Calcific tendinitis of the rotator cuff is a common disorder which predominantly affects females, generally between the ages of 30 to 60 years. The presence of calcium deposition in the rotator cuff varies widely, with reports of mineral detection by radiographs in up to 20% of asymptomatic shoulders.
Calcifications are usually located within the supraspinatus (> 70%), though have been reported in the other rotator cuff tendons. Calcific tendinitis is reported to be bilateral in 10 to 25% of patients. No consensus exists as to its etiology, but there are two prominent theories. Proponents of the degenerative theory propose that tendon degeneration, caused by both overuse and aging, leads to subsequent fiber necrosis and dystrophic calcification.
Theorists of reactive calcification state that mineral deposition is an actively mediated process that can be subdivided into three stages: pre-calcific, calcific and post-calcific. The pre-calcific stage is characterized by fibrocartilaginous metaplasia of predisposed tenocytes into chondrocytes in relatively avascular areas. The calcific phase can be further subdivided into the ‘formative’ phase (calcium deposition into matrix vesicles that coalesce to form foci of calcification), the ‘resting phase’ (termination of calcium deposition), and the ‘resorptive phase’ (phagocytic resorption of the mineral deposits and debris by multinucleated giant cells). Finally, the post-calcific phase is characterized by healing through scar maturation and type III collagen replacement by type I collagen, with subsequent longitudinal fiber realignment.
Pain and resultant limitation of range of motion are the classic presenting symptoms. The pain typically radiates to the deltoid insertion rather proximally into the neck. The patient may report worsening of pain at night, with the inability to sleep on the affected side.
Identification of stage can often be made based on clinical symptoms. Severe, acute pain is typically seen in the resorptive phase. Patients will describe waking with a sharp, stabbing pain in the shoulder, in the absence of any inciting trauma or overuse.
The pathophysiology behind the acute pain of the resorptive phase may be due to two possible mechanisms. During this phase, the deposits’ consistency is paste-like, and can rupture into the subacromial bursa causing an inflammatory bursitis. It is also likely that during the resorptive phase, local edema and cytoproliferation raise the pressure within the tendon substance, directly triggering pain.
Correlations with systemic or other focal disorders such as diabetes or adhesive capsulitis have been suggested but never scientifically proven. However, an increase in HLA-A1 has been observed in patients with this disorder.
In patients with chronic calcific tendinitis, there may be supra- and infraspinatus atrophy upon inspection. A point of maximal tenderness can often be localized. Patients with symptomatic calcific tendinitis have pain with shoulder range of motion. Some authors have reported noticing a painful arc between 70 to 110 degrees of abduction, potentially resulting from impingement between the mineral deposit and the coracoacromial ligament. Strength is usually preserved but may be limited due to pain.
A standard shoulder x-ray series, including anteroposterior (AP), Grashey, scapular-Y, and axillary views, remains the primary imaging modality. The standard AP x-ray will show calcium deposition within the tendon, usually 1.5 to 2cm away from the supraspinatus tendon insertion on the greater tuberosity (Figure 1). The arm can be rotated to optimize visualization of the different tendons. Mineral deposits within the supraspinatus can best be seen in neutral rotation, while the infraspinatus and teres minor can be viewed in internal rotation (Figure 2).
The axillary view is useful to visualize deposits in the subscapularis, which is exceedingly rare, though reported. Deposits are usually well-visualized during the formative phase as homogenous masses with clearly-defined borders. During the resorptive phase, some fragmentation of the mass can be seen.
Multiple radiographic classifications have been proposed, each with variable interobserver reliability. They generally focus on mass density and how clearly delineated it is (i.e. sharply outlined versus somewhat fluffy and heterogeneous). In general, the lesion appears dense, homogenous and well-defined during the formative or chronic phase (Table I).
During the acute, painful resorptive phase, the lesion is irregularly dense and not clearly delineated, with a fluffy or cloud-like appearance.
It has been reported that lesions with a more cloudy and transparent appearance tended to have a higher incidence of resorption after needling of the lesion. Plain films are very useful for monitoring the disorder as well.
Dystrophic calcification secondary to degenerative changes (rotator cuff or glenohumeral joint) can be distinguished from calcific tendinitis. The former are accompanied by degenerative changes, and tend to have a more stippled appearance. They are found closer to the tendon insertion on the bone.
Calcific tendinitis can also be detected using ultrasound (US) (Figure 3). The roles of high-resolution and color Doppler ultrasonography in evaluation and phase-determination have been well-reported. It has been reported that US can be more sensitive than xray.
