Lower extremity nerves Flashcards
What lower extremity nerves are at risk in abdominal surgery?
- Iliohypogastric (T12-L1) (open)
- Genitofemoral (L1-2) (laproscopic)
Iliohypogastric nerve supplies sensory innervation to where?
Suprapubic region
The iliohypogastric nerve supplies motor sensation to what muscles?
- Transverse abdominis
- Internal oblique
Burning or tingling sensation in surgical incision site radiating to inguinal and suprapubic region indicates injury to what nerve?
Iliohypogastric nerve (T12-L1)
The Genitofemoral nerve (L1-2) supplies sensory innervation to where?
- scrotum/labia majora
- Medial thigh
The genitofemoral nerve is involved in what reflex?
Cremastor reflex
(if damaged sensation to medial thigh beneath inguinal ligament will be impaired)
The lateral femoral cutaneous nerve (L2-3) supplies sensation to where?
Anterior and lateral thigh
- Injury will decrease sensation
How may the lateral cutaneous nerve (L2-3) be damaged?
- Tight clothing
- Obesity
- Pregnancy
- Pelvic procedures
What nerve supplies sensation to the medial thigh?
Obturator (decreased sensation to this area if damaged)
How may the obturator nerve be damaged?
Pelvic surgery
Obturator nerve supplies motor innervation to what muscles?
- Obturator externus
- Adductor longus
- Adductor brevis
- Gracilis
- Pectineus
- Adductor magnus
How may the femoral nerve (L2-4) be damaged?
Pelvic fracture
What muscles does the femoral nerve innervate?
- Quadraceps
- Iliacus
- Pectineus
- Sartorius
What will injury to the femoral nerve (eg pelvic surgery) result in?
- Decreased leg extension
- Decreased patellar reflex
What muscles does the sciatic nerve innervate?
- Semitendinosus
- Semimembranosus
- Biceps femoris
- Adductor magnus
What does the sciatic nerve (L4 - S3) divide into?
- Common peroneal (fibular) nerve
- Tibial nerve
What can cause injury to the sciatic nerve?
- Herniated disc
- Posterior hip dislocation
How may the common peroneal (fibular) nerve be injured?
- Trauma or compression of lateral aspect of leg
- Fibular neck fracture
What does the common peroneal (fibular) nerve supply sensation to?
Superifical and deep peroneal nerve
Superficial peroneal nerve:
- Dorsum of foot (except webspace between hallux and 2nd digit)
Deep peroneal nerve:
- Webspace between hallux and 2nd digit
What muscle does the superificial peroneal nerve innervate?
Peroneus longus and brevis
What muscle does the deep peroneal nerve innervate?
Tibialis anterior
Injury to the common peroneal nerve will result in what?
- Loss of sensation to dorsum of foot
- Foot drop - cannot dorsiflex
The tibial nerve supplies sensory innervation to where?
Sole of foot
How can the tibial nerve be injured?
- Knee trauma
- Baker cyst (proximal lesion)
- Tarsal tunnel syndrome (distal lesion)
The tibial nerve innervates what muscles?
- Flexor muscles of foot (plantarflexion)
- Biceps femoris (long head)
- Triceps surae
- Plantaris
- Popliteus
What will injury to the tibial nerve (L4- S3) result in?
- Loss of plantarflexion, inversion
- Foot everted at rest
- Inability to curl toes
- Loss of sensation to sole of foot
What muscles does the superior gluteal muscle innervate?
- Gluteus medius
- Gluteus minimus
- Tensor fascia latae
Trandelenburg sign is a result of an injury to what nerve?
Superior gluteal
What can cause injury to the superior gluteal nerve?
IM injection to superomedial gluteal region
Describe Trandelenburg sign
Pelvis tilts becuase wight-bearing leg cannot maintain alignment of pelvis through hip abduction
- Lesion is to contralateral side of hip that drops
- Ipsilateral to leg which patient stands on
The inferior gluteal nerve innervates what muscle?
Gluteus maximus
What can injury to the inf gluteal nerve (gluteus maximus) result in?
Difficulty climbing stairs, rising from seated position; loss of hip extension
Injury to the inferior gluteal nerve (L5-S2) can be caused by whaat?
Posterior hip dislocation
Sensory innervation to the perineum is supplied by what nerve?
Pudendal (S2-4)
What does the pudendal nerve innervate (motor)?
External urethral and anal sphincters
How can injury to the pudendal nerve occur?
- Stretch injury during childbirth
- Cycling, horesriding
What may injury to the pudendal nerve result in?
- Decreased sensation to the perineum and genital area
- Fecal and urinary incontinance
Where is used as a landmark for injection to target the pudendal nerve during childbirth?
Ischial spine
