The Impact of Concomitant Ipsilateral Knee Pain on Functional Outcomes in Total Ankle Arthroplasty

In end-stage ankle arthritis, little is known about the impact of concomitant knee pathology, including the impact of ipsilateral knee pain on total ankle arthroplasty (TAA) outcomes. The aim of this study was to determine the prevalence of ipsilateral preoperative knee pain in patients undergoing TAA and analyze its impact on patient-reported functional outcome measures (PROMs). A retrospective review was performed on the Vancouver End Stage Ankle Arthritis Database at a single institution. In total, 114 patients were studied, with patient demographics collected preoperatively, including the presence or absence of knee pain. Postoperative follow-up was performed at 5 years, primarily analyzing disease-specific PROMs, including the Ankle Osteoarthritis Score (AOS) and Ankle Arthritis Score (AAS). Multivariate mixed-effects linear regression models compared the scores between the groups. In total, 31 patients (27.2%) presented with concomitant ipsilateral knee pain. Despite more females in the knee pain group (64.5% vs 36.1%) there were no other significant differences at baseline between the knee pain and no knee pain groups in terms of demographics or baseline primary disease specific PROMs. At 5 years, the patients with knee pain had significantly worse AAS (37.9 +/- 23.8 vs 21.2 +/- 16.3, P = .004) and AOS total scores (38.1 +/- 24.1 vs 21.9 +/- 15.5, P = .005) compared with the no-knee pain group. Both groups improved significantly from baseline across all outcome measures; however, the magnitude of improvement was less in the knee pain group. Our study demonstrated that over one-quarter of patients with end-stage ankle arthritis undergoing TAA present with ipsilateral concomitant knee pain. If present, it is associated with worse functional outcomes at the 5-year mark. Further studies are needed to evaluate if knee pain influences complications, implant failure rates, and survival.