1418 - Cutting the pain, not the power: Posterior Femoral Cutaneous Nerve Block Restores Competitive Performance

The posterior femoral cutaneous nerve (PFCN) is a purely sensory nerve from the sacral plexus that supplies the posterior thigh, gluteal fold, and upper medial thigh. Isolated PFCN mononeuropathies are rare, underrecognized, and present with neuropathic pain without motor deficits. Posterior thigh pain is frequently misattributed to sciatic, pudendal pathology or musculoskeletal strain, leading to misdiagnosis. Although peripheral nerve blocks are increasingly used in pain management, selective ultrasound-guided blockade of the PFCN is rare.

Discussions:

A 20-year-old collegiate track athlete presented with persistent right posterior thigh, hip, and gluteal pain after a hamstring strain. Despite physical therapy and MRI excluding musculoskeletal or sciatic pathology, she reported sharp pain and numbness radiating to the posterior thigh and gluteal fold, impairing daily function and competition.

Exam revealed sensory changes in the PFCN distribution without motor weakness. An ultrasound-guided PFCN block with 0.25% bupivacaine, epinephrine, and betamethasone was performed.

The patient experienced immediate pain relief with preserved strength, returning to activity the same day. Within two weeks, she resumed full competition, reaching state finals. At four-week follow-up, she remained >90% symptom-free.

Conclusions:

This case underscores the therapeutic value of targeting the PFCN in isolated posterior thigh neuropathic pain. While nerve blocks are common for mixed motor-sensory nerves, ultrasound-guided sensory-only blocks of the PFCN are seldom described.

The PFCN lies in the gluteal deep investing fascia, lateral to the inferior gluteal artery and superficial to the sciatic nerve. Hydrodissection separates gluteus maximus from fascia to expose the PFCN. Advancing too deep risks sciatic spread and motor blockade. This precise approach enabled a purely sensory block, facilitating return to competition. It’s an effective intervention that highlights the importance of considering PFCN mononeuropathy in refractory thigh pain and demonstrates the role of targeted sensory nerve blocks in restoring function while preserving motor integrity.