title: Quantitative CT-assisted osteodensitometry of femoral adaptive bone remodelling after uncemented total hip arthroplasty.
abstract: The aim of this prospective study was to measure bone density changes and to assess adaptive bone remodelling after uncemented total hip arthroplasty with a taper-design femoral component using quantitative computer-tomography-assisted osteodensitometry. This method is able to differentiate cortical and cancellous bone structures. Twenty-seven consecutive patients (29 hips) with degenerative joint disease were enrolled in the study. Serial clinical, radiological and CT-osteodensitometry assessments were performed after the index operation. At the 2-year follow-up, the clinical outcome was rated satisfactory in all hips. The radiological assessment showed signs of osteointegration and stable fixation of all cups and stems. We observed a -17% decrease of cortical bone density and -22% decrease of cancellous bone density in the greater trochanter and femoral neck region. Cortical and cancellous bone density decrease at the level of the lesser trochanter was -9% and respectively -4%. We observed small changes of cortical bone density in the diaphyseal regions; in contrast, cancellous bone density increased (range 6% to 27%) in the diaphyseal regions. Overall, a trend of bone density recovery was observed throughout the follow-up period. Periprosthetic bone density changes at the 2-year follow-up are suggestive of stable osteointegration with proximal femoral diaphysis load transfer and moderate metaphyseal stress-shielding.
authors.affiliation: Department of Orthopaedic Surgery, University of Auckland, Auckland, New Zealand. r.pitto@auckland.ac.nz
authors.forename: Rocco P
authors.initials: RP
authors.lastname: Pitto
authors.forename: Aknaksha
authors.initials: A
authors.lastname: Bhargava
authors.forename: Salil
authors.initials: S
authors.lastname: Pandit
authors.forename: Cameron
authors.initials: C
authors.lastname: Walker
authors.forename: Jacob T
authors.initials: JT
authors.lastname: Munro
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods; D015519:Bone Density; D016723:Bone Remodeling; D005260:Female; D005269:Femur / Q000503:physiopathology*; D005272:Femur Neck / Q000503:physiopathology; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D014057:Tomography, X-Ray Computed