Lower Extremity Nerves Flashcards
What dermatome does the obturator nerve innervate?
L2-L4
What causes injury to the obturator nerve?
- Pelvic Surgery
What is the presentation of an obturator nerve injury?
Decrease thigh sensation medially and decrease adduction
What dermatome does the femoral nerve innervate?
L2-L4
What causes injury to the femoral nerve?
- Pelvic Surgery
What is the presentation of a femoral nerve injury?
- Decreased thigh flexion
2. Decreased thigh extension
What dermatome does the common peroneal nerve innervate?
L4-S2
What causes injury to the common peroneal nerve?
- Trauma or compression of the lateral aspect of the leg
2. Fibular neck fracture
What is the presentation of a common peroneal nerve injury?
- Foot drop: inverted and plantarflexed at rest, loss of eversion and dorsiflexion
- Steppage gait: loss of sensation on dorsum of foot
What dermatome does the tibial nerve innervate?
L4-S3
What causes injury to the tibial nerve?
- Knee trauma
- Baker cyst (proximal lesion)
- tarsal tunnel syndrome (distal lesion)
What is the presentation of a tibial nerve injury?
- Inability to curl toes
- Loss of sensation on sole of the foot
- In proximal lesions due to a baker cyst, foot is everted at rest with loss of inversion and plantarflexion.
What dermatome does the superior gluteal nerve innervate?
L4-S1
What causes injury to the superior gluteal nerve?
Iatrogenic due to intramuscular injection to the upper medial gluteal cleft
What is the presentation of a superior gluteal nerve injury?
- Trendelenburg sign/Giat: pelvis tilts because weight-bearing leg cannot maintain alignment of pelvis through hip abduction.
The lesion is contralateral to the side of the hip that drops, ipsilateral to the extremity on which the patient stangs.
What dermatomes does the inferior gluteal nerve innervate?
L5-S2
What causes injury to the inferior gluteal nerve?
- Posterior hip dislocation
What is the presentation of an inferior gluteal nerve injury?
- Difficulty climbing stairs
- Difficulty rising from a seated position
- Loss of hip extension
What muscles does the superior gluteal nerve innervate?
- gluteus medius
- gluteus minimus
- tensor fascia latae
What muscles does the inferior gluteal nerve innervate?
- gluteus maximus
What is the function of the Peroneal nerve?
Recall PED
The peroneal nerve everts and dorsiflexes the foot.
If injured, the foot is dropPED.
What is the function of the tibial nerve?
Recall TIP
The tibial nerve inverts, and plantarflexes the foot.
If injured, the patient cannot stand on TIPtoes.
What does the pudendal nerve innervates?
Perineum
How is the pudendal nerve blocked?
The pudendal nerve can be blocked with local anesthesia during childbirth using the ischial spine as a landmark for injection
What is the site to inject in the buttocks to avoid nerve injury?
Choose the superolateral gluteal quadrant to avoid nerve injury.
