No difference in mid-term survival and clinical outcome between patient-specific and conventional instrumented total knee arthroplasty: a randomized controlled trial

180 patients with knee osteoarthritis and scheduled for a primary unilateral total knee arthroplasty (TKA) were randomized to receive implant alignment with either with patient specific instrumentation (PSI) or conventional instrumentation (CI). Outcomes of interest included revision rate, the Knee Society Score (KSS), Oxford Knee Score (OKS), Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, pain on a Visual Analog Scale (VAS), the Euro-QoL-5D (EQ-5D) and EQ-5D on a VAS. In this follow up study, follow up was performed at 5 years. Results revealed no significant differences between the PSI and CI groups in KSS, OKS, WOMAC score, VAS pain, EQ-5D or EQ-5D VAS at 5 years. Revision surgery was reported in one case in the PSI group and three cases in the CI group.