SU825050A1 - Method of determining mobility of bone fragements - Google Patents

Description

(54) METHOD FOR DETERMINING THE MOBILITY OF BONE FRAME

and when measuring, use the calibration characteristic for the evaluation of "4.

On the ring 1 is a compression distance; In this case, the beam 2 of elastic material, on which the load cells 3 are glued, connected according to the bridge scheme, is fixed. The free end of the beam rests on the needle 4, the curvature of which is measured. The support point of the beam is located on the spoke at a distance L from the edge of the ring.

When the target is damaged by a limb, the fragment 5 is displaced, the spokes in the apparatus bend. The bending of the spokes causes deflection of the beam, which leads to an imbalance of the tensome bridge, which is pre-balanced. The imbalance signal is amplified by a strain amplifier and fed to the recorder, where it is recorded. By knowing the parameters of the beam, the gain of the amplifier and the sensitivity of the recorder, the resulting angle of the fragment is determined by the obtained diagram.

Patients with a superimposed apparatus determine the mutual mobility of the fragments using the following procedure.

Two fragments of bones are placed in a compression-distance apparatus (similar to the imposition of an apparatus on a patient's limb during fractures). One of the fragments deviates relative to the other at a number of fixed angles. The beam with strain gauges is installed at the same distance from the edge of the ring, on which the patient’s mobility measurement is assumed. After that, the movable fragment is deflected to a number of angles c4 and in this case the deviation of the pen of the recorder H is recorded. According to the measurement results, a linear dependence is constructed

 gb,

where g is the conversion factor, which is determined by the known " " > and thereafter, the patient's mobility is measured. From the measured K and the known r, the angle "L.

Example. Sick F., 19 years old, was admitted to the clinic of traumatology and orthopedics with a diagnosis: “A non-growing fracture of both bones of the right tibia in the middle third. The operation - osteosynthesis ended with the fixation of fragments by the Ilizatov apparatus. Upon repeated inspection after 3 months there is no consolidation, provided that the fragments are in the correct position and in contact. However, when determining the mutual mobility of fragments during flexion of the hip at the hip joint, it was 1.2 °, at the knee joint - 0.4 °. When moving in other joints, notes are permissible mutually

mobility of fragments. Based on this, movements in the knee and hip joints were excluded, which soon had a positive effect on the reparative process. After 1.5 months, the fusion occurred

the Ilizatov apparatus was removed, ill returned to work. On radiography, complete consolidation of fragments is noted.

Thus, the method allows to measure with high accuracy both micromobility and macromobility of fragments in

compression-distraction apparatus without additional surgical insertion and eliminates the possibility of callus destruction during the measurement process.

Claims (1)

1. Novitska N.V. and others. A device for an Ilizatov apparatus for determining the mobility of fragments during transosseous osteosynthesis. - “Orthopedists, traumatologists and prosthetics, 1975, No. 4.