title: Lateral meniscal cyst causing common peroneal palsy.
abstract: Lateral meniscal cysts are relatively common, but only in rare instances do they cause common peroneal nerve irritation. There are, we believe, no cases reported in which both the sensory and motor functions of the nerve have been compromised. We present a case of a lateral meniscal cyst that became palpable and led to symptoms of numbness and weakness in the distribution of the common peroneal nerve. The MRI findings were of an oblique tear of the lateral meniscus with an associated multiloculated meniscal cyst that coursed behind the biceps tendon before encroaching on the common peroneal nerve. Surgical resection confirmed the tract as located on the MRI and histology confirmed the mass to be a synovial cyst. Resection of the cyst and arthroscopic excision of the meniscal tear led to resolution of the symptoms in 3 months.
authors.affiliation: Department of Orthopaedic Surgery, Level 7, Royal Melbourne Hospital, Grattan Street, Parkville, Melbourne, Victoria 3050, Australia. billyjowett@gmail.com
authors.forename: Andrew J L
authors.initials: AJ
authors.lastname: Jowett
authors.forename: Jaquie F A
authors.initials: JF
authors.lastname: Johnston
authors.forename: Francesco
authors.initials: F
authors.lastname: Gaillard
authors.forename: Suzanne E
authors.initials: SE
authors.lastname: Anderson
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008592:Menisci, Tibial / Q000473:pathology* / Q000601:surgery; D020427:Peroneal Neuropathies / Q000175:diagnosis / Q000209:etiology*; D013581:Synovial Cyst / Q000150:complications* / Q000175:diagnosis / Q000601:surgery