[Scintigraphic method for the study of painful shoulder syndrome: differential count]

Pain may be present in different sites in patients with a painful shoulder syndrome. We compared (scintigraphy) 56 patients with unilateral painful shoulder syndrome and 26 controls. A differential count index (DCI) was used to evaluate painful sites. Values (mean +/- SD) obtained for patients and controls at different sites were: acromioclavicular joint 1.53 +/- 0.33 vs 1.09 +/- 0.08 (p less than 0.005); * 1.30 +/- 0.39 vs 1.07 +/- 0.07 (p less than 0.01); scapular insertion of deltoid muscle 1.61 +/- 0.40 vs 1.10 +/- 0.10 (p less than 0.005); scapular insertion of trapezius muscle 1.31 +/- 0.21 vs 1.08 +/- 0.06 (p less than 0.005). Average number of painful sites for patients 40 years and older was 2.24 vs 1.58 for younger patients (p less than 0.005). Sensitivity and specificity for pain in the various sites was: * 50% and 90%: acromioclavicular joint 85% and 88%; scapular insertion of deltoid muscle 83 and 90%; and scapular insertion of trapezius muscle 71 and 80%, respectively.