Osteoporosis Management

Bone Mineral Density (BMD) Measurement 

• Recommended every 1-2 years after initiation of therapy and every 1-3 years thereafter
• BMD measurement done while on treatment correlates with patient’s current fracture risk
• Central DXA of the spine or hip is the gold standard for serial BMD assessment
  • Should be done every 2 years
  • If spine, hip or both cannot be assessed, 33% radius site can be used
• Patient follow-up ideally should be done within the same facility using the same machine
• Age-, disease- and treatment-related BMD changes can be monitored using QCT measurement of trabecular BMD 

Bone Turnover Markers

• Bone resorption markers (eg fasting serum C-terminal crosslinking telopeptide of type I collagen) may be measured before starting therapy and 3 or 6 months after starting treatment
• Bone formation markers (eg serum procollagen type I N-terminal propeptide) may be measured before starting therapy and 6 months later
• High levels of bone resorption markers are associated with an increased risk of osteoporotic fractures
  • Resorption markers may be used for assessing fracture risk in selected patients when BMD and clinical risk factors are not sufficient to make treatment decisions

Vertebral Imaging

• Repeat vertebral imaging is indicated for patients with the following:
  • Documented height loss
  • Presence of vertebral pain
  • Changes in posture
  • Chest X-ray abnormalities
  • Due for re-evaluation of treatment with possible withdrawal of therapy
  • Presence of vertebral fracture during off-treatment interval

Reassessment of Postmenopausal Women on Long-Term Bisphosphonate Therapy 

• Postmenopausal women who have been taking oral bisphosphonates for ≥5 years or IV bisphosphonates for ≥3 years should be reassessed for presence of fractures prior to initiation and during therapy
  • Bisphosphonate therapy can be continued beyond 3-5 years in patients ≥75 years old, on high-dose oral glucocorticoid treatment, with prior history of hip or vertebral fracture, or who sustained a low-trauma fracture during therapy
• If fractures occurred, treatment with bisphosphonates may be continued or may consider the use of other agents
• If fracture-free, assess BMD T-score or fracture risk
  • If with hip BMD T-score of ≤-2.5 or with high fracture risk, consider continuing bisphosphonate therapy or may change into other alternative agents
  • If with normal bone mass and still no fractures, may consider withholding treatment and advise patient to follow-up every 2-3 years

Monitoring Therapy in Men with Osteoporosis

• Patients can be monitored with BMD measurements as recommended for postmenopausal women
  • There may be limitations to the use of spine DXA in aging men due to interference from osteophytes and vascular calcifications on the spine measurement

Treatment Failure

• Defined as (after excluding secondary osteoporosis or maximal treatment adherence) ≥2 incident fragility fractures; or one incident fracture and elevated serum CTX or P1NP at baseline with no significant reduction during treatment or a significant decrease in BMD or both; or no significant decrease in serum CTX or P1NP but a significant decrease in BMD  
• Treatment modifications may include replacing a weaker antiresorptive agent with a more potent one from the same class, replacing an oral drug with an injectable one, or replacing a strong antiresorptive agent with an anabolic agent
• Evaluate patient’s adherence to therapy and address factors associated with poor treatment adherence, eg inadequate patient/caregiver education, presence of adverse events

Specialist Referral 

• Consider referral to a specialist if:
  • Fragility fractures are experienced
  • A non-major trauma fracture is sustained by a patient with normal BMD
  • Continued bone loss or recurrent fractures happen in a patient on therapy but has no clear causes of bone loss that are treatable
  • Osteoporosis has uncommon features, is severe, or rare secondary conditions are present, eg hyperparathyroidism, increased prolactin
  • A condition is present that makes management difficult, eg chronic kidney disease, malabsorption