Pelvis and hip joint

The bony pelvis (pelvic girdle) is composed of the two hip bones, the sacrum, and the coccyx. These bones are firmly connected by the pubic symphysis anteriorly and the sacrococcygeal and sacroiliac joints posteriorly. Each hip bone consists of three fused bones: the ilium, ischium, and pubis. In female individuals, the pelvis additionally accommodates the birth canal and therefore is larger and wider than in male individuals. The pelvic girdle transmits body weight from the axial skeleton to the lower extremities and provides attachment to a large number of muscles and ligaments. The pelvic cavity is the space within the pelvic girdle; it contains abdominal and pelvic organs, which are protected by the pelvic girdle. Located in the space within pelvic girdle is the pelvic cavity, which provides protection for abdominal and pelvic organs. Anatomical spaces of the pelvic cavity (e.g., rectouterine pouch, rectovesical pouch) vary between male and female individuals because of their different reproductive organs. Located inferior to the pelvic cavity is the pelvic floor, a complex fibromuscular structure that prevents pelvic organ prolapse, helps maintain fecal and urinary continence, and separates the perineal region from the pelvic cavity. Openings in the pelvic floor allow for the passage of the rectum, vagina, and urethra. The gluteal region consists of the muscles that form the buttocks, which can be divided into a superficial and a deep muscle layer. The superficial gluteal muscles abduct and medially rotate the thigh, while the deep gluteal muscles are responsible for lateral rotation of the thigh. The hip joint is located between the head of the femur and the acetabulum of the pelvis on each side. It connects the trunk to the lower extremities and supports dynamic and static body weight. The arterial supply of the femoral head is ensured by the foveolar artery and branches of the deep femoral artery. Movements of the hip joint include flexion, extension, lateral and medial rotation, abduction, adduction, and circumflexion.

The pelvis (pelvic girdle)

• Characteristics
  • A ring-like structure of the axial skeleton that connects the vertebral column to the lower extremities (e.g., femur)
  • Largely immobile; provides stability and supports proper transfer of weight from the vertebral column to the lower extremities, especially in the upright position
  • The shape of the pelvis differs significantly between male and female individuals.
• Bones
  • The hip bones (os coxae): ilium, ischium, pubis
  • Sacrum
  • Coccyx
• Joints: lumbosacral joint, sacroiliac joint, sacrococcygeal joint, pubic symphysis, hip joint
• Ligaments and foramina of the pelvis
  • A number of ligaments (e.g., iliolumbar ligament, sacroiliac ligament) stabilize and support the joints of the pelvis.
  • The foramina of the pelvis (e.g., sciatic foramina, vascular and muscular lacuna) allow the passage of nerves, muscles, blood vessels, and lymphatics.
• Pelvic cavity: the space within the pelvic girdle
  • Allows passage of gastrointestinal and urogenital structures into the pelvis, as well as arteries veins, muscles, and nerves
  • Bounded inferiorly by the pelvic floor, which holds the organs in place
• Pelvic spaces: anatomical spaces of the pelvic cavity
  • In female individuals: rectouterine pouch, vesicouterine pouch
  • In male individuals: rectovesical pouch
  • In both male and female individuals: pararectal fossa, ischiorectal fossa, retropubic space of Retzius
• Birth canal
  • Pelvic form: gynecoid, anthropoid, android, plateylpelloid
  • Pelvic regions: pelvic inlet, pelvic cavity, pelvic outlet
  • Pelvic planes: plane of the pelvic inlet, planes of the greatest and least pelvic dimension, plane of the anatomical outlet
  • Soft tissue structures: inner portion (lower uterine segment, cervix, vagina, vulva), outer portion (pelvic floor)
• Pelvic floor: complex fibromuscular structure that holds the pelvic organs in place; separates the pelvic cavity superiorly from the perineal region inferiorly
  • Layers of the pelvic floor: pelvic diaphragm, urogenital diaphragm, superficial perineal layer
  • Perineal region: an anatomical region inferior to the pelvic floor
    • Urogenital triangle: consists of the perineal membrane and the deep and superficial perineal pouch
    • Anal triangle: consists of the anal canal, the external sphincter muscle, and the ischiorectal fossae
    • Perineum: superficial area between the anus and external genitalia
• Vessels, nerves, and lymphatics
  • Arteries: mainly derived from the internal iliac artery
  • Veins: follow the course of the arteries and are named accordingly
  • Nerves: Innervation is mainly provided by autonomic nerves and the pudendal nerve.
  • Lymphatics: travel along the iliac vessels
• The gluteal region: the group of muscles that form the buttocks
  • Superficial gluteal muscles: gluteus maximus, gluteus medius, gluteus minimus, tensor fasciae latae
  • Deep gluteal muscles: piriformis, obturator internus, superior gemellus, inferior gemellus, quadratus femoris
• Embryology: Development of the pelvis starts around week 4 of embryonic development and originates from the paraxial mesoderm.

