Clinical results and 12-year survivorship of the Physica ZUK unicompartmental knee replacement.

Abstract

BACKGROUND\nThe Physica ZUK is a fixed bearing unicompartmental knee replacement. The purpose of this prospective cohort study was to determine the mid-term clinical outcomes and survivorship of the Physica ZUK.\n\n\nMETHODS\nFrom 2005 to 2017 a total of 466 Physica ZUK prostheses were implanted in 398 patients by a single surgeon. The series consisted of 452 medial and 14 lateral unicompartmental knee arthroplasties (UKAs). Three hundred and sixty-seven medial UKAs with a minimum follow-up of two years (median 5.4\u202fyears) and 14 lateral UKAs with a minimum follow-up of 18\u202fmonths (median 5.3\u202fyears) were analysed using the Knee Society Knee Score (KS-KS) and Function Score (KS-FS) at latest follow-up. Kaplan Meier survivorship analysis was performed with implant revision as the end point.\n\n\nRESULTS\nMean age at the time of surgery was 67 (range 42-88) and 58 (47-69) years for patients undergoing medial and lateral UKA respectively. For medial UKAs the KS-KS and KS-FS improved significantly compared to the pre-operative values from 53.6 and 54.0 to 93.4 and 91.0 respectively (p\u202f=\u202f0.0001). For lateral UKAs the KS-KS and KS-FS improved significantly from 46.4 and 48.7 to 91.3 and 93.1 respectively (p\u202f=\u202f0.0001). Six cases of medial UKA were revised to total knee arthroplasty. Medial implant survivorship was 97.9% (95% confidence intervals, 95.6-99.0%) at both five and 10\u202fyears. No lateral implants were revised.\n\n\nCONCLUSION\nThis prospective cohort study shows encouraging short to mid-term clinical results and survivorship for the Physica ZUK unicompartmental knee replacement.