Total Knee Replacement After Arthroscopic Meniscectomy in Knee Osteoarthritis: A Nationwide Population-Based Cohort Study

BACKGROUND: Recent studies raise concerns that arthroscopic meniscectomy (AM) for degenerative tear may be detrimental to the maintenance of the joint structure. This study was performed to examine the rate of total knee replacement (TKR) among patients with knee osteoarthritis (OA) who underwent AM for meniscal tears and compare this rate with those who did not. METHODS: A retrospective cohort study was conducted using the National Health Insurance Database of South Korea. Among knee OA patients aged 50–79, those who were treated with AM due to meniscal damage from 2007 to 2009 were selected as the AM group while those not treated with AM despite the presence of meniscal damage were selected as control group. Both were matched based on a propensity score and followed-up until the earliest occurrence of: TKR, death, or 10 years. Cox proportional hazards models were used to compare the outcome. RESULTS: A total of 36,974 patients were included in AM groups and non-AM group after 1:1 matching. TKR occurred in 9.62% and 7.64% in AM and non-AM groups with the average duration after meniscectomy of 5.88 ± 2.77 and 5.50 ± 2.94 years, respectively. After adjustment for baseline confounders, the TKR rate in the AM group was calculated to be 25% higher than that in the non-AM group (subdistribution hazard ratio, 1.25; 95% confidence interval, 1.16–1.34). The mortality rate was 5.20%, which did not significantly differ between groups. CONCLUSION: OA patients who underwent AM for the meniscal injury had higher incidence of TKR up to 10 years of follow-up than the non-operated group. The greater TKR utilization observed in patients undergoing AM merits caution when treating OA patients with meniscal injury.