Osteoporosis: Clinical Evaluation

The identification of a patient at high risk of fracture should be followed by evaluation for factors contributing to low bone mass, skeletal fragility, falls, and fractures. Components of the evaluation include a bone density test, osteoporosis-directed medical history and physical exam, laboratory studies, and possibly skeletal imaging. A bone density test with dual-energy X-ray absorptiometry (DXA) helps with diagnostic classification, assessment of fracture risk, and provides a baseline for monitoring the skeletal effects of treatment. FRAX is a fracture risk algorithm that includes input of femoral neck bone mineral density measured by DXA. The DXA T-score and FRAX estimation of fracture risk are used with clinical practice guidelines to determine whether treatment is indicated. The medical history may reveal underlying causes of osteoporosis (e.g., nutritional deficiencies, gastric surgery, medications with adverse skeletal effects) and important risk factors for fracture (e.g., past history of fracture, family history of osteoporosis, or recent falls). Physical exam may show skeletal deformities due to unrecognized fractures (e.g., loss of height, kyphosis, or diminished rib-pelvis space), identify possible secondary causes of skeletal fragility (e.g., blue sclera with osteogenesis imperfecta, urticarial pigmentosa with systemic mastocytosis, or bone tenderness with osteomalacia), and help to recognize patients with poor balance and frailty that might lead to falls. Laboratory studies may show potentially reversible abnormalities (e.g., vitamin D deficiency, hypocalcemia, or impaired kidney function) that must be assessed and corrected, if possible, before starting pharmacological therapy. Disorders other than osteoporosis, requiring other types of treatment, may be found; for example, low serum alkaline phosphatase suggests hypophosphatasia, M-component may be due to myeloma, or hypocalciuria due to celiac disease. There are important safety considerations that can be derived from a pre-treatment assessment, as well. A patient with a blood clotting disorder should not be treated with raloxifene, a history of esophageal stricture is a contraindication for oral bisphosphonates, and previous skeletal radiation therapy precludes treatment with teriparatide. Skeletal imaging may be helpful when a fracture, malignancy, or Paget’s disease of bone is suspected. Bone biopsy is rarely performed in clinical practice, but may be helpful in some situations, such as when it is necessary to determine the underlying bone disease in a patient with stage 5 chronic kidney disease. For complete coverage of all related areas of Endocrinology, please visit our on-line FREE web-text, WWW.ENDOTEXT.ORG .