Anat Cell Biol.  2014 Mar;47(1):40-43. 10.5115/acb.2014.47.1.40.

Normal stress pattern of the pubic symphysis

• Icke C
• Koebke J

• KMID: 2168855
• DOI: http://doi.org/10.5115/acb.2014.47.1.40

Abstract

The pelvic ring is stressed by external forces: by partial body weight, by ligament tension, and by muscles forces stabilizing the hip joints. For the symphysis ossis pubis there exist data concerning the type and magnitude of stresses. In one-leg-standing pressure, shear forces are predominant, and in both-leg-standing tensile forces are acting on the pelvic ring. Rupture of the symphysis is problematic due to the variety of its movements. Most literature descriptions of stress in the symphysis reflect only the frontal plane. Our intention was to make morphological as well as experimental investigations on the symphysis ossis pubis to delineate how it will be stressed in the horizontal plane. Twenty pubic bones taken from embalmed adult human cadavers (12 male, 8 female) were used. Horizontal and frontal slices (3 mm thick) of the symphyseal part of the os pubis were made. X-rays and densitometric analysis were performed. The width of the symphysis cartilage in the dorsal and the ventral regions was measured on 15 whole skeleton specimens coming from adult human cadavers. For experimental study an embalmed pelvic ring which had no abnormality was used. The symphysis pubis was cut completely in the midsagittal plane and then the ring was stressed via the cranial sacrum. Our results demonstrate that the symphysis is stressed by bending in the horizontal plane in one-leg-standing. In both-leg-standing the symphysis is stressed by tensile forces.

Keyword

Pubic symphysis; Stress; Biomechanics

MeSH Terms

Adult
Body Weight
Cadaver
Cartilage
Hip Joint
Humans
Intention
Ligaments
Male
Muscles
Pubic Bone
Pubic Symphysis*
Rupture
Sacrum
Skeleton

Figure

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  Fig. 1 Study experimental design.

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  Fig. 2 Arrangement of bone trabeculae in the frontal plane. a, run rectangularly to the compact bone delineating the symphyseal cleft; b, compact bone lamella is thicker and denser in the caudal part.

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  Fig. 3 Arrangement of the bone trabeculae in the horizontal plane. d, dorsal bundle; v, ventral bundle; D, dorsal cortical bone; V, ventral cortical bone. The D was thicker and more dense than the V. *Bone trabeculae bundles intersecting each other.

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  Fig. 4 In one-leg-standing the symphyseal cleft is narrowest in its caudal part.

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  Fig. 5 In both-leg-standing the symphyseal cleft widens in all its parts equally.

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