The hip joint

• Definition: a joint between the head of the femur and the acetabulum of the pelvis
• Function
  • Connects the axial skeleton to the lower extremities
  • Supports static (e.g., standing) and dynamic (e.g., walking, running) weight
• Type of joint: ball-and-socket synovial joint
• Arterial supply: medial femoral circumflex artery, lateral femoral circumflex artery, foveolar artery
• Movements
  • Flexion and extension, lateral and medial rotation, abduction, adduction
  • The combination of these movements results in circumduction.
• Articular capsule: fibrous capsule that attaches to the margin of the acetabulum, the transverse acetabular ligament, and the neck of the femur

Bones of the pelvis

Hip bones

The anterior superior iliac spine helps to determine the course of the inguinal ligament. It also aids in the identification of the McBurney and Lanz points, which are important anatomical areas where localized tenderness is indicative of appendicitis.

Sacrum and coccyx

For information on the sacrum and coccyx, see “Gross anatomy” in “Vertebral column.”

Pelvic inlet

• Definition: plane that separates the abdominal and pelvic cavities
• Location: superior rim of the pelvic cavity (upper pelvic aperture)
• Boundaries
  • Anterior: pectineal line (pubis), pubic crest, superior margin of the pubic symphysis
  • Posterior: sacral promontory, anterior border of the sacral ala
  • Lateral: arcuate line (ilium)
  • Linea terminalis: the combination of the pectineal line (pubis), sacral promontory, and arcuate line (ilium); forms the boundary of the pelvic inlet
• Diameters: transverse, oblique, conjugate (anteroposterior), anatomical conjugate, diagonal, straight, median
• Structures passing through: ureter, spermatic cord, round ligament of the uterus, suspensory ligament of the ovary, median sacral vessels, gonadal vessels, iliolumbar vessels, lumbosacral trunk, sympathetic trunk, obturator nerve

Pelvic outlet

• Definition: inferior opening of the pelvis
• Location: lower pelvic aperture
• Boundaries
  • Anterior: pubic symphysis, ischiopubic ramus, inferior pubic ligament
  • Posterior: sacrum, coccyx
  • Lateral: ischial tuberosities, sacrotuberous ligaments
  • Inferior: urogenital diaphragm, pelvic diaphragm
• Diameters: sagittal, intertuberous, interspinous

Pelvic form and pelvic diameters

For information on the pelvic form and diameters, see the section “Birth canal” below.

Differences between the male and female pelvis

Joints of the pelvis

• Lumbosacral joint
  • Located between the L5 vertebra and the sacral promontory
  • Stabilized by iliolumbar ligaments
  • Symphysis joint with two facet joints
  • Site of most possible movement of the lumbar spine
• Sacroiliac joint
  • Located between the articular surfaces of the ilium and sacrum
  • Stabilized by the anterior and posterior sacroiliac ligaments
  • Synovial plane joint
  • Transmits weight from the vertebral column to the hip bones
  • Inflammation results in sacroiliitis.
• Sacrococcygeal joint
  • Located between the sacrum and coccyx
  • Stabilized by lateral, anterior, and posterior sacrococcygeal ligaments
  • Cartilaginous joint
• Pubic symphysis
  • Located between the pubic bones in the midline of the body
  • Fibrocartilaginous or cartilaginous joint
  • Compensates shear forces while walking
  • Enables childbirth by partially separating the pubic bones
• Hip joint
  • Formed by the articulation of the femur and the acetabulum
  • Ball and socket joint
  • For more details, see “Hip joint” below.

