Wear-pattern analysis in retrieved tibial inserts of mobile-bearing and fixed-bearing total knee prostheses.
Components from 73 failed knee replacements (TKRs) consisting of rotating-platform, mobile-bearing and fixed-bearing implants were examined to assess the patterns of wear. The patterns were divided into low-grade (burnishing, abrasion and cold flow) and high-grade (scratching, pitting/metal embedding and delamination) to assess the severity of the wear of polyethylene. The rotating-platform group had a higher incidence of low-grade wear on the upper surface compared with the fixed-bearing group. By contrast, high-grade wear comprising scratching, pitting and third-body embedding was seen on the lower surface. Linear regression analysis showed a significant correlation of the wear scores between the upper and lower surfaces of the tibial insert (R(2) = 0.29, p = 0.04) for the rotating-platform group, but no significant correlation was found for the fixed-bearing counterpart. This suggests that high-grade wear patterns on the upper surface are reduced with the rotating-platform design. However, the incidence of burnishing, pitting/third-body embedding and scratching wear patterns on the lower surface was higher compared with that in the fixed-bearing knee.
Lu
Y-C
YC
Mackay Memorial Hospital, Taipei, 10449 Taiwan.
Huang
C-H
CH
Chang
T-K
TK
Ho
F-Y
FY
Cheng
C-K
CK
Huang
C-H
CH
D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods; D019544:Equipment Failure Analysis / Q000379:methods; D005260:Female; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D013314:Stress, Mechanical; D013977:Tibia / Q000601:surgery*