The results of the use of the telescopic intramedullary system in the surgical treatment of patients with osteogenesis imperfecta types I and III

Background. The main orthopedic manifestation of osteogenesis imperfecta is multiple fractures. In severe disease, frequent fractures lead to malunion and deformity, which increases the risk of refracture. Surgical treatment of children with osteogenesis imperfecta is aimed at reducing the risk of complications and improving the quality of life of the child. The Fassier-Duval telescopic intramedullary system has taken the leading place among the “growing” metal fixators. In this study, we conduct a comparative analysis of the results of a longitudinal study between patients with osteogenesis imperfecta types I and III, as well as an assessment of motor activity.

Aim. To evaluate the efficiency of using the telescopic intramedullary system depending on the type of osteogenesis imperfecta.

Materials and methods. A prospective analysis of surgical treatment of 20 children with types I and III was carried out. Group I included 8 patients with type I NO, group II included 12 with type III. The average age of patients was 8.2 years. Surgical treatment was carried out on the basis of the neuroorthopedic department with orthopedics of the National Medical Research Center for Children's Health. A total of 48 intramedullary telescopic pins were installed. The average period of postoperative dynamic follow-up was 42 months. The analysis of the results of surgical treatment was carried out according to the following criteria: the frequency of migrations of metal structures, the formation of bone deformities, the number of revisions, as well as the number of bone fractures with an installed metal fixator. Evaluation of the results of motor activity was carried out using two scales: Gillette Functional Assesment Questionnaire (Gillette FAQ) and Hoffer–Bullock.

Results. There were no statistical differences in the number of complications in the two groups. Fractures among patients with type I occurred more often than in patients with type III by 19.3%. The frequency of migrations in the I study group was 7.1% (1 segment), in the II group 35.3% (12 segments). The formation of deformation was the main factor in the revision intervention, which in our case amounted to 83.3%. In the group of patients with type I, the number of repeated operations was 7.1% (1 segment in 1 patient), in the group of patients with type III – 17.6% (6 segments in 4 patients). All patients in the postoperative period had II or I level of motor capabilities on the Hoffer–Bullock scale. According to the Gillette FAQ scale in the postoperative period, the subjects showed a result above 4 points.

Conclusion. The Fassier-Duval telescopic rod is a modern and reliable metal fixator. Despite the absence of statistical differences in the two study groups (p-value²<0.005), there was an increase in the tendency to complications in severe course with NO. Correction of varus deformation when restoring normal values of DN>125° and HEA within 25–38° is the prevention of the re-formation of the truth of Coxa Vara. The motor activity of children with severe course did not statistically differ from children with mild course (p-value²>0.005) in the postoperative period with an average follow-up period of 42 months, regardless of the initial low motor capabilities in children with type III.