Ligaments of the pelvis

• Iliolumbar ligament
  • Anterior attachment between the transverse processes of L5 and the ilium
  • Supports the lumbosacral joint
• Anterior sacroiliac ligament
  • Anterior attachment between the ilium and the sacrum
  • Supports the sacroiliac joint
• Posterior sacroiliac ligament
  • Posterior attachment between the ilium and the sacrum
  • Supports the sacroiliac joint
• Sacrospinous ligament
  • Posterior attachment between the sacrum and the ischial spine
  • Supports and immobilizes the sacrum during weight transfer from the vertebral column
• Sacrotuberous ligament
  • Posterior attachment between the sacrum and the ischial tuberosity
  • Supports and immobilizes the sacrum during weight transfer from the vertebral column
• Pubic ligaments
  • Superior pubic ligament: attachment between the two pubic tubercles
  • Inferior pubic ligament: attachment between the two pubic bones inferiorly
  • Support and stabilize the pubic symphysis
• Obturator membrane
  • Spans the obturator foramen
  • Perforated by the obturator canal

For information on the ligaments of the hip joint, see “Hip joint” below.

Foramina of the pelvis

The pelvis contains many openings that allow the passage of nerves, vessels, muscles, and lymphatics.

Pelvic cavity

• Definition: the space within the pelvic girdle
• Structures passing through: parts of the gastrointestinal tract (e.g., colon and rectum), urogenital tract (e.g., ureters, bladder, uterus), major blood vessels (e.g., iliac arteries and their branches), nerves (e.g., pudendal nerve), muscles that attach to the spine and the lower limbs (e.g., psoas muscle and iliacus muscle)
• Openings
  • Superior opening: formed by the pelvic inlet
  • Inferior opening: formed by the pelvic outlet
• Boundary: pelvic floor (holds pelvic organs in place)

Pelvic spaces

The pelvic spaces include peritoneal spaces located within the pelvic cavity and extraperitoneal anatomical spaces of the pelvic cavity. They vary significantly between male and female individuals due to their different reproductive organs.

• In female individuals
  • Rectouterine pouch (pouch of Douglas)
    • Peritoneal space formed by an indentation in the layer of peritoneum covering the uterus, vagina, and the anterior rectum
    • The lowest part of the peritoneal cavity in the upright position in female individuals, where intraperitoneal fluid (e.g., ascites, blood, pus, malignant cells) and endometrial implants preferentially collect
  • Vesicouterine pouch
    • Peritoneal space formed by the peritoneal cover of the fundus and body of the uterus posteriorly and the posterosuperior surface of the bladder anteriorly
    • Bounded posterolaterally by the broad and round ligaments of the uterus
• In male individuals
  • Rectovesical pouch (pouch of Douglas)
    • Peritoneal space formed by an indentation in the layer of peritoneum that covers the posterior bladder and anterior rectum
    • The lowest part of the peritoneal cavity in the upright position in male individuals, where intraperitoneal fluid (e.g., ascites, blood, pus) preferentially collects
• In female and male individuals
  • Pararectal fossa
    • Peritoneal space formed by folds of peritoneum on either side of the rectum and the lateral wall of the pelvis
    • Laterally continuous with the rectovesical pouch in male individuals and the rectouterine pouch in female individuals
  • Ischiorectal fossae
    • Extraperitoneal, fat-filled spaces inferior to the pelvic diaphragm
    • Surround the anal canal
    • Lateral walls contain the pudendal nerve on each side of the Alcock canal.
    • Allow expansion of the anal canal during defecation
  • Retropubic space: extraperitoneal, fat-filled space between the pubis and the anterior surface of the bladder

Pelvic form

• Gynecoid (most common female form): transverse oval inlet, wide sacrum, wide sacrosciatic notch, straight side walls, wide subpubic angle
• Anthropoid (common in male individuals): long anterior-posterior diameters, short transverse diameters, wide sacrosciatic notch, narrow subpubic angle
• Android (most common male form): triangular inlet, converging side walls, narrow sacrosciatic notch, narrow subpubic angle
• Plateylpelloid (flat variation of gynecoid type): short anterior-posterior diameters, long transverse diameters, narrow sacrosciatic notch, wide subpubic angle

