Subsequent Knee Arthroplasty Does Not Influence Patient-Reported Outcomes Following Lumbar Fusion.

Study DesignRetrospective Cohort Study.ObjectivesThe impact of knee arthritis and early total knee arthroplasty (TKA) on lumbar fusion recovery remains underexplored. This study aimed to identify demographic differences between lumbar fusion patients that had subsequent TKA and patients with OA without TKA, assess perioperative differences; and compare patient-reported outcomes (PROMs).MethodsRetrospective review was performed at one tertiary care center (2016-2025). Patients undergoing lumbar fusion with concurrent knee osteoarthritis and had 1-year Oswestry Disability Index (ODI) scores were included. Patients with prior joint arthroplasty or concomitant hip arthritis were excluded. Kellgren-Lawrence grading (KL) was collected via chart review and radiographs. Cohorts were stratified by future arthroplasty status and compared using bivariate analysis, with P set at <0.05.Results148 patients were included (OA-104; TKA-44). Overall, there were no significant demographic differences between groups (Age: 64.9 years; 54.1% female). Perioperatively, patients who eventually underwent TKA had higher KL grading at the time of surgery (Grade 4: 56.8% vs 20.2%;