Study of learning curve of fixed bearing unicompartmental knee arthroplasty in the treatment of osteoarthritis

ZHAO Jin-wei; HUANG Ming-li; SUN Meng-shuai; GAO Guang-ling; JIANG Hong-jiang; JU Chang-jun

doi:10.3969/j.issn.2095-252X.2025.04.005

Abstract：Objective To investigate the learning curve characteristics of fixed bearing unicompartmental knee arthroplasty(FB-UKA)in the treatment of osteoarthritis.Methods A retrospective analysis of 100 patients with knee osteoarthritis who underwent FB-UKA completed by the same group of surgeons from June 2021 to December 2022 was performed.Learning curve was formulated according to the Cumulative Sum Analysis Method(CUSUM).All were divided into Ascending Group(29 cases)and Stationary Group(71 cases).We recorded and compared the duration of surgery,length of surgical incision,angle of prosthesis placement,visual analogue scale(VAS)and Hospital for Special Surgery(HSS)scores of knee at 7 days,1 month and 1 year after surgery,forgotten joint scores(FJS)at 6 months and 1 year after surgery,and the occurrence of postoperative complications of the two groups.Results The patients in both groups were followed up for at least 12 months without serious complications such as infection,prosthesis displacement and periprosthetic fracture.In the Stationary Group,the operation time,length of surgical incision,FJS at 6 months after operation,VAS score and HSS score at 7 days and 1 month after operation were better than those in the Ascending Group(P<0.05);there was no statistically significant difference in complication rate,VAS,HSS and FJS score at 1 year after operation between the two groups(P>0.05).The postoperative imaging measurements:compared with the Ascending Group,the FCA of Stationary Group kept larger varus angles and the differences were statistically significant(P<0.001).But the FSA,TCA and TSA of the two groups were not statistically significant when compared with each other(all P>0.05).Conclusions The learning curve ascending part of FB-UKA for osteoarthritis of the knee includes about 29 cases,and the surgeons and assistants need to continuously summarize and improve the preoperative planning and intraoperative operation skills to shorten the operation time,reduce the complications,and ultimately improve the clinical efficacy of the operation.