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Torsional strength estimates of femoral diaphyses with endosteal lytic lesions: Dual‐energy x‐ray absorptiometry study
Author(s) -
Robertson Douglas D.,
Beck Thomas J.,
Chan Brandon W.,
Scott William W.,
Sharma Gulshan B.,
Maloney William J.
Publication year - 2007
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.20419
Subject(s) - cadaveric spasm , dual energy , lesion , cortical bone , medicine , femur , nuclear medicine , x ray , dual energy x ray absorptiometry , anatomy , materials science , bone mineral , osteoporosis , surgery , pathology , physics , quantum mechanics
Pathologic fracture is a significant problem for individuals with metastatic bone disease. Current guidelines for prophylactic internal fixation are neither reliable nor easily applied. The purpose of this study was to validate dual‐energy X‐ray absorptiometry (DXA) as an accurate method for estimating torsional bone strength of diaphyseal bone with endosteal lytic lesions. Endosteal lesions of varying sizes were simulated in the diaphyses of 12 adult cadaveric femurs. Unaltered contralateral femurs served as matched controls. Machined lesions ranged from 3 to 6.5 cm in length, 1 to 3 cm in width, 15 to 48 cm 2 in elliptical area, with 10% to 100% removal of the cortical thickness. Morphology and density data obtained from DXA images were used to estimate torsional strength. All femora were mechanically tested to failure in torsion. Physically measured torsional strength was not significantly correlated to lesion elliptical area ( r = 0.542, p > 0.05) or percentage cortical thickness removed ( r = 0.257, p > 0.05). Measured torsional strength was significantly correlated to DXA‐based torsional strength estimates ( r = 0.855, p < 0.01). Lesion size alone did not correlate with the strength of bones with simulated endosteal lytic lesions. In contrast, calculations based on DXA (morphology, density) did correlate with torsional strength. This is the first step in the development of a DXA‐based tool for objectively estimating bone strength in the presence of endosteal lytic lesions. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1343–1350, 2007