FEMORAL IMPLANT LOOSENING AND FLOATING-SEGMENT REVISION PROCEDURE

Abstract

Purpose: We report a prospective series of 70 explantations of the femoral pivot via a transfemoral approach required due to septic and aseptic loosening.

Material and methods: Aseptic loosening was observed in 61 cases, septic loosening in 9. The extended posterolateral approach was used to remove the implant in all cases and a femoral segment (Wagner method). Reconstruction of the femur was achieved with locked stems without cement (65 patients) or a long stem without cement (1 patient). Reimplantation was not attempted in four patients. Bone grafts were not used. Mean follow-up in this series was 3.5 years. The PMA score was used for clinical assessment. Radiographic assessment of segment healing and bone regrowth around the implant was done by measuring the cortical index.

Results: We observed a significant gain in the PMA score of more than 9 points. We had one intraoperative fracture of the femoral segment and two episodes of early dislocation. All femoral segments healed. Osteogenesis failed in three cases with fracture of the locking screw. There were also two cases of late fracture of the trochanter. At one year, bone regrowth measured from the cortical index was greater than 10% on the average.

Discussion: We discuss the characteristic features of this type of surgery in comparison with other solutions for femoral revision: operative time, blood loss, choice of implants, later weight bearing. We also found that this technique allows easier implant removal and more effective cleaning of the femoral shaft in the event of septic surgery with fewer cases of intraoperative accidents (malposition, femoral fractures). We were able to demonstrate that this method of femur reconstruction without bone graft provides a stimulation of osteogenesis in the floating segment. Stem locking provides primary stability in 100% of the cases. Secondary stability was achieved in 90% due to the quality of the newly formed bone.