Tf. Mcgovern et al., CORTICAL BONE-DENSITY OF THE PROXIMAL FEMUR FOLLOWING CEMENTLESS TOTAL HIP-ARTHROPLASTY, Clinical orthopaedics and related research, (306), 1994, pp. 145-154
A quantitative analysis of cortical bone remodeling was performed usin
g calibrated videodensitometry. Six femoral specimens were obtained at
autopsy from 3 patients treated with unilateral porous coated femoral
components in situ > 6 years. Transverse thick sections of the remode
led and normal femora were obtained. Slab radiographs of the sections
were analyzed using computer assisted videodensitometry. Detailed dens
ity plots of each section were constructed and the average density in
defined quadrants was recorded. The density plots were also used to me
asure the cortical bone area present on each section. Two cases showed
a gradient of resorptive remodeling change with the greatest density
loss noted medially at the proximal levels (33% and 36%). The 3rd case
had porotic cortical bone in the normal femur and demonstrated a diff
erent remodeling pattern, with the greatest average resorptive change
(57%) measured in the midstem region. Changes in cortical area were va
riable: 1 showed cortical thickening in the midstem region; another ha
d decreased cortical area in the entire region adjacent to the porous
coating; and the 3rd had decreased cortical area proximally, with mini
mal changes noted in the distal levels. The volumetric densities measu
red by videodensitometry were compared with area densities measured wi
th dual energy xray absorptiometry. There was a strong linear correlat
ion between the 2 methods (r(2) = 0.80).