Pubic symphysis
Encyclopedia
The pubic symphysis or symphysis pubis is the midline cartilaginous
joint
(secondary cartilaginous) uniting the superior rami
of the left and right pubic bones
. It is located anterior to the urinary bladder
and superior to the external genitalia; for females it is above the vulva
and for males it is above the penis
. In males, the suspensory ligament of the penis
attaches to the pubic symphysis. In females, the pubic symphysis is intimately close to the clitoris
. In normal adults it can be moved roughly 2 mm and with 1 degree rotation. This increases for women at the time of child birth.
amphiarthrodial joint, and comes from the Greek word "symphysis", meaning growing together. The anterior width of the symphysis pubis is 3-5 mm greater than its intrapelvic posterior width. This joint is connected by fibrocartilage
and may contain a fluid filled cavity; the center is avascular
, possibly due to the nature of the compressive forces passing through this joint, which may lead to harmful vascular disease. The ends of both pubic bones are covered by a thin layer of hyaline cartilage
attached to the fibrocartilage. The fibrocartilaginous disk is reinforced by a series of ligaments. These ligaments cling to the fibrocartilaginous disk to the point that fibers intermix with it.
Two such ligaments are the superior
and inferior
, these being the ligaments that provide the most stability; the posterior and anterior ligaments are weaker. The strong and thicker superior ligament is reinforced by the tendons of the rectus abdominis
, obliques externus
, gracilis
and thigh adductors muscles
. The inferior ligament in the pubic arch is known as the arcuate pubic ligament.
Fibrocartilage
Fibrocartilage
is composed of small chained bundles of thick, clearly defined, type I collagen
fibers. This fibrous connective tissue bundles have cartilage cells between them; these cells to a certain extent resemble tendon cells. The collagenous fibers are usually placed in an orderly arrangement parallel to tension on the tissue. It has a low content of glycosaminoglycans (2% of dry weight). Glycosaminoglycans are long, unbranched polysaccharides (relatively complex carbohydrates) consisting of repeating disaccharide
units. Fibrocartilage does not have a surrounding perichondrium
. Perichondrium surrounds the cartilage of developing bone; it has a layer of dense irregular connective tissue and functions in the growth and repair of cartilage.
Hyaline cartilage
Hyaline cartilage
is the white, shiny gristle at the end of long bones. This cartilage has very poor healing potential, and efforts to induce it to repair itself frequently end up with a similar, but poorer fibrocartilage.
The main motions of the symphysis pubis are superior/inferior glide and separation/compression. The functions of the joint are to absorb shock during walking and allow delivery of a baby.
. Women have a greater thickness of this pubic disc which allows more mobility of the pelvic bones, hence providing a greater diameter of pelvic cavity during childbirth
.
remodel this ligamentous capsule allowing the pelvic bones to be more flexible for delivery. The non-pregnant gap of the symphysis pubis is 4-5 mm but in pregnancy there will be an increase of at least 2-3 mm, therefore, it is considered that a total width of up to 9 mm between the two bones is normal for a pregnant woman. The symphysis pubis separates to some degree during the birthing process. In some women this separation can become a diastasis of the symphysis pubis
. The diastasis could be the result of a rapid birth or a forceps
delivery or maybe even be prenatal. A diastasis of the symphysis pubis is a symptom of pelvic girdle pain
(PGP). Overall, about 45% of all pregnant women and 25% of all women postpartum suffer from PGP.
technique was available, if labor failed to progress because the head of the fetus was too large, the mother's symphysis pubis was cut and the skull of the fetus was crushed. The Caesarean section has allowed the largely safe delivery of such infants.
In remote, isolated areas, women presenting with a large baby and a small pelvis must travel great distances for medical help; a symphysiotomy
has been suggested. This practice was carried out in Europe before the introduction of the Caesarean section.
, produces widening, while ochronosis
results in calcific deposits in the symphysis. Inflammatory disease, such as ankylosing spondylitis
, results in bony fusion of the symphysis. Osteitis pubis
, the most common inflammatory disease in this area, is treated with anti-inflammatory medication and rest. Degenerative joint disease of the symphysis, which can cause groin pain, results from instability or from abnormal pelvic mechanics.