Pelvic regions

• Pelvic inlet
  • Shape: transverse ellipse
  • Boundaries: sacral promontory (posteriorly), linea terminalis (laterally), and symphysis pubis (anteriorly)
  • Diameters
    • True conjugate (∼ 11 cm): tip of the sacral promontory to the upper border of the pubic symphysis
    • Obstetric conjugate (∼ 10.5 cm): tip of the sacral promontory to the most protruding point on the posterior surface of the pubic symphysis
    • Transverse diameter (∼ 13 cm): between the iliopectineal lines
    • Oblique diameters (∼ 12 cm): sacroiliac joint to the each iliopectineal line
• Pelvic cavity (mid-pelvis)
  • Shape: round
  • Boundaries: plane of greatest and least pelvic diameter (roof and floor), sacrum (posteriorly), and symphysis pubis (anteriorly)
• Pelvic outlet
  • Shape: longitudinal oval
  • Boundaries: ischial spines (laterally), plane of least pelvic dimension (roof), pelvic outlet (floor), coccyx (posteriorly), and lower border of the pubic symphysis (anteriorly)
  • Diameters
    • Anterior-posterior diameter (∼ 13 cm)
    • Bituberous diameter (∼ 11 cm): between the ischial tuberosities
    • Bispinous diameters (∼ 10.5 cm): between the ischial spines

Pelvic planes

• Plane of the pelvic inlet (angle of pelvic inclination): at the level of the pelvic brim boundaries; forms an angle of 55° with the horizon
• Plane of greatest pelvic dimension (mid-cavity): at the level of the posterior surface of the pubic symphysis and the junction of the 2^nd and 3^rd sacral vertebra
• Plane of least pelvic dimension (obstetric outlet): at the level between the anterior lower edge of the symphysis pubis and the tip of the sacrum posteriorly
• Plane of the anatomical outlet: at the level of the anatomical pelvic outlet boundaries

Soft tissue structures

• Inner portion
  • Lower uterine segment
  • Cervix
  • Vagina
  • Vulva
• Outer portion: Pelvic floor

Pelvic floor

• Supports the abdominal and pelvic viscera
• Prevents prolapse of the pelvic organs
• Assists in increasing intraabdominal pressure
• Plays an integral role in urinary continence and defecation
  • For information on the defecation process, see “Function” in “Large intestine.”
  • For information on the urination process, see “Urinary bladder” in “Overview of the urinary tract.”
• Contains two openings formed by a gap between the levator ani muscles
  • Urogenital hiatus
    • Allows passage of urethra and vagina (in female individuals)
    • Anterior to the anus
  • Rectal hiatus
    • Allows passage of the rectum
    • Centrally positioned in the pelvic floor, posterior to the perineal body
• Stabilized by the perineal body: central tendon of the perineum, located between the anal and urogenital hiatus

Layers of the pelvic floor

Pelvic diaphragm

• Description: innermost layer of the pelvic floor
• Components
  • Levator ani muscle
    • Broad muscular sheet that forms the majority of the musculature of the pelvic floor
    • Can be divided into three separate muscles: pubococcygeus, puborectalis, iliococcygeus
  • Coccygeus muscle: posterior to the levator ani muscle
  • Surrounded by the superior and inferior fascia of the pelvic diaphragm
  • Anococcygeal ligament: a fibrous raphe mainly formed by fibers of the levator ani muscles uniting in the midline; connected to the coccyx and located posterior to the anus

Urogenital diaphragm

• Description
  • Middle layer of the pelvic floor
  • Spans between the ischial and pubic rami
  • Separates the upper pelvis from the deep perineal pouch
• Components
  • Deep transverse perineal muscle (fibers form the urethral sphincter)
  • Urethral sphincter: consists of two muscles that encircle the urethra and control the flow of urine
    • Internal urethral sphincter (smooth muscle)
    • External urethral sphincter (skeletal muscle) In male individuals: surrounds the membranous urethra
      • In female individuals: consists of three parts (sphincter muscle, compressor urethrae, urethrovaginal muscle)
  • Enclosed by the superior and inferior fascia of the urogenital diaphragm (i.e., perineal membrane).
  • The perineal body is located posterior to the deep transverse perineal muscle (between the anal and urogenital hiatus).

