Calcific tendonitis

Calcific tendonitis is a condition of unknown etiology, in which calcium hydroxyapatite crystals deposit in the tendons of the rotator cuff, causing pain and dysfunction. The pathoanatomy is characterized by three stages of calcification. The first, precalcifying stage involves fibrocartilaginous metaplasia of the tendon and is generally painless. The second, calcifying stage is subdivided into three phases: the forming phase, the resting phase and the resorption phase. The formation phase is characterized by the formation of calcifying deposits, which may or may not cause pain. The resting phase is devoid of inflammation or vascular infiltration, and may or may not cause pain. The resorption phase is characterized by phagocytic resorption and vascular infiltration, and is typically the most painful phase. The third, postcalcific stage occurs after the calcium deposit has been resorbed and the tendon repaired.

The clinical presentation of calcific tendonitis is similar to that of subacromial impingement. Patients usually present with atraumatic pain, which is most severe during the resorption phase of the disease. Other common symptoms include crackling and mechanical locking. On physical examination, muscle atrophy in the supraspinous fossa may be observed. There is often a decrease in active range of motion, and scapular dyskinesia may be present. In some cases, reduced rotator cuff strength may also be associated. Provocation tests such as subacromial impingement signs can be used to induce pain and assess the presence of calcific tendonitis.

Calcific tendonitis can be diagnosed using a variety of imaging techniques. Standard X-rays can show calcification of the supraspinatus, infraspinatus, lesser tuberosity and subscapularis. They are useful for monitoring progression over time, and for assessing the location, density, extent and delineation of the deposit. CT scans are rarely necessary, but can help characterize the three-dimensional anatomy of the shoulder. MRI is of limited use, but can be used to assess concomitant pathology (e.g. rotator cuff tears) in patients with refractory pain. Ultrasound can be useful for quantifying the extent of calcification and is also used to guide decompression and needle injection.

Conservative treatment is generally the first line of therapy for all phases of calcific tendonitis. It includes rest, anti-inflammatories, physiotherapy with stretching and strengthening exercises. Corticosteroid injections are also commonly used, but are controversial. Although conservative treatment provides relief in 60-70% of patients after six months, the duration of relief is variable, and there is a significant likelihood of failure in patients with bilateral or extensive calcifications or deposits extending to the anterior third or medial to the acromion.

Extracorporeal shockwave therapy (ESWT) is a non-invasive treatment option for refractory calcific tendonitis, particularly in the formative and resting phases. It is used to complement first-line treatments. It involves the application of shock waves to the affected area, which promotes the resorption of calcium deposits and reduces pain. ESWT can be administered in two modalities: high-energy and low-energy. High-energy therapy shows better clinical results and a higher rate of calcium deposit resorption, however, it also entails more procedural pain and local reactions such as bruising. ESWT is a safe and effective treatment option, and its use can lead to significant pain relief and improved functional outcomes in patients who have failed first-line treatments.

Ultrasound-guided lavage and needle bubbling are two minimally invasive procedures used to treat symptomatic calcific tendonitis in the resorption phase. Needle lavage involves flushing calcific deposits from the tendon with a saline solution, while needle bubbling involves inserting a needle into the deposit and breaking it up with a high-pressure jet of saline solution. Both procedures have shown promising results in type II and III calcific tendonitis.

Finally, surgical decompression of the calcium deposit, either open or arthroscopic, is indicated in the event of symptom progression, in cases refractory to non-surgical treatment, and in cases of interference with activities of daily living. Short-term outcome studies have shown good results, but there is still a risk of shoulder stiffness.

Techniques known as tenodesis and tenotomy are also sometimes indicated. Tenotomy is indicated when calcium deposits are located in a tendon that is not crucial to the shoulder, and involves cutting the affected tendon. Tenodesis is indicated when calcium deposits are located in a tendon that plays an important role in shoulder function or stability, such as the long head of the biceps or the tendons of the rotator cuff, and involves removing the affected tendon and then reattaching it. This technique is particularly relevant for people with higher physical demands.

Recovery time after surgery may vary according to the type of procedure performed, but you will generally need to rest and avoid strenuous activity for several weeks. Physiotherapy may also be recommended to help restore strength and flexibility to the affected joint.