Calcific Tendinitis of the Subscapularis Tendon
A 71-year-old woman with a history of right shoulder pain of insidious onset is unable to perform activities of daily living due to the pain and functional deficits in her shoulder. Should she receive a steroid injection, or would surgery be the better treatment option?
Richard McEntee, BS, and Daniel Davis, MD, MS
Calcific tendinitis of the rotator cuff is caused by deposition of calcium in and around the tendons of the rotator cuff. It is a relatively common cause of shoulder pain, estimated to occur in 2.5% to 7.5% of adults. [1,2] There is a gender predisposition to calcific tendonitis, with 70% of all cases occurring in women, and the majority of patients are age 40 to 60 years old. [3,4]
Although the presence of calcific tendinitis of the rotator cuff is common, only 35% to 50% of patients are symptomatic. [4,5] Rotator cuff calcific tendinitis does not affect the muscles of the rotator cuff in equal proportion. Estimates of the frequency of calcific tendinitis involving the subscapularis tendon range from 5% to 10%, while 15% to 30% of cases involve the infraspinatus tendon and 51% to 82% involve the supraspinatus tendon. [6,7]
In this article, we report on a case of subscapularis tendinitis.
A 71-year-old, right-hand dominant woman who lives alone in a retirement community apartment presented with a history of right shoulder pain of insidious onset. She denied that any particular injury or trauma had occurred at the time of the initial symptoms or in the 2 months prior to presentation, during which time the pain became more severe.
The patient was unable to perform activities of daily living due to the pain and functional deficits in her right shoulder. She had attempted to manage the pain primarily with over-the-counter anti-inflammatory drugs but had experienced only minimal relief for the 2 months prior to presentation. She had no history of remote trauma or surgery to the right shoulder.
- Height: 5 feet, 3 inches; weight: 159 pounds; BMI: 28
- No gross deformity or ecchymosis of the shoulder on inspection
- Positive tenderness to palpation over the coracoid process; no tenderness over the acromioclavicular joint, acromion, or greater tuberosity
- Passive forward elevation of 140o, with pain above 90o; passive external rotation of 50o with the arm adducted, with more significant pain at the end range; internal rotation to the side, with significant anterior shoulder pain
- 4+/5 strength with resisted external rotation, limited by pain; 3/5 strength with resisted internal rotation, significantly limited by pain-related weakness
Imaging: Plain Radiographs
- No abnormalities noted on the AP views, with normal glenohumeral joint space and no fracture
- Large calcific deposit overlying the lesser tuberosity seen on the scapular Y view and more clearly on the axillary view (Figure 1)
- Smaller and less radiodense calcific deposit viewed on comparative axillary radiographs from 10 months prior to presentation (Figure 2)
Figure 1. No abnormalities are seen on the AP radiograph (top, left), but the scapular Y (top, right) and axillary (bottom) radiographs show the large calcific deposits.
Figure 2. An earlier axillary radiograph shows a smaller and less radiodense calcific deposit.
- Large calcific deposit overlying the lesser tuberosity and within the substance of the subscapularis; partial-thickness tearing (Figure 3)
- Partial tear of the supraspinatus
- No high-grade partial- or full-thickness tears of the rotator cuff
- No loose bodies
Figure 3. MRI images show the large calcific deposit overlying the lesser tuberosity.
- Calcific tendinitis of the subscapularis tendon creating subscapular weakness and subcoracoid impingement
The patient was becoming more symptomatic, with imaging showing increased calcification of the deposit within the subscapularis. She was offered a cortisone injection but decided against it due to the uncertainty of reliable pain relief.
A discussion was then had about surgical management with shoulder arthroscopy, debridement of the calcific deposit, and repair of the subscapularis as indicated. The risks, benefits, and alternatives were discussed, and the patient signed informed consent for the procedure.
- The patient was placed in the beach chair positioner with all bony prominences padded and the operative extremity prepped and draped in the standard fashion.
- A standard posterior starting portal was created, and the arthroscope was introduced into the glenohumeral joint.
- Diagnostic arthroscopy revealed partial-thickness undersurface tearing of the supraspinatus, intact biceps anchor with no tearing, Grade II cartilage changes of the inferior glenoid, degenerative labral tearing, and upper border tearing of the subscapularis tendon (Figure 4).
- An anterior portal was created through the inside-out technique over the superior lateral portion of the subscapularis tendon.
- A shaver and electrocautery were used to open the rotator interval and debride the space anterior to the subscapularis tendon.