For more information on the muscles of the urinary tract, see “Overview of the urinary tract.”

Superficial perineal layer

• Outermost layer of the pelvic floor
• Components
  • Ischiocavernosus muscle
  • Bulbocavernosus muscle (bulbospongiosus muscle in male individuals)
  • External anal sphincter
  • Superficial transverse perineal muscle
    • Origin: ischial tuberosities, ischial rami
    • Insertion: perineal body
    • Function: stabilizes the perineal body
    • Innervation: pudendal nerve

Perineal region

• Definition: an anatomical region inferior to the pelvic diaphragm
• Boundaries
  • Anterior: pubic symphysis
  • Posterior: coccyx
  • Lateral: inferior rami of the ischial and pubic bones, sacrotuberous ligament
  • Superior: pelvic diaphragm
  • Inferior: skin

Divisions of the perineal region

The perineal region can be divided by an imaginary line between the ischial tuberosities. This line forms two triangles within the perineal region, the urogenital triangle anteriorly and the anal triangle posteriorly. The contents of each triangle are listed below.

• Urogenital triangle
  • Deep perineal pouch
    • Space between the superior and inferior fascia of the urogenital diaphragm (perineal membrane)
    • Contains the deep transverse perineal muscle, urethral sphincter, part of the urethra, and the vagina in female individuals
  • Perineal membrane
    • A triangular-shaped sheet of dense fibrous tissue
    • Provides attachment to the muscles of the external genitalia
    • Allows passage of the urethra and vagina
  • Superficial perineal pouch
    • Space between the inferior fascia of the urogenital diaphragm (perineal membrane) and the Colles fascia
    • Contains erectile tissues of the clitoris and penis, the Bartholin glands, the ischiocavernosus muscle, the bulbocavernosus muscle (bulbospongiosus muscle in male individuals), and the superficial transverse perineal muscle
• Anal triangle
  • Anal canal and orifice
  • External anal sphincter muscle
  • Ischiorectal fossae
• Perineum
  • A diamond-shaped, superficial area between the anus and external genitalia
  • Bounded laterally by the medial thighs, anteriorly by the mons pubis (in female individuals) or the base of the penis (in male individuals), and posteriorly by the superior end of the intergluteal cleft

Arteries

Internal iliac artery

The blood supply of the pelvis is primarily derived from the internal iliac artery, which originates from the bifurcation of the common iliac artery. The internal iliac artery divides into the anterior trunk and the posterior trunk.

• Anterior trunk
  • Umbilical artery
    • Artery to the ductus deferens
    • Superior vesical arteries: blood supply for the superior aspect of the bladder
  • Inferior vesical artery: supplies the fundus of the bladder and lower part of the ureter; in male individuals also supplies the prostate gland, seminal vesicles, and ductus deferens
  • Vaginal artery: supplies the anterior and posterior wall of the vagina
  • Uterine artery (in female individuals)
    • Superior branch: supplies the body and fundus of the uterus
    • Vaginal branch: supplies the cervix of the uterus and the vagina
    • Anastomoses with the ovarian artery
  • Inferior gluteal artery: supplies the gluteal region and thigh
  • Middle rectal artery
    • Supplies the lower rectum, upper anal canal, and the ureter
    • In male individuals: supplies the prostate gland and seminal vesicles
    • In female individuals: supplies the vagina
  • Obturator artery: supplies the medial compartment of the thigh and the head of the femur (via the foveolar artery)
  • Internal pudendal artery: supplies the perineum, genitalia, anal canal, and erectile tissues
• Posterior trunk
  • Iliolumbar artery
    • Iliac branch: supplies the ilium and the iliacus muscle
    • Lumbar branch: supplies the quadratus lumborum muscle and the psoas major muscle
  • Lateral sacral arteries: supply the skin posterior to the sacrum
  • Superior gluteal artery: supplies the muscles and skin of the gluteal region

Other arteries

• Median sacral artery
  • Arises from the posterior wall of the aorta, proximal to the bifurcation
  • Supplies the coccyx, lumbar vertebrae, and sacrum
• Superior rectal artery
  • Continuation of the inferior mesenteric artery
  • Supplies the anal canal above the pectinate line (upper ⅔ of the rectum)
• Ovarian artery
  • Arises from the abdominal aorta inferior to the renal arteries
  • Crosses the proximal end of the external iliac artery
  • Supplies the ovary and the lateral third of the fallopian tube through the suspensory ligament of the ovary
  • Forms an anastomosis with the ovarian branch of the uterine arteries

Veins

The veins follow the course of the arteries and are named accordingly, and they drain the same structures supplied by the arteries (e.g., internal iliac artery and internal iliac vein).

