Isabel Nip, MD, MS
Physical Medicine & Rehabilitation Resident
UConn Health/Hartford Hospital/Gaylord Specialty Healthcare
West Hartford, Connecticut, United States
Farah Maryam, BA
Medical Student
Boston University Chobanian and Avedisian School of Medicine
Melville, New York, United States
David Gutierrez, MD
Spine Program Director, Division of PM&R
UCONN/ Hartford Healthcare
Torrington, Connecticut, United States
Post-Op Saphenous Neuritis
Case Description: 33-year-old male with chronic right knee pain status-post right knee tibial tubercle osteotomy and medial patellofemoral ligament (MPFL) reconstruction presented with right medial knee hyperalgesia and allodynia consistent with post-op saphenous neuritis. Five months post-op, he subsequently had arthroscopic debridement, hardware removal, and surgical neurolysis without improvement. Over the following year, he was also refractory to topical and oral analgesia and physical therapy. Further failed interventions included genicular nerve block including the infrapatellar branch of the saphenous nerve, peripheral nerve stimulation along the medial femoral nerve, and genicular nerve radiofrequency ablation including the infrapatellar branch of the saphenous nerve. MRI was negative for obvious scar tissue compression of the saphenous nerve. After temporary improvement with a diagnostic saphenous nerve block with lidocaine and triamcinolone, the patient underwent alcohol neurolysis with 60% relief and improvement with ambulation.
Discussions:
Irritation of the saphenous nerve, such as from compressive or surgical etiologies, can lead to saphenous neuritis. Initial treatment focuses on non-surgical methods, although in some cases, the condition may require surgical intervention. Limited evidence exists regarding the optimal situations in which alcohol neurolysis may provide the most benefit in peripheral neuralgia or its effectiveness. Implemented in terminal malignancy pain or as an option in spasticity management or chronic pancreatitis, chemical neurolysis may be employed when other more conservative options fail. To our knowledge, this is the only case in literature in which alcohol neurolysis successfully decreased pain in post-op saphenous nerve neuritis unresponsive to a variety of conventional interventions. With alcohol neurolysis, the patient avoided additional surgery and had positive outcomes in comfort, function, and therefore quality of life.
Conclusions: One may therefore consider alcohol neurolysis in refractory nerve injury, particularly if a diagnostic block suggests potential success. Additionally, alcohol neurolysis may be considered before more permanent or invasive options.
