Comparative analysis of applying an advanced rod monolateral external fixator with the classical method of long tubular bones distraction based on a circular multi-axis system in achondroplasia

The work aimed to evaluate the effectiveness of the developed distraction system based on the rod external monolateral fixation mechanisms by comparing it with the classical technique of long tubular bones distraction based on the circular multi-axial system. The study included patients with a genetically confirmed diagnosis of achondroplasia. The main group consisted of 14 patients who underwent surgical limb lengthening by the rod monolateral external fixator with a distraction system developed by the authors.). In the majority of patients of the main group the lengthening value close to the planned one as well as the deformation correction was achieved. The fixation period was averagely 83.8±3.7 days, the regenerate length was 8.5±0.6 cm, and the mechanical strength of the distraction regenerate was 10.3±2.18º. The fixation time was significantly lower, and the length of the regenerate was longer compared to that in the control group. The rod external fixator with a control distraction system developed by the authors has small dimensions and low weight of the external supporting elements of high durability. It is reported to provide a good psychological tolerance of the treatment process and significantly outperforms the circular multi-axis system.