Nerves

Autonomic innervation

• Parasympathetic and sympathetic fibers
  • Superior hypogastric plexus: distribution of fibers to the nerve plexus of the urogenital organs (e.g., testicular plexus, ureteric plexus); innervates ovaries, testes, hindgut, and the middle third of the ureter
  • Inferior hypogastric plexus (pelvic plexus)
    • Distribution of fibers to the nerve plexus of urogenital organs (e.g., prostatic plexus, uterovaginal plexus, ovarian plexus) and thereby innervates a majority of viscera within the pelvic cavity (e.g., distal third of the ureter, ovaries, uterus, upper vagina, prostate)
    • Directly innervates rectum, internal anal sphincter, bladder, and urethra
  • Hypogastric nerve: responsible for the emission of semen into the posterior urethra in male individuals
• Parasympathetic fibers: pelvic splanchnic nerves innervate the hindgut and pelvic organs (e.g., bladder)
• Sympathetic fibers: sacral splanchnic nerves synapse at the inferior hypogastric plexus

For additional information on the autonomic innervation of the pelvis, see “Nerves of the abdominal cavity” in “Abdominal cavity.”

Somatic innervation

• Pudendal nerve (S2–S4)
  • Innervated structures
    • Motor: external urethral sphincter, external anal sphincter, levator ani, bulbospongiosus muscle, ischiocavernosus muscle
    • Sensory
      • Perineum, penis/clitoris, posterior scrotum/labia, anal canal
      • Responsible for reflex erection
    • Sympathetic
      • Fibers to the penis/clitoris
      • Responsible for male ejaculation

For additional information on the lumbar and sacral plexus see ”Thigh, knee, and popliteal fossa” and for information on the innervation of the gluteal muscles, see “The gluteal region” below.

Lymphatics

The pelvic lymphatics course along the internal iliac vessels and drain into the lymph nodes listed below.

• Inferior mesenteric and aortic lymph nodes: receive lymph from the upper part of the rectum
• Paraaortic lymph nodes: drain the ovaries, fallopian tubes, and the fundus of the uterus
• Internal and external iliac lymph nodes: drain the body and cervix of the uterus, bladder, prostate, and rectum

The gluteal region consists of a group of muscles that form the buttocks. These muscles arise from the pelvic girdle, are innervated by nerves that leave the pelvis through the greater sciatic foramen, and receive vascular supply from the superior and inferior gluteal arteries.

All superficial gluteal muscles abduct and medially rotate the thigh. All deep gluteal muscles and the gluteus maximus laterally rotate the thigh.

The pelvis is derived from paraxial mesoderm and originates from two separate cartilaginous hemipelves. All three primary bone components are present around month 6–8. Important steps in the development of the pelvis, identified by weeks of embryonic development, are listed below.

• Week 4: development of the lower limb buds
• Week 6-7: chondrification of iliac masses
• Week 7-8: chondrification of ischial and pubic masses
• Week 8: formation of immature acetabulum and pubic symphysis
• Week 9: ilium starts to ossify via endochondral ossification
• Week 12: complete cartilaginous pelvis is present in the embryo
• Week 12–13: beginning of ossification in the anterior superior iliac spine (ASIS) and pubis
• Week 15: beginning of ossification in the ischium

Articulating bones

• Acetabulum
  • Cup-like structure on the lateral side of the bony pelvis that articulates with the round femoral head
  • Covered by the acetabular labrum: ring of cartilage that provides an articular surface for the femoral head
  • Stabilized by capsular ligaments (iliofemoral ligament, ischiofemoral ligament, pubofemoral ligament)
  • Surrounded by a fibrous capsule
    • Attaches to the margin of the acetabulum and to the transverse acetabular ligament
    • Attaches to the neck of the femur
      • Anterior: intertrochanteric line (anterior) and the greater trochanter
      • Posterior: intertrochanteric crest
    • Encloses the femoral head and neck
• Femur: See “The femur” in “Thigh, knee, and popliteal fossa.”

