The hip joint (see the picture below) is a ball-and-socket synovial joint: the round is the femoral head, and the socket is the acetabulum. The hip joint is the articulation of the pelvis with the femur, i beg your pardon connects the axial skeleton v the lower extremity. The adult os coxae, or i know good bone, is developed by the blend of the ilium, the ischium, and also the pubis, which wake up by the finish of the teenage years. The 2 i know well bones kind the bony pelvis, together with the sacrum and the coccyx, and also are unified anteriorly through the pubic symphysis.

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hip joints, anterior view.
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Gross Anatomy

Bones and osteology


The femur is the longest and heaviest bone in the person body. It consists of a premium or proximal end, a shaft, and an inferior or distal end (see the image below).

components of femur.
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The superior finish of the bone is the articulating next of the femur to the acetabulum. The upper femoral epiphysis closes by 16 year of age.

The trabecular bone construction in the proximal femur obeys Wolff"s Law, which states that bony frameworks orient us in type and mass so as to best stand up to extrinsic forces. The primary compressive group, the major tensile group, the greater trochanteric group, the secondary tensile group, the secondary compressive group, and, finally, Ward"s triangle deserve to be found.

The superior end of the femur consists of a head, a neck, and also greater and also lesser trochanters. The head of the femur is angled superomedially and slightly anteriorly as soon as articulating v the acetabulum. The head is attached to the femoral human body or obelisk by the neck the the femur.

The remarkable border that the neck begins just lateral come the femoral head and also ends distally in ~ the greater trochanter. The inferior border of the neck starts lateral to the femoral head and also extends come the inferior trochanter. The exceptional border is shorter and thicker 보다 the worse border. The anterior surface of the neck is stormy in comparison come the smooth femoral head. The neck’s posterior surface has actually a concave appearance. The head and neck are at an edge of 130º (± 7º) come the shaft. The edge is larger at birth and also decreases with age.

The higher trochanter is a bony prominence on the anterolateral surface of the proximal column of the femur, distal to the femoral neck. That serves as the insertion website for the gluteus medius and also gluteus minimus. The lesser trochanter is a bony prestige on the proximal medial aspect of the femoral shaft, simply distal come the femoral neck. The serves as the iliopsoas insertion site.

The intertrochanteric line is a increased area that extends from the greater to the lesser trochanter anteriorly. This link posteriorly is called the intertrochanteric crest, which consists of the calcar femorale, one more anatomic place on the femoral neck. The calcar femorale is a vertically oriented plate of dense cancellous bone indigenous the posteromedial part of the femoral column radiating superiorly towards the greater trochanter. <1>


At birth, each pelvic half consists the 3 separate primary bones: the ilium, the ischium, and the pubis (see the pictures below). This bones space joined by hyaline cartilage.

components of pelvis.
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Pelvis and acetabulum, v muscle attachment sites.
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In infants and also children, these huge parts the the i know well bones are incompletely ossified. In ~ puberty, the 3 main bones are still be separated by a Y-shaped triradiate cartilage focused in the acetabulum. The main bones begin to fuse in ~ 15-17 years. Blend is complete in between 20-25 years of age. The reality that these bones were initially separate is reasonably undetectable in adult skeletal on imaging. Although the parts of the i know well bone are fused in adulthood, they room still referred to by their different origins. <2>


The ilium is the largest component of the hip bone and makes up the superior component of the acetabulum. The ala gives an insertion allude for the gluteal muscles laterally and the iliacus muscle medially.

Anteriorly, the ilium has an anterior premium iliac spine (ASIS); worse to this is an anterior inferior iliac spine. Native the ASIS, anteriorly, the iliac crest comes roughly laterally and continues posterior come the posterior exceptional iliac spine (PSIS). The PSIS marks the superior point of the higher sciatic notch.

The lateral surface ar of the ilium has 3 stormy curved lines: the posterior, anterior, and also inferior gluteal lines. Medially, the ilium has actually an iliac fossa. Posteriorly, the medial aspect of the ilium has an auricular surface. <2>


The ischium is the inferior facet of the pelvis. The superior component of the body of the ischium fuses v the pubis and ilium, creating the posteroinferior aspect of the acetabulum.

The ramus of the ischium joins the worse ramus the the pubis to kind a bar that bone called the ischiopubic ramus, i m sorry constitutes the inferomedial boundary of the obturator foramen. The posterior border of the ischium develops the lower margin of a deep indentation the better sciatic notch. The big triangular ischial spine in ~ the worse margin of this notch is a sharp demarcation separating the better sciatic notch native a smaller rounded worse indentation referred to as the lesser sciatic notch.

The bony projection at the inferior finish of the body of the ischium and its ramus is the ischial tuberosity. <2>


The pubis renders up the anteromedial part of the hip bone and also contributes the anterior component of the acetabulum. The pubis has a level body and also 2 rami: superior and also inferior.

