Meta-analyses showed no clinical ly relevant differences in terms of revision rates , clinical outcome scores or patient-reported outcome measures between MB and FB TKRs .
It appears that theoretical assumptions of superiority of MB over FB TKR are not borne out in clinical practice
Mobile-bearing ( MB ) total knee replacement ( TKR ) was introduced to reduce the risk of aseptic loosening and wear of polyethylene inserts .
However , no consistent clinical advantages of mobile- over fixed-bearing ( FB ) TKR have been found .
In this study we evaluated whether mobile bearings have an advantage over fixed bearings with regard to revision rates and clinical outcome scores .
Furthermore , we determined which modifying variables affected the outcome .
Fixed-bearing versus mobile-bearing total knee arthroplasty: a prospective randomised, clinical and radiological study with mid-term results at 7 years.
Mobile-bearing ( MB ) total knee arthroplasty ( TKA ) was developed as an alternative to the established fixed-bearing ( FB ) design because of theoretical advantages . Short-term studies comparing these design s have not shown any differences in clinical and radiographic results . We compared the results at 7 years of a r and omised study of patients undergoing TKA using either a FB or a MB variant of the same prosthesis . Fifty-two patients ( 52 knees ) with an average age of 70 years received a FB posterior-stabilized prosthesis , and 50 patients ( 52 knees ) with an average age of 72 years , a MB prosthesis .  All implants were cemented and the patella was routinely resurfaced . Preoperatively , there were no differences between the two groups , and surgical procedure and postoperative protocol were the same for both . At an average follow-up of 7.1 years , no significant differences of FB over MB design could be demonstrated with respect to the American Knee Society score ( AKSS ) , pain score , a question naire of general health ( SF-12 score ) , range of motion ( ROM ) , or complication rates . Radiographs showed no significant difference in prosthetic alignment or evidence of loosening . Two knees with a MB design required reoperation , one for persistent joint stiffness and another to treat septic loosening . One patient with a MB prosthesis with signs of tibial component loosening was asymptomatic . We conclude that at mid-term follow-up there is no evidence to prove the superiority of MB over FB TKA with regard to the clinical and radiographic results
Meta-analyses showed no clinical ly relevant differences in terms of revision rates , clinical outcome scores or patient-reported outcome measures between MB and FB TKRs .
It appears that theoretical assumptions of superiority of MB over FB TKR are not borne out in clinical practice
Mobile-bearing ( MB ) total knee replacement ( TKR ) was introduced to reduce the risk of aseptic loosening and wear of polyethylene inserts .
However , no consistent clinical advantages of mobile- over fixed-bearing ( FB ) TKR have been found .
In this study we evaluated whether mobile bearings have an advantage over fixed bearings with regard to revision rates and clinical outcome scores .
Furthermore , we determined which modifying variables affected the outcome .