- The calcific deposit was palpated in the anterior subscapularis with a probe. Arthroscopic scissors were used to open the tendon sheath overlying the deposit.
- A shaver was used to debride and excise the calcific fragments of the deposit. The probe was again used to palpate the tendon to ensure removal of all fragments (Figure 5).
- After debridement, a defect that required repair was noted in the subscapularis tendon.
- A 4.75-mm double-loaded suture anchor was placed in the lesser tuberosity. Sutures were passed through the subscapularis tendon in a horizontal mattress fashion using a sharp, crescent-shaped suture passer and tied arthroscopically to reduce the tendon to the tuberosity (Figure 6).
- A biceps tenotomy was performed due to the inherent instability created by the biceps sling.
- Incisions were closed in the standard fashion. A sterile dressing and abduction sling were placed.
Figure 4. Diagnostic arthroscopy shows partial-thickness undersurface tearing of the supraspinatus, intact biceps anchor with no tearing, Grade II cartilage changes of the inferior glenoid, degenerative labral tearing, and upper border tearing of the subscapularis tendon.
Figure 5. A shaver was used to debride and excise the calcific fragments of the deposit, and then a probe was used to palpate the tendon to ensure removal of all fragments.
Figure 6. Sutures were passed through the subscapularis tendon in a horizontal mattress fashion using a sharp, crescent-shaped suture passer and tied arthroscopically to reduce the tendon to the tuberosity.
The patient followed the standard postoperative protocol for rotator cuff repair. She was immobilized in an abduction sling for 1 month postoperatively and was allowed only elbow, wrist, and hand range of motion. At 1 month, she was weaned from the sling and progressed to passive stretching exercises limited to 40o external rotation and 140o forward elevation.
The patient reported that her pain had decreased to a 1/10 or 2/10 in the morning at 2 months postoperatively. She also had improved passive range of motion and was started on active strengthening. By 3 months after surgery, she had progressed to full range of motion, with active forward elevation to 150o and external rotation to 40o. She had 4/5 weakness with resisted external rotation.
At the 6-month and 1-year follow-up visits, the patient had progressed to full range of motion and full strength, with no pain in the operative extremity. Postoperative radiographs demonstrated resolution of the calcific deposit.
Calcific tendinitis of the rotator cuff is a common cause of shoulder pain, with the subscapularis tendon found to be calcified only on rare occasions. The pathogenesis of calcific tendinitis is currently unclear, but a number of mechanisms have been proposed. They range from metaplastic transformation of chondrocytes, inducing calcification inside the tendon, to degenerative processes leading to necrosis and dystrophic calcification of the tendon. [3,8]
According to Uthoff et al,  the development of rotator cuff calcific tendinitis occurs in 3 stages:
- Precalcific stage, which involves fibrocartilaginous transformation, leading to tissue dysfunction and damage.
- Calcific stage, which consists of 3 phases: the formative phase, the resting phase, and the resorptive phase. In the formative phase, the fibrocartilagenous damage acts as a nidus for calcium crystal deposition. Once the deposition of calcium ceases, there exists a period of inactivity, after which the calcium deposits slowly become resorbed. This occurs during the resorptive phase.
- Postcalcific stage, in which granulation tissue occupies the area previously occupied by calcium deposits, eventually forming a scar.
Treatment of calcific tendinitis of the subscapularis tendon should begin conservatively, and it is estimated that 70% of cases become asymptomatic within 49 months.  Positive outcomes can be achieved non-surgically with: 
- Non-steroidal anti-inflammatory drugs
- Steroid injections
- Extracorporeal shock-wave therapy
- Ultrasound-guided needling barbotage
If conservative modalities fail to reduce symptoms, surgical treatment can be considered, including arthroscopic excision or open surgical removal.  Arthroscopic treatment of calcific tendonitis refractory to conservative measures has been shown to be effective. [13,14]
Eight other cases of calcific tendinitis of the subscapularis tendon have been reported in the literature. [3,12,15-19] All 8 cases describe patients with calcifying subscapularis tendonitis who have failed conservative therapy. Of the 8, 7 patients underwent arthroscopic removal with successful outcomes and pain relief at final follow-up.
One patient, as reported by Mitsui et al,  underwent diagnostic arthroscopy, but the calcification could not be localized. In this case, the subscapularis required extensive debridement to identify and remove the deposit. Once the deposit was removed, the tendon was re-attached using a suture anchor technique. The patient experienced significant improvement in range of motion and pain relief, and a radiograph 2 years after surgery was free of calcifications.
