Bone Histomorphometry in Subjects Undergoing Total Hip Replacement

Inclusion Criteria:

- Subject has provided informed consent/assent prior to initiation of any study-specific
activities/procedures

- Ambulatory postmenopausal women and men with osteoporosis

- Scheduled to undergo elective THR due to osteoarthritis of the hip

- Received at least 2 doses of denosumab 60 mg subcutaneously over 18 months

- Last dose of denosumab within 6 months of scheduled THR

Exclusion Criteria:

- Received treatment for osteoporosis other than denosumab in one year prior to THR

- Subjects with current diagnosis of any of the following conditions are excluded

- Current, uncontrolled hypo- or hyperthyroidism (subjects who have controlled
hypo- or hyperthyroidism may be eligible, provided that they have been on a
stable therapy for at least 3 months [per subject report])

- Current, hypo- or hyperparathyroidism

- Osteomalacia

- Paget's disease of bone

- Other bone diseases which affect bone metabolism (eg, osteopetrosis, osteogenesis
imperfecta)

- Severe chronic kidney disease (CKD), defined as CKD stage 4 or greater

- Malignancy within the last 5 years (except cervical carcinoma in situ or basal cell
carcinoma)

- Self-reported alcohol or drug abuse within the previous 12 months

- Currently receiving treatment in another investigational device or drug study, or less
than 30 days since ending treatment on another investigational device or drug study(s)

- Other investigational procedures while participating in this study are excluded

- Subject has known sensitivity to any of the products to be administered (eg,
tetracycline, demeclocycline) during study

- Subject likely to not be available to complete all protocol-required study visits or
procedures, and/or to comply with all required study procedures to the best of the
subject and investigator's knowledge

- History or evidence of any other clinically significant disorder, condition or disease
(with the exception of those outlined above) that, in the opinion of the investigator
or Amgen physician, if consulted, would pose a risk to subject safety or interfere
with the study evaluation, procedures or completion