Patient-Reported Outcome Measures of Total Knee Arthroplasties for Post-Traumatic Arthritis versus Osteoarthritis: A Short-Term (5- to 10-year) Retrospective Matched Cohort Study.

BACKGROUND: The objective of the study was to compare the patient-reported outcome measures (PROM) of patients with post-traumatic arthritis (PTA) versus patients with osteoarthritis (OA) undergoing total knee arthroplasty (TKA) and compare the rates of revision among these two groups. METHODS: Using a prospectively held institutional registry, we retrospectively reviewed patients ≥60 years of age who underwent unilateral TKA between May 2007 and February 2012. Patients with previous or concomitant diagnosis of inflammatory arthropathy or an initial open fracture were excluded. PTA patients were matched 1:5 with OA patients undergoing TKA. Validated PROMs were recorded at baseline before index TKA and the last follow-up. Reason and time to revision surgery was reported, and survivorship was compared using Kaplan-Meier curves. RESULTS: Seventy-five PTA patients were matched to 375 OA patients. There was no difference between these groups with respect to age (67.7 ± 5.6 vs 67.8 ± 5.5 years; P = .876), body mass index (28.6 ± 5.4 vs 28.7 ± 5.3 kg/m2; P = .948), sex (65.3% vs 65.3% females; P = .999), Charlson Comorbidity Index (21.3% vs 21.3% Index 1-2, P = .999), and time to follow-up (93.0 ± 13.4 vs 88.2 ± 13.7 months; P = .999). No statistically significant difference was found in PROMs at baseline and the last follow-up (P > .05), the rate or time to revision surgery between the two groups (P-value = .635; log-rank test). CONCLUSION: Unlike previous studies, TKA for PTA does not pose lower PROMs or higher revision rates when compared to TKA for OA. These results could help provide surgeons with a frame of reference in terms of expectations for patients with PTA undergoing TKA.