Primary Hip Osteoarthritis clinical trials

Fitmore Versus CLS Stem in Total Hip Arthroplasty. Bilateral One-stage Operations

Main question: Will use of a stem design that allows anatomical reconstruction of the hip joint improve the outcome in terms of hip function and patient satisfaction without causing any adverse effects? Background: Total hip arthroplasty with use of the most well documented implants is a safe and cost-effective procedure. In the Swedish Hip Arthroplasty register the CLS stem has a 16 years implant survival of 97, 5 %. It is a classic design which requires resection of most of the neck. The stem also intrudes into the greater trochanter which in patients with certain types of proximal hip anatomy makes proper introduction of the stem difficult. Finally it has a standard stem length which will jeopardise future stem removal should there occur any late infection or instability problems. Short uncemented stems have been introduced to enable a more anatomic reconstruction of the hip joint and to cause less invasion of the femoral canal to facilitate future revision should it be necessary. A more conservative resection of neck could also be of value to improve the clinical outcome by improved hip function and patient satisfaction. Purpose of the present study and design: In a prospective study the clinical outcome, stem fixation and bone remodelling around a short stem (Fitmore) will be studied. The main focus will be to evaluate patient reported outcomes especially concerning function, over all satisfaction, pain and activity. All patients will receive the same cup (Trilogy). This cup is chosen because it has a very thorough documentation in prospective RSA studies and in the Swedish hip arthroplasty register. All cups will be supplied with insert made of high molecular polyethylene (Longevity). Number of hips in the study: 44 consecutive cases