A NOVEL TECHNIQUE FOR FEMUR REVISION IN THE EVENT OF COMBINED BONE LOSS AND FEMORAL DEFORMATION

Abstract

Purpose: Femoral revision can be difficult when associated with important loss of bone stock and femoral deformation, particularly when the deformation prevents using a long prosthesis despite major loss where it would be useful. We describe a novel technique allowing a simultaneous solution to these two problems and report preliminary results in five patients.

Material and methods: The technique was applied in five patients. Briefly, one or several osteotomies at different levels were performed to correct the deformation in one or more planes, and fixed with a locked femoral implant. Femorotomy was associated in four patients to facilitate removal of prior implants and constituted one of the correction osteotomies. In one patient, non-union of the greater trochanter was treated with a plated autograft. The series included three men and one woman, mean age 72 years (65–83). According to the SOFCOT score, femoral bone loss was grade II in four patients and grade III in one. All femurs had varus deformation (mean 21°, range 16°–40°), and two femurs exhibited permanent flexion (40° and 45°). One shaft osteotomy was used in four patients and two osteotomies in one. The locked femoral implant measured 250 mm in three and 300 mm in two.

Results: Mean follow-up was 3.5 years (0.5–5). One patient committed suicide at six months. The mean Postel Merle d’Aubigné score improved from 9.4 (7–11) to 16.4 (15–18). The trochanter non-union and all osteotomies head at three to four months except one case of shaft non-union which was well tolerated (PMA=16, in a patient without femorotomy who did not require recalibration of the proximal femur). In these healed cases, remodelling and/or spontaneous reconstruction of the femur was observed without grafting for the shaft. There was no stress shielding aspect in the patients with the longest follow-up although they had non-cemented stems with distal locking and no surface treatment.

Conclusion: The technique proposed for this specific indication enables resolution of the double problem of fixation and correction of deformation while allowing spontaneous reconstruction around the non-cemented locked implant. Use of femorotomy is recommended to allow recalibration and stabilisation of the proximal femur around the stem. Longer follow-up is needed to ascertain longevity of the spontaneous reconstruction. Nevertheless, these non-reintegrated implants behave like locked centromedullary nailing.