Calcifications will likely be apparent on computed tomography (CT), but is not recommended routinely. MRI can be used as well, though is not generally used for the evaluation of isolated calcific tendinitis. The mineral deposit demonstrates decreased signal intensity on T1, though T2 sequences will show increased intensity surrounding the lesion because of edema.
Initial treatment in a patient with symptomatic calcific tendonitis includes rest, physical therapy, NSAIDs, subacromial cortisone injections, extracorporeal shock wave therapy (ESWT), and ultrasound guided needle lavage.
Extra–corporeal shock-wave therapy (ESWT)
Extra-corporeal shock-wave therapy (ESWT) can be considered after 6 months if no improvement is observed with other nonoperative modalities. The radiographic appearance of the deposit should correspond with Gartner Type I or Type II, as Gartner Type III deposits tend to have a higher rate of spontaneous remission. Type II deposits respond more than Type I deposits. Multiple studies have reported varying results. It appears that the effect of calcium disintegration or alteration in the deposit’s consistency are derived from direct energy transfer. Phagocytic resorption then ensues to clear the deposit.
A meta-analysis demonstrated a 50% success rate with this modality. Authors have suggested that a deposit of at least 10 mm in diameter should be present prior to contemplation of therapy. In addition to the mechanical effect of deposit fragmentation, there may be a secondary analgesic effect through hyperstimulation analgesia, or possibly through inhibition or denervation of pain receptors.
No clear consensus exists regarding relevant variables related to the treatment regimen, though efficacy is influenced by the total energy delivered, shock wave amplitude and frequency, and guidance method. Observed trends include a better dissolution rate with: high-energy versus low-energy, and when utilized for single calcific deposits rather than less-solid, paste-like lesions. One study demonstrated that higher energy afforded better deposit resolution, decreased frequency of sessions required, and fewer residual calcifications or pain recurrences. Better results are seen when treatment is fluoroscopically-guided or when using computer-assisted navigation rather than relying on patient feedback (i.e. point of maximal tenderness ascertained through palpation).
Complications of this treatment can include formation of a hematoma and localized pain following the treatment. Local soft tissue swelling and cutaneous erosions are possible. A transient cutaneous erythema is possible, though tends to resolve within 1-2 days. Higher energy-delivery is associated with increased post-treatment pain. Recurrence after ESWT has been reported in up to 6.5%. When compared to other modalities, ESWT delivers more favorable functional and pain results than TENS and cobalt gamma rays. Two reports of osteonecrosis following this treatment have been reported, but definitive causality was not certain.
Needling and lavage has been reported to augment the relief of acute pain during the resorptive phase in the presence of radiographic evidence of such. Multiple perforations of the lesion can decrease pressure within the tendon substance. Additionally, a two-needle technique which facilitates lavage and deposit outflow can be performed. During the procedure, lidocaine can be injected, followed by administration of a corticosteroid. The corticosteroid can help to prevent formation of a subacromial bursitis and address the current pain. Dry needling has been advocated in other conditions of the rotator cuff to promote tendon healing through bleeding and release of platelet-derived growth factors. It is thought that this technique can be utilized to accelerate mineral resorption as well. Ultrasound-guidance has been shown to be successful in providing accurate needle-localization during these procedures.
Indications for Surgery
Surgical management should be considered after 6 months if symptoms progress or fail to improve with conservative management, or earlier if activities of daily living are significantly impacted. Surgery may also be indicated if there is continued pain despite ultrasound guided lavage. Deposit removal is typically performed arthroscopically.
Adequate deposit evacuation often requires tendon fiber incision. Reports suggest a higher incidence of partial rotator cuff tears seen after deposit removal. Depending on the state of the rotator cuff at the time of surgery, or if iatrogenic cuff damage results, the tendon can be repaired in either a side-to-side manner or using suture anchors.
It has been reported that concomitant subacromial decompression can reduce post-operative pain. Of note, the patient should understand that a reduction in pain will likely occur over a period of months following surgery, and that complete immediate pain-relief is unlikely.
30 degree arthroscope
Standard shoulder arthroscopy instrument tray
Arthroscopic oval burr
18 gauge spinal needle
Our preference is for the beach chair, rather than lateral, position. At our institution, general anesthesia is routinely administered along with interscalene nerve block which is performed for postoperative analgesia. We use saline irrigation mixed with epinephrine to minimize bleeding. Sequential compression devices are placed on the lower extremities. The arm is positioned using the Spider Limb Positioner (Smith and Nephew, TN). The standard posterior portal is established followed by placement of the direct anterior portal. A diagnostic arthroscopy of the glenohumeral joint is performed using a 30-degree scope. The arthroscope is then removed from the posterior portal and inserted into the subacromial space. A bursectomy is performed to afford proper visualization of the tendon.
