The shoulder is a ball and socket joint in which the round head of the upper arm bone (humerus) fits into a shallow cup in the shoulder blade (scapula), allowing for a wide range of motion. This joint is enclosed by a capsule. When one develops frozen shoulder, or adhesive capsulitis, this joint capsule that surrounds the joint becomes inflamed, thickened and stiff. This results in pain, reduced mobility and a gradual loss of range of motion. Consequently, daily activities such as dressing and reaching overhead can be painful and difficult.
Frozen shoulder typically progresses through three stages – although not always:
Freezing stage – Increasing pain and stiffness
Frozen stage – Restriction in movement
Thawing phase – Gradual improvement over months
Diabetes and Frozen Shoulder
Frozen shoulder can happen to any individual. However, diabetes is a risk factor – this means that if you have diabetes, you are more likely to develop a frozen shoulder in your lifetime. It is estimated that about 10-20% of patients with diabetes will develop frozen shoulders, compared to 2-5% in non-diabetics.
Compared to non-diabetics, frozen shoulder in diabetics tend to occur at a younger age, be more severe and longer lasting, and can affect both shoulders over time. Patients also respond less predictably to treatment.
While the association between diabetes and frozen shoulder is well-established, the exact mechanism is not well understood. Nevertheless, there are some postulated reasons for this:
Sugar stiffens the shoulder capsule
When blood sugar stays high for a long time, the sugar bonds to collagen fibers to form advanced glycation end-products or AGEs. As these changes make the shoulder capsule thicker and denser, resulting in stiffening of the joints.
Reduced blood flow to the shoulder tissues
Diabetes can lead to damage of the small blood vessels, resulting in a reduced blood supply to tissues. The reduction in blood supply results in a reduction in oxygen and nutrient delivery to the shoulder joint capsule. This results in delayed healing, chronic oxygen shortage and increased tissue fibrosis. Over time, these changes result in the stiffening and thickening of the shoulder capsule.
Chronic inflammation
Diabetes is a pro-inflammatory state. Increased circulation of inflammatory molecules such as IL-6, TNF-alpha and TGF-beta can result in stimulation of cells that produce collagen. This excessive collagen buildup results in thickening of the joint capsule which can limit joint mobility.
Treatment of Frozen shoulder in Diabetics
Treatment of frozen shoulder in diabetics is very similar to treatment of frozen shoulder in non-diabetics. Apart from controlling one’s sugar levels, some of the treatment measures include:
- Participating in shoulder range of movement exercises
- Shoulder Joint Injections
- Hydrodilatation
- Surgery
If you have shoulder pain or have been diagnosed with Frozen shoulders, make an appointment to see our shoulder pain specialist at Alleviate Pain Clinic today.
