Secondary causes of osteoporosis in fracture patients.

OBJECTIVE

Identification and treatment of osteoporosis in the fragility fracture population and interventions to reduce the risk of future fracture are improving in orthopaedic practice. This study investigated the prevalence of vitamin D insufficiency and deficiency and other secondary causes of low bone density in patients who have sustained a fragility fracture and were referred from fracture clinic to a metabolic bone disease clinic (MBDC) for further assessment.

DESIGN

Retrospective chart audit.

SETTING

University hospital fracture clinic.

PATIENTS: Three hundred ninety-nine patients referred from the orthopaedic division to the MBDC over a 3-year period.

INTERVENTION: A standardized chart audit form was developed, and electronic charts were retrospectively audited.

MAIN OUTCOME MEASUREMENTS: Secondary causes of osteoporosis and routine blood test results.

RESULTS

Three hundred eight of 399 patients had blood investigations completed. A total of 98 patients (32%) had 125 secondary causes of osteoporosis other than vitamin D deficiency or insufficiency recorded in their electronic chart, including medication use, premature ovarian failure, hypogonadism, smoking, excessive alcohol use, renal impairment, gastrointestinal conditions, and endocrine conditions. Mean serum vitamin D level was 69.0 nmol/L in 83 men and 75.4 nmol/L in 186 women. Serum vitamin D levels were deficient at ≤25 nmol/L in 7 patients, insufficient at 26-74 nmol/L in 137 patients, and sufficient at ≥75 nmol/L in 125 patients. Investigation of causes of secondary osteoporosis can inform and influence specific treatment regimens.

CONCLUSIONS

More than one-half of patients sustaining a fragility fracture and referred to the MBDC were vitamin D insufficient or deficient, and nearly one-third had a secondary cause of osteoporosis other than vitamin D insufficiency/deficiency. A standardized list of blood and urine analyses and radiographs has been implemented for fragility fracture patients and selected other fracture patients who are undergoing investigation for osteoporosis.

LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.