Clinical and experimental study of micro-mobility of fragments of the tibia under external fixation rod

Abstract

Research the mobility of bone fragments after the fracture and its impact on reparative regeneration is essential and urgent. Physical parameters (amplitude, direction of displacement), transposition of fragments that stimulate regeneration and, con­versely, destroy regenerate should be emphasized out of the un­determined data. It is also necessary to clarify the dependence of these parameters on the location, injury characteristics and bone regeneration stage, is always mobility leads to the forma­tion of callus and its absence to the initial fusion, or should be fragments nobility taken into consideration during implant de­veloping. Objective:to investigate the mobility of tibial fracture fragments under the conditions of external single-rod fixation in the clinical situation. Methods: unilateral external fixation support, which provides the possibility of tibial longitudinal fixation of stiffness adjusting is developed. For clinical studies specific stand developed, allowing self-loaded by patients of damaged leg until the pain symptoms. Using special device load segment and mutual longitudinal displacement of frag­ments recorded. Results: for the first 6 weeks amplitude dis­placement of tibial bone fragments decreased from (2.3 ± 0.2) to (0.8 ± 0.2) mm. The shift occurred under the influence of the axial load of (210 ± 15) to (751 ± 15) N. After 6 weeks fixator stiffness and increased bone regenerate resistance prevented regenerate functional training and restructuring. Conclusions:pain occurring in the area of the fracture may be the mar­ginal criterion of breaking load. The necessary (stimulatory) and acceptable (regenerate nondestroying) amplitudes of bone fragments displacement are specific to each location and type of fracture, under conditions of regeneration stage and fixation.