lead to de-tensioning of the meniscus, increased contact forces, and cartilage damage. Management of older patients with root tears is controversial and the efficacy of different treatment options is unclear. Purpose: To compare the clinical outcomes of patients with moderate knee osteoarthritis who underwent an all-inside meniscus root repair technique versus nonoperative management for either medial or lateral meniscus root tears. Study Design: Cohort study; Level of evidence, 2. Methods: Patients with a diagnosed posterior meniscus root tear who underwent arthroscopic repair (AR: 30 knees) or nonoperative treatment with observation (O: 18 knees) were followed for a minimum of 2 years (mean follow-up, 4.4 years). The arthroscopic repair included all-inside sutures to reduce the root back to its remnant (reduction sutures), thereby re-tensioning the meniscus, and 1 mattress suture to strengthen the repair by reapproximating the construct to the posterior capsule. The data collected included the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm, Tegner, and Veterans RAND 12-Item Health Survey (VR-12) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores and conversion to total knee arthroplasty (TKA). Results: Medial meniscus root tears comprised 80.0% of the AR group and 77.8% of the O group. The average Kellgren-Lawrence grade was 2 in both groups. The baseline scores for the KOOS Symptoms subscale were lower for AR (50.2 ± 19.3) than for O (66.5 ± 16.1) ( P = .003), as were the KOOS Knee-Related Quality of Life scores (AR, 26.7 ± 16.1; O, 39.6 ± 22.1) ( P = .046). No differences were found between groups for the absolute values at follow-up except that follow-up Tegner scores were lower in the O group than in the AR group ( P = .004). Significant improvements were seen in the AR group from baseline to ultimate follow-up in average KOOS subscale scores ( P < .001), Lysholm scores ( P < .001), Tegner scores ( P = .0002), and VR-12 PCS scores ( P < .001), whereas the O group had a significant improvement only in average KOOS Pain ( P = .003), KOOS Function in Daily Living ( P = .006), and VR-12 PCS ( P = .038) scores. Compared with the O group, the AR group had a significantly larger improvement from baseline to follow-up in average KOOS Pain ( P = .009), KOOS Symptoms ( P = .029), and Lysholm scores ( P = .016). During follow-up, 3.3% of the AR group underwent a TKA compared with 33.3% of the O group ( P = .008). The hazard ratio of TKA conversion was 93.2% lower for the AR group compared with the O group ( P = .013). Conclusion: All-inside medial or lateral meniscus root repair showed improved functional outcomes and decreased TKA conversion rates compared with nonoperative treatment and may be considered as a treatment option for the management of meniscus root tears in older patients with moderate osteoarthritis.