Disclosures: Ryan C. Coy, MD: No financial relationships or conflicts of interest
Case Description: The patient had recently had right lower extremity (RLE) arterial bypass from the above-knee popliteal artery to the tibioperoneal trunk using the greater saphenous vein. As her surgical site healed she developed severe uncontrolled pain in her RLE. This was briefly helped by a femoral nerve block during her acute hospital stay the but the pain returned within a few hours. She presented to musculoskeletal ultrasound clinic and was noted to have right saphenous nerve swelling near the site where the saphenous vein was harvested. Nerve conduction studies (NCS) and electromyography (EMG) showed no response on the right saphenous sensory nerve exam with normal responses on the left.
Setting: Musculoskeletal clinic at a tertiary medical center
Patient: A 51 year-old female with past medical history of peripheral arterial disease (PAD) presents to musculoskeletal ultrasound clinic with right medial lower extremity allodynia. Assessment/
Results: The patient was diagnosed with right saphenous mononeuropathy. Under sonographic guidance, we used 5 mL of 1% and 5mg of dexamethasone to hydrodissect around the saphenous nerve just proximal to where it appeared to be entrapped by scar tissue The patient reported complete relief of her symptoms.
Discussion: A careful history and physical exam are helpful in directing further testing in patients with severe post-surgical pain. Neuromuscular ultrasound gives the clinician immediate information that they can use in conjunction with other diagnostic modalities such as NCS and EMG to provide an accurate diagnosis. Once a diagnosis is made, neuromuscular ultrasound can then be used to guide percutaneous treatments.
Conclusion: Neuromuscular ultrasound is useful for the diagnosis and treatment of post-surgical mononeuropathies.
Level of Evidence: Level V
To cite this abstract in AMA style:
Coy RC, Norbury J. Neuromuscular Sonography and Nerve Conduction Studies Used to Diagnose Post-Surgical Saphenous Nerve Entrapment: A Case Report [abstract]. PM R. 2020; 12(S1)(suppl 1). https://pmrjabstracts.org/abstract/neuromuscular-sonography-and-nerve-conduction-studies-used-to-diagnose-post-surgical-saphenous-nerve-entrapment-a-case-report/. Accessed May 15, 2025.« Back to AAPM&R Annual Assembly 2020
PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/neuromuscular-sonography-and-nerve-conduction-studies-used-to-diagnose-post-surgical-saphenous-nerve-entrapment-a-case-report/