[Revision of interlocking rod for loosening of THP. Concept--preliminary results]

This revision rod, used temporarily, is interlocked in the distal healthy part of the femur. It is indicated in the treatment of loosening, even with extensive destruction, whether this is done by filling the fragile part of the femur with bone chips and marrow or by reconstruction accomplished by gliding the femoral heads on the rod. The clinical results were observed for 21 replacements, performed between 1987 and 1990, for the following indications: 14 loosenings, of which 10 had major bone defects; 4 fractures, of which 3 received a prosthesis; 2 infected resection prostheses; and one broken porous metal Judet prosthesis. There was one failure due to flare-up of infection in a prosthesis that was initially infected. The complete treatment, with implantation of a standard prosthesis, was only performed in 5 cases. We left the revision rod in place in elderly patients, in major reconstructions, or when the patients refused a new operation. The anatomical results are encouraging. There was good assimilation of the bone grafts, confirmed by histology in cases of revision. There was no rupture or displacement of the material. The functional results were good with respect to pain and range of motion; they were less good with respect to stability, as could be expected in repeatedly operated patients.