Supraspinatus outlet view in the diagnosis of stages II and III impingement syndrome

Purpose: To compare supraspinatus outlet view (SOV) findings at different s tages of the impingement syndrome (IS) with findings in asymptomatic age- a nd sex-matched controls. Material and Methods: Pre-operative SOVs were obtained of 37 shoulders of p atients scheduled for unilateral open repair of a full-thickness rotator cu ff tear (stage III IS) and 74 shoulders of patients scheduled for open (n=4 6) or arthroscopic (n=28) acromioplasty for tendinitis (stage II IS). Each view of a patient's shoulder was paired with a control view obtained from a n age- and sex-matched person with no shoulder problems (n=111). Results: There were no significant differences in acromial morphology as ev aluated on the scale devised by BIGLIANI et al. or in the tilt, slope or le ngth of the acromion between the study groups and their controls. However, hooked acromion seemed to be more common in the patients. The thickness of the anterior part of the acromion at the tendinitis stage and the acromial angle at the tear stage of IS were the only parameters that showed signific ant differences between patients and controls. Conclusion: Variation of the morphology of the acromion as evaluated on a b asis of the SOV is associated with IS, but the association is weak and its value in the diagnosis of IS is therefore only as an adjunctive to other di agnostic modalities.