If the calcium deposit is seen directly, a spinal needle can be inserted into the lesion. Extrusion of paste-like material from the needle during withdrawal may be visualized and is confirmatory of the correct location. More commonly, the consistency tends to be flake-like or particulate (Figure 4). If necessary, one can make small incisions in line with the fibers of the tendon, with care to not create full-thickness cuts if possible. The deposit can be curetted out, with care to avoid creating a void in the tendon. The shaver can be used as well. Our preference is to repair defects made in the tendon, with either side-to-side sutures or a suture anchor if the defect is greater than 50% of the tendon width.
Acromioplasty can be performed if indicated based on pre-operative radiographs or intra-operative visualization. Some authors have reported routinely performing an acromioplasty in the setting of Type II or Type III acromions, as classified by Bigliani et al.
Localization of the lesion is one of the most challenging aspects of this procedure. Several techniques have been described. Some authors have reported high success-rates using pre-operative ultrasound-localization. If so, one can use the biceps tendon or greater tuberosity as reference points, relying on measurements made from each landmark. Simple bursoscopy with needling at the time of surgery has proven effective as well. Intraoperative fluoroscopy may also be useful to localize calcium deposits and confirm extent of excision.
The surgeon should note that the entirety of the calcium deposits may not be accessible, regardless of technique (i.e. open or arthroscopic) or number of incisions made in the tendon (12 – 15% residual deposits in some reports). Although some have reported persistent pain being correlated with residual deposits, it has been observed that complete pain relief can be achieved without removing the entirety of the calcific lesion.
Pearls and Pitfalls of Technique
Obtain a full series of shoulder xrays to view all of the deposits possible
Pre and intraoperative ultrasound or x-ray guidance can augment localization
Search for an inflammatory focus within the tendon and use a needle to identify and palpate the lesion intra-operatively
Attempts to debride the entirety of the lesion may cause excessive dissection and tissue damage, especially if a shaver is used
If possible, avoid creating a large defect in the rotator cuff
Avoid extensive post-operative immobilization
Complications of this procedure are rare, but include hematoma formation, infection, adhesive capsulitis, nerve injury, persistent pain, and iatrogenic rotator cuff tears. It is important to rule out possible rotator cuff tears in a patient with persistent pain after ultrasound or arthroscopic calcium deposit removal.
Unless a concomitant rotator cuff repair is performed, a sling is used only for a few days for comfort and a protocol of immediate range-of-motion exercises is initiated. The patient should be encouraged to perform pendulum exercises, passive range of motion, active and active assist range of motion exercises. At 1 month post-operatively, the patient should have full, painless active range of motion. Return to sports typically occurs by 3 months postoperative.
Outcomes/Evidence in the Literature
Oliva, F, Giai Via, A, Maffulli, N. “Calcific Tendinopathy of the Rotator Cuff Tendons”. Sports Med Arthrosc Rev. vol. 19. 2011. (Although many advances have been made in devising treatment strategies for calcific tendinitis, the exact etiology remains unclear. Symptom resolution, whether spontaneous or following therapeutic management, results in tendon restoration to its normal structure.)
Maier, D, Jaeger, M, Izadpanah, K, Bornebusch, L, Suedkamp, NP, Ogon, P. “Rotator cuff preservation in arthroscopic treatment of calcific tendinitis”. Arthroscopy. vol. 29. 2013. pp. 824-831. (There is debate on whether the entirety of a calcium deposit must be removed during arthroscopic surgery for calcific tendinitis, as doing so may result in iatrogenic rotator cuff injury. A comparison of two groups demonstrated that following surgery, remnant calcifications ultimately resolved in almost all patients, and were not of clinical significance. Preservation of the rotator cuff integrity yielded good to excellent results in 90% of patients.)
Uhthoff, HK, Loehr, JW. “Calcific Tendinopathy of the Rotator Cuff: Pathogenesis, Diagnosis, and Management”. J Am Acad Orthop Surg. vol. 5. 1997. pp. 183-191. (Calcific tendinopathy is characterized by multi-focal, cell mediated calcification of living tissue. Specific phases are identifiable by radiographic appearance and clinical presentation, and have implications for type and timing of operative intervention should conservative treatment fail. However, conservative treatment remains the mainstay of its management.)
