Semi-quantitative arthroscopic scoring system is related to clinical outcomes in patients after medial meniscus posterior root repair

Abstract

Background

Different methods are available to assess the healing status of repaired root for medial meniscus posterior root tears (MMPRT) using second-look arthroscopy. However, few studies are comparing them or validating their usefulness. Therefore, it was hypothesized that the semi-quantitative arthroscopic score might correlate more with 1-year clinical outcomes in patients with MMPRT than the qualitative evaluation.

Methods

Data of 61 patients who underwent MMPRT pullout repair and second-look arthroscopy were retrospectively evaluated. The semi-quantitative arthroscopic scoring system was divided into three evaluation criteria: scores from 0 to 10 points include the width of the bridging tissue, stability of the repaired root, and synovial coverage. The qualitative evaluation was classified into 4 status; complete healing, lax healing, scar tissue healing, and failed healing according to the stability and mobility of the repaired root. Multivariate linear regression analyses were used to identify predictors of 1-year postoperative clinical outcomes, including Knee Injury and Osteoarthritis Outcome, Lysholm, or International Knee Documentation Committee scores. Spearman's correlation analysis was used to analyze the correlation between second-look arthroscopic score/qualitative evaluation and 1-year postoperative clinical outcomes. In addition, the optimal cutoff point of semi-quantitative arthroscopic score was determined by receiver operating characteristic (ROC) curve. The Mann–Whitney U test was used to compare clinical outcomes between patients with semi-quantitative arthroscopic scores ≥8 and scores <8.

Results

All clinical scores significantly improved at 1 year postoperatively. A good correlation was observed between the semi-quantitative score and clinical scores, but none between qualitative evaluation and clinical scores. The optimal cutoff point of semi-quantitative second-look arthroscopic score was 8 points. Significantly, better clinical outcomes were observed in patients with semi-quantitative scores ≥8 points.

Conclusions

All 1-year postoperative clinical scores were significantly improved. The semi-quantitative arthroscopic scores correlate more with 1-year clinical outcomes in patients with MMPRT than the qualitative evaluation.

Level of evidence

IV case series study.

Introduction

The meniscus transfers load and absorbs shock [1]. It increases the contact surface area between the femoral condyle and the tibial plateau, further playing an important role in maintaining the biomechanical stability of the knee joint as the collagen fibers of the meniscus maintain hoop tension under the pressure, which conducts the load [2]. Medial meniscus (MM) posterior root tear (PRT) results in loss of hoop tension, which loses the load transmission of the meniscus, leading to cartilage degeneration and the progression of osteoarthritis (OA) [3].

The treatment of MMPRT has been improved using several techniques [[4], [5], [6]]. Arthroscopic transtibial pullout repair reduces tibial-femoral contact pressure by increasing the contact area, which has achieved satisfactory clinical outcomes [7,8]. In qualitative second-look arthroscopic evaluation, some researchers have classified 4 healing statuses of the meniscus as complete healing, lax healing, scar tissue healing, and failed healing [9] or 3 healing statuses as complete healing, partial healing, and retear [10]. Seo et al. found that the healing status of the repaired meniscus through qualitative second-look arthroscopic evaluation did not seem to be related to the improvement of clinical symptoms [9]. In order to further explore the relationship between repair status and postoperative clinical outcomes, Furumatsu et al. described a semi-quantitative scoring system that is used to evaluate healing status, showing a good correlation between arthroscopic score and clinical evaluations, such as quality of life (QOL) score and visual analogue scale (VAS) pain score [11].

There is no unified standard for evaluating the healing status of the repaired meniscus or verifying its correlation with postoperative clinical outcomes. Therefore, our study investigated the correlation between semi-quantitative arthroscopic scores and 1-year clinical outcomes compared to qualitative evaluation. It was hypothesized that the semi-quantitative arthroscopic score might correlate more with 1-year clinical outcomes in patients with MMPRT than the qualitative evaluation.