The case by Mitsui et al  is most similar to the case described in this article. After evaluation of the subscapularis and careful debridement, our patient had a defect left in the tendon that required repair. In both reports, the patients recovered well, with good function and no pain. Thus, these reports suggest safety and efficacy in performing an anterior calcific deposit debridement, even if repair of the subscapularis tendon is required.
Richard McEntee, BS, is a medical student at Sidney Kimmel School of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania. Daniel E. Davis, MD, MS, is an orthopaedic surgeon with The Rothman Institute, Philadelphia, Pennsylvania. He specializes in the treatment of shoulder and elbow conditions.
Shoulder and Elbow Editor, Rothman Institute Grand Rounds
The authors have no disclosures relevant to this article.
- Speed CA, Hazelman BL. Calcific tendinitis of the shoulder. N Engl J Med 1999; 340: 1582-4.
- Bosworth BM. Calcium deposits in shoulder and subacromial bursitis: survey of 12,122 shoulders. Jama 1941; 116:2477-2482.
- Chianca V, Albano D, Messina C, Midiri F, Mauri G, Aliprandi A, et al. Rotator cuff calcific tendinopathy: from diagnosis to treatment. Acta Biomed. 2018 Jan 19;89(1-S):186-96.
- Porcellini G, Paladini P, Campi F, Paganelli M. Arthroscopic treatment of calcifying tendonitis of the shoulder: Clinical and ultrasonograophic findings at two to five years. J Shoulder Elbow Surg 2004;13:503-508.
- Fields LK, Muxlow CJ, Caldwell PE,3rd. Arthroscopic treatment of subscapularis calcific tendonitis. Arthrosc Tech. 2014 Sep 8;3(5):e571-3.
- Vinanti GB, Pavan D, Rossato A, Biz C. Atypical localizations of calcific deposits in the shoulder. Int J Surg Case Rep. 2015;10:206-10.
- Gartner J, Heyer A. Calcific tendinitis of the shoulder. Orthopade 1995; 24: 284-302.
- Ark JW, Flock TJ, Flatow EL, Bigliani LU. Arthroscopic treatment of calcific tendonitis of the shoulder. Arthroscopy 1992;8:183-188.
- Uthoff HK, Sarkar K. Calcifying tendinitis. Baillieres Clin Rheuymatol 1989; 3:567-81.
- Wolk T, Wittenberg RH. Calcifying subacromial syndrome – clinical and ultrasound outcome of non-surgical therapy. Z Orthop Ihre Grenzgeb. 1997;135:451-547.
- Umamahesvaran B, Sambandam SN, Mounasamy V, Gokulakrishnan PP, Ashraf M. Calcifying tendinitis of shoulder: A concise review. J Orthop. 2018 May 20;15(3):776-782.
- Ifesanya A, Scheibel M. Arthroscopic treatment of calcifying tendonitis of subscapularis and supraspinatus tendon: a case report. Knee Surg Sports Traumatol Arthrosc. 2007 Dec;15(12):1473-7.
- Hurt G, Baker CL Jr. Calcific tendinitis of the shoulder. Orthop Clin N Am. 2003; 34:567-75.
- De Carli A, Pulcinelli F, Rose GD, Pitino D, Ferretti A. Calcific tendinitis of the shoulder. Joints 2014; 2:130-6.
- Arrigoni P, Brady PC, Burkhart SS. Calcific tendonitis of the subscapularis tendon causing subcoracoid stenosis and coracoid impingement. Arthroscopy. 2006 Oct;22(10):1139.e1,1139.e3.
- Chen YP, Ho WP, Chuang TY. Arthroscopic management of calcific tendonitis of the subscapularis tendon with subcoracoid stenosis. J Orthop Sci. 2015 Sep;20(5):935-8.
- Franceschi F, Longo UG, Ruzzini L, Rizzello G, Denaro V. Arthroscopic management of calcific tendinitis of the subscapularis tendon. Knee Surg Sports Traumatol Arthrosc. 2007 Dec;15(12):1482-5.
- Tung KL, Woo SB. Arthroscopic debridement for bilateral calcific tendinitis of the subscapularis tendons: a case report. J Orthop Surg (Hong Kong). 2015 Apr;23(1):116-9.
- Mitsui Y, Gotoh M, Tanesue R, Shirachi I, Shibata H, Nakama K, Okawa T, Higuchi F, Nagata K. Calcific tendonitis of the rotator cuff: an unusual case, Case Rep. Orthop. 2012 (2012) 806769.