How Can Calcium Granules in the Tendons of the Shoulder Hurt so Much?! All You Need to Know About Calcifying Tendonitis

Few shoulder conditions will occasionally bring individuals to tears, literally. Calcifying tendonitis is one of them. Although this condition improves on its own most of the time, it can be really painful for a while! Luckily, most individuals with calcifying tendonitis do not require surgery; however, when required, surgical removal of the deposits of calcium can feel like a life-saver…, and it is done using minimally invasive arthroscopic surgery.

What is Calcifying Tendonitis?

The rotator cuff is a group of muscles and tendons very important for the function of the shoulder joint. Wear or injury of these tendons, commonly know as rotator cuff tear, is a very common reason for shoulder pain. Calcifying tendonitis is a different condition that affects these same tendons. One or more granules of calcium are deposited in the tendon substance. The supraspinatus and infraspinatus tendons are most commonly affected, but the subscapularis and teres minor tendons can also be sites of calcification. Most of the time, calcium deposits are laid down slowly over time. Eventually, these deposits fragment into smaller pieces and disappear.

The supraspinatus and infraspinatus tendons are most commonly affected by calcifying tendonitis.jpg
The supraspinatus and infraspinatus tendons are commonly affected by calcifying tendonitis

As frustrating as it sounds, most of the time, the reasons why these calcifications occur are not completely clear. The mechanisms through which these calcium deposits become painful are also a matter of speculation. Some believe that severe episodes of pain happen when the calcific deposits are being fragmented, although not everyone shares this view. Others consider that pain may be secondary to (1) excessive pressure inside the tendon, (2) thickening of the tendon in an already compromised space (in a normal shoulder, the space for the rotator cuff is somewhat limited by the bone on top, called the acromion), and (3) the slow release of small particles of calcium that can irritate and inflame the area.

What are the main symptoms?

Individuals suffering from calcifying tendonitis will experience either a dull lingering pain or a short episode of excruciating pain. Some individuals go through both, experiencing weeks or months of shoulder ache, followed by a sudden increase in pain that will last for a few days. The dull achiness associated with chronic calcifying tendonitis is present day and night, interferes with sleep, and typically becomes worse with attempted motion. Longstanding calcific tendonitis may lead to secondary stiffness. Patients suffering from an acute episode are barely able to move the arm and may present in tears due to the intensity of their pain.

How is it diagnosed?

Calcium deposits can usually be seen on plain radiographs. Sometimes they are difficult to visualize, either because the density of the calcium deposit is faint, or because the granule is small and can only be seen if the radiographs are obtained from multiple angles. Other imaging studies, such as magnetic resonance or ultrasound, will also show the calcification, but typically they are not obtained unless additional problems are being ruled out.  Ultrasound can also be used to guide an injection or aspiration.

Radiograph shows an area of calcifying tendonitis.jpg
Radiograph shows an area of calcifying tendonitis

How to get some relief during the acute episode

In our experience, the fastest, most effective way to alleviate the excruciating pain felt during an acute episode is injecting a combination of a local anesthetic and a corticosteroid in the space around the rotator cuff (called subacromial space). The injection can be performed with or without ultrasound guidance. Occasionally, the calcium deposit is somewhat fluid (with a consistency similar to toothpaste), and can be aspirated with the needle used for injection. Use of nonsteroidal anti-inflammatory drugs (i.e. ibuprofen) helps as well.

Injection of corticosteroids in the subacromial space

Treatment alternatives

Outside of the acute phase, most patients with calcifying tendonitis are treated initially with nonsteroidal anti-inflammatory drugs and physiotherapy; one subacromial injection may be considered as well. Removal of the calcium granules can be attempted under local anesthesia and ultrasound guidance by breaking the granule into smaller pieces with a needle, then aspirating them. Some have reported breakage of the calcification with use of extracorporeal shock wave therapy (waves of energy sent through the tissues can lead to fragmentation of the calcific granules). Patients not responding to any of these alternatives are considered for surgical removal of the calcific deposits.

Arthroscopic surgery involves the introduction of a camera through a small skin incision and use of instruments through one or more separate small incisions, visualizing the procedure in a display. The calcific deposit is typically identified with a needle and removed using a variety of instruments. If other structural abnormalities are found at the time of arthroscopy, they can be addressed as well. Formal repair of the tendon at the time of arthroscopy is seldom required when the calcific deposits removed are extremely large and leave a defect in the tendon.

After surgery, the use of a sling for comfort during the first few days of recovery is recommended for most patients. Physical therapy may or may not be necessary. Do not be surprised if some calcium can still be seen in radiographs obtained after surgery! Some residual calcium may still stain a few tendon fibers.