Chapter 7 Lower Limb Crucial in locomotion and movement weight bearing 7 1 Bones of the Lower Limb Big toe has two phalangeal bones other digits have three 7 1a Hip Bone Join together in front at symphysis pubis Two of them on either side of sacrum and coccygeal bones Three parts Figure 7 3 o Ilium upper part Upper part ala wing Curved superior border iliac crest o Palpable beneath skin can be used for bone marrow biopsy has accessible red bone marrow Lower part body Medial view of ilium Iliac fossa smooth lateral part on ala Iliac tuberosity rough medial part on back sacrum in pelvis Auricular surface smooth part of the bone between the iliac fossa and the iliac tuberosity site of articulation with sacrum at sacroiliac joint Lateral view gluteal surface Three gluteal lines give origin to gluteal muscles o Ischium posteroinferior part lower in the back Has a body and a ramus Obturator foramen in between rami of pubis and ischium Joins pubic bone at acetabulum joins pubic bone at inferior ramus of the pubis o Pubis anteroinferior part lower in the front Has a body and a superior and inferior ramus Obturator foramen lies between the rami of the pubis and ischium 7 1b Sacrum In pelvis Figure 7 4 Five sacral vertebrae fused to each other Intervertebral disks in between Followed by 4 5 coccygeal vertebrae Articulates with hip bones at sacroiliac joints 7 1c The Ligaments of the Pelvis Figure 7 6 Sacrospinous ligament between ischial spine and sacrum o Turns greater sciatic notch into greater sciatic foramen Greater sciatic foramen piriformis muscle and sciatic nerve Sacrotuberous ligament between ischial tuberosity and sacrum Sacrospinous and sacrotuberous ligaments cross each other o Form lesser sciatic foramen obturator internus muscle and pudendal nerve and vessels internal pudendal artery and vein Obturator membrane covers the obturator foramen leaves small opening called obturator canal o Obturator nerve and vessels pass through canal Symphysis pubis fibrocartilage tissue between symphysial surfaces of the pubic bones o Reinforced by superior and inferior pubic ligaments Ilioliumbar ligament strong important lies between transverse process of lumbar vertebra and iliac crest o Supports connection of vertebrae to hip bone 7 1d Pelvic Inlet Diameters of the Pelvic Inlet iliopubic eminence on opposite side promontory Pelvic inlet extends posteriorly from the middle of the first sacral bone promontory laterally to the terminal line of both sides to the pectinate line and to the symphysis pubis anteriorly A Transverse diameter 13 5 14 cm Across middle of pelvic inlets B Oblique diameter I 12 12 5 cm Distance between the right sacroiliac joint and the opposite C Oblique diameter II 11 5 12 cm Between the left sacroiliac joint and the iliopubic eminence D Anatomical conjugate 12 cm Between upper border of the symphysis to the middle of E True obstetric conjugate 11 5 cm between the posterosuperior aspect of the symphysis and a Narrowest fixed diameter of pelvic inlet calculate by subtracting approximately 1 5 cm F Diagonal conjugate 13 cm distance between inferior border of symphysis pubis and the the middle of the promontory from diagonal conjugate middle of the promontory a Measured via vaginal examination i Using two fingers measure distance from mark to tip of fingers after promontory is touched Differences between the Male and Female Pelvis Female pelvis wider and shallower larger pubic angle Figure 7 7 7 1e Pelvic Outlet Diameters of the Pelvic Outlet Diamond shaped border between the coccyx and the ischial tuberosities laterally and the inferior rami of the pubic bones to inferior border of the symphysis pubis Interspinous diameter 10 cm between two ischial spines crucial distance Median conjugate 11 5 cm distance between interior border of symphysis pubis to inferior border or sacrum Straight conjugate 9 5 10 cm from inferior border of symphysis pubis to the tip of coccyx distance is variable due to flexibility and slight movement of the coccyx 7 1f Femur Long bone in thigh has body neck a proximal end and distal end Proximal end head of femur o Fovea depression on head site of attachment of teres ligament Neck of femur connects to body shaft at 126 in adults angle of inclination o Wider in children 145 smaller in old people 120 Adductor tubercle prominence on superomedial aspect of medial epicondyle o Have a curvature in sagittal axis that increases toward the back o Curvatures are not equal responsible for an obligatory medial rotation of the lef at the knee joint when knee is fully flexed Intercondylar fossa provides base for the triangular are above it popliteal surface 7 1g Hip Joint Ball and socket joint synovial Between head of femur and acetabulum of hip bone Movements flexion extension abduction adduction rotation and circumduction Features an articular lip at the edge of the acetabulum Ligaments around and in the Hip Joint Five ligaments 4 extracapular 1 intracapsular Extracapular o Iliofemoral ligament lateral part prevents lateral rotation and adduction of the femur medial part prevents medial rotation of femur o Ischiofemoral ligament prevents medial rotation of femur o Pubofemoral ligament prevents femur abduction o Orbicular zone maintains contact between the head and the socket Intrascapular o Teres ligament between acetabulum and the head of the femur and contains the acetabular artery branch of obturator artery 7 1h Patella Knee Joint Largest sesamoid bone bone that develops in the tendon on the muscles o Develops in tendon of quadriceps femoris muscle o Tendon inserts into patella Patellar ligament tissue between the patella and the tibial tuberosity Apex faces downward base faces upward Hinge bicondylar type of synovial joint Bones providing articular surfaces distal end of femur proximal end of tibia and the patella Lateral and medial menisci facilitate movements of the joint Ligaments that provide joint capsule support o Medial tibial and lateral collateral ligaments o Iliotibial tract lateral o Lateral and medial patellar retinaculae anterior o Patellar ligament anterior o Oblique and arcuate popliteal ligaments posterior outside joint capsule Intinsic ligaments o Anterior and posterior cruciate ligaments Anterior prevents backward slipping of the femur provides medial rotation and locks knee in extension Posterior Prevents femur from forward slipping Both are not inside the joint cavity o Meniscofemoral ligaements o Transverse ligament Movement flexion