Brief introduction of pelvic measurement

Directory 1 Pinyin 2 Overview 3 Pelvic Clinical Measurement 3. 1 General Examination 3.2 Pelvic Observation, which should include 3.3 Extrapelvic Measurement and 3.4 Pelvic X-ray Measurement 4. 1 Entrance Plane 4.2 Intermediate Plane 4.3 Exit Plane 5 Other 1 Pinyin g ǔ pé né cé lià ng

Conclusion Pelvis is a necessary passage for fetal delivery, and its size and shape have a direct impact on delivery.

The pelvis consists of sacrum, coccyx and two hip bones. Hip bone connects sacrococcygeal joint, pubic symphysis connects in front. The pelvis can be divided into two parts by the line connecting the superior margin of pubic symphysis, iliopubic line and the superior margin of sacrum. Above the line is the false pelvis (also called the big pelvis), and below the line is the real pelvis (also called the small pelvis). False pelvis is not directly related to delivery, but the value of pelvic caliber line can be calculated indirectly by measuring the diameter line of false pelvis. The anatomical structure and diameter scale of true pelvis are very important for delivery.

In order to describe the measured value of pelvic diameter, the pelvic cavity can be divided into three planes, namely, the entrance plane, the middle plane and the exit plane.

Pelvic measurement can be divided into clinical measurement and X-ray measurement, among which the accuracy of X-ray measurement has been recognized by people, but it cannot be classified as routine examination. The usual clinical measurement methods are neither systematic nor comprehensive. Therefore, it is difficult to truly reflect the real situation. Therefore, the following new clinical measurement methods are established on the basis of the usual clinical measurement methods, and they are supplemented and revised for the sake of being systematic and comprehensive.

3 Clinical measurement of pelvis 3. 1 General examination ① Height measurement: Height is related to the size of pelvis, subject to the entrance area, and generally height is proportional to the entrance area of pelvis. The average height of women in North China is 156.8cm, and the entrance area is 143cm2. ② Head observation: Due to scoliosis or pelvic morbidity, the weight center of gravity shifts and the head position is skewed, so whether the head is skewed is of certain significance to the diagnosis of pelvic morbidity. ③ Shoulder observation: Scoliosis and pelvic deformation can lead to shoulder inclination. ④ Spinal examination: Spinal lesions and pelvic lesions interact with each other, and attention should be paid to whether there is scoliosis and kyphosis in the spine. ⑤ Observation of lower limbs: Lesions of lower limbs can be the cause of pelvic pathology, and attention should be paid to the length of lower limbs, paralysis and other lesions.

3.2 Pelvic observation should include ① bilateral iliac crest: the examiner should face the pregnant woman's back and pay attention to whether the bilateral iliac crest is symmetrical and deformed. ② Mie's rhombus in the long summer: exposed to lumbosacral region, regular rhombus can be seen when the pelvis is normal, but asymmetrical if it is a diseased pelvis. ③ Observation of buttocks: For women with normal pelvis, both sides of buttocks are symmetrical, the edges are vertical, the two gluteal grooves are at the same level, and the buttocks are split in the middle. If the above physiological morphology changes, it can be regarded as a sign of pathological pelvis.