Medially, the symphyseal surface of the human body of the pubis articulates in ~ the pubic symphysis v the surface of the human body of the contralateral pubis. The anterosuperior border the the united bodies and symphysis forms the pubic crest. The pubic tubercles, small projections at the lateral ends of this crest where the inguinal ligaments connect medially, room extremely important landmarks that the inguinal regions. The posterosuperior element of the remarkable ramus that the pubis is called the pectin pubis.

The obturator foramen is one oval opening formed by the rami that the pubis and the ischium. The obturator canal dwellings the obturator nerve and also vessels. <2>


As suggested above, the acetabulum is formed from components of the ilium, ischium, and pubis. The acetabulum is the cup-shaped socket ~ above the lateral facet of the pelvis, i m sorry articulates v the head of the femur to type the hip joint.

The margin that the acetabulum is deficient inferiorly. Second fibrocartilaginous margin the the acetabulum is described as the acetabular labrum. The labrum features to deepen the acetabulum, for this reason holding the femoral head an ext securely. The lunate is the articular surface of the acetabulum come the femoral head. The stormy depression in the floor the the acetabulum is the acetabular fossa, i beg your pardon is constant with the acetabular notch.

The transverse acetabular ligament is located along the inferior element of the acetabulum; it avoids the femoral head from relocating inferiorly through deepening the acetabulum inferiorly.


The i know good joint includes a solid fibrous capsule the attaches proximally to the acetabulum and also transverse acetabular ligament and also distally to the neck of the femur anteriorly at the higher trochanter (see the picture below). Posteriorly, the fibrous capsule crosses to the neck 1-1.5 centimeter proximal to the intertrochanteric crest.

hip ligaments.
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Most that the fibers go from the i know good bone to the intertrochanteric line, but some deeper yarn go around the neck, creating the orbicular zone, i beg your pardon holds the femoral neck in the acetabulum. The anterior capsule that the i know well is the strongest and also thickest part.

This capsule is written of 3 ligaments. The iliofemoral ligament, periodically referred to as the Y ligament that Bigelow, attaches come the anterior worse iliac spine and also the acetabular pickled in salt proximally and also takes one inferolateral direction come insert ~ above the intertrochanteric heat distally. It is the strongest part of the capsule. The iliofemoral ligament prevents hyperextension that the i know well joint throughout standing by stop the femoral head within the acetabulum.

The ischiofemoral ligament reinforces the capsule posteriorly. That originates ~ above the ischial part of the acetabular rim and spirals superolaterally to the neck of the femur, medial to the higher trochanter. This ligament, choose the iliofemoral, additionally prevents hyperextension and holds the femoral head within the acetabulum.

The pubofemoral ligament reinforces the capsule anteriorly and inferiorly. It begins from the obturator stakes of the pubic bone and passes inferolaterally to join the fibrous capsule of the i know well joint. This ligament stays clear of overabduction of the hip joint. <2>

An iliopectineal bursa lies anteriorly over the gap in the ligaments, beneath the iliopsoas tendon.

There room several added structures of prominence related to the fibrous capsule. Lining the fibrous capsule is the synovial membrane. It covers the neck of the femur between the attachment of the fibrous capsule and the leaf of the articular cartilage of the head; it also covers the nonarticular area that the acetabulum, offering a covering for the ligament of the femoral head.

Retinacula, i beg your pardon contain blood vessels, space deep longitudinal fibers of the capsule the go superiorly native the femoral neck and also blend through the periosteum. The bursa is considered the synovial extension past the cost-free margin the the fibrous capsule top top the posterior aspect of the femoral neck.

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The ligament of the femoral head is weak. It attaches to the spare of the acetabular notch and also the transverse acetabular ligament; that narrow end attaches to the pit in the head the the femur. Commonly the ligament includes a little artery to the head the the femur. <2>

A fat pad in the acetabular fossa is spanned with synovial membrane. It filling the acetabular area that is not filled by the femoral head.

Nerve supply

The nerve it is provided to the hip share is outlined in Table 1 and also the photos below. <3>

Table 1. Nerves of Hip share (Open Table in a new window)


Root level





Proximal anteromedial thigh

None in hip and thigh



Inferomedial thigh

Gracilis (anterior division)

Adductor longus (anterior division)

Adductor brevis (anterior/posterior division)

Adductor magnus (posterior division)

Lateral femoral cutaneous


Lateral thigh




Anteromedial thigh

Psoas major


Articularis genus

Rectus femoris

Vastus lateralis

Vastus intermedius

Vastus medialis



None in thigh

Biceps femoris (long head)



Common fibular (peroneal)


None in thigh

Biceps femoris (short head)

Posterior femoral cutaneous nerve


Posterior thigh


i know well nerves, lateral view.
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i know good nerves, anterior view.
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The muscles of the i know good joint are outlined in Table 2 and also the pictures below. <3>