title: Bone metabolism analyzed by PET and DXA following revision THA using a distally fixed stem. A pilot study.
abstract: In a pilot study we analyzed bone remodeling using ¹⁸F-PET (positron emission tomography) scanning or DXA (dual-energy x-ray absorptiometry) in 3 patient groups, one with a loose femoral stem and 2 after revision using a modular stem (MP). In loose implants (group 1), bone formation activity compared to the contralateral healthy femur was 261 %. In the proximal part of the femur bone formation was increased by 253 % one week after revision (group 2) and did not normalize within 1 year. In the distal region it decreased to normal after one year. In the second revision group DXA showed decreased bone mineral density at 6 and 24 months (group 3). The PET technique provided evidence of bone healing despite osteolysis and prosthetic loosening which continued after revision. Decreasing BMD after revision in the third group is multifactorial, but suggests that despite intensive bone formation resorption was still higher.
authors.affiliation: Department of Orthopaedics, Gävle Hospital and Centre for Research & Development, Uppsala University/County Council of Gävleborg, Sweden. gosta.ullmark@lg.se
authors.forename: Gösta
authors.initials: G
authors.lastname: Ullmark
authors.forename: Johan
authors.initials: J
authors.lastname: Kärrholm
authors.forename: Jens
authors.initials: J
authors.lastname: Sörensen
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects; D015519:Bone Density; D016723:Bone Remodeling / Q000502:physiology*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010014:Osteolysis / Q000209:etiology / Q000378:metabolism* / Q000601:surgery; D010865:Pilot Projects; D049268:Positron-Emission Tomography; D011475:Prosthesis Failure; D012086:Reoperation