Lower preoperative Kellgren–Lawrence grade is associated with improved long‐term survivorship following medial meniscus posterior root repair

Abstract Purpose The purpose of this study was to determine whether there was an association between preoperative Kellgren–Lawrence (KL) grade and long‐term failure rates, reoperation free survival rates, and patient reported outcomes of patients undergoing medial meniscal posterior root repair (MMPRR). Methods Consecutive skeletally mature patients who underwent primary isolated MMPRR performed at a single institution between January 2005 and September 2022 were included. Preoperative radiographs were evaluated by three independent orthopaedic surgeons and classified utilising the KL grading system. Chi‐squared tests were used to assess associations between categorical variables, while T‐test and Rank sum tests were used for continuous variables, and Kaplan–Meier estimates were used to assess reoperation free survival rates using log‐rank test. Results In total, 240 patients were identified, and 170 patients were included (71% follow‐up rate). The final cohort was composed of 93 patients with KL grade 0–1 and 77 patients with KL grade 2–4. Intra‐class correlation coefficient (ICC) score for absolute agreement among three raters was 0.79 (95% confidence interval CI 0.64–0.86) for the mean of raters indicating good reliability and 0.55 (95% CI 0.37–0.68) for single measurements indicating moderate reliability. The failure rate in the KL 0–1 group was 13% (12/93) compared with 23% (18/77) in the KL 2–4 group, which was not significantly different ( p = 0.075). In terms of reoperation free survival, the KL 0–1 group demonstrated a significantly higher survival probability of 51% at 14.9 years compared with the KL 2–3 group demonstrating a survival probability of 16% at 15.8 years ( p = 0.046). Conclusions This study demonstrated that preoperative KL grade was associated with reoperation free survivorship in patients undergoing MMPRR with low‐grade (0,1) KL scores demonstrating significantly longer survivorship and lower risk of reoperation than high‐grade (2,3) KL scores. These results allow us to have further informed discussions with our patients undergoing MMPRR and can help guide patient expectations regarding long‐term outcomes. Level of Evidence Level IV.