Mouzopoulos, G, Stamatakos, M, Mouzopoulos, D, Tzurbakis. “Extracorporeal shock wave treatment for shoulder calcific tendonitis: a systematic review”. (Extracorporeal shock wave therapy can serve as a viable, minimally-invasive treatment option for treatment of rotator cuff calcific tendonitis. Multiple mechanisms may be responsible for the therapeutic effect, including lesion fragmentation, neovascularization, hyperstimulation analgesia and potential pain receptor denervation. Further studies are necessary prior to this procedure becoming popularized.)
Gartner, J. “Tendinosis calcarea – results of treatment with needling”. Z Orthop Ihre Grenzgeb. vol. 131. 1993. pp. 461-9. (The likelihood of calcific deposit resorption after needling can be correlated with the radiographic appearance and classification of the lesion. In 235 patients observed over 3 years, complete resorption was seen in 33% of type I lesions (sharply outlined and densely structured), 85% of type III lesions (cloudy limitations and transparent in structure), and 71% of type II lesions (combination of types I and III).)
Ark, JW, Flock, TJ, Flatow, EL, Bigliani, LU. “Arthroscopic Treatment of Calcific Tendinitis of the Shoulder”. Arthroscopy. vol. 8. 1992. pp. 183-188. (Following failure of conservative treatment (> 1 year), 23 patients (average age 49 years) underwent arthroscopic calcium removal and subacromial bursectomy for the treatment of calcific tendinitis. After average follow-up of 26 months, a good result was achieved in 50%, a satisfactory result in 41%, and an unsatisfactory result in 9%.)
Balke, M, Bielefeld, R, Schmidt, C, Dedy, N, Liem, D. “Calcifying Tendinitis of the Shoulder: Midterm Results After Arthroscopic Treatment”. Am J Sports Med. vol. 40. 2012. pp. 657(After arthroscopic removal of supraspinatus tendon calcium deposits in 70 shoulders, an improvement in pain and function (by ASES and Constant scores) were noted, though scores remained lower than the healthy shoulders after a mean of 6 year follow-up. Subacromial decompression was performed in 44/70 shoulders with no significant difference observed in scores as compared to those without decompression (though the sub-item ‘pain’ was significantly better). An increased rate of partial supraspinatus tendon tears was noted on ultrasound follow-up after surgical removal.)
Jerosh, J, Strauss, JM, Schmiel, S. “Arthroscopic treatment of calcific tendinitis of the shoulder”. J Shoulder Elbow Surg. vol. 7. 1998. pp. 30-7. (21-month follow-up on 48 patients who underwent arthroscopic calcium deposit removal after at least 6 months of unsuccessful conservative treatment demonstrated that patients in whom calcium deposits were undetectable after surgery had the most favorable result, and that a correlation was seen with lower post-operative benefit and residual deposits.)
Rupp, S, Seil, R, Kohn, D. “Preoperative Ultrasonographic Mapping of Calcium Deposits Facilitates Localization During Arthroscopic Surgery for Calcifying Tendinitis of the Rotator Cuff”. Arthroscopy. vol. 14. 1998. pp. 540-542. (Arthroscopic localization of calcium deposits is technically demanding. Verifying the location of the deposit can be facilitated by knowing its position relative to visible landmarks such as the greater tuberosity and biceps tendon using pre-operative ultrasonography, and by directly probing of the lesion with a spinal needle intra-operatively.)
Calcific tendinitis of the shoulder is a potentially debilitating disorder that can have a chronic course with the acute-onset of severe pain. Though the pathophysiology has been investigated, its exact etiology remains elusive. The radiographic appearance of the disorder has been well-classified, and its stage can be correlated with clinical symptoms. Knowledge of the characteristics of each stage can guide the clinician’s management. Conservative management remains the mainstay of treatment, as the majority of lesions will spontaneously resolve, unlike in cases of degenerative calcification, an entity which must be differentiated from this disorder. Operative intervention has proven successful in cases of failed conservative therapy.
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- The Problem
- Clinical Presentation
- Diagnostic Workup
- Radiographic Classification
- Non–Operative Management
- Extra–corporeal shock-wave therapy (ESWT)
- Needle Therapy
- Indications for Surgery
- Surgical Technique
- Pearls and Pitfalls of Technique
- Potential Complications
- Post–operative Rehabilitation
- Outcomes/Evidence in the Literature