06 Nov Low Birth Weight Linked To Increased Adult Hip Replacement Risk
Medical Research: What is the background for this study? What are the main findings?
Prof. Cicuttin: Previous research found that low birth weight and preterm birth have been linked to hypertension, cardiovascular disease, insulin resistance and reduced bone mass in adulthood. Given these adverse outcomes related to birth weight and preterm birth we set out to investigate if low birth weight and preterm birth also played a role in increase risk of joint replacement surgery as adults.
We found that low birth weight and preterm birth were associated with a 2-fold increased risk of hip but not knee replacement surgery.
Medical Research: What should clinicians and patients take away from your report?
Prof. Cicuttin: There is increasing evidence that the risk factors for knee and hip osteoarthritis (OA) differ, with the shape of the bones and the joint having a very significant role in hip osteoarthritis compared to knee OA. Both congenital and developmental diseases of the hip, such as mild hip dysplasia, may influence the development of hip osteoarthritis in adulthood. The formation of the acetabulum is incomplete at birth in preterm babies with preterm infants often developing a postural deformation of the legs which persists till early childhood. These factors may influence the development of the hip, resulting in abnormal hip joint shape which has been shown to be an important risk factor for hip preterm birth.
Medical Research: What recommendations do you have for future research as a result of this study?
Prof. Cicuttin: Clarifying the mechanisms for the relationship between low birth weight and preterm birth and hip OA is important. LBW and preterm birth may result in abnormal hip development because these babies are born early and the acetabulum is underdeveloped. Post-delivery, the hips are extended rather than being maintained in a flexed and abducted in utero position. This altered hip position may potentially be responsible for an increased incidence or severity of acetabular dysplasia. If this is proven to contribute to the development of hip preterm birth, then modifying hip position through postural support and perhaps the use of double nappies may be beneficial for babies born with low birth weight or preterm, and they may need to be targeted for screening and early treatment of hip dysplasia. As the number of low birth weight and preterm births is increasing, if they are proven to be at increased risk of hip OA, the impact of proactive strategies to reduce hip preterm birth, such as the prevention of obesity will be greater.
Some of the above questions will be able to be answered by examining birth cohorts where the effect of factors in early life on hip structural changes in early adulthood will be able to be examined.
Sultana Monira Hussain, Yuanyuan Wang, Anita E. Wluka, Jonathan E. Shaw, Dianna J. Magliano, Stephen Graves, Flavia M. Cicuttini. Association of low birth weight and preterm birth with the incidence of knee and hip arthroplasty for osteoarthritis. Arthritis Care & Research, 2014; DOI: 10.1002/acr.22475