Analysis on the risk factors of second fracture in osteoporosis-related fractures

To explore the clinical characteristics and risk factors of refracture in patients suffering from osteoporosis-related fractures as well as effective interventions.

From January 2006 to January 2008, both out-patients and in-patients in our hospital who were over 50 years old and suffered from osteoporosis-related fractures were selected for this research. They were divided into fracture group and refracture group. The refracture rate was followed up for 2 years, during which 11 patients developed refracture, thus were included in the refracture group. Therefore, 273 patients, 225 first-fracture cases, aged (67.7+/-8.5) years, and 48 refracture cases, aged (72.7+/-9.5) years, were included in this study. General data including age and sex, fracture types, femoral neck bone mineral density (BMD) T-scores tested by dual-energy X-rays absorptiometry (DEXA), Charlson index, time-frame between two fractures as well as mobility skill assessment were collected and analyzed by single-factor and multivariate statistical methods.

Females accounted for 70.2% of the fracture group and 77.1% of the refracture group. The most common refracture type was vertebral fracture for the first time and femoral neck fracture for the second time during the follow-up. The second fracture happened 3.7 years after the first one on average. The refracture rate was 2.12% within one year, and 4.66% within two years. Risk factors for a second fracture in osteoporotic fracture patients included age (larger than 75 years, HR equal to 1.23, 95%CI 1.18-1.29; larger than 85 years, HR equal to 1.68, 95% CI 1.60-1.76), female sex (HR equal to 1.36, 95%CI 1.32-1.40), prior vertebral fractures (HR equal to 1.62, 95%CI 1.01-2.07), prior hip fractures (HR equal to 1.27, 95%CI 0.89-2.42), BMD T-score less than -3.5 (HR equal to 1.38, 95%CI 1.17-1.72) and weakened motor skills (HR equal to 1.27, 95%CI 1.09-1.40).

The risks of second fracture among patients with initial brittle fracture are substantial. There is adequate time between the first and second fractures for interventions to reduce the risks of refracture, especially for the old women with a vertebral or hip fracture. Medication, motor functional rehabilitation and fall-down prevention training are helpful.