Rotating Platform versus Fixed-bearing Total Knees: An In Vitro Study of Wear

摘要: One of the assumed benefits mobile bearings is reduction UHMWPE wear. However, to date, such benefit has not been categorically proven. To test hypothesis that rotating platform total knee arthroplasty would have less wear than a fixed-bearing same design, this in vitro study compared and kinematics (which influence wear) one type with tibial components otherwise identical design. We tested four fixed bearing (FB) platforms (RP) on force control simulators using ISO standard inputs simulated soft tissue restraint for 6 million walking cycles. The internal/external rotations peaked just before toe off, reaching an average maximum 7° internal (tibial rotation) RP, 1.5 times FB, which at approximately 4.5° internally. Two RP specimens showed infrequent mostly temporary dislocations insert. rate FB averaged 8.14 ± 2.63 mg/million cycles 6.78 1.74 Both were very low rates most other implants similarly laboratory. concluded polyethylene was similar both designs.