Cartilage
Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...
joint
Joint
A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...
(secondary cartilaginous) uniting the superior rami
Superior pubic ramus
The superior pubic ramus is a part of the pubic bone which forms a portion of the obturator foramen.It extends from the body to the median plane where it articulates with its fellow of the opposite side...
of the left and right pubic bones
Pubis (bone)
In vertebrates, the pubic bone is the ventral and anterior of the three principal bones composing either half of the pelvis.It is covered by a layer of fat, which is covered by the mons pubis....
. It is located anterior to the urinary bladder
Urinary bladder
The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...
and superior to the external genitalia; for females it is above the vulva
Vulva
The vulva consists of the external genital organs of the female mammal. This article deals with the vulva of the human being, although the structures are similar for other mammals....
and for males it is above the penis
Penis
The penis is a biological feature of male animals including both vertebrates and invertebrates...
. In males, the suspensory ligament of the penis
Suspensory ligament of the penis
In males, the suspensory ligament of the penis is attached to the pubic symphysis, which holds the penis close to the pubic bone and supports it when erect....
attaches to the pubic symphysis. In females, the pubic symphysis is intimately close to the clitoris
Clitoris
The clitoris is a sexual organ that is present only in female mammals. In humans, the visible button-like portion is located near the anterior junction of the labia minora, above the opening of the urethra and vagina. Unlike the penis, which is homologous to the clitoris, the clitoris does not...
. In normal adults it can be moved roughly 2 mm and with 1 degree rotation. This increases for women at the time of child birth.
Anatomy
Symphysis pubis is a nonsynovialSynovium
Synovial membrane is the soft tissue found between the articular capsule and the joint cavity of synovial joints....
amphiarthrodial joint, and comes from the Greek word "symphysis", meaning growing together. The anterior width of the symphysis pubis is 3-5 mm greater than its intrapelvic posterior width. This joint is connected by fibrocartilage
Fibrocartilage
White fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions. It owes its flexibility and toughness to the former of these constituents, and its elasticity to the latter...
and may contain a fluid filled cavity; the center is avascular
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
, possibly due to the nature of the compressive forces passing through this joint, which may lead to harmful vascular disease. The ends of both pubic bones are covered by a thin layer of hyaline cartilage
Hyaline cartilage
Hyaline cartilage consists of a slimy mass, pearly bluish in colour with firm consistency and considerable collagen. It contains no nerves or blood vessels, and its structure is relatively simple....
attached to the fibrocartilage. The fibrocartilaginous disk is reinforced by a series of ligaments. These ligaments cling to the fibrocartilaginous disk to the point that fibers intermix with it.
Two such ligaments are the superior
Superior pubic ligament
The superior pubic ligament connects together the two pubic bones superiorly, extending laterally as far as the pubic tubercles....
and inferior
Inferior pubic ligament
The inferior pubic ligament is a thick, triangular arch of ligamentous fibers, connecting together the two pubic bones below, and forming the upper boundary of the pubic arch.Above, it is blended with the interpubic fibrocartilaginous lamina; laterally, it is attached to the inferior rami of...
, these being the ligaments that provide the most stability; the posterior and anterior ligaments are weaker. The strong and thicker superior ligament is reinforced by the tendons of the rectus abdominis
Rectus abdominis muscle
The rectus abdominis muscle, also known as the "six pack", is a paired muscle running vertically on each side of the anterior wall of the human abdomen . There are two parallel muscles, separated by a midline band of connective tissue called the linea alba...
, obliques externus
Abdominal external oblique muscle
The external oblique muscle is the largest and the most superficial of the three flat muscles of the lateral anterior abdomen.-Structure:...
, gracilis
Gracilis muscle
The gracilis is the most superficial muscle on the medial side of the thigh. It is thin and flattened, broad above, narrow and tapering below.-Origin and insertion:...
and thigh adductors muscles
Muscles of the hip
In human anatomy, the muscles of the hip joint are those muscles that cause movement in the hip. Most modern anatomists define 17 of these muscles, although some additional muscles may sometimes be considered...
