lumbosacral plexus sciatic and femoral nerves - nu.edu.sd plexus.pdf · by the end of the lecture,...
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Lumbosacral plexusSciatic and Femoral
nerves
Dr. Mohammed ElfaTihMBBS,MSc
By the end of the lecture, students should be able to:
§ Describe the formation of lumbosacral plexus (site & root value).
§ List the main branches of lumbosacral plexus.§ Describe the course of femoral & sciatic nerves.§ List the motor and sensory distribution of femoral
& sciatic nerves.§ Describe the main motor & sensory effects in
cases of lesion of femoral & sciatic nerves.
Ø Formation: Ø Ventral (anterior) rami of the upper 4 lumbar spinal nerves (L1,2,3 and L4).Ø Site: Within the substance of the psoas major muscle.Ø Main branches:Ø Iliohypogastric & ilioinguinal: to skin of the anterior abdominal wall.Ø Genitofemoral: to skin of the thigh & cremaster muscle.Ø Obturator: to medial (adductor) group of the thigh.Ø Femoral: to anterior group of the thigh.
Ø Origin:Ø From lumbar plexus
( L2,3,4).Ø Course:• Descends lateral to
psoas major & enters the thigh behind the midpoint of the inguinal ligament.
• Passes lateral to femoral artery, then divides into anterior & posterior divisions.
Femoral N
MUSCULAR BRANCHES OF
FEMORAL NERVE
• In abdomen: To iliacus (flexor of hip
joint).• In lower limb: • To the muscles of the
anterior compartment of the thigh:
Flexors of hip joint: Sartorius & PectineusExtensors of knee joint: Quadriceps femoris.
S A R T
P
CUTANEOUS BRANCHES OF
FEMORAL NERVE
• To antero-medial aspect of the thigh.
• To medial side of:• Knee,• Leg and • Foot (saphenous nerve).
INJURY OF THE FEMORAL NERVE
Paralysis of
Movement affected
Iliacus Flexion of the hip
Sartorius Flexion and abduction of the hip
Pectineus Flexion and adduction of the hip
Quadriceps femoris
Extension of the knee
Ø MOTOR EFFECT:Iliacus
Pectinus
sartorius
Quadriceps
FEMORAL NERVE INJURY
SACRAL PLEXUS
Main branches:• Pelvic splanchnic
nerve: preganglionic parasympathetic to pelvic viscera & hindgut.
• Pudendal nerve: to perineum.
• Sciatic nerve: to lower limb.
Sciatic nerve
SCIATIC NERVE
Ø Course:Ø Leaves the pelvis through
greater sciatic foramen, below piriformis & passes in the gluteal region (between ischial tuberosity & greater trochanter) then to the posterior compartment of the thigh.
Ø Termination:Ø Divides into tibial &
common peroneal (fibular) nerves in the middle of the back of the thigh.
BRANCHES OF THE SCIATIC NERVE
q MUSCULAR:• To Hamstrings (flexors of knee &
extensors of hip).• To all muscles below the knee (in
leg & foot).1. Common peroneal: Muscles of anterior & lateral
compartments of leg (Dorsi flexors of ankle, Extensors of toes, Evertors of foot).
1. Tibial: Muscles of posterior compartment
of leg & intrinsic muscles of sole (Planter flexors of ankle, Flexors of toes, Invertors of foot except tibialis anterior).
qCUTANEOUS: To all leg & foot
EXCEPT: areas supplied
by the Saphenous nerve (branch of Femoral nerve).
TIBIAL NERVEØ Course:• Descends through popliteal
fossa to the posterior compartment of leg.
• Accompanied with posterior tibial vessels.
• Passes behind the medial malleolus (deep to flexor retinaculum) to reach the sole of foot where it divides into 2 terminal branches, (Medial & Lateral planter nerves).
CAUSES OF SCIATIC NERVE INJURY
II-Posterior dislocation of the hip joint
SCIATICA • Sciatica describes the condition in which patients have pain along the sensory distribution of the sciatic nerve.
• Thus the pain is experienced in the posterior aspect of the thigh, the posterior and lateral sides of the leg, and the lateral part of the foot.
Sciatica can be caused by: Ø Prolapse of an intervertebral disc, with pressure on
one or more roots of the lower lumbar and sacral spinal nerves.
Ø Pressure on the sacral plexus or sciatic nerve by an intrapelvic tumor.
Ø Inflammation of the sciatic nerve or its terminal branches.
Common Peroneal Nerve Injury
The common peroneal nerve is commonly injuredIn Fractures of the neck of the fibula and By pressure from casts or splints.
Common Peroneal Nerve Injury
Common Peroneal Nerve Injury
Sensory :Sensation is lost between the first and second toes.Dorsum of the foot and toes.Medial side of the big toe. Lateral side of the leg.
Superficial peroneal
Tibial Nerve Injury
Tibial Nerve Injury
Sensory: Sensory Loss over: Lateral side of the leg and foot (sural nerve).Trophic ulcers in the sole.