title: Cancellous and cortical bone mineral density around an elastic press-fit socket in total hip arthroplasty.
abstract: Background and purpose - The acetabular component has remained the weakest link in hip arthroplasty for achievement of long-term survival. One of the possible explanatory factors for acetabular failure has been acetabular stress shielding. For this, we investigated the effects of a cementless elastic socket on acetabular bone mineral density (BMD). Patients and methods - During 2008-2009, we performed a single-center prospective cohort trial on 25 patients (mean age 64 (SD 4), 18 females) in whom we implanted a cementless elastic press-fit socket. Using quantitative BMD measurements on CT, we determined the change in BMD surrounding the acetabular component over a 2-year follow-up period. Results - We found a statistically significant decrease in cancellous BMD (-14% to -35%) and a stable level of cortical BMD (5% to -5%) surrounding the elastic press-fit cup during the follow-up period. The main decrease was seen during the first 6 months after implantation. During the second year, cancellous BMD showed a further decrease in the medial and lower acetabular regions. Interpretation - We found no evidence that an elastic press-fit socket would prevent acetabular stress shielding during a 2-year follow-up.
authors.affiliation: a Department of Orthopaedic surgery , Sint Maartenskliniek.
authors.forename: Dean F M
authors.initials: DF
authors.lastname: Pakvis
authors.affiliation: b Sint Maartenskliniek Research , Nijmegen , the Netherlands.
authors.forename: Petra J C
authors.initials: PJ
authors.lastname: Heesterbeek
authors.affiliation: b Sint Maartenskliniek Research , Nijmegen , the Netherlands.
authors.forename: Marianne
authors.initials: M
authors.lastname: Severens
authors.affiliation: a Department of Orthopaedic surgery , Sint Maartenskliniek.
authors.forename: Maarten
authors.initials: M
authors.lastname: Spruit
mesh_terms: D015502:Absorptiometry, Photon; D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D015519:Bone Density / Q000502:physiology*; D000071538:Cortical Bone / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000175:diagnosis / Q000601:surgery*; D011446:Prospective Studies; D011474:Prosthesis Design; D013997:Time Factors; D055815:Young Adult