Email this article Development of mathematical methods for calculation of the pubic arch angle
- Authors: Mudrov V.A.1, Mochalova M.N.1, Mudrov A.A.1
-
Affiliations:
- Chita State Medical Academy
- Issue: Vol 67, No 6 (2018)
- Pages: 106-111
- Section: Articles
- URL: https://journals.rcsi.science/jowd/article/view/10976
- DOI: https://doi.org/10.17816/JOWD676106-111
- ID: 10976
Cite item
Full Text
Abstract
Hypothesis/aims of study. The frequency of adverse intranatal outcomes is significantly increased when the pubic arch angle (PAA) is less than 90°. The accuracy of the manual method for determining PAA depends on a large number of parameters, such as obesity of a woman, as well as stereometric sensation and the experience of a doctor. Determination of PAA using ultrasound and X-ray pelviometry is generally available and reliable; however, it requires special training. The aim of this study was to develop mathematical methods for calculation of PAA.
Study design, materials and methods. The study included a retrospective and prospective analysis of 120 birth histories based on the Regional Clinical Hospital Perinatal Center (the Chita city, the years 2017/2018), which were divided into three equal groups. Group 1 consisted of patients with body weight deficit, group 2 included patients with normal body mass index, and group 3 comprised patients with alimentary constitutional obesity. On the eve of the birth, external pelviometry, the manual method for determining PAA, and ultrasound pelviometry by translabial access were performed.
Results. PAA determined by the manual method was 99.6 ± 11.3° in group 1, 100.1 ± 14.2° in group 2, and 98.2 ± 10.7° in group 3. When ultrasound pelviometry was performed, the value of PAA was 97.4 ± 10.7° in group 1, 104.8 ± 13.8° in group 2, and 104.1 ± 12.3° in group 3. The error of the manual method was 2.2% in group 1, 4.5% in group 2, and 7.6% in group 3. On the basis of mathematical modeling of external pelviometry data, a pattern is defined, which is expressed by the formula: PAA = 180° – arccos (0,5 ∙ S1S2/S1P) – arccos (0,5 ∙ B1B2/(B2S1 – S1P), where PAA is the pubic arch angle (°); S1S2, Distantia spinarum; S1P, the distance between the anterior superior spine of the ilium to the lower edge of the symphysis; B2S1, the distance between the anterior superior spine of the ilium to the tuberosity of the opposite ischium; B1B2, the transverse size of the output plane. The coefficient of determination (R-squared) is 0.82. Thus, mathematical modeling allows determining PAA with a high degree of reliability.
Full Text
##article.viewOnOriginalSite##About the authors
Viktor A. Mudrov
Chita State Medical Academy
Author for correspondence.
Email: mudrov_viktor@mail.ru
MD, PhD, Associate Professor, Department of Obstetrics and Gynecology, the Medical and Dental Faculties
Russian Federation, ChitaMarina N. Mochalova
Chita State Medical Academy
Email: marina.mochalova@gmail.com
MD, PhD, Associate Professor, the Head of The Department of Obstetrics and Gynecology, the Medical and Dental Faculties
Russian Federation, ChitaAndrey A. Mudrov
Chita State Medical Academy
Email: andrey.mudrov@mail.ru
Student, Medical Faculty
Russian Federation, ChitaReferences
- Письмо Министерства здравоохранения РФ № 15-4/10/2-3402 от 23 мая 2017 г. О направлении клинических рекомендаций (протокола лечения) «Оказание медицинской помощи при анатомически и клинически узком тазе». [Letter from Ministry of Health care №15-4/10/2-3402 from 23 May 2017 “O napravlenii klinicheskikh rekomendatsiy (protokola lecheniya) “Okazanie meditsinskoy pomoshchi pri anatomicheski i klinicheski uzkom taze””. (In Russ.)]
- Albrich SB, Shek K, Krahn U, Dietz HP. Measurement of subpubic arch angle by three-dimensional transperineal ultrasound and impact on vaginal delivery. Ultrasound Obstet Gynecol. 2015;46(4):496-500. doi: 10.1002/uog.14814.
- Gilboa Y, Kivilevitch Z, Spira M, et al. Pubic arch angle in prolonged second stage of labor: clinical significance. Ultrasound Obstet Gynecol. 2013;41(4):442-446. doi: 10.1002/uog.12304.
- Rizzo G, Aiello E, Bosi C, et al. Fetal head circumference and subpubic angle are independent risk factors for unplanned cesarean and operative delivery. Acta Obstet Gynecol Scand. 2017;96(8):1006-1011. doi: 10.1111/aogs.13162.
- Эберхард М. Ультразвуковая диагностика в акушерстве и гинекологии. - М.: МЕДпресс-информ, 2011. [Eberhard M. Ul’trazvukovaya diagnostika v akusherstve i ginekologii. Moscow: MEDpress-inform; 2011. (In Russ.)]
- Korhonen U, Taipale P, Heinonen S. Assessment of bony pelvis and vaginally assisted deliveries. ISRN Obstet Gynecol. 2013;2013:763782. doi: 10.1155/2013/763782.
- Левин И.А., Манухин И.Б., Пономарева Ю.Н., Шуметов В.Г. Методология и практика анализа данных в медицине. - М.: АПЛИТ, 2010. [Levin IA, Manukhin IB, Ponomareva YN, Shumetov VG. Metodologiya i praktika analiza dannykh v meditsine. Moscow: APLIT; 2010. (In Russ.)]
- Колесов В.В. Математика для медицинских вузов: учебное пособие. - М.: Феникс, 2015. [Kolesov VV. Matematika dlya meditsinskikh vuzov: uchebnoe posobie. Moscow: Feniks; 2015. (In Russ.)]
- Autodesk. Официальный курс обучения пакету 3ds MAXНТ. - М.: НТ Пресс, 2007. [Autodesk. Ofitsial’nyy kurs obucheniya paketu 3ds MAXNT. Moscow: NT Press, 2007. (In Russ.)]
Supplementary files
