EVALUATION OF NEW TECHNOLOGIES FOR TOTAL HIP-REPLACEMENT - ECONOMIC MODELING AND CLINICAL-TRIALS

Cost is a factor in the choice of prosthetic components in joint repla cement, For a given performance, the least expensive components are th e most cost-effective, When evaluating a new prosthesis with an unknow n outcome, the use of an economic model allows estimation of potential cost-effectiveness. We used published data for the survival of cement ed total hip replacements from Sweden, and cost and demographic inform ation from New South Wales, Australia, in such a model. In young activ e total hip recipients a new prosthetic design which offered a 90% imp rovement in survivorship over 15 years and a 15% reduction in the cost of revision surgery, could be sold at a price of 2 to 2.5 times that of conventional cemented components such as the Charnley Low Friction Arthroplasty and still be cost-effective, Using more likely estimates of the improved performance of new technology, however, the upper limi t of cost-effectiveness is an increase of 1.5 to 1, Only a very small increase in the cost of a prosthesis could ever be justified for older patients of either sex, Most of the potential benefits of a better le vel of survivorship appear towards the end of the 15-year period. The results of modelling may be incorporated in clinical trial design.Give n the known performance of some well-established and relatively inexpe nsive designs of prostheses, very large randomised studies would be re quired to prove an improvement in performance.