Pelvic Girdle And Hip Joint Flashcards
Bones in pelvic girdle
Innominates and sacrum
Innominate bones
Ilium, ischium, pubis
Type of joint articulating sacrum and ilium POSTERIORLY
Fibrous
Type of bone between the medial surfaces of the body of each pubic bone (pubic symphysis)
Secondary cartilaginous
Functions of pelvic girdle
- It supports and protects the pelvic viscera.
- It supports body weight transmitted through the vertebrae, thence through the sacrum, across the
sacroiliac joints to the innominate and then to the femora in the standing position, or to the ischial tuberosities when sitting. - During walking, the pelvis swings from side to side by a rotatory movement at the hip joint which occurs together with small movements at the lumbar intervertebral joints; when the hip joints are fused pelvic rotation is taken up by the thoracic spine enabling a patient to walk reasonably well.
- As with all but a few small bones in the hand and foot, the pelvis provides attachments for muscle.
- In females it provides bony support for the birth canal.
Sacroiliac joint
Auricular surface of the ilium and the ala of the sacrum
Classification of SI joint
Synovial plane joint
Type of cartilage covering the sacrum
Hyaline cartilage
Type of cartilage covering the ilium
Fibrocartilage
Anterior sacroiliac ligament
Ala and pelvic surface of sacrum to auricular surface of the ilium
Types of posterior sacroiliac ligaments
interosseus and long and short posterior sacroiliac ligaments
Interosseus sacroiliac ligaments
Short but strong and runs from sacrum to ilium on the posterior side
Long posterior sacroiliac ligament
Fibres run obliquely and medially
PSIS to the 3rd and 4th transverse tubercles of sacrum
Resist downwards movement of the sacrum with respect to the ilium
Short posterior sacroiliac ligaments
1st and 2nd tubercles of the sacrum to the iliac tuberosity
Resist forward movement of the sacral promontory
Sacrotuberous ligaments
Superiorly to the posterior border of the ilium between superior and inferior iliac spines to the back and side of the sacrum below the auricular surface and to the side of the upper part of the coccyx to the ischial tuberosity
Fibres pass inferolaterally towards the ischial tuberosity
Sacrospinous ligaments
Edge of the lower sacral and upper coccygeal segments anterior to the sacrotuberous ligament to the ischial spine
Blood supply to the SI joint
Branches of Iliolumbar artery anteriorly
Branches of superior gluteal artery posteriorly
Drained by iliolumbar vein anteriorly and drained by superior gluteal vein posteriorly to the internal iliac vein
Lymphatics of the SI joint
Internal iliac group of nodes
Nerve supply to the SI joint
Sacral plexus and dorsal rami of S1 and S2
Superior gluteal and obturator nerves as they pass close to the joint
Roots L4 to S2
Movements of SI joint
Slight gliding and rotatory movement between the two bones
When standing the sacrum moves down 2mm and rotates in a forward direction 5 degrees
Movements of SI joint in pregnancy
Movement of the sacrum due to the softening of SI ligament = diameters of the pelvic inlet and outlet increasing to facilitate passage to of the fetal head
The sacral promontory moves superiorly and posteriorly increasing the anterosuperior diameter of the pelvic inlet by between 3 and 13 mm.
After the fetal head has entered the pelvic canal the sacral promontory then moves inferoanteriorly increasing the anteroposterior diameter of the pelvic outlet by 15-18mm
Hip joint
Articulation of the head of the femur and acetabulum of the innominate
Classification of hip joint
Synovial ball and socket
Articular surfaces
Acetabulum is formed by = 1/5 pubis, 2/5 ischium, 2/5 ilium
Femur = covered in hyaline cartilage
Acetabular labrum
Continues across the acetabular notch as the transverse ligament giving attachment to the ligament of the head of the femur
Fibrocartilaginous structure
Iliofemoral ligament
Lower part of the ASIS and adjacent acetabular rim and base to the intertrochanteric line
Pubofemoral ligament
Iliopubic eminence and superior pubic ramus to the lower part of the intertrochanteric line
Ischiofemoral ligament
Body of the ischium to the superior part of the neck and root of the greater trochanter
Ligamentum teres
Two bands that originate on the ischial and pubic sides of the acetabular notch and blend with the acetabular transverse ligament between the two attachment sites. The two bands insert on the fovea capitals of the femoral head.
Blood supply to the hip joint
Medial and lateral circumflex femoral, obturator and superior and inferior gluteal arteries forming a periarticular anastamosis around the joint.
Lymphatics to the hip joint
Arise from the synovial membrane and drain to the deep inguinal and iliac lymph nodes and then to the common iliac nodes.
Nerve supply to the hip joint
Lumbar plexus branches - femoral and obturator nerves
Sacral plexus - superior gluteal nerve and nerve to quadratus femoris (L2-S1)
Hip flexor muscles
Flex the hip and raise the knee
Iliopsoas - L2-L4 nerve roots
Rectus femoris - femoral nerve
Sartorius - femoral nerve
Pectineus - femoral nerve
Hip extensor muscle
Extend the hip
Biceps femoris - sciatic nerve
Semitendinosus - sciatic nerve
Semimembranosus - sciatic nerve
Gluteus maximus - inf. gluteal nerve
Hip abductor muscles (away from midline)
Abducts the hip
Gluteus minimum - superior gluteal nerve
Gluteus medius - superior gluteal nerve
Gluteus maximus - inferior gluteal nerve
Tensor fascia lata - superior gluteal nerve
Hip adductor muscles (towards the midline)
Adducts the hip
Adductor longus - obturator nerve
Adductor brevis - obturator nerve
Adductor Magnus - obturator nerve
Gracilis - obturator nerve
Pectineus - femoral nerve
Medial rotators of the hip
Medially rotate the hip
Anterior part of gluteus medius - superior gluteal nerve
Anterior part of gluteus minimus - superior gluteal nerve
Tensor fascia lata - superior gluteal nerve
Iliopsoas - L2-L4 nerve roots
Lateral rotators of the hip
Laterally rotate the hip
Gluteus maximus - inferior gluteal nerve
Piriformis - anterior rami of sacral plexus
Gemellus superior - nerve to obturator internus
Gemellus inferior - nerve to quadratus femoris
Obturator externus - posterior branch of obturator nerve
Obturator internus - nerve to obturator nerve
Type of joint articulating sacrum and ilium ANTERIORLY
Synovial plane
SI Joint capsule
Complete fibrous capsule that surrounds the joint attaching to the articular margin
Capsule of hip joint
