Sacral plexus

Sacral plexus its formation, course, innervation and clinicals

1. SACRAL PLEXUS
Dr. Saneed Khaliq
MBBS, MPHIL ANATOMY
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2. •To explain sacral plexus, its formation, course and Innervation
with clinical aspects
OBJECTIVE
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3. FORMATION OF SACRAL PLEXUS
•The sacral plexus is a network of
nerve fibers that lies on the posterior
pelvic wall in front of the piriformis
muscle
•It is formed by anterior rami of L4-
L5 (lumbosacral trunk) and S1-S4
•The lumbosacral trunk joins the
sacral nerves as they emerge from the
anterior sacral foramina
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4. Anteriorly:
•The internal iliac vessels
and their branches and the
rectum
Posteriorly:
•The piriformis muscle
RELATIONS
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5. 1.Superior gluteal nerve
2.Inferior gluteal nerve
3.Posterior cutaneous femoral nerve
4.Nerve to piriformis
5.Nerve to Obturator internus
6.Nerve to Quadratus femoris
7.Sciatic nerve
• Tibial portion
• Common peroneal portion
8. Pudendal nerve
BRANCHES OF SACRAL PLEXUS
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6. SUPERIOR GLUTEAL NERVE
•Course:
•Leaves the pelvis via the greater
sciatic foramen
•Enters the gluteal region superiorly
to the piriformis muscle
•Innervation:
•Gluteus medius
•Gluteus minimus
•Tensor fasciae latae muscles
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7. INFERIOR GLUTEAL NERVE
•Course:
•Leaves the pelvis via the greater
sciatic foramen
•Enters the gluteal region inferiorly
to the piriformis muscle
•Innervation:
•Gluteus maximus muscle
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8. NERVE TO PERIFORMIS
•Course:
•It arises from the posterior division of
the ventral rami of the first and
secondsacral nerves, and enters the
anterior surface of
thepiriformismuscle
•Innervation:
•Piriformis muscle
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9. PERIFORMIS SYNDROME
•Piriformis syndromeis a
neuromuscular disorderthat is
caused when the piriformis
muscle compresses the sciatic
nerve
•Muscle spasm causes buttock
pain that radiates down the back
of the leg along the sciatic nerve
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10. NERVE TO OBTURATOR INTERNUS
•Course:
•It arises from the anterior rami of
spinal nervesL5, S1 and S2.
•The nerve travels inferior to
piriformis and courses around the
ischial spine
•Innervation:
•Obturator internus
•Superior gemellus muscles
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11. NERVE TO QUADRATUS FEMORIS
•Course:
•It arises from anterior divisions
of the anterior rami of theL4,
L5 and S1spinal nerves
•Travels inferior to sciatic nerve
•Innervation:
•Quadratus femoris
•Inferior gemellus muscles
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12. PERFORATING CUTANEOUS NERVE
•Course:
•It arises from fibers of the
anterior rami of spinal
nervesS2 and S3
•Passes through the greater
sciatic foramen
•Pierces the sacrotuberous
ligament and gluteus maximus.
•Innervation:
•Skin over medial aspect of
buttock
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Perforating
cutaneous neve

13. POSTERIOR CUTANEOUS NERVE OF THE THIGH
•Course:
•It receives fibers from both anterior
and posterior divisions of anterior
rami.
•Posterior divisions: S1 and S2
•Anterior divisions: S2 andS3.
•Innervation:
•Skin over posterior surface of thigh
•Popliteal fossa
•Lower part of buttock
•Scrotum or labium majus
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14. SCIATIC NERVE
(L4, 5; S1, 2, 3)
•Course:
•It enters the gluteal region via
greater sciatic foramen
•Inferiorly to the piriformis muscle
and descends in an inferolateral
direction
•At popliteal fossa, it bifurcates into
the tibial and common fibular
nerves.
•Divisions:
•Tibial nerve
•Common fibular nerve
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15. TIBAL AND COMMON FIBULAR NERVE
•Tibial nerve
•It innervates posterior compartment of the
thigh and the hamstring component of
adductor magnus. Innervates all the muscles
in the posterior compartment of the leg and
sole of the foot.
•Common fibular nerve
•Short head of biceps femoris, all muscles in
the anterior and lateral compartments of the
leg and extensor digitorum brevis
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16. SCIATICA
•Sciaticais a condition in which
patients have pain along the sensory
Innervation of the sciatic nerve
•Causes:
•Prolapse of an intervertebral disc
•Pressure on sciatic nerve
•Nerve inflammation
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17. PUDENDAL NERVE
•Course:
•It leaves the pelvis via the greater
sciatic foramen, then re-enters via
the lesser sciatic foramen
•Innervation:
•Muscles of perineum
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