METHOD FOR PREOPERATIVE PLANNING OF DEROTATION SUPRACONDYLAR OSTEOTOMY OF A FEMORAL BONE IN RECURRENT DISLOCATION OF A PATELLA Russian patent published in 2019 - IPC A61B17/00 

FIELD: medicine.

SUBSTANCE: method for preoperative planning of a derotation supracondylar osteotomy of a femoral bone in recurrent dislocation of a patella consists in performing a computed tomography of the knee joint and detecting individual relationships of anatomical structures of the knee joint in an axial projection. Computer tomography of the knee joint is processed in a program for viewing and processing medical images, axis X is passed through a center of the patella in a program window of the sagittal projection, an Y axis through the center of the patella in a program window of an axial projection, in which a knee joint partition is obtained, in this partition a transcondylar line is passed through the tops of the posterior sections of the femoral condyles, a transverse line through the intercondylar sulcus to the center of the transcondylar line, on the transverse line the hip segment is marked between the anterior and posterior edges of the femoral bone, in the center of this segment, a point is marked, through which a patellar line is passed through the point of the lateral edge of the patella to the center of the femoral segment, an angle of lateralization of the patella n between the patellar line and the anterior portion of the femoral segment is measured. At value of angle n less than or equal to 45° orthopedic correction is not required. If angle n is more than 45° determining the value x – the number of degrees, on which it is necessary to turn femoral condoms to the inside after the above-muscle osteotomy is performed by formula: x=n-y, where y – average lateralization angle normally equal to 40°. If value x is less than 30°, condyles are turned inside by the obtained number of degrees. If the value of x is greater than or equal to 30°, then in that case femoral condyles turn inwards to maximum permissible number of degrees equal to 29°.

EFFECT: invention provides higher accuracy of relation of patellofemoral joint structures.

1 cl, 3 dwg, 2 ex