Hip Joint Rania Gabr

Objectives Know the type and formation of hip joint. Differentiate the stability and mobility between the hip joint and shoulder joint. Identify the muscles that act at the hip joint.

Type & Articular Surfaces Synovial, ball & socket joint. Articular Surfaces: Acetabulum of hip (pelvic) bone Head of femur The lunate surface  and the head of the femur(except for the fovea) are covered by hyaline cartilage The nonarticular acetabular fossa contains loose connective tissue.

Acetabular labrum: C-shaped fibro-cartilaginous collar attached to margins of acetabulum, increases its depth for better retaining of head of femur.

Capsule The hip joint is enclosed within strong fibrous capsule lined by synovial membrane . Proximally: it is attached to the acetabulum, and to the transverse acetabular ligament . Distally: Anteriorly: covers the neck & is attached to intertrochanteric line Posteriorly: covers medial half of the neck of femur

POSTERIOR ANTERIOR Intertrochanteric line

Synovial Membrane The synovial membrane lines the capsule and the nonarticular surfaces. It reflects along the femoral neck to the edge of the femoral head

The arteries that supply the femoral head and neck course within the synovial folds. They are called retinacular vessels

Ligaments: 3 Extracapsular Pubofemoral ligament: Located antero-inferior to joint Limits abduction & lateral rotation Iliofemoral ligament: Y-shaped Located anterior to joint Limits extension Ischiofemoral ligament: Located posterior to joint Limits medial rotation

Ligaments: 2 Intracapsular (Extrasynovial) Ligament of femoral head: carries vessels to head of femur Transverse acetabular ligament: formed by the acetabular labrum as it bridges the acetabular notch converts acetabular notch into foramen through which pass acetabular vessels

Movements of the hip Flexion. Extension,

Abduction. Adduction.

Medial and lateral rotation. Circumduction.

Hip Flexion Psoas Major Iliopsoas(composite muscle) Chief flexor of HIP: Psoas major iliacus Origin: 1- Anterior surfaces of the transverse processes of T12-L5 vertebrae 2- Upper two thirds of the iliacus Insertion:  Lesser trochanter of the femur after being joined by the iliacus Action:  1-Flexion of thigh at hip 2- Assists in extension of the lumbar spine 3. Lateral Flexion of the spine when acting unilaterally Innervation:  Lumbar plexus (L2,3,4) Psoas Major

Iliacus Origin Iliac fossa within abdomen Insertion Lowermost surface of lesser trochanter of femur, after joining psoas Action Flexes &laterally rotates hip Nerve Femoral nerve in abdomen (L2,3)

Hip extension Gluteal region: iliotibial tract Tensor Fasciae Latae Gluteus maximus Gluteal region: -Gluteus maximus (most powerful extensor, also lateral rotator) Insertion: Gluteal tuberosity + Iliotibial tract (band) gluteus maximus Gluteus Maximus and Tensor Fascia Lata insert into Iliotibial Tract - Iliotibial tract is a thickening of the deep fascia (fascia lata) that extends from the ilium to the tibia. - Tension from contraction of gluteus maximus and tensor fasciae latae stabilizes the lower limb as a weight-bearing column.

Hip Adduction Medial Compartment main function = adduction Obturator externus Adductor brevis Adductor longus Adductor magnus Gracilis Most innervated by: Obturator nerve (L2-L4) (lumbar plexus) Exception: -Hamstring component of adductor magnus (extensor) (tibial division of sciatic nerve) obturator externus obturator nerve adductor brevis Adductor magnus adductor longus gracilis

Lateral Rotation of the hip gluteus medius gluteus maximus gluteus minimus Deep to gluteus maximus: -Abductors: gluteus medius gluteus minimus (anterior fibres medially rotate) -Lateral (external) rotators: piriformis obturator internus (associated gemelli) quadratus femoris [obturator externus is also a lateral rotator] piriformis superior gamellus obturator internus quadratus femoris inferior gamellus

Movements of the Hip Joint (ball and socket) Summary Movements of the Hip Joint (ball and socket) Flexion - Anterior + medial compartments of thigh (iliopsoas, sartorius, rectus femoris, adductor) group) Extension - Gluteal region /posterior compartment of thigh (gluteus maximus, hamstrings, adductor magnus) Adduction - Medial (adductor) compartment of thigh Abduction - gluteus medius & minimus, Tensor Fascia Lata Rotation: Lateral - Gluteus maximus, lateral rotators Medial - anterior parts of gluteus medius & minimus, + Tensor Fascia Lata

Vascular supply to the hip joint 1- Obturator artery. 2-Medial & 3-Lateral circumflex femoral arteries. 4- Superior and inferior gluteal arteries. 5- First perforating branch of the deep artery of the thigh. The articular branches of these vessels form a network(anatomosis) around the joint .

Nerve Supply of the hip joint The hip joint is innervated by articular branches (Hilton’s Law) from: Femoral. Obturator. Superior gluteal nerves Nerve to the quadratus femoris. Sciatic nerve.

Applied anatomy Perthes disease Perthes' disease is a condition where the top of the thigh bone in the hip joint (the femoral head) softens and breaks down. It occurs in some children and causes a limp and other symptoms. The bone gradually heals and reforms as the child grows. The aim of treatment is to make sure the femoral head reforms back into its normal shape so that the hip joint can work well.

Coxa vara and Coxa Valga

Avascular Necrosis of the Head of the Femur