LOCKED FEMORAL IMPLANTS AND BONE RECONSTRUCTION: PRELIMINARY RESULTS IN 94 CASES AT 19 MONTHS

Abstract

Purpose: Using the transfemoral approach for a locked resurfaced implant without cement appears to be an interesting solution for reconstruction after loss of bone stock.

Material and methods: We report a multicentric consecutive series of a homogeneous group of 94 revision femoral implants in 26 women and 68 men, mean age 67 years (38–88). Mean follow-up was 19 months (12–38 months). All the patients were operated via the transfemoral approach which allowed removal of the implant, insertion of a new locked stem without cement and stabilisation of the femoral fragment in close contact with the implant. The cause of the revision was loosening of the femoral component in 83% of the cases in association with important loss of femoral bone. In addition, this technique was applied for stem fracture (6.5%), prosthesis fracture (5.5%), or another cause (3.5%). The loosened stem had been cemented in 87% of the cases; a first stem in 68% and a second one in 27%.

Clinically, the patients were assessed with the Postel Merle d’Aubigné (PMA) and Harris scores using the SOFCOT and Picault-Vives scores. We also assessed healing of the femoral fragment, the stability of the implant, and the bone response around the implant. Preoperative PMA and Harris scores were 8.5 (1–17) and 38 (5–86) respectively. In 91% of the cases, bone construction was important radiographically. The locked stem without cement was short in 32% of the cases, and long in 68%.

Results: At last follow-up the PMA and Harris scores were 15 (9–18) and 78 (37–99) respectively. The femoral fragment healed in 93% of the cases at one year. In 72%, bone reconstruction was significant. Two patients died. Four others required revision of the femoral implant.

Discussion: The advantages of this technique compared with other solutions is discussed. The main points of the operation are recalled. The causes of failure are analysed.

Conclusion: The transfemoral approach allows reconstruction of the bone defect. The primary stability allowed by locking gives time for osteointegration of the implant. These preliminary results confirm that secondary stability of the implant is achieved. In case osteointegration does not occur, a less aggressive surgical solution could be discussed.