Osteolysis in well-functioning fixed- and mobile-bearing TKAs in younger patients.
BACKGROUND
Periprosthetic osteolysis is an increasingly prevalent complication of TKA. To reduce the polyethylene wear and periprosthetic osteolysis, particularly in young patients, the design of the contemporary fixed-bearing TKAs has been modified and mobile-bearing TKAs have been introduced.


OBJECTIVE
We asked whether the prevalence of osteolysis would be less in well-functioning mobile-bearing TKAs than in well-functioning contemporary fixed-bearing TKAs in young patients.


METHODS
We compared 488 patients (894 knees) who received fixed-bearing knee prostheses with 445 patients (816 knees) who received mobile-bearing knee prostheses. There were 187 men and 301 women (mean age, 58.6 years; range, 33-65 years) in the fixed-bearing group and 167 men and 278 women (mean age, 55.7 years; range, 33-65 years) in the mobile-bearing group. The mean followup was 12.6 years (range, 10-17 years) in the fixed-bearing group and 12.9 years (range, 10-17 years) in the mobile-bearing group.


RESULTS
The incidence of osteolysis was 1.6% (14 of 894 knees) in the fixed-bearing group and 2.2% (18 of 816 knees) in the mobile-bearing group at the final review. The mean postoperative Knee Society knee and function scores were 92.9 points and 83.5 points, respectively, in the fixed-bearing group and 90.7 points and 83.8 points, respectively, in the mobile-bearing group. The revision rates were 3.7% (33 of 894 knees) in the fixed-bearing group and 2.7% (22 of 816 knees) in the mobile-bearing group.


CONCLUSIONS
We found the incidence of osteolysis, rate of revision, and implant survivorship were similar between fixed-bearing and mobile-bearing TKAs in younger patients.
Kim
Young-Hoo
YH
The Joint Replacement Center of Korea, Ewha Womans University School of Medicine, 911-1, MokDong, YangChun-Gu, Seoul, 158-710, Korea. younghookim@ewha.ac.kr
Choi
Yoowang
Y
Kim
Jun-Shik
JS
D000328:Adult; D000367:Age Factors; D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000295:instrumentation; D005260:Female; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D010014:Osteolysis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D015995:Prevalence; D011474:Prosthesis Design; D011475:Prosthesis Failure; D020127:Recovery of Function; D056910:Republic of Korea; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome