HOST study – HIV in orthopaedic skeletal trauma study : protocol for a multicentre case-cohort study
CITATION: Graham, S. M., et al. 2018. HOST Study – HIV in Orthopaedic Skeletal Trauma Study : protocol for a multicentre case-cohort study. SA Orthopaedic Journal, 17(3):53-58, doi:10.17159/2309-8309/2018/v17n3a7.
Background: Human immunodeficiency virus (HIV) and antiretroviral therapy (ART) have both been shown to reduce bone mineral density, mineralisation and bone turnover. Our study group and other researchers have suggested that HIV may impair fracture healing, based on extrapolation from basic science. These observations prompted this study as the true effect of HIV and highly active antiretroviral therapy (HAART) on bone healing is very poorly understood and has not previously been investigated. Methods: HOST Study is a multicentre case-cohort study being undertaken at two orthopaedic trauma centres in Cape Town, South Africa. All adult patients older than 18 years with fresh (within 2 weeks of injury), closed and open, tibia and femur fractures who undergo intramedullary (IM) nailing for fracture fixation will be eligible or the study. Participants will be recruited over 24 months and undergo a baseline questionnaire, HIV testing and assessment of their bone mineral density (BMD). They will be followed up at 2 and 6 weeks, and at 3, 6, 9 and 12 months. All adult patients who develop delayed bone union at the 6-month follow-up will be considered cases. Adult patients who show evidence of radiological union at 6 months or less will be considered controls. We will then determine if HIV is a risk factor for the development of delayed bone union. HIV prevalence levels in the cases and controls will be summarised using IRR (incidence rate ratio) statistics with their 95% confidence intervals. Negative binomial regression methodswill be used to adjust the IRR estimates for the possible effects of confounding factors and/or important covariates. Results: Outcomes from the primary manuscript will be disseminated through publications in academic journals and presentations at relevant orthopaedic conferences. We will communicate trial results to all participating sites. Participating sites will communicate results with patients who have indicated an interest in knowing the results.