. The inferior ligament in the pubic arch is known as the arcuate pubic ligament.
Fibrocartilage
Fibrocartilage
Fibrocartilage
White fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions. It owes its flexibility and toughness to the former of these constituents, and its elasticity to the latter...
is composed of small chained bundles of thick, clearly defined, type I collagen
Collagen
Collagen is a group of naturally occurring proteins found in animals, especially in the flesh and connective tissues of mammals. It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content...
fibers. This fibrous connective tissue bundles have cartilage cells between them; these cells to a certain extent resemble tendon cells. The collagenous fibers are usually placed in an orderly arrangement parallel to tension on the tissue. It has a low content of glycosaminoglycans (2% of dry weight). Glycosaminoglycans are long, unbranched polysaccharides (relatively complex carbohydrates) consisting of repeating disaccharide
Disaccharide
A disaccharide or biose is the carbohydrate formed when two monosaccharides undergo a condensation reaction which involves the elimination of a small molecule, such as water, from the functional groups only. Like monosaccharides, disaccharides form an aqueous solution when dissolved in water...
units. Fibrocartilage does not have a surrounding perichondrium
Perichondrium
The perichondrium is a layer of dense irregular connective tissue which surrounds the cartilage of developing bone. It consists of two separate layers: an outer fibrous layer and inner chondrogenic layer. The fibrous layer contains fibroblasts, which produce collagenous fibers. The chondrogenic...
. Perichondrium surrounds the cartilage of developing bone; it has a layer of dense irregular connective tissue and functions in the growth and repair of cartilage.
Hyaline cartilage
Hyaline cartilage
Hyaline cartilage
Hyaline cartilage consists of a slimy mass, pearly bluish in colour with firm consistency and considerable collagen. It contains no nerves or blood vessels, and its structure is relatively simple....
is the white, shiny gristle at the end of long bones. This cartilage has very poor healing potential, and efforts to induce it to repair itself frequently end up with a similar, but poorer fibrocartilage.
Physiology
Analysis of the pelvis shows the skinny regions function as arches, transferring the weight of the upright trunk from the sacrum to the hips. The symphysis pubis connects these two weight-bearing arches, and the ligaments that surround this pelvic region maintain the mechanical integrity.The main motions of the symphysis pubis are superior/inferior glide and separation/compression. The functions of the joint are to absorb shock during walking and allow delivery of a baby.
Development
In the newborn, the symphysis pubis is 9-10 mm in width, with thick cartilaginous end-plates. By mid-adolescence the adult size is achieved. During adulthood the end-plates decrease in width to a thinner layer. Degeneration of the symphysis pubis accompanies aging and postpartumPostnatal
Postnatal is the period beginning immediately after the birth of a child and extending for about six weeks. Another term would be postpartum period, as it refers to the mother...
. Women have a greater thickness of this pubic disc which allows more mobility of the pelvic bones, hence providing a greater diameter of pelvic cavity during childbirth
Childbirth
Childbirth is the culmination of a human pregnancy or gestation period with the birth of one or more newborn infants from a woman's uterus...
.
Pregnancy
During pregnancy in the human, hormones such as relaxinRelaxin
Relaxin is a protein hormone first described in 1926 by Frederick Hisaw.The relaxin-like peptide family belongs in the insulin superfamily and consists of 7 peptides of high structural but low sequence similarity; relaxin-1 , 2 and 3 , and the insulin-like peptides, INSL3, INSL4, INSL5 and INSL6...
remodel this ligamentous capsule allowing the pelvic bones to be more flexible for delivery. The non-pregnant gap of the symphysis pubis is 4-5 mm but in pregnancy there will be an increase of at least 2-3 mm, therefore, it is considered that a total width of up to 9 mm between the two bones is normal for a pregnant woman. The symphysis pubis separates to some degree during the birthing process. In some women this separation can become a diastasis of the symphysis pubis
Diastasis symphysis pubis
Diastasis symphysis pubis is the separation of normally joined pubic bones, as in the dislocation of the bones, without a fracture.- Diagnosis :...
