Disclosures: Kirk Sheplay: No financial relationships or conflicts of interest

Case Diagnosis: A 42-year-old male with right Posterior Femoral Cutaneous Nerve (PFCN) impingement

Case Description: The patient developed right lower buttock pain two weeks after running a marathon. The pain was located medial and superior to the ischia tuberosity and extended distally to the right scrotum with no testicular pain. The pain progressed such that he was unable to sit down for over a year and stopped running and cycling. An initial MRI showed right hamstring tendonitis. Consults with sports medicine and hip orthopedics provided no clear diagnosis. He failed to improve with NSAIDS, physical therapy, massage, PRP injection, two Ganglion of Impar Nerve blocks, and trial of Pregabalin. The diagnosis was confirmed with temporary relief following a PFCN block. He was then advised to have the nerve resected because of failure of non-surgical treatment.

Setting: OutpatientAssessment/

Results: Following surgical resection of the nerve, the patient experienced posterior buttock numbness initially which gradually resolved over a year. He progressed in sitting tolerance and was able to return to walking, running, and cycling.

Discussion: This is the first reported case of a PFCN Impingement post long-distance running. Anatomically, the PFCN exits the pelvis through the sciatic foramen and continues distally in the midline along the posterior thigh superficial to and between the long head of the biceps femoris and semitendinosus musculature. In this case, the findings of scarring of the PFCN in the proximity of the hamstring tendonitis confirmed the mechanism of the injury.

Conclusion: After excluding the more common etiologies of buttock pain and sitting intolerance such as: hamstring tendinitis, sacroiliac dysfunction, gluteal myofascial syndrome, piriformis syndrome, pudendal nerve impingement, ischial stress reaction, and hip pathology, practitioners should consider the rarer condition of the impingement of the PFCN in runners.

Level of Evidence: Level V

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PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/posterior-femoral-cutaneous-nerve-impingement-post-marathon-a-case-report/