The epidemiology and injury patterns of acetabular fractures: are the USA and China comparable?

Abstract

Background: Acetabular fractures are rare injuries in heterogeneous patient groups, making it difficult to develop adequately powered prospective single-center clinical trials in the USA or Europe. Chinese trauma centers treat a high volume of these injuries, and if the patient population and injury patterns are comparable to those in the USA, this might support development of multicenter studies in Level I trauma centers in the two countries.

Questions/purposes: We determined whether the following parameters were similar between operative acetabular fractures treated at Chinese and US trauma centers: (1) epidemiology of injured patients, (2) mechanism of injuries and fracture types, and (3) hospital stay parameters, including symptomatic postoperative deep vein thrombosis (DVT) rate.

Methods: We extracted data from trauma databases for patients admitted with acetabular fractures managed surgically from 2005 to 2012 for one Chinese center and from 2008 to 2012 for one US center. Sex, age, mechanism of injury, fracture classification, Injury Severity Score (ISS), time from injury to surgery, length of hospital stay, and symptomatic DVT rate were analyzed. We included 661 Chinese patients (539 men, 122 women) and 212 US patients (163 men, 49 women).

Results: Mean age at time of injury was different between China and the USA, at 40 years with a unimodal distribution and 44 years with a bimodal distribution (p<0.001), respectively. Incidence of surgically treated acetabular fractures has been increasing in China but decreasing in the USA. Mean ISSs were comparable. Although the distribution of mechanisms of injury was different (p=0.004), high-energy injuries (motor vehicle accidents, falls>10 feet) still accounted for most fractures in both centers. Fracture classifications (per Letournel) were comparable, with posterior wall fractures most common. Mean time from injury to surgery and mean hospital stay were longer in China than in the USA (9 versus 3 days [p<0.001] and 26 versus 11 days [p<0.001], respectively). Symptomatic DVT rates were comparable.

Conclusions: Although we identified differences between the two centers, we also noted important similarities. Multicenter clinical studies involving these locations should be performed with caution and focus on similar end points, taking into account the populations' baseline differences. Because of the potential for such differences, this kind of validation study should be performed before embarking on resource-intensive multicenter trials.

Level of evidence: Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Fig. 1

A line graph, derived from a histogram, shows the age distribution of operative acetabular fractures in Shijiazhuang, China, and Denver, CO, USA, during study period.

Fig. 2

A graph shows the incidence of operative acetabular fractures in Shijiazhuang, China, from 2005 to 2012 and Denver, CO, USA, from 2008 to 2012.