A study of the influence of technical adequacy on the clinical result of Moore hemiarthroplasty.

The Moore and Thompson hemiarthroplasties are still commonly used for the displaced subcapital fracture in the elderly. The cemented Thompson has been claimed to be superior to the uncemented Moore prosthesis. However, the use of cement is associated with greater risks and the uncemented Moore appears to give good results in approximately two-thirds of patients. The technical adequacy of uncemented hemiarthroplasty has rarely been considered in assessing the outcome. This study indicates that, on the basis of four radiological criteria, incorrect insertion of the prosthesis leads to a high chance of a poor clinical result at 6 months. Good results are more likely when the postoperative radiograph shows the prosthesis to have been inserted accurately. This is possible in most cases, except where the femur is grossly osteoporotic with a wide intramedullary canal. Uncemented hemiarthroplasty can produce satisfactory results but, like uncemented total joint replacement, is a more demanding procedure.