title: Changes in bone mineral density and femoral neck narrowing in the proximal femur three to five years after hip resurfacing versus conventional total hip arthroplasty.
abstract: We studied whether bone mineral density (BMD) is preserved without significant femoral neck narrowing (FNN) after hip resurfacing (RHA) (n=42) versus small diameter metal-on-metal total hip arthroplasty (MoM THA) (n=40). In this three to five year randomized trial BMD was measured in the calcar with dual energy absorptiometry (DXA) preoperatively, at three and six months, one, two, three and five years postoperatively. Four additional BMD regions of interest (ROIs) and femoral neck narrowing (FNN) were measured after RHA. BMD in the calcar increased to 107% (P<0.001) at one year and remained stable. Additional ROIs in the femoral neck and trochanter-area BMD changes fluctuated between 99.9% and 104.1%. FNN was minimal with a mean of 1.3% at three years. After THA BMD decreased in the calcar to 80% at one year (P<0.001) and stabilized. This bone stock preserving nature of RHA must be weighed against potential disadvantages caused by specific metal-on-metal bearing problems.
authors.affiliation: Department of Orthopedics, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Davey M J M
authors.initials: DM
authors.lastname: Gerhardt
authors.affiliation: Department of Orthopedics, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: José M H
authors.initials: JM
authors.lastname: Smolders
authors.affiliation: Department of Orthopedics, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Ton A J M
authors.initials: TA
authors.lastname: Rijnders
authors.affiliation: Department of Orthopedics, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Annemiek
authors.initials: A
authors.lastname: Hol
authors.affiliation: Department of Orthopedics, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Job L C
authors.initials: JL
authors.lastname: van Susante
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D015519:Bone Density; D005260:Female; D005272:Femur Neck / Q000503:physiopathology* / Q000601:surgery*; D006621:Hip Joint / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
keywords: bone mineral density; femoral neck narrowing; hip resurfacing arthroplasty; metal-on-metal; randomized controlled trial; total hip arthroplasty