3.3 Extrapelvic measurement, in the following order: ① sacrum external diameter measurement: pregnant women take the left position. The left leg flexes and the right leg is straight. The anterior point is below the superior margin of pubic symphysis 1cm, and the posterior point is at the apex of Michaelis area, with a distance of 20.51.02 cm. This diameter line can indirectly estimate the anteroposterior diameter of pelvic entrance. The upper corner of the rhombus corresponds to the position of the spinous process of the fifth lumbar vertebra, and both sides correspond to the posterior superior iliac spine. The lower corner is the intersection of gluteal muscles on both sides. The spinous process of the fifth lumbar vertebra is about 2 ~ 2.5 cm above the midpoint of the line between the two posterior superior iliac spines, and also about 65438±0.5cm below the midpoint of the line between the two iliac ridges. If the diamond shape is not obvious, the position of the spinous process of the fifth lumbar vertebra can be found according to the iliac crest line. ② Measurement of the diameter between iliac spines: The pregnant woman lies on her back, and the data point is the outer edge of the two anterior superior iliac spines, and the distance is 25.2 1.4 1cm+0 cm. This path indirectly estimates the transverse diameter of the entrance. ③ Measurement of the inter-iliac crest diameter: The iliac crest is an arch structure with no definite data points. When measuring, trace the two ends of the measuring ruler along the outer edges of the two ridges to the maximum distance between the two ridges, that is, the diameter between the iliac ridges, which is also used to estimate the transverse diameter of the entrance. The spacing is 28.4 1. 1 1 cm. After the above measurement, the pregnant woman's legs are slightly bent, and the examiner faces * * *, and the following examination is carried out. ④ Height of the anterior pelvis: the pelvic depth is estimated. The upper point is the upper line of the transverse branch of pubic bone, and the lower point is the middle area of ischial tubercle. The distance is 9.3±0.75cm⑤. ⑤ The pubic symphysis height is also an index to estimate the pelvic depth. The upper point is the upper edge of pubic symphysis and the lower point is its lower end. 5.6 0.48cm ⑥ Examination of pubic arch: The curvature of pubic sciatic branch can be known by sliding both thumbs down along pubic branch, so it can be estimated whether the pubic arch is female or male, and its apex angle is 84.20 7.35. ⑦ outlet transverse diameter: the distance between two ischial tubercles, and pregnant women lie on their backs. Hold your knees tightly with both hands, so that the hip joint and knee joint can fully flex and the ischial tubercle can protrude. The distance from the inner edge of the anterior point of ischial tubercle is measured, and the clinical measurement value is 9.0±0.75cm. This diameter line is the transverse diameter of pelvic outlet, which is generally measured by Thoms and Delee. 8. The anteroposterior diameter of the outlet is the distance from the lower edge of pubic symphysis to the external surface of sacrococcygeal joint, which is12.31.17cm. ⑨ Posterior sagittal diameter of outlet: the distance from the midpoint of transverse diameter of outlet to the external surface of sacrococcygeal joint is 9.3±0.8cm; ⑩ Anterior and posterior diameter of available outlet: When practical, the anterior and posterior diameter of available outlet can be directly measured by Coriolis pelvic outlet measuring instrument. If the value exceeds 10.0cm, the fetal head with good flexion can pass through the outlet, for example, when the fetal head gives birth in the pillow position. Kirschner wire pelvic outlet measuring instrument is designed by combining the dynamics of delivery and the special shape of pelvic outlet. Its main body is a semicircular plate with a diameter of-9.5 cm, which represents the diameter between the two tops of the normal fetal head. The handle is connected to the right side of the semicircular plate. When in use, the semicircular plate is placed in the pubic arch area with the left hand to show the real state of the fetal head passing through the pubic arch area. Several radial lines on the semicircular plate are used to measure the transverse diameter of the outlet. The top end of the semicircular plate is attached with a bending ruler, and the user can put the end of the bending ruler on the outer surface of the sacrococcygeal joint with his right hand, so that the value of the available outlet diameter can be measured.

3.4 Intra-pelvic measurement When estimating pelvic type and size, internal measurement is more important and valuable than external measurement. Need to measure: ① Anterior and posterior diameter of the middle section: put the middle finger and the middle finger in * * * to check the coccyx activity and sacrococcygeal joint position, then move the index finger up to touch the transverse process of the 4th-5th sacrum joint, and use it as the posterior measuring point, and the anterior measuring point is at the lower end of pubic symphysis. The spacing is 1 1.5 0.64 cm. ② Middle transverse diameter: The distance between two ischial spines can be measured with a ruler, which is10.0 0.66 cm. ③ The bottom of the ischial notch: it is the distance from the ischial spine to the lateral margin of sacrum, and there is an oblique sacrospinal ligament between them. The width can be estimated by putting the right hand food and the middle finger on it, which is generally three fingers wide. At the same time, pay attention to whether the bottoms of both sides are consistent, such as one side is wide and the other side is narrow, suggesting the existence of pathological pelvis. ④ Palpation of the anterior sacral surface: The anterior sacral surface is smooth with proper curvature, which is beneficial to the rotation of the fetal head in the pelvic cavity. ⑤ Inner diameter of sacrum: it is the distance from the lower edge of pubic symphysis to the sacral promontory. The examiner puts the food of the hand and the middle finger in front of the sacrum. On the one hand, measure sacrum concavity. On the other hand, look for the sacral promontory. When looking for the sacral promontory, put the tip of the middle finger on the sacral promontory, and stick the upper edge of the index finger on the lower edge of the pubic symphysis. Fix this contact point as accurately as possible with the index finger of the other hand, then take out your hand and measure the distance from the tip of the middle finger to the marked point on the index finger, which is the length of the inner diameter of the sacrum (also called diagonal diameter). The normal value should be greater than11.5 ~12cm. During the examination, if the root of the thumb has touched the lower edge of the pubic arch, but the middle fingertip still can't touch the sacral promontory, the internal diameter of the sacrum is about 1 1.5 ~ 12 cm. This diameter minus 1.5 ~ 2 cm is the length of the anteroposterior diameter of the pelvic entrance.

