The capsule of hip joint, articular capsule, or capsular ligament is strong and dense attachment of the

hip joint In vertebrate anatomy, the hip, or coxaLatin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) (: ''coxae'') in medical terminology, refers to either an anatomical region or a joint o ...

. Anterosuperiorly, it is attached to the margin of the

acetabulum The acetabulum (; : acetabula), also called the cotyloid cavity, is a wikt:concave, concave surface of the pelvis. The femur head, head of the femur meets with the pelvis at the acetabulum, forming the Hip#Articulation, hip joint. Structure The ...

5 to 6 mm beyond the labrum behind; but in front, it is attached to the outer margin of the labrum, and, opposite to the notch where the margin of the cavity is deficient, it is connected to the transverse ligament, and by a few fibers to the edge of the

obturator foramen The obturator foramen is the large, Bilateral symmetry, bilaterally paired opening of the bony pelvis. It is formed by the pubis and ischium. It is mostly closed by the obturator membrane except for a small opening, the obturator canal, through wh ...

. It surrounds the neck of the femur, and is attached, in front, to the

intertrochanteric line The intertrochanteric line is a line upon the anterior aspect of the proximal end of the femur, extending between the lesser trochanter and the greater trochanter. It is a rough, variable ridge. Structure The intertrochanteric line marks the bound ...

; above, to the base of the neck; behind, to the neck, about 1.25 cm above the

intertrochanteric crest The intertrochanteric crest is a prominent bony ridge upon the posterior surface of the femur at the junction of the neck and the shaft of the femur. It extends between the greater trochanter superiorly, and the lesser trochanter inferiorly. An ...

; below, to the lower part of the neck, close to the lesser trochanter. From its femoral attachment some of the fibers are reflected upward along the neck as longitudinal bands, termed ''retinacula''. The capsule is much thicker at the upper and forepart of the joint, where the most resistance is required; behind and below, it is thin and loose. It consists of two sets of fibers, circular and longitudinal. The circular fibers, ''

zona orbicularis The zona orbicularis or annular ligament is a ligament on the neck of the femur formed by the circular fibers of the articular capsule of the hip joint In vertebrate anatomy, the hip, or coxaLatin ''coxa'' was used by Celsus in the sense "hi ...

'', are most abundant at the lower and back part of the capsule, and form a sling or collar around the neck of the

femur The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femo ...

. Anteriorly they blend with the deep surface of the iliofemoral ligament, and gain an attachment to the

anterior inferior iliac spine The anterior inferior iliac spine (AIIS) is a bony eminence on the anterior border of the hip bone, or, more precisely, the wing of the ilium. Structure The AIIS is a bony eminence on the anterior border of the ilium. It is below the anterior ...

. The longitudinal fibers are greatest in amount at the upper and front part of the capsule, where they are reinforced by distinct bands, or accessory ligaments, of which the most important is the iliofemoral ligament. The other accessory bands are known as the pubofemoral ligament and the

ischiofemoral ligament The ischiofemoral ligament (ischiocapsular ligament or ischiocapsular band) consists of a triangular band of strong fibers on the posterior side of the hip joint. It is one of the four ligaments that reinforce the hip joint. It attaches to the p ...

. The external surface of the capsule is rough, covered by numerous muscles, and separated in front from the

psoas major The psoas major ( or ; from ) is a long fusiform muscle located in the lateral lumbar region between the vertebral column and the brim of the lesser pelvis. It joins the iliacus muscle to form the iliopsoas. In other animals, this muscle is e ...

and

iliacus The iliacus is a flat, triangular muscle which fills the iliac fossa. It forms the lateral portion of iliopsoas, providing flexion of the thigh and lower limb at the acetabulofemoral joint. Structure The iliacus arises from the iliac fossa on t ...

by the iliopectineal bursa, which not infrequently communicates by a circular aperture with the cavity of the joint.

Pathologies

Hip Capsule Contracture This pathology is similar to the frozen shoulder. It may be caused by arthritis or by a long period of immobilization Capsular Pattern : * According to Cyriax : ROM of Medial rotation, flexion and abduction are more reduced than extension End-Feels * The end-feel is abnormal when there's a capsule contracture. * you may feel a firm capsular end-feel, but it's before the complete ROM. * it may be empty, caused by severe pain

References

Ligaments of the lower limb {{Portal bar, Anatomy