Over a 5-year period, 75 shoulders that met Codman's criteria for primary f
rozen shoulder were treated. Nine patients improved with nonoperative treat
ment, and the remaining 66 patients underwent manipulation under anesthesia
. The shoulders in 41 patients successfully released with manipulation. Tho
se in 25 failed to release with manipulation, and therefore, these patients
underwent open surgical release of the contracted shoulder. We reviewed th
e cases of all of the surgically treated patients at 19.52 months' average
follow-up, using the history and clinical examination technique recommended
by the American Shoulder and Elbow Surgeons. The surgical findings in this
group of 25 patients showed a consistent alteration in the rotator interva
l and coracohumeral ligament. The rotator interval was obliterated, and the
coracohumeral ligament was transformed into a tough contracted band. The h
istology of this contracture was examined in 12 patients and consisted of a
dense matrix of type III collagen populated with fibroblasts and myofibrob
lasts. The contracted coracohumeral ligament was excised with immediate rel
ease of the external rotation deficit. Pain scores on visual analogue scale
improved from 8.28 to 2.0. The average score for function, with a maximum
score of 30, improved from 6.08 to 78.9. Twenty patients had excellent or g
ood results, and 3 had fair results. The shoulders of 2 patients failed to
improve: 1 was an insulin-dependent patient with diabetes, and 1 had severe
bilateral Dupuytren's contractures. The results in the patients without di
abetes were very satisfactory, with visual analogue scale scores of pain de
creasing from 8.4 to 1.1, function increasing from 6.4 to 20.1, flexion inc
reasing from an average of 96 degrees to an average of 131 degrees, and ext
ernal rotation increasing from an average of 10.0 degrees to an average of
46.7 degrees. Surgical release of frozen shoulder is a useful option in tho
se few patients with severe disease whose shoulders fail to release with ma
nipulation under anesthesia. Caution should be used in insulin-dependent pa
tients with diabetes.