Impact of time to revision total knee arthroplasty on outcomes following aseptic failure.

INTRODUCTION: Prior studies have demonstrated an association between time to revision total knee arthroplasty (rTKA) and indication; however, the impact of early versus late revision on post-operative outcomes has not been reported.

MATERIALS AND METHODS: A retrospective, observational study examined patients who underwent unilateral, aseptic rTKA at an academic orthopedic hospital between 6/2011 and 4/2020 with > 1-year of follow-up. Patients were early revisions if they were revised within 2 years of primary TKA (pTKA) or late revisions if revised after greater than 2 years. Patient demographics, surgical factors, and post-operative outcomes were compared.

RESULTS: 470 rTKA were included (199 early, 271 late). Early rTKA patients were younger by 2.5 years (p = 0.002). The predominant indications for early rTKA were instability (28.6%) and arthrofibrosis/stiffness (26.6%), and the predominant indications for late rTKA were aseptic loosening (45.8%) and instability (26.2%; p < 0.001). Late rTKA had longer operative times (119.20 ± 51.94 vs. 103.93 ± 44.66 min; p < 0.001). There were no differences in rTKA type, disposition, hospital length of stay, all-cause 90-day emergency department visits and readmissions, reoperations, and number of re-revisions.

CONCLUSIONS: Aseptic rTKA performed before 2 years had different indications but demonstrated similar outcomes to those performed later. Early revisions had shorter surgical times, which could be attributed to differences in rTKA indication.

LEVEL OF EVIDENCE: III, retrospective observational analysis.