In vivo linear penetration in total hip arthroplasty (THA) exhibits similar values for 28mm and 32mm femoral head diameter with considerable variations between and within the studies. It indicates factors other than femoral head diameter influence polyethylene wear. This study is intended to test the effect of patient׳s individual geometry of musculoskeletal system, acetabular cup orientation, and radius of femoral head on wear. Variation in patient׳s musculoskeletal geometry and acetabular cup placement is evaluated in two groups of patients implanted with 28mm and 32mm THA heads. Linear wear rate estimated by mathematical model is 0.165-0.185mm/year and 0.157-0.205mm/year for 28 and 32mm THA heads, respectively. Simulations show little influence femoral head size has on the estimated annual wear rate. Predicted annual linear wear depends mostly on the abduction angle of the acetabular cup and individual geometry of the musculoskeletal system of the hip, with the latter having the greatest affect on variation in linear wear rate.

• MeSH
• Acetabulum anatomy & histology   physiology   MeSH
• Femur Head anatomy & histology   physiology   MeSH
• Muscle, Skeletal anatomy & histology   physiology   MeSH
• Hip Prosthesis * MeSH
• Middle Aged MeSH
• Humans MeSH
• Arthroplasty, Replacement, Hip * MeSH
• Patient-Specific Modeling MeSH
• Polyethylene MeSH
• Aged MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

We analysed data from 155 revisions of identical cementless hip prostheses to determine the influence of patient-, implant- and surgery-related factors on the polyethylene wear rate and size of periprosthetic osteolysis (OL). This was calculated by logistic regression analysis. Factors associated with an increased/decreased wear rate included position of the cup relative to Kohler's line, increase in abduction angle of the cup, traumatic and inflammatory arthritis as a primary diagnosis, and patient height. Severe acetabular bone defects were predicted by an increased wear rate (odds ratio, OR = 5.782 for wear rate above 200 mm(3)/y), and increased height of the patient (OR = 0.905 per each centimetre). Predictors of severe bone defects in the femur were the increased wear rate (OR = 3.479 for wear rate above 200 mm(3)/y) and placement of the cup outside of the true acetabulum (OR = 3.292). Variables related to surgical technique were the most predictive of polyethylene wear rate.

• MeSH
• Acetabulum surgery   pathology   MeSH
• Adult MeSH
• Femur Head surgery   pathology   MeSH
• Hip Joint surgery   physiopathology   MeSH
• Hip Prosthesis MeSH
• Middle Aged MeSH
• Humans MeSH
• Logistic Models MeSH
• Stress, Mechanical MeSH
• Arthroplasty, Replacement, Hip adverse effects   MeSH
• Odds Ratio MeSH
• Osteolysis epidemiology   etiology   pathology   MeSH
• Polyethylene MeSH
• Prosthesis Design MeSH
• Reoperation MeSH
• Risk Factors MeSH
• Prosthesis Failure MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH