Évaluation de la densité osseuse péri acétabulaire après resurfaçage versus prothèse totale de la hanche métal-métal non cimentée
We undertook a retrospective study to evaluate bone remodeling around two uncemented press-fit acetabular components: (1. Hip resurfacing (HR) and 2. total hip replacement (THR)) at a minimum of 21 months after implantation.  We measured by DEXA (Dual energy X ray absorptiometry) the bone mineral density (BMD) in the supra acetabular area in 60 patients (44 HR, 16 THR). We found no significant difference in the average BMD of the global zone and central zone of the acetabulum between the operated hip and the opposite non-operated hip in both treatment groups. However, the BMD of the medial and lateral cortico-cancellous areas on the side of surgery was significantly higher compared to non-operated side in HR group with the cobalt chrome cup; (p=0,014 and 0,031 respectively) As for THR with a titanium cup, we found no significant difference in BMD at these areas (p=0,130 and 0,733). These data show that with more rigid cups, there seems to be greater load transfer to the periphery of the acetabulum without significant stress shielding.  This is the first study to assess peri-acetabular bone remodeling with HR. We showed that BMD is relatively preserved. Stress transfer to the periphery may be beneficial in maintaining the stability of the primary implant while conserving bone stock for possible revisions of the press-fit cup of the HR.
Dexa stress shielding bone remodelling Dexa load strain modulus of elasticity preservation of bone stock finite element models stress shielding