Knee Arthroplasty Risk After Arthroscopy in Patients Over Age 50 Correlates with the Presence of Diagnosis Codes for Osteoarthritis and Obesity.

Abstract

Purpose: The purpose of this study was to assess the 10-year arthroplasty-free survivorship of patients over 50 years of age who underwent knee arthroscopy and to assess whether this survivorship is affected by the diagnoses of knee osteoarthritis (OA) or obesity at the time of arthroscopy.

Methods: The New York Statewide Planning and Research Cooperative System (SPARCS) administrative database from 2010 to 2020 was queried to identify all patients over the age of 50 who underwent knee arthroscopy. Kaplan-Meier survival analysis was used to assess arthroplasty-free survivorship. Cox proportional hazards models were performed to assess the effect of the diagnoses of knee OA and obesity at the time of arthroscopy based on ICD-9 and 10 codes.

Results: A total of 300,587 patients aged 50 years or older underwent knee arthroscopy. The arthroplasty-free survivorship rate following knee arthroscopy is 83.0% at 5 years. However, at 10 years, the arthroplasty-free survivorship decreased to 66.6%. Patients without knee OA nor obesity had an arthroplasty-free survivorship of 84.1% at 5 years and 68.5% at 10 years. However, patients with a diagnosis of both knee OA and obesity based on ICD-9 and 10 codes had an arthroplasty-free survivorship of 66.2% at 5 years and 15.4% at 10 years. (HR: 2.38; 95% CI: 2.18, 2.60; p < 0.001) CONCLUSION: At five years there is an 83% rate of arthroplasty-free survivorship. This effect deteriorates at the 10-year mark, and many are eventually destined for knee arthroplasty. Presence of diagnosis codes for both knee OA and obesity are risk factors for knee arthroplasty following knee arthroscopy in patients 50 years and older.

Level of evidence: IV, Prognostic, Case Series.