Saphenous Neuropathy Secondary to Extraneural Ganglion Cyst 15 Years After Reconstruction of the Anterior Cruciate Ligament

• Published in: PM & R 2014-05, Vol.6 (5), p.451-455
• Main Authors: Sole, Joshua S., MD, Pingree, Matthew J., MD, Spinner, Robert J., MD, Murthy, Naveen S., MD, Sellon, Jacob L., MD
• Format: Article
• Language: English
• Subjects: Adult; Anterior Cruciate Ligament Reconstruction; Female; Femoral Neuropathy - etiology; Femoral Neuropathy - surgery; Ganglion Cysts - diagnosis; Ganglion Cysts - surgery; Humans; Joint Capsule - pathology; Knee Joint - innervation; Knee Joint - pathology; Magnetic Resonance Imaging; Menisci, Tibial - surgery; Physical Medicine and Rehabilitation
• ISSN: 1934-1482; 1934-1563
• DOI: 10.1016/j.pmrj.2013.11.003

This case report describes a 43-year-old woman with a previous anterior cruciate ligament reconstruction and medial meniscectomy who presented with right knee dysesthesias radiating into her medial ankle with associated allodynia. An extensive work-up was pursued, without a definitive diagnosis found or improvement in the patient's symptoms. Eventually, she was referred to Pain Medicine for an ultrasound-guided saphenous nerve (SN) block, where a scan before the injection revealed a large cyst anteromedial to the sartorius in the expected location of the SN. Magnetic resonance imaging and surgical pathology confirmed a juxta-articular ganglion cyst compressing the main SN, just above the take-off of the infrapatellar branch. The cyst was successfully resected, with improvement noted in the patient's neuropathic symptoms postoperatively. Saphenous neuropathy is a rare condition, and to our knowledge this case is the first reported of saphenous neuropathy caused by a knee joint capsule−derived ganglion cyst.