Application of interlocking intramedullary nailing in fibrous dysplasia of proximal femur / 中华骨科杂志

ABSTRACT

Objective:To retrospectively analyze and evaluate the effect of interlocking intramedullary nail in the treatment of proximalfemoral fibrous dysplasia (FD) and to discuss its application techniques and treatment strategies.Methods:The patients with proximal femoral FD who received treatment with interlocking intramedullary nail in our department from April 2014 to August 2018 were retrospectively reviewed. The inclusion criteria included having complete data with more than 3 years follow-up. A total of 31 cases with 32 thighs were included in the present study. Among them, there were 24 males and 7 females. The mean age at operation was 11.4±2.3 years. The mean follow-up duration was 3.9±1.1 years. The surgical methods were osteotomy or in situ interlocking intramedullary nailing, and femoral neck reconstruction nails pass through the epiphyseal plate in some cases. Preoperative, postoperative and final follow-up radiographic changes, including femoral neck shaft angle, proximal femoral diaphyseal deformity, and femoral alignment were compared. Univariate analysis of the influencing factors of postoperative femoral neck shaft angle loss.Results:In this group, 13 patients had coxa varus deformity, and the angle of the neck shaft was 107.3±7.1°, and 23 patients had the bending deformity of the proximal femur, and angled 29.5°±9.1°. 10 cases of coxa varus combined with proximal femoral diaphyseal deformity received double osteotomy and internal fixation, 17cases of simple coxa varus or diaphyseal deformity received single osteotomy and internal fixation, and 5 cases had no significant deformity, underwent in situ intramedullary nailing due to pathological fractures and pain. Postoperative femoral neck shaft angle was 133.2°±5.2°. Complete correction of proximal femoral flexion deformity was obtained and the diaphyseal axis was within the normal range. At the last follow-up, the neck shaft angle of 7 patients (21.9%, 7/32) decreased from 133.6°±3.9° to 125.7°±3.4°. Univariate analysis showed that the proportion of neck shaft angle loss in cases with proximal femoral locking nails passing through the epiphyseal plate was significantly lower than that in the cases without (0 vs. 43.8%, χ 2=6.58, P=0.010). Conclusion:The application of interlocking intramedullary nails in the treatment of proximal femoral fibrous dysplasia can achieve good results, according to the situation of coxa varus or diaphysis bending deformity, single or double osteotomy can be performed. There is a risk of femoral neck shaft angle loss after surgery, which can be avoided by femoral neck reconstruction locking screw fixation crossing epiphyseal plate.