The purpose of this study is to evaluate the clinical and radiographic results of 20 patients(27 hips) who underwent primary bipolar hemiarthroplasty with non-cemented femoral stem and biarticular cup from January 1989 to April 1999 who were followed for more than nine years. Average follow up was 13.4 years(range: 9~19 years). The type of non-cemented femoral stem was Harris-Galante type in ten hips, Multilock porous coated stem in seven hips, and Multilock porous and tricalcium phosphate coated stem in ten hips. The etiology of osteonecrosis of the femoral head was idiopathic in eleven hips, alcohol abuse in twelve hips and steroid administration in four hips. According to Ficat’s grading system, all twenty-seven hips were in stage. Clinically, we evaluated the Harris Hip scores. We also evaluated the radiographic measurements around the femoral stems and the bipolar cups.

The average Harris Hip score improved from 57.2 points to 89 points; and 2(7.4%)hips were associated with thigh pain and 5(18.5%) hips with groin pain. Around the femoral stem there was progressive radiolucent line more than 1mm in width in 1(3.7%) hip, and osteolysis was present in 9(33.3%) hips. On evaluation of radiographs for stability of fixation, we found that 21 hips(77.8%) showed osseous ingrowth, 5 hips(18.5%) showed stable fibrous ingrowth and one hip(3.7%) showed unstable fixation. The osteolysis around the acetabulum was found in 9 hips(33.3%). Two hips showed evidence of migration of the bipolar cup. Five hips(18.5%) showed acetabular cartilage erosion more than 1mm. Seven hips(25.9%) required conversion to total hip arthroplasties, and in two hips, femoral stems were revised. The causes of failure of bipolar cup was central migration in 2 hips, and dissociation of femoral head, extensive osteolysis, and unknown groin pain after trauma in one each. Two bipolar cups were converted to acetabular cup at revision of the femoral stem. The overall failure rate of the primary operation was 26%. The survivorship of non-cemented femoral stem was 92.6% and 74% in bipolar cup at minimum 9 years follow up.

The current study demonstrated favorable results after bipolar hemiarthroplasties with non-cemented femoral stems. However, the osteolysis around the femoral stems and the acetabular cup emerged as main causes of need for surgical revision.

Background: There area some controversies about the need for revision of well fixed femoral stem during the revision total hip arthroplasty. The purpose of this study is to evaluate the state of unretrieved femoral stem, in revision total hip arthroplasty where only acetabular component was revised.

Methods: From January 1998 to December 2004, thirty-one patients underwent revision total hip arthroplasty whose well fixed femoral stem was retained and acetabular components revised. Twenty-six patients(29hips) with a minimum follow-up of three years were included in this study. Out of those twenty-six patients, sixteen patients(18hips) were male and ten patients(11hips) were female with an average age of 54.3 years for the study group. The average time from the primary operation until the revision surgery was 9.2 years and the average follow-up period after the revision was 5 years. The femoral head component was exchanged in all cases and same size femoral head component was used in eleven hips. The clinical results wee analyzed using Harris Hip Score, and the radiographs were reviewed for stability of acetabular components, femoral stem, and degree of osteolysis and radiolucent lines.

Results: The average Harris Hip score improved from 56.3 points preoperatively to 89.8 points postoperatively. Femoral stems were found to be stable in all hips. Sixteen hips(55.2%) showed evidence of osteolysis and seven hips(24.1%) showed non-progressive radiolucent lines. The osteolysis was detected at Gruen Zone I and VII in most of the affected hips except for two hips which showed distal osteolysis. The average life of femoral stem from primary operation until the final follow up varied from 10.8 years to 18.2 years, with the average being 14.2 years.

Conclusions: We recommended that well fixed, stable femoral components can be retained at the time of revision total hip arthroplasty.

Level of evidence: Therapeutic Level IV