Comparison of Single‐Radius with Multiple‐Radius Femur in Total Knee Arthroplasty: A Meta‐Analysis of Prospective Randomized Controlled Trials

Abstract

Background Whether there was clinical superiority for the single‐radius prosthesis over the multi‐radius prothesis in total knee arthroplasty (TKA) still remains to be clarified. We updated a meta‐analysis including prospective randomized controlled trials (RCTs) to compare the clinical prognosis of patients receiving single‐radius TKA (SR‐TKA) or multi‐radius TKA (MR‐TKA). Methods We searched the databases of PubMed, Web of Science, EMBASE, Cochrane Library, MEDLINE for eligible RCTs. Two reviewers evaluated the study quality according to the Risk of Bias tool of the Cochrane Library and extracted the data in studies individually. The extracted data included the baseline data and clinical outcome. The baseline data include the author's name, country, and year of included studies, the name of knee prosthesis used in studies, sample size, follow‐up time, and BMI of patients. The clinical data comprised primary indicators including postoperative knee range of motion (ROM), sit‐to‐stand rest, severe postoperative scorings, such as visual analog scale (VAS), American Knee Society knee score (AKS), Oxford knee scoring (OKS), and SF‐36 Quality of Life Scale, as well as various secondary indicators of complications including anterior knee pain, postoperative infection, aseptic prosthesis loosening, and prosthesis revision. The data analysis was performed using Review Manager 5.3 software and STATA 12.0. The sensitivity analysis was performed using STATA 12.0. Results A total of 13 RCTs, along with 1720 patients and 1726 knees, were finally included in our present meta‐analysis. We found that patients in SR‐TKA group performed better in the sit‐to‐stand test (OR = 1.89, 95% CI: 1.05–3.41, p = 0.03) and satisfaction evaluation (OR = 3.27, 95% CI: 1.42–7.53, p = 0.005), which were only evaluated in two included RCTs. While no significant difference was found between SR‐TKA and MR‐TKA groups in terms of postoperative ROM, VAS scoring, AKS scoring, SF‐36 scoring, OKS scoring, and various complications including anterior knee pain, postoperative infection, aseptic prosthesis loosening, and prosthesis revision. Conclusion In conclusion, our present meta‐analysis indicated that SR implants were noninferior to MR implants in TKA, and SR implants could be an alternative choice over MR implants, since patients after SR‐TKA felt more satisfied and performed better in the sit‐to‐stand test, with no significant difference in complications between SR‐TKA and MR‐TKA groups. While more relevant clinical trials with long‐term follow‐up time and specific tests evaluating the function of knee extension mechanism should be carried out to further investigate the clinical performance of SR implants.

Asymmetry of Posterior Condyles in Resection Plane and Axial Curvature for Total Knee Arthroplasty

“…Accurate sizing and bone‐implant matching of prosthetic components are vital factors for the success and long‐term survival of total knee arthroplasty (TKA) 1 , 2 , 3 , 4 , and designs of currently available prostheses have been developed based on the natural geometric and kinematic characteristics of the knee.…”

“…The size and surface of the femoral posterior condyles comprises the joint surface during the flexion phase of the knee joint motion 4 . Throughout flexion, the normal knee exhibits a medial pivot motion with external rotation of the femur relative to the tibia 5 , 6 .…”

“…Morphometric asymmetries are designed based on several temporary prostheses (e.g. Journey II; Smith & Nephew) to improve knee motion after TKA 4 . However, few studies have described the asymmetries of the coronal radius of the posterior condyle.…”