Much less common in lower than upper limbs.
- most common = common peroneal
More prone in penetrating wounds to the abdomen than limb.
Pelvic masses eg haematomas or neoplasms may affect it.
- even catheterisation of the femoral artery
- or laparoscopic repair of a femoral hernia.
¨ loss of quads extension of knee, weak hip flexion
¨ sensory loss over front of thigh
¨ possible pain as far as medial foot (saphenous branch)
Test: rectus femoris
Compression possible in iliac fossa or passing from abdomen ¨ thigh deep to / through ing lig.
¨ meralgia paraesthetica (felt in lateral thigh)
Deep; trauma = rare
Obstetric procedures may, or pelvic disease eg ovarian tumours
¨ loss of hip adduction: not noticed in walking, but eg when sitting one leg cannot be crossed over.
Misplaced gluteal injections (most common), pelvic disease, severe hip trauma
- 7% dislocations and 16% #-dislocations
¨ paralysis of hamstrings and all muscles of leg and foot of tibial and common peroneal nerves
- foot drop will be obvious, hamstrings may be difficult to test due to pain
¨ sensory loss below knee, but nor medially on the leg or upper calf (saphenous from femoral and posterior femoral cutaneous nerves)
Test: plantar / dorsiflexion
Approach: expose at lower border of glut max (retract semitendinosus and long head of biceps medially
Direct trauma / pressure by casts
¨ foot drop = paralysis of extensors supplied by deep peroneal branch (high stepping gait)
¨ peroneus longus / brevis in lateral compartment (superficial branch)
¨ sensory loss over lower lateral leg and dorsum of foot
Test: dorsiflexion.
Approach: exposed at lateral popliteal fossa (medial to biceps tendon) ¨ follow it down.
Uncommon.
¨ paralysis of calf muscles
¨ sensory loss on lower calf and sole
Test: stand on tip-toes
Approach: expose in middle of popliteal fossa; split superficial calf muscles vertically to follow it.
Lower part in front of medial malleolus is at risk in varicose vein surgery / harvesting of great saphenous for arterial bypass.