title: Changes in bone mineral density of the distal femur following uncemented total knee arthroplasty.
abstract: The aim of the study was to quantitate changes in bone mineral density (BMD) in the distal femur following uncemented porous-coated total knee arthroplasty. Eight patients with total knee arthroplasties (PCA Primary, Howmedica, Rutherford, NJ) (female:male ratio, 6:2; mean age, 70 years; range, 51-77 years) were scanned by dual-photon absorptiometry within 3 months after surgery and at 2 years. An average decrease of 36% (P = .01) was found in BMD behind the anterior flange of the femoral prosthesis. Proximal to the fixation pegs, BMD increased by 22% (P = .12), but behind the posterior flange of the femoral component, BMD remained unchanged (P = .53). Stress shielding anteriorly in the distal femur occurred in all patients examined 2 years after surgery, and the increase in BMD proximal to the fixation pegs was probably a result of increased and altered mechanical loading.
authors.affiliation: Department of Orthopaedic Surgery U, Rigshospitalet, University of Copenhagen, Denmark.
authors.forename: M M
authors.initials: MM
authors.lastname: Petersen
authors.forename: C
authors.initials: C
authors.lastname: Olsen
authors.forename: J B
authors.initials: JB
authors.lastname: Lauritzen
authors.forename: B
authors.initials: B
authors.lastname: Lund
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D001843:Bone Cements; D015519:Bone Density / Q000502:physiology*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000502:physiology; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011877:Radionuclide Imaging; D013997:Time Factors; D016474:Weight-Bearing / Q000502:physiology
chemical_list: D001843:Bone Cements