Are Midterm Patient-Reported Outcome Measures Between Rotating-Platform Mobile-Bearing Prosthesis and Medial-Pivot Prosthesis Different? A Minimum of 5-Year Follow-Up Study.
Both rotating-platform (RP) mobile-bearing and medial-pivot (MP) fixed-bearing prostheses allow axial femorotibial rotation using a highly conforming polyethylene insert. However, limited comparative data are available between the 2 designs. This study was performed to compare the midterm clinical outcomes and patient-reported outcome measures (PROMs) of RP and MP prostheses.



We retrospectively reviewed the records of 52 total knee arthroplasties using RP mobile-bearing prosthesis and 49 total knee arthroplasties using MP fixed prosthesis with a minimum follow-up period of 5 years. Clinical and radiological outcomes, failure rates, and PROMs, including the Western Ontario and McMaster Universities Osteoarthritis Index score and satisfaction, were compared.



There was no difference in clinical or radiographic outcomes (P > .1 for all comparisons), with the exception of the larger flexion contracture (FC) in the MP group (0.3° in RP vs 2.3° in MP, P < .01). No failure in either group was recorded during the study period. PROMs were comparable (P > .1 in all comparisons), with the exception of higher satisfactions in the RP group while performing light household duties (P < .01) and leisure or recreational activities (P = .014) in patients without FC.



The midterm clinical results with both the RP mobile-bearing and MP fixed-bearing prostheses were satisfactory. Although both prostheses provided comparable PROMs, patients with an RP prosthesis were more satisfied than those with an MP prosthesis for highly demanding activities that are strongly associated with the presence of postoperative FC.
Department of Orthopaedic Surgery, St. Paul's Hospital, Seoul, Korea; Department of Orthopaedic Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Nam Y
NY
Choi
Department of Orthopaedic Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea; Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, Seoul, Korea.
Yong
Y
In
Department of Orthopaedic Surgery, St. Paul's Hospital, Seoul, Korea.
Jae-Ho
JH
Bae
Department of Orthopaedic Surgery, St. Paul's Hospital, Seoul, Korea.
Jung-Hoon
JH
Do
Department of Orthopaedic Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Seung J
SJ
Chung
Department of Orthopaedic Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea; Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, Seoul, Korea.
In J
IJ
Koh
D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D000071066:Patient Reported Outcome Measures; D020959:Polyethylene; D011474:Prosthesis Design; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies
D020959:Polyethylene
medial-pivot prosthesis; midterm; patient-reported outcome measures; rotating-platform mobile-bearing prosthesis; total knee arthroplasty