Differentiated Approach to Surgical Treatment of Blount's Disease and Rickets-Like Diseases

Abstract

Relevance. Blount's disease and vitamin-D-dependent rickets (VDDR) are nosologically different skeletal diseases in childhood. Considering the similarity of the clinical and radiological picture, orthopedists and pediatricians make mistakes in diagnostics, which leads to wrong treatment tactics.
 Objective: to establish clear indications for surgical treatment of Blount's disease and rickets-like diseases.
 Materials and Methods. Surgical treatment of 13 patients with varus lower extremity deformities with vitamin-D-dependent rickets and 29 patients with Blount's disease was carried out; 26 and 42 surgical interventions were made, respectively. The patients' age ranged from 6 months to 14 years.
 Results. Multilevel osteotomies with blocking and growing intramedullary rods should be performed for the treatment of rickety deformities. Applied plates are used only in single-level corrective osteotomies. The use of eight-shaped plates is indicated in the process of the growth zone functioning. In Blount's disease, we recommend: (1) blocking growth zones in patients with 1-4 degrees of deformity, II-VI stages according to Langenskiöld, and skeletal maturity of 23 to 33 points; (2) semicircular dissection in patients with 1-2 degrees of deformity, I-II stages according to Langenskiöld, and skeletal maturity of 18 to 23 points; (3) corrective osteotomies combined with simultaneous blocking of growth zones in patients with 3-4 degrees of deformity, V-VI stages according to Langenskiöld, and skeletal maturity of 30 to 33 points.
 Conclusions. The presented laboratory diagnostics enables differentiate diagnostics of the etiological affiliation of the varus deformity of the lower leg. If rickets is detected, pathogenetic conservative treatment should be performed; in case of Blount's disease, surgical treatment should be started using minimally invasive methods. In the absence of positive dynamics in case of rickets, guided growth should be applied. In case of multiplanar deformities, one should apply the methods of corrective and reinforced surgical treatment: multilevel osteotomies with a blocking intramedullary rod after the closure of the growth zones and osteotomy with a telescopic intramedullary rod in case of preserved growth zone. If Blount's disease is diagnosed early, timely and correctly, growth zone blocking is the method of choice. In case of recurrence, corrective osteotomies with blockage of growth zones should be performed.