Second hip fracture in Hong Kong - Incidence, demographics, and mortality

The aim of this study is to investigate the incidence of second hip fractures after a previous hip fracture and subsequent mortality in Chinese men and women.

Data of patients aged 65 years or above with operatively treated hip fracture in the years 2000-2011 in Hong Kong were retrieved from Hospital Authority clinical database. During the follow-up period, second contralateral operatively treated hip fractures were identified. The incidence of a second fracture was determined using survival analysis.

A total of 2399 second hip fractures were identified. The cumulative incidence of a second fracture was 1.24% at 1 year and 4.42% at 5 years with 60% of second fractures occurring within 4 years after the initial fracture. In cox regression model, a higher incidence was observed as age increased (hazard ratio [HR], 1.08; P < 0.001). The cumulative mortality at 1 and 5 years after a second fracture was 16.9% and 54.8%, respectively. The median survival after single fracture was 4.9 years, while after a second fracture it was 3.8 years (P < 0.05). Lower survival was observed after the second fracture (HR, 5.44; P < 0.05), in men (HR, 1.91; P < 0.05) and older patients (HR, 1.061; P < 0.05).

Patients with history of hip fracture are at high risk to develop a second fracture. Initiation of treatment and fragility fracture prevention program after primary hip fracture should be started in order to reduce second fracture incidence and related mortality.