This winter season (or at least as close to winter as we seem to get in California) seems like the perfect time to talk about perhaps the most misunderstood orthopedic pathology - Adhesive Capsulitis - otherwise known as the dreaded "Frozen Shoulder".
The pathologic processes associated with frozen shoulder are well documented on tissue section and involve extensive fibrosis (scarring) of the capsule accompanied by the infiltration of inflammatory cells.
In contrast, the biologic origins of Adhesive capsulitis are somewhat of a mystery. We know that it seems to be associated with certain metabolic and immunologic factors - namely thyroid disease, kidney disease, diabetes, immunologic diseases and fluctuations in estrogen levels (most commonly observed in women between 40-60 years old), but we do not yet understand the causal link between these factors and the onset of disease.
Clinically, the most relevant exam finding indicating a frozen shoulder is a restricted passive range of motion (range of motion assisted by the examiner) which essentially provides an indication of the flexibility of the capsular membrane surrounding the shoulder. Imaging findings for adhesive capsulitis are less reliable. When they do appear it is typically as scarring and inflammation noted in the inferior sling of the shoulder capsule.
The diagnosis of a frozen shoulder is a double edge sword. On the one hand, it is good, because it means that 95% of the time there will be no surgery required or permanent issues associated with the disease. On the other hand, the course of frozen shoulder can be very protracted and very difficult to predict. Significant symptoms of frozen shoulder may last for only 3 weeks or persist for up to 18 months following their onset.
In Part 2 of this article I am going to be talking more about the treatment of Frozen Shoulder and giving some tips on management.