Disclosures: David Bakal, MD: No financial relationships or conflicts of interest

Case Diagnosis: A 16-year-old male with chronic exertional left buttock pain diagnosed with entrapment of the posterior femoral cutaneous nerve (PFCN).

Case Description: A 16-year-old male presented to the sports medicine clinic with 6 months of insidious-onset, sharp, non-radiating left buttock pain with explosive movements during soccer. He had been diagnosed with piriformis myofascial pain and proximal hamstring tendinopathy by an outside provider, but his symptoms persisted despite physical therapy (PT) and two platelet-rich-plasma injections to the proximal hamstrings. Physical exam was notable for mild tenderness to palpation of the left piriformis muscle and ischial tuberosity. Differential diagnosis included piriformis syndrome, obturator internus bursitis, ischial bursitis, hip intra-articular pain, high hamstring tendinopathy, and PFCN entrapment. Imaging studies over the course of follow up, including pelvic x-ray, hip MRI, and MR neurogram, were unremarkable. Treatment over the course of follow-up, including PT, acupuncture, shockwave therapy to the proximal hamstrings, and ultrasound-guided injections to the lesser trochanter and ischial tuberosity by an outside provider, did not resolve his symptoms. Ultimately, he was referred for a PFCN hydrodissection and block, and was able to return to full sports activity.

Setting: Outpatient sports medicine clinic.Assessment/

Results: After PFCN hydrodissection/block, the patient was able to return to full sports activity.

Discussion: The PFCN is a sensory branch of the sacral plexus that supplies the skin of the posterior thigh and buttock. Entrapment of the PFCN has been found to occur after gluteal injections, or from compression due to prolonged sitting/bicycling. Although PFCN entrapment often presents with pain and sensory abnormalities in the posterior buttock and thigh, physical exam can otherwise be unremarkable.

Conclusion: This is the first documented case of PFCN entrapment in the pediatric population. PFCN entrapment should be considered as a potential cause of chronic buttock and posterior thigh pain in young athletes, even those lacking the commonly cited risk factors.

Level of Evidence: Level IV

« Back to AAPM&R Annual Assembly 2021

PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/chronic-buttock-pain-from-posterior-femoral-cutaneous-nerve-entrapment-in-a-competitive-youth-soccer-player/