The Hip Joint
Definition
Ball and socket synovial type joint, stable, weight bearing joint
Between the head of the femur and acetabulum of the pelvis
Joins the lower limb to the pelvic girdle
Structures
Articulating Surfaces
The femoral head and acetabulum of the hip joint
The acetabulum - formed by parts of ilium, ischium and pubis - concave - acetabular labrum increases its depth
Both the acetabulum and head of femur are covered in articular cartilage, which is thicker at the places of weight bearing.
Ligaments
increase stability
two groups – intracapsular and extracapsular
Intracapsular :
ligament of head of femur : runs from the acetabular fossa to the fovea of the femur - a branch of obturator artery inside
Extracapsular :
Iliofemoral : attached inferior to the anterior inferior iliac spine and intertrochanteric line - Y shaped - prevents hyperextension
Pubofemoral : attaches iliopubic eminance and obturator membrane, blends with the articular capsule - prevents excessive abduction and extension.
Ischiofemoral : posteriorly attached to ischium and the greater trochanter - prevents excessive extension
Movements and Muscles
Flexion : Iliosoas, rectus femoris, sartorius
Extension : Gluteus maximus, semimembranous,semitendinosus and biceps femoris
Abduction : Gluteus medius, gluteus minimus and the deep gluteals (piriformis, gemelli etc)
Adduction : Adductors longus, brevis and magnus,pectineus and gracillis
Lateral rotation : Biceps femoris, gluteus maximus, and the deep gluteals (piriformis, gemelli etc)
Medial rotation : Gluteus medius and minimus, semitendinosus and semimembranosus
The degree to which flexion at the hip can occur depends on whether the knee is flexed, which relaxes the hamstrings, and increases the range of flexion.
Blood Supply
Medial and lateral circumflex femoral arteries
Artery to head of femur.
The circumflex arteries are branches of the profunda femoris artery.
Nerve Supply
Femoral nerve
Obturator nerve,
Superior gluteal nerve
Nerve to quadratus femoris.
