Medial pivot versus (cam post) posterior stabilised total knee arthroplasty, systematic review and meta-analysis of 3837 knees

Abstract

In the current literature, there is no consensus as to whether the medial pivot (MP) or posterior-stabilised (PS) knee provides the best result for the patient in the context of post-operative range of motion (ROM) and patient reported outcome measures (PROMs). The aim of this systematic review is to provide this equipoise with some clarity. We conducted this study following both the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement (PRISMA) and the Cochrane Handbook for systematic reviews and meta-analysis. Studies comparing the MP and PS knees from all regions and written in any language were included. Twenty- one studies were included in this meta-analysis. They were prepared and analysed using Review Manager V5.0 [Computer Program] (RevMan5). We calculated the risk ratio to measure the treatment effect, taking the heterogeneity of the studies into consideration. Random-effect models were also utilised. MP knees were found to have a significant advantage over PS knees in terms of WOMAC score at the midterm follow up, and insignificant advantages over PS knees in terms of ROM and FJS at one and two years follow- up. Additionally, the PS knees demonstrated an in significantly higher Knee Society Score (KSS) at short and midterm follow up. In terms of ROM, KSS, OKS and FJS this meta-analysis suggests a non-significant advantages for the MP knee compared with the PS prothesis in the short term. The MP implant also showed a significantly superior WOMAC score at short-term follow-up. An extended follow-up period is required to evaluate whether the MP knee is superior than the PS in the long-term.

Medial pivot design does not yield superior results compared to posterior-stabilised total knee arthroplasty: a systematic review and meta-analysis of randomised control trials

“…Our observations showed no clear advantage for any of the groups regarding all these functional scoring algorithms. This finding corroborates with all four previous meta‐analyses but only for KSS [9, 24, 26, 38]. Contrary to our findings, two reviews reported significantly better WOMAC score for the MP knees [9, 24].…”

“…This finding corroborates with all four previous meta‐analyses but only for KSS [9, 24, 26, 38]. Contrary to our findings, two reviews reported significantly better WOMAC score for the MP knees [9, 24]. However, the mean difference value was less than the minimum clinically important difference (MCID) of 15 points [10].…”

“…Nisar et al in a previously published meta-analysis noted comparable ROM between the two implants [26]. Similarly, three other meta-analyses failed to prove any advantage of MP for ROM [9,24,38]. Our study found better ROM for MP knees at the irst 2 years postoperatively but the results did not support any statistical superiority, which is in line with the aforementioned studies.…”