. The diastasis could be the result of a rapid birth or a forceps
Forceps
Forceps or forcipes are a handheld, hinged instrument used for grasping and holding objects. Forceps are used when fingers are too large to grasp small objects or when many objects need to be held at one time while the hands are used to perform a task. The term 'forceps' is used almost exclusively...
delivery or maybe even be prenatal. A diastasis of the symphysis pubis is a symptom of pelvic girdle pain
Pelvic girdle pain
Pregnancy related Pelvic Girdle Pain causes pain, instability and limitation of mobility and functioning in any of the three pelvic joints...
(PGP). Overall, about 45% of all pregnant women and 25% of all women postpartum suffer from PGP.
Symphysiotomy
Before the Caesarean sectionCaesarean section
A Caesarean section, is a surgical procedure in which one or more incisions are made through a mother's abdomen and uterus to deliver one or more babies, or, rarely, to remove a dead fetus...
technique was available, if labor failed to progress because the head of the fetus was too large, the mother's symphysis pubis was cut and the skull of the fetus was crushed. The Caesarean section has allowed the largely safe delivery of such infants.
In remote, isolated areas, women presenting with a large baby and a small pelvis must travel great distances for medical help; a symphysiotomy
Symphysiotomy
Symphysiotomy is a surgical procedure in which the cartilage of the pubic symphysis is divided to widen the pelvis allowing childbirth when there is a mechanical problem.- Introduction :...
has been suggested. This practice was carried out in Europe before the introduction of the Caesarean section.
Diseases of the symphysis pubis
Metabolic disease, such as renal osteodystrophyRenal osteodystrophy
Renal osteodystrophy or chronic kidney disease-mineral and bone disorder is a bone pathology, characterized by bone mineralization deficiency, that is a direct result of the electrolyte and endocrine derangements that accompany chronic kidney disease...
, produces widening, while ochronosis
Ochronosis
Ochronosis is the syndrome caused by the accumulation of homogentisic acid in connective tissues. The phenomenon was first described by Rudolf Virchow in 1865. The condition was named after the yellowish discoloration of the tissue seen on microscopic examination...
results in calcific deposits in the symphysis. Inflammatory disease, such as ankylosing spondylitis
Ankylosing spondylitis
Ankylosing spondylitis , previously known as Bekhterev's disease, Bekhterev syndrome, and Marie-Strümpell disease is a chronic inflammatory disease of the axial skeleton with variable involvement of peripheral joints and nonarticular structures...
, results in bony fusion of the symphysis. Osteitis pubis
Osteitis pubis
Since 1924, osteitis pubis has been known as a noninfectious inflammation of the pubis symphysis causing varying degrees of lower abdominal and pelvic pain. Osteitis pubis was first described in patients who had undergone suprapubic surgery and remains a well-known complication of invasive...
, the most common inflammatory disease in this area, is treated with anti-inflammatory medication and rest. Degenerative joint disease of the symphysis, which can cause groin pain, results from instability or from abnormal pelvic mechanics.
Injury
The pubic symphysis widens slightly whenever the legs are stretched far apart. In sports where these movements are often performed, the risk of a pubic symphysis blockage is high, in which case, after completion of the movement, the bones at the symphysis do not realign correctly and can get jammed in a dislocated position. The resulting pain can be quite severe, especially on further strain put upon the affected joint. In most cases, the joint can only be successfully reduced into its normal position by a trained medical professional.Use in forensic anthropology
Pubic symphyses have importance in the field of forensic anthropology, as they can be used to estimate the age of adult skeletons. Throughout life, the surfaces are worn at a more or less predictable rate. By examining the wear of the pubic symphysis, it is possible to estimate the age of the person at death.External links
- Pelvic Instability Network Support (PINS) - "Major Joints of the Lower Extremity - hip and sacrum (anterior view)" - "The Male Pelvis: Hemisection of the Male Pelvis"