Revision total hip arthroplasty: the limits of fully coated stems

Femoral revision with a 7-inch or 8-inch fully porous-coated stem may not provide reliable long-term results in patients with moderate bone loss. The purpose of this study was to evaluate the limits of fully porous-coated stems and to create a treatment algorithm for femoral deficiencies. Fifty-one patients with either a 10-inch or 9-inch calcar fully porous-coated stem, 10 patients with impaction bone grafting, and 10 patients with a modular tapered stem were evaluated at an average 4.2 years postoperatively. The mechanical failure rate among the 9-inch and 10-inch fully porous-coated stems was 0% in Type III B defects with femoral canals less than 19 mm (15 patients), 18% in Type IIIB defects with femoral canals greater than 19 mm (2 of 11 patients) and 37.5% in Type IV defects (three of eight patients). There were no mechanical failures observed among the bone packing or modular tapered stems. Patients with Type IIIB defects and a femoral canal less than 19 mm can be treated successfully with either a 10-inch or 9-inch calcar fully porous-coated stem. However, patients with Type IIIB defect and an endosteal canal greater than 19 mm or a Type IV defect require alternative methods of reconstruction such as a modular tapered stem or a bone packing procedure.