X-ray measurement of pelvis is more direct and accurate than clinical measurement. In addition to measuring the anatomical diameter of pelvis, we can better understand the shape of pelvis, the size and position of fetal head and the relationship between head and pelvis. Therefore, it is of great value to diagnose the relationship between head and pelvis. X-ray measurement projects three films, namely lateral image, entrance image and pubic arch image. The following radial lines can be measured by x-ray.

4. The entrance plane1starts from the protruding point below the superior margin of pubic symphysis 1cm, passes through sacroiliac joint along two iliopubic lines, and intersects at a point below the posterior sacroiliac promontory 1 ~ 2 cm. There are five radial lines on this plane: ① The distance between the two data points before and after the radial system is11.61.44 cm. ② The maximum distance between two iliopubic lines in the transverse diameter system is12.3 0.67 cm. ③ The distance from the center of transverse diameter to the posterior point in the posterior sagittal diameter system is 5.2±0.76cm. ④ The oblique diameter is equal to the left and right oblique diameter between one sacroiliac joint and the opposite iliopubic tubercle. ⑤ The inner diameter of sacrum is the distance from the lower edge of pubic symphysis to the headland, and its length is13.3 0.92 cm.

4.2 The middle plane starts from the lower end of pubic symphysis, passes through two ischial spines and the bottom of ischial notch, and reaches the 4th-5th sacrum joint. There are three radial lines on this plane: ① The front and rear diameter is the distance between the front and rear points, which is12.2 0.92 cm. ② The transverse diameter is the distance between two ischial spines, and the length is10.5 0.69 cm. ③ The distance from the midpoint of the transverse diameter of the posterior sagittal diameter system to the 4th to 5th sacral joints is 4.4±0.73cm.

4.3 The exit plane encircles the two ischial tubercles from the sacral end and reaches the lower end of pubic symphysis along the two pubic ischial branches. The posterior margin is bounded by the tubercle ligament of sacrococcygeal bone, and the coccyx can move freely, such as sacrococcygeal joint fixation, and the posterior point is the coccyx end. The exit plane consists of two triangles in different planes. The top of the anterior triangle is the lower edge of pubic symphysis, and the descending pubic branch is on both sides. The sacrococcygeal joint is at the top of the posterior triangle, and the sacrococcygeal ligament is on both sides. The base of two triangles is the connecting line of ischial tubercle.

The ischial tubercle has a long oval structure, and there is a bend at the transition between the posterior end and the ischial body, which is the distance point of the outlet transverse diameter. The distance between the two distance points is the outlet transverse diameter, and the length is11.8 0.69 cm. The anteroposterior diameter is the distance from the lower edge of pubic symphysis to the end of sacrum, and the length is11.8 0.87 cm. The distance from the midpoint of the transverse diameter of the posterior sagittal diameter system to the end of sacrum is 5.7 0.94 cm. The angle of pubic arch is the apex angle of the triangle before the exit, which is 87.6 7.3. The pubic arch was 88.2% in females and 1 1.8% in males.

5 others ① The height of pubic symphysis is the distance between the upper and lower edges of pubic symphysis, with a length of 4.2±0.36cm and a width of 0.5 0.2 cm ② The length of sacrum is the vertical distance from the point of sacrum to the end of sacrum, which is11.81.22 cm, and its width refers to the width of the upper ends of the two sacrum wings. 72.5% of the sacrum is moderately curved, 65,438+06.4% is completely upright, and 65,438+065,438+0.1%is extremely curved. ③ The inclination of the pelvic side wall refers to the mutual inclination of the two sides, which can be obtained by comparing the values of the transverse diameter of the entrance and the transverse diameter of the exit. The difference between the two radial lines is less than 0.5cm, accounting for 50.1%; Cohesion occurs when the transverse diameter of the entrance is greater than 0.5cm from the transverse diameter of the exit, accounting for 48.3%. Abduction occurs when the entrance transverse diameter is less than 0.5cm above the exit transverse diameter, accounting for 65,438+0.6%. ④ Pelvic inclination refers to the angle formed between the pelvic entrance plane and the horizon when standing, with an average of 565,438 0.2, which can decrease with age.