title: Dual-energy x-ray absorptiometry measurement and accuracy of bone mineral after unilateral total hip arthroplasty.
abstract: The standard technique for monitoring bone mineral in hip arthroplasty has been dual-energy x-ray absorptiometry (DEXA). The accuracy of DEXA in the cortical bone adjacent to femoral components has not been established. This study evaluated bone mineral in the cortical bone adjacent to the femoral component comparing DEXA and ashing. Seven pairs of human femora from postmortem donors with unilateral hip implants were examined. Twenty-eight ashed core specimens from both the medial and lateral sides were taken. Cortical bone loss was seen to be greater in the proximal and medial regions of the implanted femora. Dual-energy x-ray absorptiometry failed to show an acceptable level of accuracy compared with ash data (r = 0.56; P = .002). It did show relative patterns of bone loss. Bone loss was consistent with implant-induced stress shielding.
authors.affiliation: Bone and Joint Research Laboratory, Salt Lake City Veterans Administration Health Care System, Salt Lake City, UT, USA.
authors.forename: Roy D
authors.initials: RD
authors.lastname: Bloebaum
authors.forename: Derek W
authors.initials: DW
authors.lastname: Liau
authors.forename: D Kevin
authors.initials: DK
authors.lastname: Lester
authors.forename: Teri G
authors.initials: TG
authors.lastname: Rosenbaum
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D001344:Autopsy; D015519:Bone Density; D016001:Confidence Intervals; D005260:Female; D005269:Femur / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period