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

Abstract

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).

Prospective Consecutive Clinical Outcomes After Transtibial Root Repair for Posterior Meniscal Root Tears: A Multicenter Study

“…The amount of overall meniscal extrusion increased from an average of 1.9 mm preoperatively to 2.6 mm postoperatively (P ¼ .03). 15 No significant differences were seen in IKDC scores based on preoperative malalignment or meniscal extrusion (Table 5). In addition, preoperative cartilage status of the femur (P ¼ .550) and tibia (P ¼ .723), cartilage status at 6-month follow-up (P ¼ .817 and P ¼ .958 for femur and tibia, respectively), subchondral bone changes (P ¼ .801), and meniscal healing (P ¼ .663) did not affect IKDC scores.…”

“…The amount of overall meniscal extrusion increased from an average of 1.9 mm preoperatively to 2.6 mm postoperatively ( P = .03). 15 …”

“…14 The postoperative MRI results have been published and were used for correlation of clinical outcomes in the current study. 15 …”

Benefits of Meniscal Repair in Selected Patients Aged 60 Years and Older

“…To fulfill this function, the meniscus roots need to be intact and stable to prevent extrusion during compression. 11 , 26 , 39 Meniscus root tears drastically alter native tibiofemoral biomechanics and have similar biomechanical effects to meniscus-deficient knees. Similarly, partial meniscectomy for degenerative root tears significantly alters biomechanics and is associated with a high risk of TKA conversion.…”

“… 27 MRI evaluation of the meniscus roots must be viewed in light of certain limitations and should always be augmented by physical examination and patient history. 7 Krych et al 26 demonstrated that the rate of preoperatively identified posterior root tears on MRI scans read by fellowship-trained musculoskeletal radiologists was only 33%, with only 50% of missed tears clearly evident when retrospectively reviewing known tears.…”