Short-term clinical outcomes of robotic-assisted unicompartmentalknee arthroplasty

Objective To assess the short-term clinical outcomes of robotic-assisted unicompartmental knee arthroplasty (UKA). Methods Ten patients who underwent robotic-assisted UKA treatment in Shanghai Jiao Tong University Affiliated Sixth People’s Hospital from September 2016 to December 2016 were followed up. Inclusion criteria: medial unicompartmental osteoarthritis; without severe varus deformity; integrity of anterior and posterior cruciate ligaments. There were two males and eight females, with a mean age of (65±6) years. All the procedures were performed with MAKO RIO robotic-assisted surgical system and RESTORIS MCK unicompartmental knee prosthesis (STRYKER MAKO Surgical, USA). Relevant clinical data, including patients’ preoperative and postoperative imaging data, daily activities, Knee Society scores, and the forgotten joint score were recorded and analyzed. Statistical analysis was done with paired-samples t test. Results All the patients were followed-up at an average time of (22.2±1.5) months. The Knee Society clinical score improved from (58.8±13.7) preoperatively to (96.0±2.8)at the last follow-up, and the functional score improved from (59.5±19.0)preoperatively to (88.5±15.2) at the last follow-up. The range of motion of the knee joint increased from (90.7±6.1) ° preoperatively to (127.9±7.2) °at the last follow-up (t=-8.588, P<0.01). The forgotten joint score was (83±24)at the latest follow-up visit, indicating that patients had feelings close to their native knee joint. The imaging findings of the 10 patients were good. The varus deformity of the knee was corrected from (8.8±3.5) ° before surgery to (4.0±2.0) °at the last follow-up (t=7.294, P<0.01). The alignment of the prosthesis was optimal and there was no radiolucent line. There was no adverse event such as prosthesis subsidence or loosening of the prosthesis. No patient had secondary osteoarthritis in the lateral compartment. Conclusion Robotic-assisted UKA can provide optimal prosthesis alignment and soft tissue balance, insuring good functional outcomes and native knee joint feelings for patients, which shows excellent short-term clinical outcomes; further follow-up is needed for the long-term clinical benefits. Key words: Osteoarthritis; Arthroplasty, replacement, knee; Robotic surgical procedures