Reconstruction of the trochanteric zone in primary arthroplasty of unstable pertrochanteric fractures

Abstract

The aim: To justify the concept and features of acetabular reconstruction during primary endoprosthesis for transcatheter fractures from the standpoint of radiological data, biomechanical calculations and intraoperative observations. Materials and methods: A retrospective analysis of the use of primary cement arthroplasty for osteoporotic fractures of the trochanteric zone in 52 elderly and senile patients was conducted. Before implantation of the femoral component, fragments of the proximal metaphysis were fixed with cerclage tightening loops which depended on the type of fracture. For fractures 31-A2.1, 31-A2.2, 31-A2.3, reconstruction of the destroyed trochanteric zone and the walls of the bone marrow canal opening was performed using our own methodology. Finite-element modeling with the SolidWorks program was used to investigate the influence of the reconstruction of the trochanteric zone on the distribution of strain on the bone tissue around the implant under osteopenic conditions and load during single-support standing. Results: Clinical and X-ray results were studied in 39 (74.36%) operated patients within 3 to 33 months. There were no complications associated with reconstruction of the proximal part of the femur and implantation of endoprostheses. Restoration of movements in the hip joint and full loading of the operated limb was allowed the day after surgery, depending on the patients` physical condition. The results of finite-element modeling indicate a significant reduction of the strain on the proximal metaphysis in the zone of predominant destruction of the medial and posterior walls of the bone marrow canal of the trochanteric zone reconstruction and ensuring the stability of the femoral component. Conclusions: Clinical results and biomechanical calculations confirm the possibility and feasibility of using primary arthroplasty in unstable osteoporotic fractures of the trochanteric zone with the aim of early restoration of the support function of the damaged limb in individuals with limited physical capabilities. Reconstruction of the intertrochanteric area with a ring-shaped autograft contributes to the achievement of primary stability of the femoral component, restoration of the total femoral offset and stabilizing function of muscles around the joints.