Analysis of the Radiological Anatomy of the Proximal Femur after the Intramedullary Nailing of Trochanteric Fractures

Background. Despite the high rate of the intramedullary osteosynthesis of proximal femur fractures, the incidence of implant-associated complications exceeds 50%. Poor reduction and incorrect implant positioning significantly increase the risk of mechanical complications and the frequency of unsatisfactory treatment outcomes. The aim of the study was to evaluate various fragment positions after the intramedullary nailing of proximal femur fractures using the developed radiological criteria for assessing the quality of reduction, and to determine the association between the quality of the restoration of the proximal femur, implant position and fracture type. Methods. In a retrospective single-center study we analyzed the primary X-rays of 108 patients with type 31A fractures. Radiological criteria were preliminarily defined. According to them, the position of the fragments and implants was considered satisfactory if the value of the neck-diaphyseal angle was more than 125 degrees, anteversion did not exceed 20 degrees, medial diastasis was not more than 10 mm, and there were no negative medial support, no femoral neck lengthening of more than 10 mm compared with the healthy side, and no penetration of the blade into the joint. Patients were divided into three groups according to the fracture type. We analyzed and compared the proportions of satisfactory and unsatisfactory radiological results within the groups and between them. Results. Satisfactory reduction was noted in 83 patients (76.9%) out of 108, unsatisfactory - in 25 patients (23.1%), and 16 patients (14.8%) had incorrect implant position. Patients with type 31A1 fractures were 3.5 times less likely to have an unsatisfactory reduction than patients with type 31A2 fractures (OR 3.511; 95% CI 1.202-10.261) and 6.7 times less likely to have an unsatisfactory reduction than patients with type 31A3 fractures (OR 6.714; 95% CI 1.685-26.752). The probability of incorrect implant positioning was 6 times higher in type 31A3 fractures than in type 31A1 fractures (OR 6.000; 95% CI 1.410-25.528). Conclusion. To improve the quality of surgical treatment, it is worth paying an increased attention to the quality of the achieved reduction, implant selection, technical peculiarities of the fixation of types A2 and A3 fractures, improvement of preoperative planning algorithms, as well as development of criteria for intraoperative radiological assessment of the quality of the restoration of the proximal femur anatomy.