METHOD OF X-RAY DETERMINATION OF RELATIVE CHANGES OF EXTREMITY LENGTH AT HIP JOINT LEVEL Russian patent published in 2013 - IPC A61B6/00 

FIELD: medicine.

SUBSTANCE: invention relates to field of medicine, namely to traumatology and orthopedics, and can be applied in determination of change of affected extremity length, which represents manifestation of hip joint pathology with change of position of its elements relative to vertical axis. Method consists in obtaining X-ray images of examined joints, selection of reference point - greater trochanter top on images, determination of selected reference point projection on reference line, measurement of distances from selected reference point projection to projection of elements of hip joint on reference line, comparison of said distances and determination of extremity length changes. As additional X-ray reference points on images, point of teardrop figure top, lateral point of terminal line of aperture of pelvis minor, cranial point of support surface of acetabular roof, point, corresponding to lower edge of sacroiliac joint, cranial point of femur head are selected. As reference lines, Keller's line and median vertical axis of femur are selected. After that, on each image determined are: sacro-acetabular distance, height of acetabulum, height of clearance between pelvic bone and hip head, height of hip bone head location above acetabulum. For each of images said parameters are used to calculate vertical indices of acetabula - VIA (1,2), indices of upper lateral clearance of hip joint IULC (1,2), supratrochanteric indices of hip head SIHH (1,2); after which indices of vertical acetabular-hip ratio IVAHR 1 and IVAHR 2 are determined by formulas: IVAHR1= VIA1 - IULC1 - SIHH1; IVAHR2= VIA2 - IULC2 - SIHH2.

EFFECT: application of claimed invention makes it possible to carry out X-ray assessment in reliable way, determine ratio of length of lower extremities at the level of hip joints; as well as quantitatively determine change of length of one of extremities on a series of hip joint X-ray images, taken at different time.

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