The Wagner revision stem in alloarthroplasty of the hip

Abstract

Forty-one Wagner revision stems were implanted at the Orthopedic Department of the University of Tübingen between July 1990 and January 1993. We report the results of 37 patients at an average follow-up of 27 months (13-48 months) postoperatively. The main indication was stem loosening with considerable loss of bone. In addition, we used the implant 4 times in primary arthroplasty. At follow-up examination 33 patients (89%) were satisfied with the postoperative outcome. According to the Merle D'Aubigné score (12-point scale), 32 patients showed a poor functional result of less than 6 points preoperatively. Postoperatively, the results of 36 patients could be classified as very good to good. To categorise the radiological destruction of the implant bed, we used the femoral shaft defect classification of the DGOT (Deutsche Gesellschaft für Orthopädie und Traumatologie) in conjunction with the classification of Pak and Paproski [5, 11]. Twenty patients presented with trochanteric and calcar defects, and 11 patients with a combination of a calcar and shaft defect. We found a circular shaft defect in 2 patients. In 7 cases we assessed the bone remodelling postoperatively as very good, with strong newly formed bone structures, and in 25 cases as good, with remodelling of the old stem bed and bony structuring of the osteolyses. A secondary sinking in of the Wagner stem was seen in 7 cases. Only one stem had to be revised because of pain symptoms and loosening; in all other cases a secondary stabilisation of the revision-stem took place. With the Wagner revision stem, there is the possibility of achieving mechanical stability even in situations with massive bone loss. The evacuation of bone cement and granulation tissues is facilitated by the transfemoral approach, bony remodelling is accelerated, and bone grafting is often not necessary. As our short-term results show, the concept is a promising one. Nevertheless, we will be very careful in following these patients in the long term, as we have noticed stem sinkage in a small percentage of cases.

Stem and Osteotomy Length are Critical for Success of the Transfemoral Approach and Cementless Stem Revision

“…There was no secondary displacement of the osteotomy flap in the remaining five patients without radiographic bony consolidation at final followup, leading us to conclude a fibrous fixation of the flap had taken place in these patients. Others have described similar high union rates [8,10,12,26]. A slightly higher consolidation rate (98.5%) of the osteotomy flap with the transfemoral approach was described in a study on the transfemoral osteotomy using a curved modular revision stem [6].…”

Development of a new modular titanium femoral prosthesis consisting of a head and shaft component. Indications, operation and optimization of the tapered socket connection

“…This complication is known to occur with other long-stem prostheses where poor distal fixation combined with an excessively narrow shaft diameter has allowed excessive subsidence to take place [19]. Subsidence of revision prostheses by up to 1 cm is a well-known feature [21,23,27,29], but ingrowth of bone still occurs for the reasons described above. This represents a difference from primary hip arthroplasty, where subsidence by more than 2 mm is regarded as a sure sign of loosening [30].…”

Uncemented revision stem for biological osteosynthesis in periprosthetic femoral fractures

“…The stem is fixed temporarily by distal interlocking when osteointegration of the proximal stem is impeded by micromovements. Proximal load transfer cannot be achieved in other types of uncemented revision [9]. Further weakening of the proximal femur can occur due to stress shielding.…”

“…The procedure is planned and a preoperative drawing made. The transfemoral approach is used [9,25] with some modifications. A long lateral incision is Fig.…”