Posterior dislocation of the acromioclavicular joint with the lateral end of the clavicle locked behind the acromion has only rarely been described. This paper present such a case diagnosed two weeks after the shoulder was injured in an accident. The clavicle was locked behind the articular surface of the acromion, restricting the movement of the shoulder and causing considerable pain. Anteropo...

We examined cultured osteoblasts derived from paired samples from the greater tuberosity and acromion from eight patients with large chronic tears of the rotator cuff. We found that osteoblasts from the tuberosity had no apparent response to mechanical stimulation, whereas those derived from the acromion showed an increase in alkaline phosphatase activity and nitric oxide release which is norma...

Radiographs of the shoulders of 84 asymptomatic individuals aged between 40 and 83 years were evaluated to determine changes in 23 specific areas. Two fellowship-trained orthopaedic radiologists graded each area on a scale of 0 to II (normal 0, mild changes I, advanced changes II). Logistic regression analysis indicated age to be a significant predictor of change (p < 0.05) for sclerosis of the...

PURPOSE Despite routine use, clinical tests used to diagnose subacromial impingement often display poor diagnostic accuracy. A lack of anatomical validity may contribute to the poor diagnostic accuracy. The current study aimed to examine the anatomical validity of measuring subacromial pressure in the Hawkins-Kennedy impingement test in a cadaveric shoulder. METHODS Subacromial pressures were...

Introduction: In scapula, the acromion process projects forwards almost at right angles from the lateral end of the spine. The coracoacromian ligament spans between tip of acromian and coracoid process thus it forms coraco-acromial arch. The space below the arch gives passage to the tendons of muscles forming musculorotator cuff. As morphometry of the acromion process of the scapula is an impor...

Muscle fiber conduction velocity (CV) was estimated in 20 healthy subjects with a multichannel technique using a linear electrode array placed on the upper trapezius (UT) muscle during isometric voluntary contractions at 20% of the maximal voluntary effort. The array had 16 contacts spaced by 5mm and was centered in the middle of the line connecting C7 and the acromion. The effect of array disp...

The Neer and Hawkins impingement signs are commonly used to diagnose subacromial pathology, but the anatomy of these maneuvers has not been well elucidated in vivo. This 3-dimensional open magnetic resonance imaging study characterized shoulder anatomy and rotator cuff impingement in 8 normal volunteers placed in the Neer and Hawkins positions. Subacromial and intraarticular contact of the rota...