Calcific shoulder tendinitis

What it is

Calcium hydroxyapatite crystals are deposited in a rotator cuff tendon, most often supraspinatus. The deposit itself is frequently painless and is often found incidentally on x-rays of shoulders that have never hurt.

The severe pain comes during the resorptive phase, when the body breaks the deposit down. The deposit becomes soft and increases in volume and pressure, and the accompanying inflammatory response produces some of the most severe musculoskeletal pain there is. It is self-limiting: the resorption is the resolution.

What it feels like

• Sudden onset of severe shoulder pain, sometimes over hours
• Pain out of proportion to anything that happened
• Often worst at night, and difficult to find any comfortable position
• Very reluctant to move the arm at all during the acute phase
• In the chronic phase, a much milder ache and a catch on certain movements

What causes it

Most people have more than one of these at once, and they feed each other. Read the list looking for the two or three that sound like your week rather than for the one true answer — the ones that describe you are the ones worth acting on.

Calcium deposition in the tendon

Crystals accumulate within the tendon substance, most often in supraspinatus. Why this happens is not fully understood, though a local change in tendon cell behaviour appears to be involved.

The resorptive phase

When the body starts to break the deposit down it becomes semi-liquid, its volume and pressure rise, and an intense inflammatory response accompanies it. This is the severe pain, and it means the process is resolving.

Deposit rupturing into the bursa

The softened material can burst out of the tendon into the subacromial bursa, producing sudden severe pain and marked inflammation - the most dramatic version of the presentation.

Age and sex

Most common between thirty and sixty and more common in women, which distinguishes it from degenerative cuff disease that increases with age.

Diabetes and thyroid disease

Both are associated with a higher incidence, and diabetes is associated with a longer and more resistant course.

Reduced local blood supply

The area of supraspinatus where deposits form has a relatively poor blood supply, which is one of the proposed contributing factors.

Not primarily an overuse condition

Unlike most tendon problems this is not clearly related to load or activity. People are often puzzled that nothing happened, and nothing did.

Who tends to get it

• Adults between thirty and sixty, more often women
• People with diabetes or thyroid disease
• Anyone with a previous episode, which can recur
• It is not strongly related to activity level, which surprises people
• Often found incidentally in people with no symptoms at all

What makes it worse, and what settles it

The qFIT routine for this

Ready-made routineShoulder Relief & Overhead Range

qFIT already has this one built. It runs massage first, then stretching, then strength — the order that works on a body that is already sore — and every activity in it carries the reason it is there.

The button below opens your Checklist with this routine already selected, so instead of your whole list you land on just its Categories, Targets and Exercises, each with its checkbox, ready to tick as you work through them.

Have more than one problem? Tick yours under My Problems on My Profile and your Checklist's Routine list gains Recommended for my problems — every routine for the problems you picked, merged into one. Your picks stay private; that filter is the only thing they feed.

Get it checked if…

Severe unremitting shoulder pain with fever needs infection excluded; the acute resorptive phase can be mistaken for a septic joint

And whatever the body part: chest pain or unusual breathlessness on exertion; a fever alongside the pain; unexplained weight loss; pain that is constant and unrelated to how you move; new numbness, weakness or loss of bladder or bowel control; or one calf that is swollen, warm and painful. Any of those, stop and get assessed.

How it usually goes

The acute resorptive phase is severe but short - typically one to two weeks - and the deposit frequently disappears entirely afterwards. Most cases resolve without any intervention. For persistent, painful deposits, ultrasound-guided barbotage is effective. The important message is that severity of pain does not indicate severity of damage here; the worst pain coincides with the body dissolving the problem. A stiff shoulder developing afterwards is worth treating promptly, since a secondary frozen shoulder is the main complication.

Prevalence basis: Shoulder imaging studies

Others the same routine covers

These share the Shoulder Relief & Overhead Range routine, so the work is the same. If one of them also sounds like you, that is a reason to expect more from it, not less.

This is general information, not a diagnosis, and it cannot examine you. If it matches you, use it to ask better questions of a clinician rather than to replace one.