A mobile-bearing total knee prosthesis compared with a fixed-bearing prosthesis

Abstract

Before proceeding to longer-term studies, we have studied the early clinical results of a new mobile-bearing total knee prosthesis in comparison with an established fixed-bearing device. Patients requiring bilateral knee replacement consented to have their operations under one anaesthetic using one of each prosthesis. They also agreed to accept the random choice of knee (right or left) and to remain ignorant as to which side had which implant. Outcomes were measured using the American Knee Society Score (AKSS), the Oxford Knee Score (OKS), and determination of the range of movement and pain scores before and at one year after operation. Preoperatively, there was no systematic difference between the right and left knees. One patient died in the perioperative period and one mobile-bearing prosthesis required early revision for dislocation of the meniscal component. At one year the mean AKSS, OKS and pain scores for the new device were slightly better (p < 0.025) than those for the fixed-bearing device. There was no difference in the range of movement. We believe that this is the first controlled, blinded trial to compare early function of a new knee prosthesis with that of a standard implant. It demonstrates a small but significant clinical advantage for the mobile-bearing design.

Functional outcome of PFC Sigma fixed and rotating-platform total knee arthroplasty. A prospective randomised controlled trial

“…The Cochrane Review [11] highlighted that there were only few comparative studies with acceptable methodological quality [4,5]. Inconsistent reporting did not allow for meta-analysis of the data.…”

“…Various studies have been published comparing mobile-and fixed-bearing knee replacements [4][5][6][7][8][9][10], but often different types and designs of prostheses were compared. The studies also differ in methodology, patient selection, operative technique and outcome measures.…”

Osteolysis in Well-functioning Fixed- and Mobile-bearing TKAs in Younger Patients

“…Numerous studies of prostheses with a fixed-bearing design report an incidence of osteolysis ranging from 0.3% to 27% at 4.3 to 15.5 years followup after TKA [1, 7, 10, 14, 17, 18, 26-28, 30-32, 34]. Other studies of prostheses with a mobilebearing design report an incidence ranging from 0% to 7% at 9 to 15 years followup [6,8,9,21,22,25,27,33,35]. However, all of these reports on the incidence of osteolysis present combined data for failed and/or well-functioning fixed-and mobile-bearing TKAs in an older population (C 65 years).…”

Comparison of Fixed and Mobile-Bearing Total Knee Arthroplasty at a Mean Follow-up of 116 Months

“…Furthermore, mobile-bearing total knee arthroplasty has not been shown to be clinically superior or more durable compared with fixed-bearing total knee arthroplasty [18][19][20][21] . However, some of these previous studies comparing mobile-bearing with fixed-bearing total knee arthroplasty Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work.…”

“…involved relatively short-term follow-up 19,20 . Therefore, the purpose of the present study was to prospectively compare the intermediate-term results of fixed-bearing and mobilebearing total knee arthroplasty at a mean of nearly ten years of follow-up.…”