A Modular Cementless Femoral Prosthesis for Revision HipArthroplasty

ABSTRACT

Purpose: The goal of study was to evaluate the clinical and radiographic performance of the proximal modular cementless femoral stem for use in revision total hip arthroplasty. Material and method: Fifty seven patients (57 hips) were followed for longer than 24 months or up to 8.4 years after performing revision total hip arthroplasty with using the proximal modular cementless femoral stem between January 1997 and December 2002. The preoperative diagnosis included 45 cases of aseptic loosening, 5 cases of septic loosening (re-revision operation), 6 cases of periprosthetic fracture and 1 case of recurrent dislocation. The bone deficiencies were classified according to the Paprosky classification there were 27 cases of Type I and II, 19 cases of Type IIIA, 9 cases of Type IIIB and 2 cases of Type IV. Results: The average Harris hip score improved from 47 to 87.6. Clinically satisfactory results were noted in 50 patients (87.7%). Radiographically, distal stable fixation was observed in 54 patients (94.7%). Intraoperative complications included two greater trochanteric fractures and two proximal femur fractures. Postoperative complications included 5 femoral stem subsidences (2hips20mm), 4 deep infections, 2 non-unions of the greater trochanter and the osteotomy site and set screw dissociation was noted in 1 case. 5 proximal component changes were done due to progressive subsidence in two cases, non-union at the osteotomy site and trochanteric displacement in two cases and set screw dissociation in one hip. For the infection cases, the proximal segment was removed and re-revised with a 2nd stage operation. (Ed note check this.) The subsidence of the femoral stems was showed in 3 Paprosky grade IIIA cases and in 2 cases of grade IIIB or more. There was no postoperative periprosthetic fracture observed at the last follow-up. Conclusion: Revision total hip arthroplasty using the proximal modular cementless femoral stem showed good results in the face of the infection of the proximal component and deficient proximal bony support. This procedure appears to be convenient for the surgeon to correct anteversion of the femoral head and leg length discrepancy.