Workbook questions 7 & 8 Flashcards
On a diagram -
Point out the ilium, pubis, and ischium.
Label the Head of femur greater trochanter lesser trochanter patella lateral epicondyle lateral condyle medial epicondyle medial condyle tibial tuberosity medial malleolus head of fibula lateral malleolus calcaneum talus navicular cuboid cuniform
See notes
In the standing position, which are the main weight bearing bones in the lower limb?
Femur, tibia and calcaneum
Hence, should an individual fall from a height and land on their feet, what parts of the skeleton should you x-ray and why?
X-rays of the whole of the lower limb and the vertebral column. The direction of the force passes up from the feet, through the lower limb to the pelvis and vertebra. Hence any weight bearing bones and joints can be affected, e.g. calcaneal fracture, acetabular fracture and lumbar vertebral fracture.
What is the function of the femoral canal?
The canal contains no discrete structures other than a lymph node or two. The canal acts as a “dead space” to allow for the distension of the femoral vein, particularly during heavy exercise, to accommodate venous return from the limb.
Which structures does the femoral sheath enclose?
Femoral artery, femoral vein and femoral canal, but not the femoral nerve
What are the actions of the quadriceps femoris muscle (2 X ½ marks) and the purpose of the smooth fascial covering of the rectus femoris muscle (1 mark)?
The quadriceps acts to extend the knee joint. Since one of its components, the rectus femoris takes origin above the hip joint, acting on its own assists in the flexion of the hip; the smooth fascial covering of the muscle helps its to move smoothly over the adjacent muscles.
Explain why the vastus medialis muscle has horizontal fibres to the patella?
(Hint: consider patella dislocation).
During movements of the knee, there is a tendency for the patella to be displaced laterally. In order to overcome this, the horizontal fibres of vastus medialis help to prevent this displacement. Moreover, the lateral condyle of the femur is at a slightly higher elevation compared to the medial condyle. This also assists in patellar stability.
Where and how would you locate the femoral vein to obtain venous blood in a collapsed patient?
The femoral vein lies within the femoral triangle. It is medial to the femoral artery. To locate the femoral vein, one needs to establish the position of the femoral artery whose pulsations can be felt easily 2 to 3 inches below the inguinal ligament. The artery enters the thigh passing underneath the inguinal ligament at the mid-inguinal point.
Why might a patient complain of pain and paraesthesia on the medial side of the lower leg following stripping of the long saphenous vein for varicosities? (Hint: consider cutaneous nerve supply to that area)
The long saphenous vein in the leg is accompanied by a cutaneous (sensory)
branch (saphenous nerve) of the femoral nerve. Stripping of the vein may lead to trauma or injury to this nerve which innervates the medial side of the lower leg.
Look at the route of the femoral nerve on its way through the pelvis (but remember the nerve lies on the iliacus and psoas muscles) and explain how the nerve could be damaged.
The femoral nerve arises from L2, L3 and L4 lumbar nerves in the substance of the psoas muscle and enters the thigh deep to the inguinal ligament. The psoas muscle lies anterior to the sacro-iliac joint. The nerve passes underneath the inguinal ligament which stretches between the pubic tubercle on the superior pubic ramus and the anterior superior iliac spine.
How would you test (i) the power of flexion of the hip, (ii) the power of knee extension?
i. Ask the patient to lie on their back and acutely flex the hip on the abdomen to flatten the lumbar spine.
ii. Ask the patient to sit on a chair and extend the knee against resistance.
Explain why sensation over the lateral side of the thigh was preserved.
The lateral side of the thigh is supplied by the lateral (femoral) cutaneous nerve of the thigh from the lumbar plexus; the front and intermediate aspects of the thigh are innervated by the anterior and medial cutaneous nerves which are branches of the femoral nerve.
The x-rays showed that the previously disrupted right sacro-iliac joint was now well aligned and the fractures in the ischial and pubic rami were healing.
What other nerve supplying the thigh passes close to the sacro-iliac joint and might have been injured by this fracture?
The obturator nerve.
Which hip movement would you examine to test the integrity of this other nerve?
Adduction – the adductors of the hip (adductor longus, brevis, magnus, gracilis, pectineus and obturator externus) are all supplied by the obturator nerve.
If the femoral nerve was divided (in this case it was stretched and partially damaged), why would there be sensory loss in part of the foot and state where?
A sensory branch of the femoral nerve called the saphenous nerve (running alongside the great saphenous vein) innervates the medial aspect of the foot.
