Test your knowledge: AC joint pathology
This week, we’ll discuss the case of a patient presenting with long-lasting shoulder pain. This 73 year-old man suffers from anterior and superior shoulder pain, during night-time. The mean pain intensity is 3 on a scale of 10. When assessing mobility, no abnormalities were found, except for a limited range of motion towards horizontal adduction.
When further examining the shoulder, no signs of cuff rupture or instability of the long head of the biceps tendon were found. However some signs of pathology were established using ultrasonography. In the top right image you can see the acromioclavicular (AC) joint having an increase in intra-articular fluid. The picture at the bottom is the supraspinatus tendon with a filled subacromial bursa.
What process can cause both of these pathological signs in the shoulder?
The correct answer is: AC joint osteoarthritis.
This man has recently gardened a lot, and did a substantial amount of of overhead work trimming a hedge. Most likely, osteophytes present in the inferior part of his AC joint tore the cranial layer of his subacromial bursa.
In the image at the bottom you see the subacromial bursa filled with fluid AND some blood clots (Yellow). The fluid observed in the AC joint is called a “Geysir Sign”. Bursal fluid and blood clots are migrating into the AC joint and the superior capsule of this joint. No additional/ secondary cuff ruptures were found in this patient’s shoulder.