title: Are spinoglenoid ganglion cysts early markers of glenohumeral arthritis?
abstract: OBJECTIVE
  The objective of this study was to improve our understanding of the pathogenesis and symptoms of ganglion cysts (GCs) in the spinoglenoid notch. Two hypotheses were tested: (1) the labral tears responsible for these cysts are mainly degenerative and nontraumatic, (2) spinoglenoid cysts are early magnetic resonance image (MRI) markers of eccentric posterior glenoid wear.
  
  
  METHODS
  This was a descriptive diagnostic study. Patients were included when a spinoglenoid cyst was discovered after complaints of pain in the posterosuperior aspect of the shoulder. MRI and arthroscopy were used to classify the glenoid GC and characterize the glenohumeral joint. The GCs were classified into 1 of 3 types: GC0 (isolated cyst), GC1 (cyst and associated labral lesion), and GC2 (cyst and associated labral and cartilage lesion).
  
  
  RESULTS
  Twenty patients (average age, 43 years) were included between 2000 and 2014. There were 7 GC0, 8 GC1, and 5 GC2 type cysts. Isolated labral tears (GC1) were always located posteriorly, without anterior extension or glenoid detachment. The humeral subluxation index was above 55% in 75% of shoulders, including all of the type GC2 shoulders. The 5 GC2 shoulders had type B1, B2, or C glenoids.
  
  
  CONCLUSIONS
  The management of paraglenoid labral cysts must go beyond addressing the suprascapular nerve compression related to traumatic labral detachment, and surgeons should look automatically for associated degenerative joint damage. The diagnosis of GCs should be supplemented by humeral subluxation index measurement on computed tomography scan or MRI, and the patient should be informed that joint-related posterior shoulder pain might persist in cases of GC1 and GC2.
  
  
  METHODS
  Basic Science Study; Anatomy; Imaging and In Vivo.
authors.affiliation: Orthopedics and Trauma Department, Pontchaillou University Hospital, Rennes, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Thomazeau
authors.affiliation: Orthopedics and Trauma Department, Pontchaillou University Hospital, Rennes, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Raoul
authors.affiliation: Orthopedics and Trauma Department, Pontchaillou University Hospital, Rennes, France.
authors.forename: Anthony
authors.initials: A
authors.lastname: Hervé
authors.affiliation: Orthopedics and Trauma Department, Pontchaillou University Hospital, Rennes, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Basselot
authors.affiliation: Orthopedics and Trauma Department, Pontchaillou University Hospital, Rennes, France.
authors.forename: Harold
authors.initials: H
authors.lastname: Common
authors.affiliation: Orthopedics and Trauma Department, Pontchaillou University Hospital, Rennes, France; M2S Lab (Mouvement Sport Santé), University Rennes 2 - Ecole Normale Supérieure Bretagne-Université Européenne de Bretagne, Campus de Ker Lann, Bruz, France. Electronic address: mickael.ropars@chu-rennes.fr.
authors.forename: Mickaël
authors.initials: M
authors.lastname: Ropars
mesh_terms: D000293:Adolescent; D000328:Adult; D001168:Arthritis / Q000209:etiology*; D001182:Arthroscopy; D005260:Female; D045888:Ganglion Cysts / Q000150:complications* / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012540:Scapula; D012783:Shoulder Dislocation / Q000000981:diagnostic imaging / Q000209:etiology; D000070599:Shoulder Injuries; D012785:Shoulder Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D020069:Shoulder Pain / Q000209:etiology; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Paralabral ganglion cyst; arthritis; glenoid; labral tears; magnetic resonance imaging; subluxation