O2102: Is It Worth to Repair Unstable Discoid Meniscus? A Long-Term Analysis Following Discoid Meniscus Repair with a Minimum of 5 Years Follow-Up

Background: Discoid meniscus (DM) repair is the gold standard treatment for unstable symptomatic DM. Although the DM pathological anatomy can negatively affect its healing capacity, good-to-excellent early clinical outcomes have been reported following DM repair. However, it is unclear if these outcomes can be sustained over time due to the dearth of long-term studies. The purpose of this study is to report the clinical outcomes following DM repair with a minimum of 5 years of follow-up.

Methods: A retrospective review was performed at a single institution consisting of patients under 21 years old who underwent arthroscopic treatment for symptomatic DM from January 2014 to December 2023 with a minimum of 5-year follow-up. Patients with stable DM underwent isolated saucerization, and those with unstable DM had saucerization with meniscal repair. Data collection included demographics, clinical presentation, meniscal pathology, surgical technique, re-operation rates, and complication rates. Patient reported outcome (PRO) scores were collected post-operatively starting at the 1-year follow-up. Patients were also called at final follow-up to confirm their function level. Continuous variables were analyzed via t-tests or Wilcoxon rank-sum tests; chi-square or Fisher's exact tests were done for categorical variables. Wilcoxon rank-sum tests compared the PRO scores between the stable and unstable meniscus groups.

Results: There were 39 patients who underwent surgical management at a mean age 13.13 ± 3.75 years with a median follow-up time of 6.66 years (IQR 4.96 – 7.98). Of these, 18 (46.1%) had stable and 21 (53.9%) had unstable DM. Patients that presented with unstable DM were younger (12.2 vs 14.1, p< 0.001) and had fewer chondral lesions (0 vs 4, p=0.04). Of the 39 patients called at final follow-up, 38 responded (97.4%) and 36 (92.3%) reported their knee function had returned to pre-injury level. Among the four patients who experienced complications following their initial surgeries, three underwent a second surgical intervention (Table 1). Subgroup analysis at a median 7.36 years from surgery demonstrated significantly better PROs for the repair group compared to the non-repair group as seen on Tengner Lysholm (99.0 vs 85.5, p=0.02), Pedi-IKDC (98.3 vs 88.5, p< 0.01), KOOS Child Symptom (100 vs 87.8, p< 0.01), and KOOS Child ADL (100 vs 99.0, p=0.04) PROs (Table 2).

Conclusion: The majority (95%) of patients returned to their pre-injury function level at a minimum of 5 years of follow-up from DM surgery and at an average of 7 years post-operatively. Long term subgroup analysis demonstrated better PROs in the DM repair group compared with non-repair group. Our findings support DM preservation surgery as an effective and safe technique that leads to sustainable long-term clinical outcomes.