Neer's 1983 paper consolidates his landmark work on subacromial impingement, building on his 1972 preliminary report. It draws on cadaveric studies and experience with more than 400 anterior acromioplasties. The paper defines a three-stage classification, the impingement sign and injection test, and the anatomic rationale for anterior over lateral acromioplasty.
The three-stage framework this paper introduced gave surgeons a shared language and treatment algorithm that shaped shoulder surgery for decades — and every attending who says 'do an acromioplasty with every cuff repair' is quoting Neer's 95% figure.
When a patient has shoulder pain with forced forward elevation, perform the impingement test: inject 10 cc of 1% xylocaine into the subacromial space. If pain resolves, impingement is confirmed. If pain persists, broaden your differential to frozen shoulder, glenohumeral arthritis, or instability.
For Stage II patients (ages 25–40) who want surgery, the threshold is 18 months of failed conservative treatment. Not 6 or 12 months. For Stage III patients over 40 with a confirmed complete tear on arthrogram, anterior acromioplasty is performed at the same time as the repair.
One critical nuance on biceps pathology: do not tenodese the long head for impingement-related tenosynovitis alone. The long head depresses the humeral head, and removing that function escalates impingement. Contemporary practice has since questioned the sufficiency of the pure mechanical impingement model, and the shift toward 'subacromial pain syndrome' terminology reflects ongoing debate about how completely this framework explains the full spectrum of disease.
Neer's 1983 paper consolidates his landmark work on subacromial impingement, building on his 1972 preliminary report. It draws on cadaveric studies and experience with more than 400 anterior acromioplasties. The paper defines a three-stage classification, the impingement sign and injection test, and the anatomic rationale for anterior over lateral acromioplasty.
The three-stage framework this paper introduced gave surgeons a shared language and treatment algorithm that shaped shoulder surgery for decades — and every attending who says 'do an acromioplasty with every cuff repair' is quoting Neer's 95% figure.
When a patient has shoulder pain with forced forward elevation, perform the impingement test: inject 10 cc of 1% xylocaine into the subacromial space. If pain resolves, impingement is confirmed. If pain persists, broaden your differential to frozen shoulder, glenohumeral arthritis, or instability.
For Stage II patients (ages 25–40) who want surgery, the threshold is 18 months of failed conservative treatment. Not 6 or 12 months. For Stage III patients over 40 with a confirmed complete tear on arthrogram, anterior acromioplasty is performed at the same time as the repair.
One critical nuance on biceps pathology: do not tenodese the long head for impingement-related tenosynovitis alone. The long head depresses the humeral head, and removing that function escalates impingement. Contemporary practice has since questioned the sufficiency of the pure mechanical impingement model, and the shift toward 'subacromial pain syndrome' terminology reflects ongoing debate about how completely this framework explains the full spectrum of disease.