Measurement of polyethylene wear in cementless total hip arthroplasty.
We made a clinical study of polyethylene wear in 240 hips of 187 patients having primary total hip arthroplasties from 1989 to 1990, using uncemented Osteonics components, with a head size of 26 mm. We excluded cups with anteversion of over 20 degrees and measured linear wear by a new method using a digitiser and special software of our design. Follow-up was from two to five years (mean 4.3). The mean age at operation was 50.3 years, with more men than women (1.4:1). The mean linear wear per year was 0.15 mm; this did not increase with the longevity of the prosthesis (p = 0.54). In 59 hips showing evidence of osteolysis, the mean linear wear rate was significantly higher at 0.23 mm/year (p <0.001). The mean linear wear rate also correlated significantly with age at the time of operation (p = 0.008), but we found no significant correlations with body-weight, gender, aetiology of the disease, thickness of polyethylene, or cup position. Our new method of measurement is time-saving and reproducible. The results confirm the greater rate of linear wear of polyethylene in patients showing osteolysis and in those who are younger.
Shih
C H
CH
Chang Gung Medical College, Taiwan, Republic of China.
Lee
P C
PC
Chen
J H
JH
Tai
C L
CL
Chen
L F
LF
Wu
J S
JS
Chang
W H
WH
D000328:Adult; D000368:Aged; D001672:Biocompatible Materials; D001843:Bone Cements; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging; D006622:Hip Prosthesis / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010014:Osteolysis / Q000000981:diagnostic imaging; D011095:Polyethylenes; D011474:Prosthesis Design / Q000706:statistics & numerical data; D011475:Prosthesis Failure; D011859:Radiography; D015203:Reproducibility of Results; D013997:Time Factors
D001672:Biocompatible Materials; D001843:Bone Cements; D011095:Polyethylenes