The purpose of this study was to assess the regional variation in the incidence of hip fractures in patients over 65 years. in New Zealand. Data from the National Minimum Data Set (NMDS) for hip fractures from 1 July 1998 to 31 June 2000 was obtained. The data was divided into 21 District Health Board (DHB) regions by mapping from domicile code to DHB. Population of interest as at 30 June 1999 was estimated on the basis of previous census in 1996. The incidence of hip fracture per 100,000 for each region was calculated and divided into age and sex cohorts. There is a significant difference between DHBs in the sex and age adjusted incidence of hip fractures. The rates ranged from 556 per 100,000 to 838 per 100,00. As expected there was a higher fracture rate in women and the fracture rate increased with age. There was a weak correlation with sunshine hours (p=0.029) with increasing fracture incidence as sunshine hours decrease. This study demonstrates a large variation in the incidence of hip fractures per DHB region. The cause for this is unclear, but the cost implications are significant. DHB’s with a high incidence of hip fractures in their region may wish to investigate strategies for reducing the incidence.
There is controversy regarding the best way to manage fit, independent patients with acute hip fractures. The aim of this study was to compare, nationally, the early complication rates of total hip arthroplasty (THA) in those patients with an acute fractured neck of femur (NOF) with a similar group of THA’s performed in patients with a diagnosis of osteoarthritis. Using the National Hip Joint Register and the New Zealand Health Information Service Database, 200 patients with acute hip fractures undergoing THA were identified and compared to 1102 THA’s performed on osteoarthritis patients. The mortality, revision, dislocation and infection rates were analysed at a minimum of one year. Acute THA had a 7.5% one-year mortality rate compared with 2.5% in the OA group (p <
0.01). The revision rate was 2.5% vs 1.8% in the acute and OA groups respectively. The dislocation rate was 4.3% for the whole group with a 8.5% for the acute group and 3.5% for the OA group (p<
0.01). In the acute group the dislocation rate using the posterior approach was 17.1 % compared to 3.1% for the lateral approach (p<
0.01). We conclude that acute THA is a useful procedure in fit patients with a fracture of the neck of the femur but that a posterior approach should be avoided.