Cementless modular hip revision arthroplasty using the MRP Titan Revision Stem: outcome of 79 hips after an average of 4 years' follow-up

Introduction. As primary total hip replacements (THRs) become more common in older patients and younger, physically active patients, the number of revision arthroplasties will also increase. Femoral bone loss, joint instability and possible infections are a challenge for a surgeon performing revision arthroplasty of the hip. The severe proximal femoral bone loss indicates the use of revision stems with a distal fixation. Materials and methods. In this study the clinical and radiological outcomes of 79 cementless stem revisions using the MRP Titan Revision Stem with an average follow-up time of 4 years were prospectively examined. Results. The Harris Hip Score improved from preoperative 50.8+/-25.2 to postoperative 86.8+/-13.2. In all cases healing of bony defects could be found. For stem diameters larger than 17 mm, atrophy of the proximal femur and non-progressive radiolucent lines in zones 1 and 7 according to Gruen were detected. No disadvantages or complications of the Morse taper junctions were observed, and no osteolysis was detected in this region. Primary stable fixation was achieved in all but two cases. Three cases were revised again due to periprosthetic fracture (1) and persisting infection (2). Conclusion. Given the encouraging results with the MRP Titan Revision Stem, the principle of uncemented diaphyseal fixation appears to solve most of the technical problems in cases of significant bone loss and obviously offers good preconditions for bony restoration.