RU2381009C2 - Method for evaluation of external rotation contracture of hip joint - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine and covers evaluation of the external rotation contracture of hip joints by computed tomography (CT) sections. The patient undergoes the CT of hip joints. The CT section containing a transverse section of femoral bone at the level of greater trochanter, neck and head, and also a section of cotyloid cavity is used to determine a longitudinal axis of neck and head of the femoral bone with using an ischiometre. A line of the longitudinal axis of neck and head of the femoral bone and a line connecting anterior and posterior edges of cotyloid cavity are restored. It is followed with finding a cross point of said line and the line of the longitudinal axis of neck and head of the femoral bone. An intersection angle of two lines is determined to be related with the axial inclination of neck and head of the femoral bone in the cotyloid cavity. The difference of the derived axial inclination of neck and head of the femoral bone in the cotyloid cavity and a normal axial inclination of neck and head of the femoral bone in the cotyloid cavity that corresponds to the external rotation contracture of hip joint.

EFFECT: method allows for rapid and reliable external rotation contracture of hip joints by the CT sections.

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Description

The invention relates to medicine, namely to radiation diagnostics, and can be used in orthopedics for early diagnosis and timely effective treatment of revealed pathology.

A known method for determining the magnitude of the external rotational contracture of the hip joint (Orthopedic diagnostics: Guide-reference. / V.O. Marx. - Minsk: Science and technology, 1978. - P.67-91) using the goniometer. However, this technique does not allow to accurately determine the horizontal inclination of the head and neck of the femur in the acetabulum, the knowledge of which is important for hip joint replacement.

The concept of horizontal inclination and its magnitude lead N.V. Kornilov et al. In the book: “Surgical treatment of degenerative-dystrophic lesions of the hip joint” / N.V. Kornilov, A.V. Voitovich, V.M. Mashkov, G.G. Epstein. - SPb., 1997 .-- 291 p. and others) and A.I. Kolesnik (New technological solutions and prevention of complications in hip joint replacement. Diss. Doctors of medical sciences / A.I. Kolesnik; MMA named after I.M.Sechenov. - M., 2002. - P.110), however, the authors do not describe the methodology for determining the horizontal inclination of the head and neck of the femur in the acetabulum.

The objective of the invention is to develop a reliable method for determining the degree of external rotational contracture of the hip joint.

The task is achieved in the following way.

A CT scan of the hip joints is performed on the patient in a diagnostic plan, and a CT section including a transverse section of the femur at the level of the greater trochanter, neck and head, as well as a section of the acetabulum, determine the longitudinal axis of the neck and head of the femur using an ischiometer, and then restore the longitudinal line the axis of the neck and head of the femur, then restore the line connecting the front and rear edges of the acetabulum, find the intersection point of this line with the line of the longitudinal axis of the neck and head the femur, determine the value of the angle of intersection of the two lines, which will correspond to the value of the axial inclination of the neck and head of the femur in the acetabulum, then find the difference between the obtained value of the axial inclination of the neck and head of the femur in the acetabulum and the normal value of axial inclination of the neck and head of the femur bones into the acetabulum, which will correspond to the size of the external rotational contracture of the hip joint.

The invention is illustrated by drawings.

In figure 1. A CT section is shown, including a transverse section of the femur at the level of the greater trochanter, neck and head, as well as a section of the acetabulum.

In figure 2. shows a CT slice with the determination of the longitudinal axis of the neck and femoral head using an ishiometer.

In figure 3. shows a CT slice with drawn lines to determine the angle of the outer rotational contracture.

The method is as follows.

Before the operation, the patient performs CT of the hip joints and on one of the CT sections, on which there is a transverse section of the femur at the level of the greater trochanter, neck and head, as well as the section of the acetabulum (Fig. 1), we determine the longitudinal axis of the neck and head of the femur with using an ischiometer (figure 2).

Next, we restore the line of the longitudinal axis of the neck and femoral head AA1 (Fig. 3), which passes through the center of the head and the middle of the femoral neck. However, due to the presence of severe forms of coxarthrosis in patients and, accordingly, deformations of the femoral heads (Fig. 1), we first determine the center of the head and the middle of the femoral neck using an ishiometer and the technique described by O.V. Marx, which he used to determining the center of the head and the middle of the neck of the femur on the face radiographs of the hip joints (Orthopedic diagnostics: Manual-reference. / V.O. Marx.- Minsk: Science and technology, 1978. - S.400-402).

