Palpable Bony Landmarks in the Lower limb PDF

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Palpable Bony Landmarks in the Lower limb...

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Palpable Bony Landmarks in the Lower limb Overview of the Lower limb  The lower limb can be divided into the following sub-regions: o The Gluteal Region o Thigh o Leg o Ankle o Foot  The sub-regions being linked by major joints: o Joints of The Pelvis o Hip Joint (pelvic bone with femur) o Knee Joint (distal femur with proximal tibia) o Tibio-Fibular Joint (Proximal) o Ankle Joint (distal end of tibia & fibula with the bones of the upper foot) o Joints of the Foot Iliac Crests  Iliac crests: the highest points of the left and right ilium bones.  They signify the highest anatomical points of the lower limbs  Supracristal Plane (L4): an imaginary horizontal anatomical plane that joins the iliac crests  This plane signifies: o The vertebral level at which a lumbar puncture can be carried out safely, to take a sample of CSF  Needle inserted between L3-L4  It is safe as the spinal cord terminates at T12-L1 level. o The vertebral level at which epidural anaesthesia can be administered in regional blocks  anaesthetise the lower limb. o It is also a landmark for determining sites for aspiration of bone marrow (hip bone has flat elements)

Greater Trochanter  It is a subcutaneous bony prominence of the femur  It is readily palpable  Its position signifies o A change in direction of the femur from its neck to its shaft of femur o Indirect landmark for:  Position of the hip joint  Outlines of the capsule of hip joint  Extra-capsular ligaments of the hip are at this level too.  They reinforce the hip joint.

Anterior Superior Iliac Spine (ASIS)  It is a subcutaneous bony landmark of the superior anterior margin of the pelvis  It is palpable  It is a clinically important landmark: o McBurney's Point: the name given to the point over the right side of the abdomen that is one-third of the distance from the anterior superior iliac spine to the umbilicus (navel)  This point roughly corresponds to the most common location of the base of the appendix (where it is attached to the cecum)  This is where the incision for an appendectomy is made

Inguinal Ligament (Poupart's ligament)  It attaches: o Supero-laterally to the Anterior Superior Iliac Spine o Infero-medially to the Pubic Tubercle  The inguinal ligament is an important anatomical landmark of the lower limb: o It defines the anatomical border between the abdomen and the lower limb  If we palpate the ASIS and the pubic tubercle we can define the end of abdominal region and start of lower limb. o It is a site of passage for structures between these anatomical regions. o It is also a site for potential tissue herniation The Femoral Triangle  Location: superomedial aspect of the anterior thigh.  Function: It acts as a conduit for structures entering and leaving the thigh  Boundaries o Roof: Fascia Lata o Floor: pectineus, iliopsoas, adductor longus muscles o Superior border: Inguinal ligament (runs from anterior superior iliac spine to pubic tubercle) o Lateral border: medial border of sartorius muscle, o Medial border: medial border of abductor longus muscle.  Structures that pass deep to the inguinal ligament include (medial to lateral) o Femoral Nerve o Femoral artery o Femoral vein  The femoral artery and vein are contained in a fascial compartment called the Femoral sheath o Femoral Canal: contains deep lymph nodes and vessels  NB: There is a space between the femoral sheath and femoral canal. This allows for expansion of the femoral vein. For those who go to the gym, the amount of blood pumped by quadricep increases so vein dilates into the space created for it by the femoral canal.  Acronym for the contents of the femoral triangle (lateral to medial) – NAVEL: Nerve, Artery, Vein, Empty space, Lymph nodes.

Lateral Cutaneous Nerve of Thigh  [Can be seen in previous image]  The lateral cutaneous nerve of the thigh passes under the inguinal ligament.  It can therefore sometimes compress by it.  This can lead to a Meralgia Paraesthetica: o A neurological condition which presents as a painful patch of numbness on the side of the upper part of the thigh

Structures That Pass Deep to The Inguinal Ligament  These include: o Psoas major, iliacus, pectineus o Femoral nerve, artery, and vein o Femoral Canal o Lateral cutaneous nerve of thigh [see above] o Lymphatics

Structures that pass superior to the Inguinal Ligament  The inguinal canal is a short passage that extends inferiorly and medially through the inferior part of the abdominal wall  It is superior and parallel to the inguinal ligament  It joins the deep inguinal ring (opening) to the superficial inguinal ring (exit)  Boundaries: o Anterior wall: aponeurosis of external oblique and reinforced by internal oblique laterally o Posterior wall: transversalis fascia.  The spermatic cord passes through the inguinal canal. o Spermatic cord is a collection of arteries, veins, nerves and lymph vessels that supply the testes.  The canal allows communication between the abdominal cavity and the scrotal sack.

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Hernias  Inguinal hernias: o Occurs above inguinal ligament. o It is protrusion of viscera of the abdomen through inguinal canal. o It can end up being deposited in scrotal sac or subcutaneously Femoral hernias o Occurs below inguinal ligament. o It is the protrusion of viscera of the abdomen through the femoral canal o It can end up being deposited in the femoral triangle....