Posterior Femoral Cutaneous Nerve

The posterior femoral cutaneous nerve is a sensory nerve of the lower limb that arises from the sacral plexus. It provides cutaneous innervation to the posterior surface of the thigh, inferior buttock, and perineum. Though it is a purely sensory nerve, it is clinically significant due to its wide distribution and proximity to sciatic nerve pathways. It is also one of the longest cutaneous nerves in the body, extending from the pelvis to just above the popliteal fossa.

Structure

The posterior femoral cutaneous nerve is formed from the ventral rami of spinal nerves S1, S2, and S3. It exits the pelvis through the greater sciatic foramen and travels alongside other major nerves of the posterior thigh. The nerve divides into several cutaneous branches as it descends.

• Roots: S1, S2, S3 (sacral plexus)
• Type: Purely sensory (afferent)
• Branches:
  • Inferior cluneal nerves (to lower buttock)
  • Perineal branches (to posterior scrotum or labia)

Location

The posterior femoral cutaneous nerve exits the pelvis via the greater sciatic foramen, inferior to the piriformis muscle. It then travels deep to the gluteus maximus and superficial to the long head of the biceps femoris muscle. It continues down the posterior thigh to the popliteal fossa, giving off cutaneous branches along its course.

Function

• Cutaneous Sensation: Supplies skin over the posterior thigh, inferolateral buttock (via inferior cluneal branches), and part of the perineum
• Perineal Innervation: Sends branches to posterior scrotum (in males) or posterior labia (in females)
• Reflex Pathways: Contributes to sensory feedback for lower limb skin, especially posteriorly

Clinical Significance

• Nerve Entrapment: Can cause paresthesia or pain in the posterior thigh (e.g., cyclist’s syndrome)
• Misdiagnosis Risk: Symptoms from this nerve may be mistaken for sciatic nerve pathology
• Surgical Landmark: Important to avoid during posterior approaches to the hip and buttock surgeries