Conversion from hemiarthroplasty to total HIP replacement: problems and early outcome

ABSTRACT

Conversion of hemi to total hip replacement [CTHR] is a common but difficult operation. The aim of this study is to evaluate the results of CTHR using long stem femoral prosthesis with or without bone grafting for the acetabulum. Thirty four hemiarthroplasty in 34 patients aged between 54 and 67 years old were converted to total hip arthroplasty. The mean period of follow up was 33 months. The indication of hemiarthroplasty was fracture neck of femur in all cases. There were 20 cemented Thomson and 14 Austin Moore prostheses. Pain was the main indication for conversion arthroplasty. Two types of cemented longstem femoral prostheses were used. Acetabular impaction morselized bone grafting was needed in four cases two of them had reconstruction rings. The mean Harris hip score improved significantly from 55 to 87.3 points. There was high incidence of significant radiolucent lines at the distal end of the stem [47%]. Two failures happened due to infection and recurrent dislocation. We had many intraoperative femoral fracture [18%] but with no direct effect on the results at the last follow-up. We concluded that conversion arthroplasty is a high risk operation but with high success rate. Infection and recurrent dislocation are the most difficult complications to manage. The use of longstem is very helpful but distal cementation technique need to improve