Improved early clinical outcomes of RP/PS mobile-bearing total knee arthroplasties.
The rotating-platform posterior-stabilized (RP/PS) prosthesis was developed to take advantage of the benefits of the traditional RP mobile-bearing system and the posterior-stabilized design. This nonconsecutive cohort study compared the clinical outcomes of TKAs performed using a RP/PS mobile system or a floating-platform (FP) system. The clinical outcomes of 93 TKAs with a RP/PS prosthesis were compared with the same number of TKAs with a FP mobile-bearing prosthesis at 6, 12, and 24 months after surgery. Clinical outcomes differed between the FP and RP/PS groups as a function of length of followup. In the FP group, most outcomes peaked at 12 months and then deteriorated, whereas in the RP/PS group, outcomes stabilized or continued to improve between 12 and 24 months. The RP/PS group had greater maximum flexion throughout followup and better clinical outcomes 24 months after surgery. Patient satisfaction was superior in the RP/RS group. This study suggests the RP/PS prosthesis provides better functional outcomes, including greater maximum flexion and better patient satisfaction. We propose the RP/PS mobile-bearing system is a more attractive option than the FP mobile-bearing system for patient populations of elderly women similar to patients enrolled in our study.


METHODS
Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Kim
Tae Kyun
TK
Joint Reconstruction Center, Seoul National University Bundang Hospital, 300 Gumidong, Bundangu, Seongnam-si, Gyunggido, 463-707, Korea. osktk@snubh.org
Cho
Hyung Joon
HJ
Kang
Yeon Gwi
YG
Kim
Sung Ju
SJ
Chang
Chong Bum
CB
D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000517:prevention & control*; D007720:Knee Prosthesis; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011336:Probability; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular / Q000502:physiology; D018570:Risk Assessment; D013314:Stress, Mechanical; D013997:Time Factors; D016896:Treatment Outcome; D016474:Weight-Bearing