Outcomes of Total Knee Arthroplasty in Patients With a Prior Contralateral Above-Knee Amputation: A Retrospective Review of a Nationwide Database

BACKGROUND: Total knee arthroplasty (TKA) in patients with a prior contralateral above-knee amputation (AKA) is uncommon, with limited literature describing the outcomes. We used a national database to compare the outcomes of primary TKA in above-knee amputees and nonamputees. METHODS: A retrospective review of TKA recipients with prior contralateral AKA was performed using the PearlDiver database from 2010 to Q2 of 2019. Subjects and outcomes were identified using Current Procedural Terminology and International Classification of Diseases, Ninth and Tenth Revisions (ICD-9 and ICD-10). Patients were identified and matched at a 1-to-3 ratio with nonamputee (AKA group = 931; nonamputee group = 2792 patients). Perioperative outcomes and length of stay (LOS) were compared at 90 days, 6 months, 1 year, 3 years, and 5 years after TKA. RESULTS: The AKA group had a longer LOS (5.19 vs 3.00, P < .001) and higher overall complications rate (33.8% vs 11.8%). At all studied time intervals, the AKA group had higher periprosthetic infections, revisions, mechanical complications, and respiratory failure (P < .001), as well as surgical site infection, pneumonia, and blood transfusion (P < .05). CONCLUSION: Our study revealed higher overall complications and longer LOS among TKAs in prior contralateral above-knee amputees. Surgeons should evaluate the risks and benefits of performing a TKA on patients with prior contralateral AKA.