Robotic arm–assisted cementless cruciate retaining total knee arthroplasty: The Hong Kong experience

Abstract

Introduction: Robotic arm technology improves bone cut precision and facilitates cementless fixation in total knee arthroplasty (TKA). While the China Food and Health Administration (CFDA) has yet to approve its application in Mainland, Hong Kong is the first region to report on early results in Chinese patients. Materials and Methods: We retrospectively analysed all robotic arm assisted TKAs performed between January 2019 and May 2020 at a tertiary hospital. All operations were performed using Mako TKA 3.0 application with cementless cruciate retaining implants. Complications, Knee Society knee score (KSKS) and Knee Society functional assessment (KSFA) were analysed. Postoperative mechanical axes were independently assessed by two observers on standing long films. Results: In total, 77 knees from 64 patients were included with mean follow-up of 9 months. Mean age was 63 years and 29 were male. Mean preoperative alignment was 10.6° varus. Mean KSKS improved significantly from 53 before surgery to 91 at 6 months (p<0.001) and 93 at 1 year (p<0.001) after surgery, while KSFA improved from 47 before surgery to 66 at 6 months (p<0.001) and 71 at 1 year (p<0.001) after surgery. There were no complications apart from one tibial pin site infection treated by debridement. Mean mechanical alignment after surgery was 0.1° varus with 98% within 4° of neutral and demonstrated moderate correlation with intraoperative plans (R=0.41, p<0.001). All implants were well fixed at latest follow-up with no sign of loosening. Discussion and Conclusions: This is the first study to report on early results of robotic TKA in Chinese patients. Early clinical and radiological results are promising