RADIOGRAPHIC MEASUREMENT OF WEAR IN 5 COHORTS OF PATIENTS OBSERVED FOR 5 TO 22 YEARS

Standardized wear measurements using a tablet digitizer were made on l ong-term serial radiographs for 5 cohorts of total hip replacements to determine any differences in acetabular component polyethylene wear r ates. The 5 groups included 4 cemented acetabular component series and 1 cementless acetabular component series. Comparing the rates of line ar wear for the 5 groups, 22-mm-head components had similar wear when compared with the 28-mm-head components, both cemented and uncemented, and volumetric wear rates were greater for the cemented 28-mm-head co mponents than for the 22-mm-head components. Although molded 22-mm-hea d components had less wear than the machined 22-mm-head components, th ere was no statistically significant difference between the 2. The unc emented metal-backed component with 28-mm-head articulation showed no accelerated wear when compared with the cemented metal-backed componen ts at a shorter 5-year followup. The constant variable in all series w as a cemented femoral component.