Lower extremity injuries (Lumbosacral plexus) Flashcards
Mechanism of injury for superior gluteal nerve
IM injection to upper medial gluteal region
Complications of lunate fracture
Cmopressoin of median nerve (carpal tunnel syndrome)
Landmark used for pudendal nerve block during childbirth
Ischial spine
Femoral nerve sensory + motor innervation
Sensory: Anterior thigh + medial leg/ foot
Motor: Quadriceps + iliopsoas
Why does thenar eminence atrophy but sensation spared in carpal tunnel syndrome
Palmar cutaneous branch from median nerve enters hand external to the carpal tunnel
Nerve affected in colles fracture
Median nerve
Iliohypogastric nerve
T12-L1
Sensory + motor innervation of pudendal nerve
Sensory- perineum
Motor- external urethral + anal sphincters
Presentation of common peroneal nerve injury
Foot drop (deep peroneal nerve) + foot inveresion (superficial peroneal nerve)
Loss of sensation on dorsum of foot
Steppage gait- exaggerated hip and knee flexion due to foot drop
Obturator nerve motor + sensory innervations
Sensory: Medial thigh
Motor:
- Adductors (adductor longus, brevis, magnus): adducts thigh at the hip
- Gracilis: Adducts thigh at hip, flexes leg at knee, helps rotate knee medially (crosses knee while seated)
Tibial nerve
L4-S3
Nerve affected in supracondylar fracture
Median + possibly radial
(Also brachial artery)
Mechansim of injury to common peroneal nerve
Fibular neck fracture blow to leg, compressoin of lateral aspect of leg (e.g. tight leg casts, prolonged lying during surgery)
Mechanisms of sciatic nerve injury
Herniated disc, posterior hip dislocation (most common)
Sciatic nerve sensory + motor innervations
Sensory: posterior thigh + leg
Motor: muscles of posterior thigh / hamstringes; extends thigh at hip, flexes leg at knee
Nerves of femoral nerve
L2-L4
Sensory + motor innervation of tibial nerve
Sensory: sole of foot
Motor:
posterior compartment muscles- plantarflexes foot, inverts foot
Foot flexor muscles
Signs + sx of femoral nerve injury
Motor: Weak hip flexion (iliopsoas), Loss of knee extension + Atrophy of quads
Sensory loss: Loss of sensation in anterior thigh/ medial leg/foot
Quadriceps gait
Iliohypogastric nerve motor + sensory innervation
Sensory: suprapubic region
Motor: transversus abdominis + internal oblique
Signs + sx of carpal tunnel syndrome
Compression of median nerve leads to paresthesia, pain, numbness in distribution of median nerve
Thenar eminence atrophy but sensation is spared (palmar cutnaeous branch enters hand extenral to carpal tunneL)
Signs + sx of inferior gluteal nerve injury
Difficulty climbing stairs, rising from seated position (loss of hip extension)
Gluteus maximus gait: pt keeps weight back during heel strike to prevent body from swinging forward due to momentum
Mechansim of injury to tibial nerve
Knee trauma + Baker cysts (proximal lesion)
Tarsal tunnel syndrome (distal lesion)
Mechanism of femoral nerve injury
- Pelvic fracture
- Spontaneous retroperitoneal hematoma (psoas muscle)- leads to femoral nerve compression
Mechanism of inferior gluteal nerve injury
Posterior hip dislocation
Presentation of tibial nerve injury
All of muscles in back of leg + sole of foot paralyzed- opposing muscles dorsiflex foot at ankle + evert the foot (can’t stand on tiptopes)
Inability to curl toes
Loss of sensation on sole
Common peroneal nerve
L4-S2
Nerves of obturator nerve
L2-L4
Signs + sx of sciatic nerve injury
Sensory: below knee involves entire peroneal, tibial, sural territories (most significant finding)
Motor: Foot drop, wasting of calf muscles, loss of Achilles reflex (paralysis of muscles supplied by tibial + common peroneal nerves)
Signs + sx of superior gluteal nerve injuy
Positive Tredelengberg gait: inability to keep pelvis level when standing on one foot or during gait; lesion is contralateral to the side of hip that drops
Mechanism of injury of pudendal nerve + presentation
Mechanism: strethc injury during childbirth
Presentation: decreased sensation in perineum + genital area; can cause fecal or urinary incontinence
Inferior guteal nerve sensory + motor innervation
Sensory: none
Motor: gluteus maximus; major extensor of hip joint
Sciatic nerve
L4-S3
Two nerves (tibial nerve + common peroneal nerve) that separate just proximal to popliteal fossa
Nerves of superior gluteal nerve
L4-S1
Pudendal nerve
S2-S4
Signs + sx of obturator nerve injury
Loss of sensation in medial thigh + loss of thigh adduction
Description of posterior hip dislocation
Right hip flexed, internally rotated, adducted
Nerves of inferior gluteal nerve
L5-S2
Superior gluteal nerve sensory + motor innervation
Sensory: none
Motor: Gluteus minimus + medius– keeps pelvis level when opposite level off the ground
Common peroneal nerve sensory + motor innervation
Sensory: dorsum of foot, lateral portion of lower leg
Motor:
- deep peroneal nerve- anterior compartment of leg; dorsiflexion of foot + extension of toes
- Superficial peroneal nerve- lateral comparment of leg; everts foot
Mechansim of injury of iliohypogastric nerve + presentation
Abdominal surgery; burning or tinglign pain in surgical incision site radiating to inguinal/suprapubic region
