Radiological study to assess the stability of a polished, tapered cemented short stem used for Total Hip Arthroplasty

Total Hip Arthroplasty (THA) is a procedure commonly performed in patients who have end-stage hip osteoarthritis. The primary goal of THA is to provide pain relief, reduce disability, improve quality of life and functional status. Despite high implant success rates, up to 15% of patients remain dis-satisfied after surgery. This has been postulated to be due to several factors, including implant loosening (stem migration), fractures and reduced functional movement, which lead to poorer patient outcomes. This has triggered the need to experiment with various materials and develop new and improved implants, that have a higher degree of bone osseointegration, provide greater range of joint movement, stability, minimised wear and reduced risk of fracture. A new cemented stem (known as X-ACTA short) has been developed in an attempt to overcome some of these shortcomings. The newly designed X-ACTA short stem device was recently introduced into the Australian market, however, its radiological performance in relation to stem stability and migration, is yet to be evaluated. One method that is commonly used to measure the degree of migration is radiostereometric analysis (RSA). This technique has been shown to be a highly precise and safe technique in assessing stem migration. Given the safety and reliability of the RSA technique, the purpose of this investigation will be to assess the stability and migration of the X-ACTA cemented short stem over a 2-year period following THA surgery and determine how this correlates with patient outcomes. All study participants will be enrolled in the trial for a period of 2-years following THA surgery. Each patient will have x-rays done at four time points (immediately post-operatively and then again at 6-months, 12-months and 2-years following surgery). Each radiological examination is expected to take 15 minutes.