Session 8 Flashcards
Describe the Hip Joint
Strong and stable multi axial ball and socket type of joint.
During standing, the entire weight of the upper body is transmitted through the hip bones to the heads and necks of the femur.
What is the Greater Sciatic Foramen?
Formed on the posterolateral pelvic wall and is the major route for structures to pass through the pelvis and the gluteal region and leg
The pisiformis muscle passes out of the pelvis into the gluteal region through the greater sciatic foramen and separates the foramen into two parts.
What structures pass through the greater sciatic foramen?
Above the pisiformis muscle: superior gluteal nerve, artery and vein
Below the pisiformis muscle: sciatic nerve, inferior gluteal nerve, inferior gluteal artery, inferior gluteal vein, pudendal nerve, internal pudendal artery and vein, posterior femoral cutaneous nerve, nerve to obturator internus and superior gemullus muscles, nerve to quadratus femoris and inferior gemullus muscles
What is the Lesser Sciatic Foramen?
Inferior to the greater sciatic foramen on the posterolateral pelvic wall.
It is also inferior to the posterolateral pelvic wall.
It is also inferior to the lateral attachment of the pelvic floor to the pelvic wall and therefore connects the gluteal region to the perineum (nerves and vessels passing through supply the perineum)
What structures pass through the lesser sciatic foramen?
Obturator internus muscle tendon
Pudendal nerve and internal pudendal vessels pass into perineum from gluteal region.
What is the acetabulum?
Large cup-shaped cavity or socket on the lateral aspect of the hip bone that articulates with the head of the femur.
All 3 pelvic bones forming the pelvic bone contribute to the formation of the acetabulum.
What is the Acetabulum labrum?
Lip-shaped fibrocartilaginous rim attached to the margin of the acetabulum, increasing acetabular articular contact area by nearly 10% (deepening the joint).
Helps strengthen the joint.
What is the Transverse Acetabular Ligament?
A continuation of the acetabular labrum, bridges the the acetabular notch.
As a result of the height of the rim and labrum, more than half of the femoral head fits with the acetabulum.
Describe the joint capsules surrounding the hip joints
Formed of a loose external fibrous layer (fibrous capsule and an internal synovial membrane).
The joint capsule covers more of the joint anteriorly than posteriorly.
The joint capsule is strengthened by ligaments which pass in a spiral fashion from the pelvis to the femur.
Extension winds the spiralling ligaments and fibres more tightly, constricting the capsule and drawing the femoral head tightly into the acetabulum. The tightened fibrous layer increases the stability of the joint but restricts extension of the joint to 10-20 degrees behind the vertical position.
Flexion increasingly unwinds the spiralling ligaments and fibres. This permits considerable flexion of the hip joint with increasing mobility.
What are the 3 intrinsic ligaments of the hip joint?
Anteriorly and superiorly Y-shaped Iliofemoral ligament (attached ASIS and acetabuluar rim proximally, the intertrochanteric line distally). Strongest ligament, prevents hyperextension of the hip joint during standing.
Anteriorly and inferiorly is the Pubofemoral ligament which arises from the obturator crest of the public bone and blends with the medial part of the Iliofemoral ligament and tightens during both extension and abduction - prevents overabduction of the hip joint - limits extension and abduction.
Posteriorly is the Ischiofemoral ligament which is the weakest and spirals Superolaterally to the femoral neck - limits extension and medial rotation.
What are the accessory ligaments of the hip joint?
Ligament of head of femur: its wide end attaches to the margins of the acetabular notch and transverse acetabular ligament, its narrow end attaches to the fovea for the ligament of the head. It contains the artery to the head of femur (branch of the obturator nerve)
Transverse acetabular ligament.
What are the flexors of the hip joint?
Iliopsoas (strongest)
Rectus femoris
Sartorius
Tensor fascia latae
Pectineus
Adductor longus
Adductor brevis
Adductor Magnus - anterior-aponeurosis part only
Gracilis
What are the adductors of the hip joint?
Pectineus
Adductor longus
Adductor brevis
Adductor Magnus
Obturator externus
Gracilis
What is the Adductor Minimus?
The most superior part of the adductor Magnus is called the adductor minimus if it forms a distinct muscle.
What are the lateral rotators of the hip joint?
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Pisiformis
Superior gemullus
Obturator internus
Inferior gemullus
Quadratus femoris
Obturator externus
Gluteus maximus
What are the hip extensors?
Gluteus maximus (primary extensor from flexed to standing position and from this point posteriorly, extension is mainly achieved by the hamstrings)
Hamstrings: semitendinosus, semimembranosus, long head of biceps femoris, Posterior part of adductor Magnus
What are the hip abductors?
Gluteus medius
Gluteus minimus
Tensor fasciae latae
Describe the blood supply to the hip joint
Medial and lateral circumflex femoral arteries which are usually branches of the profunda femoris artery but occasionally they arise as branches of the femoral artery.
The artery to the head of femur which is a branch of the obturator artery (via ligament of head of femur)
Main blood supply is from the retinacular arteries arising as branches of the circumflex femoral arteries. Retinacular arteries arising from the medial circumflex artery are most abundant, bringing more blood to the head and neck of the femur because they are able to pass beneath the unattached posterior border of the joint capsule. Retinacular arteries arising from the lateral circumflex femoral artery must penetrate the thick Iliofemoral ligament and are smaller and fewer.