title: Prevalence of subacromial-subdeltoid bursitis in shoulder pain: an ultrasonographic study.
abstract: OBJECTIVE
  The presence of the subacromial-subdeltoid (SASD) bursa inflammation has recently been proposed as a primary radiologic factor predicting persistent limitation and pain in operated patients. The aim of the study was to verify the hypothesis that pain, or increased shoulder pain, could be associated with SASD bursitis not only in operated patients but also in general population.
  
  
  METHODS
  A consecutive series of 1940 shoulder ultrasound examinations were performed by our Department over a 5-year period using linear multi-frequency probes. All reports of examination executed for shoulder pain were reviewed. The video clips were independently reviewed by two radiologists: effusion in the SASD bursa and the presence of other pathological conditions were evaluated and confirmed.
  
  
  RESULTS
  A total of 1147 shoulder video clips were re-evaluated, and 1587 pathologies were detected; 65.5 % of patients had only one pathology, 30.4 % had two and 4.1 % presented three pathologies. The difference between the group with and without effusion is statistically significant for acromioclavicular joint arthritis, supraspinatus tendon calcific tendinopathy, full-thickness and superficial tear of the supraspinatus, traumas and rheumatoid arthritis with a p value <0.01.
  
  
  CONCLUSIONS
  Our study shows that the effusion in the SASD bursa is frequently associated with shoulder pain often independently from the underlying pathology; further studies are needed to confirm the statistical significance of this relationship by clarifying possible confounding factors.
authors.affiliation: Department of Radiology, IRCCS Policlinico San Matteo Foundation, P.le Golgi 2, 27100 Pavia, Italy.
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Draghi
authors.affiliation: Biostatistics and Clinical Epidemiology Unit, IRCCS Policlinico San Matteo Foundation, P.le Golgi 2, 27100 Pavia, Italy.
authors.forename: Luigia
authors.initials: L
authors.lastname: Scudeller
authors.affiliation: Department of Radiology, IRCCS Policlinico San Matteo Foundation, P.le Golgi 2, 27100 Pavia, Italy.
authors.forename: Anna Guja
authors.initials: AG
authors.lastname: Draghi
authors.affiliation: Department of Radiology, IRCCS Policlinico San Matteo Foundation, P.le Golgi 2, 27100 Pavia, Italy.
authors.forename: Chandra
authors.initials: C
authors.lastname: Bortolotto
keywords: Bursal inflammation; Shoulder pain; Subacromion-subdeltoid bursa; Ultrasound