To do this, we compare the image of the head cut with concentric circles (Fig. 2) and determine the center of the head O (Fig. 3). If there are difficulties in determining the center of the head associated with the presence of severe deformation of the head, we compare the concentric circles of the ischiometer with the curvature of the articular surface of the acetabulum and determine the size of the concentric circle of the ischiometer that will correspond to the size of the femoral head (O.V. Marx, 1978). A certain concentric circle is compared with the contour of the undeformed part of the deformed head and mark the center of the head O (Fig.3). Noting the center of the head and without shifting the ishiometer, we find the intersection points of M and H (Fig. 3) of the concentric circles with the contours of the front and back edges of the neck in the part farthest from the head (at the base of the edge of the greater trochanter) and restore the SD line (Fig. 3 ) The middle O1 of the line of diabetes (Fig.3), drawn through the points of intersection of M and H of concentric circles with the contours of the neck, and will be the middle of the neck of the femur.

Then restore the line BB1 (figure 3), which connects the front and rear edges of the acetabulum.

We find the intersection point of the line BB1 with the line of the longitudinal axis of the neck and femoral head AA1 (Fig. 3) and determine the angle α formed by the intersection of lines BB1 and AA1. This angle value will correspond to the axial inclination of the neck and femoral head into the acetabulum.

Then we find the difference between the obtained value of the axial inclination of the neck and head of the femur in the acetabulum and the normal value of the axial inclination of the neck and head of the femur in the acetabulum, which will correspond to the value of the external rotational contracture of the hip joint. According to A.I.Kolesnik (A.I. Kolesnik, New technological solutions and prevention of complications in hip joint arthroplasty: Doctor of Medical Sciences / A.I. Kolesnik; Sechenov MMA. - M., 2002. - С .295), the average inclination value of the longitudinal axis of the neck and femoral head into the acetabulum in the horizontal plane on the CT slice is 66 degrees.

Clinical example. Patient Abramov S.N. On August 15, 1956, he was admitted to the traumatology department of the Design Bureau No. 1 of Kursk on October 3, 2007. Diagnosis at admission: right-sided dysplastic coxarthrosis of the 3rd stage, decompensated form, severe pain, external rotational contracture of the right thigh. NF of the right hip joint of the 3rd degree.

In a clinical study in a patient using an inclinometer, an external rotational contracture of the right hip joint of 27 degrees was determined. To clarify the diagnosis and anatomical and morphological disorders of the hip joint and surrounding soft tissues, the patient underwent CT of the hip joints at 3 levels. On CT sections, the external rotational contracture of 23 degrees was determined using the method used.

During preoperative planning, a decision was made to perform intraoperative elimination of external rotational contracture.

Thus, this method allows you to quickly and reliably determine the angle of axial inclination of the head and neck of the femur into the acetabulum and determine the magnitude of the external rotation of the femur (external rotational contracture), which allows us to develop a specific surgical plan in the preoperative period and, if necessary, perform intraoperative correction identified pathology.

Claims (1)

A method for determining the external rotational contracture of the hip joints by computed tomographic (CT) sections, characterized in that the patient is diagnosed with CT scan of the hip joints and CT section, including a transverse section of the femur at the level of the greater trochanter, neck and head, as well as section of the acetabulum, determine the longitudinal axis of the neck and head of the femur using an ischiometer, and then restore the line of the longitudinal axis of the neck and head of the femur, then restore t the line connecting the front and rear edges of the acetabulum, find the intersection point of this line with the line of the longitudinal axis of the neck and head of the femur, determine the angle of intersection of the two lines, which will correspond to the axial inclination of the neck and head of the femur in the acetabulum, then find the difference between the obtained value of the axial inclination of the neck and femoral head in the acetabulum and the normal axial inclination of the neck and femoral head in rtluzhnuyu cavity, which will correspond to the value of the outer rotational contracture of the hip joint.

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