The overall objective of the proposed study is to quantify bone loss around non-cemented
total hip replacement femoral and acetabular components using DEXA analysis in patients
receiving Prolia (denosumab) in the first year of follow up after total hip joint replacement
surgery, and to compare this to bone loss in control hip replacement patients receiving a
placebo.
The primary outcome variable will be the difference in loss of bone mineral density between
the experimental group taking denosumab and the placebo control group, calculated as a
percentage, in Gruen Zone 7, the proximal medial calcar region of the femur, over a follow-up
period of 12 post-operative months.
The secondary objectives will be to assess the following variables:
- Bone turnover differences between the experimental group taking denosumab and the
placebo control group, utilizing serum C-terminal cross-linking telopeptides of type I
collagen (CTX-I) (bone resorption) and N-terminal propeptides of type I procollagen
(P1NP) (bone formation).
- Difference in loss of bone mineral density between the experimental group taking
denosumab and the placebo control group, calculated as a percentage, in each of Gruen
Zones 1 through 6, periprosthetic femur.
- Difference in loss of bone mineral density between the experimental group taking
denosumab and the placebo control group, calculated as a percentage, in each of DeLee
and Charnley's Zones 1 through 3, periprosthetic acetabulum.
Exploratory objectives will be to assess difference in loss of bone mineral density in the
contralateral, or non-operated femur for both experimental and control groups, and to
determine the role that covariates such as weight, gender, age, baseline BMD, and implant
type have on percent change in BMD at 12 months.