Incidence of Total Knee Arthroplasty After Arthroscopic Surgery for Knee Osteoarthritis: A Secondary Analysis of a Randomized Clinical Trial.

Importance: It is unclear whether arthroscopic resection of degenerative knee tissues among patients with osteoarthritis (OA) of the knee delays or hastens total knee arthroplasty (TKA); opposite findings have been reported. Objective: To compare the long-term incidence of TKA in patients with OA of the knee after nonoperative management with or without additional arthroscopic surgery. Design, Setting, and Participants: In this ad hoc secondary analysis of a single-center, assessor-blinded randomized clinical trial performed from January 1, 1999, to August 31, 2007, 178 patients were followed up through March 31, 2019. Participants included adults diagnosed with OA of the knee referred for potential arthroscopic surgery in a tertiary care center specializing in orthopedics in London, Ontario, Canada. All participants from the original randomized clinical trial were included. Data were analyzed from June 1, 2021, to October 20, 2022. Exposures: Arthroscopic surgery (resection or debridement of degenerative tears of the menisci, fragments of articular cartilage, or chondral flaps and osteophytes that prevented full extension) plus nonoperative management (physical therapy plus medications as required) compared with nonoperative management only (control). Main Outcomes and Measures: Total knee arthroplasty was identified by linking the randomized trial data with prospectively collected Canadian health administrative datasets where participants were followed up for a maximum of 20 years. Multivariable Cox proportional hazards regression models were used to compare the incidence of TKA between intervention groups. Results: A total of 178 of 277 eligible patients (64.3%; 112 [62.9%] female; mean [SD] age, 59.0 [10.0] years) were included. The mean (SD) body mass index was 31.0 (6.5). With a median follow-up of 13.8 (IQR, 8.4-16.8) years, 31 of 92 patients (33.7%) in the arthroscopic surgery group vs 36 of 86 (41.9%) in the control group underwent TKA (adjusted hazard ratio [HR], 0.85 [95% CI, 0.52-1.40]). Results were similar when accounting for crossovers to arthroscopic surgery (13 of 86 [15.1%]) during follow-up (HR, 0.88 [95% CI, 0.53-1.44]). Within 5 years, the cumulative incidence was 10.2% vs 9.3% in the arthroscopic surgery group and control group, respectively (time-stratified HR for 0-5 years, 1.06 [95% CI, 0.41-2.75]); within 10 years, the cumulative incidence was 23.3% vs 21.4%, respectively (time-stratified HR for 5-10 years, 1.06 [95% CI, 0.45-2.51]). Sensitivity analyses yielded consistent results. Conclusions and Relevance: In this secondary analysis of a randomized clinical trial of arthroscopic surgery for patients with OA of the knee, a statistically significant association with delaying or hastening TKA was not identified. Approximately 80% of patients did not undergo TKA within 10 years of nonoperative management with or without additional knee arthroscopic surgery. Trial Registration: ClinicalTrials.gov Identifier: NCT00158431.

Secondary surgical intervention after primary glaucoma filtration surgery: an Ontario population-based study.

OBJECTIVE: To identify factors associated with secondary surgical intervention after glaucoma filtration surgery. DESIGN: Population-based retrospective cohort. METHODS: Patient records with billing claims for a primary glaucoma filtration surgery occurring between April 2003 and March 2015 were identified. Each identified record was examined for instances of secondary glaucoma surgeries within the patient's first postoperative year. Baseline characteristics of patients who required secondary surgical intervention were compared with those who did not. A multivariable Cox proportional hazards model was used to calculate hazard ratios. RESULTS: Within a cohort of 10,097 patients, 349 (3.46%) underwent a secondary surgical intervention within the first postoperative year. Interventions were less frequent after surgeries that included an indwelling drainage device (HR=0.58 95% CI, 0.37-0.89), phacoemulsification (HR=0.33, 0.21-0.52), or both (HR=0.09, 0.03-0.31). Patients with preoperative aminoglycoside and mydriatic exposure had significantly increased risk of secondary surgical intervention (HR=3.19, 1.89-5.36) and (HR=2.32, 1.49-3.61). Patients who underwent surgery on their contralateral eye experienced secondary surgical interventions more frequently: 7.44 per 10,000 person-days (versus 1.18 per 10,000 person-days, p < 0.0001). No significant differences in the rates of secondary surgical intervention were observed for patients taking different classes of glaucoma medications or those exposed to higher amounts of benzalkonium chloride. CONCLUSIONS: In Ontario, the overall rates of secondary surgical interventions in the first postoperative year are low but significantly higher in certain patient populations. Further work is required to address the higher rate of secondary surgical intervention in patients with a history of certain perioperative eye drop medications and those who require sequential-bilateral procedures.