Ligaments of the hip joint

Arterial supply of the hip joint

• Superior and inferior gluteal arteries
• Deep femoral artery: main branch of the femoral artery
  • Medial femoral circumflex artery
    • Arises from the posteromedial side of the profunda femoris artery
    • Supplies the head and neck of the femur
  • Lateral femoral circumflex artery
    • Arises from the lateral side of the profunda femoris artery
    • Supplies the head and neck of the femur
• Foveolar artery
  • Most commonly arises from the obturator artery and less commonly from the medial circumflex femoral artery
  • Passes through the ligament of the femur head
  • Supplies the head of the femur

Movements of the hip joint

The muscles enabling movement of the hip joint can be divided into the gluteal muscles (see “The gluteal region” above) and the musculature of the thigh (see “Muscles of the thigh” in “Thigh, knee, and popliteal fossa”).

• Flexion
  • Iliacus and psoas major
  • Rectus femoris
  • Tensor fasciae latae
  • Pectineus
  • Sartorius
  • Gluteus medius and minimus (anterior fibers)
  • Adductor longus, brevis, and minimus
  • Gracilis
• Extension
  • Gluteus maximus
  • Semitendinosus
  • Semimembranosus
  • Biceps femoris
  • Gluteus medius and minimus (posterior fibers)
  • Adductor magnus (hamstring part)
• Abduction
  • Gluteus medius and minimus
  • Gluteus maximus (upper fibers)
  • Tensor fasciae latae
  • Piriformis
  • Obturator externus
  • Sartorius
• Adduction
  • Adductor magnus
  • Adductor longus
  • Adductor brevis
  • Gluteus maximus (lower fibers)
  • Obturator externus
  • Pectineus
  • Gracilis
• Internal rotation (medial rotation)
  • Gluteus medius and minimus (anterior fibers)
  • Tensor fasciae latae
• External rotation (lateral rotation)
  • Iliacus and psoas major
  • Gluteus maximus
  • Piriformis
  • Obturator externus and internus
  • Gluteus medius and minimus (posterior fibers)
  • Superior and inferior gemellus
  • Quadratus femoris
  • Pectineus
  • Sartorius

• Sacroiliitis (associated with e.g., ankylosing spondylitis, inflammatory bowel disease)
• Pelvic organ prolapse
• Obturator hernia
• Femoral hernia
• Hip replacement
• Hip fractures
• Coxarthrosis
• Avascular necrosis of the femoral head (due to insufficient supply by the foveolar artery)
• Trendelenburg sign: Injury to the superior gluteal nerve leads to paralysis of the gluteus medius and minimus that results in a positive Trendelenburg sign and a Trendelenburg gait.
• Pudendal nerve block: injection of a local anesthetic into the pudendal canal to block transmission within the pudendal nerve
  • Most commonly used during childbirth prior to an episiotomy or during surgical procedures involving the perineum
  • The ischial spine is used as a landmark for injection.
• Pudendal nerve injury (due to, e.g., pelvic trauma, pelvic surgery) → urinary and/or fecal incontinence
• Piriformis syndrome
  • A condition caused by entrapment of the sciatic nerve due to trauma or strain of the piriformis muscle
  • Manifests with buttock pain and paresthesia in the distribution of the sciatic nerve
• Urinary incontinence
• Premature ejaculation
• Pouch of Douglas
  • In the upright position, the pouch of Douglas is the lowest part of the peritoneal cavity, where blood, pus, malignant cells, and endometrial implants preferentially collect.
  • Important in the diagnosis of gynecological conditions and emergencies (e.g., ectopic pregnancy, pelvic inflammatory disease)

Kegel exercises involve the contraction of the entire levator ani. These exercises especially strengthen the pubococcygeus muscles, which can treat stress incontinence, urge incontinence, and pelvic organ prolapse and assists in ejaculation.