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Arthroscopic Removal of Intraosseous and Intratendinous Deposits in Calcifying Tendinitis of the Rotator Cuff
Arthroscopic Removal of Intraosseous and Intratendinous Deposits in Calcifying Tendinitis of the Rotator Cuff Aksel Seyahi, M.D., and Mehmet Demirhan, M.D.
Purpose: The purpose of this study was to evaluate the surgical outcome of arthroscopic removal of intraosseous deposits in calcifying tendinitis of the rotator cuff. Methods: We studied the results of arthroscopic treatment in 30 shoulders in 28 patients with calcifying tendinitis (mean age, 48.3 years; age range, 26 to 83 years), with a mean follow-up of 38 months. According to the localization of calcification, the patients were divided into 2 groups: those with pure tendinous/soft-tissue involvement (n ⫽ 25) (group I) and those with tendinous/soft-tissue and osseous involvement (n ⫽ 5) (group II). After routine tendon debridement, debridement and curettage of the bone lesion were also performed in patients with bone involvement. Clinical outcome was evaluated by use of the pain score on a visual analog scale and the Constant score, and a special inquiry was used for selfassessment. Results: The pain scores and functional Constant scores improved significantly after the operation in both groups (P ⫽ .043 for pain score and P ⫽ .0001 for Constant score in group I and P ⫽ .042 for pain score and P ⫽ .0001 for Constant score in group II). The median Constant score increased from 42 (range, 22 to 65) preoperatively to 100 (range, 80 to 100) postoperatively in group I and from 40 (range, 25 to 55) to 100 (range, 85 to 100) in group II. The mean pain score was 6.5 ⫾ 1.4 (range, 4 to 9) before treatment and 0.2 ⫾ 0.5 (range, 0 to 2) at follow-up in group I, and it was 6.2 ⫾ 1.48 (range, 4 to 8) and 0.4 ⫾ 0.55 (range, 0 to 1), respectively, in group II. There was no significant difference between the 2 groups in terms of the final Constant (P ⫽ .85) and pain scores (P ⫽ .26). Conclusions: Arthroscopic removal of intraosseous and intratendinous deposits to treat calcifying tendinitis with osseous involvement seems to be as safe and effective a treatment method as the arthroscopic removal of intratendinous deposits in cases of tendinous involvement only. Level of Evidence: Level IV, therapeutic case series. Key Words: Calcifying tendinitis—Bone erosion— Intraosseous calcification—Rotator cuff—Arthroscopy.
O
sseous involvement in calcifying tendinitis is a relatively new and not well-recognized entity. The condition has been characterized by erosion of the underlying cortex and bone marrow changes. Although it has been hypothesized that osseous involvement may be an important cause of pain, the actual clinical relevance of this pathology and its treatment options are not well known.1-5
From the Departments of Orthopaedic Surgery, VKV American Hospital (A.S.), and Istanbul Faculty of Medicine, Istanbul University (M.D.), Istanbul, Turkey. The authors report no conflict of interest. Address correspondence and reprint requests to Mehmet Demirhan, M.D., Department of Orthopaedic Surgery, Istanbul Faculty of Medicine, Istanbul University, Çapa, 34390 Aksaray, Istanbul, Turkey. E-mail: [email protected] © 2009 by the Arthroscopy Association of North America 0749-8063/09/2506-8506$36.00/0 doi:10.1016/j.arthro.2008.12.024
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In the absence of osseous involvement, arthroscopic removal of the calcific deposit is an effective treatment option for chronically painful calcifying tendinitis of the rotator cuff.6-14 In this study we report a series of patients with calcifying tendinitis of the rotator cuff with an unusual “intraosseous” extension. The purpose of the study was to evaluate the surgical outcome of arthroscopic removal of intraosseous deposits. We hypothesized that the patients with osseous involvement would benefit from the arthroscopic debridement as much as the patients with pure tendinous involvement.
METHODS Between September 2002 and June 2007, 30 shoulders in 28 patients with calcifying tendinitis underwent arthroscopic treatment at our institution. We
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 25, No 6 (June), 2009: pp 590-596
CALCIFYING TENDINITIS OF ROTATOR CUFF studied the results of arthroscopic treatment in these 28 patients, 10 men and 18 women, with a mean age of 48.3 years (range, 26 to 83 years). There were 21 right shoulders (70%) and 9 left shoulders (30%). According to the localization of calcification, the patients were divided into 2 groups. Group I included patients with pure tendinous/soft-tissue involvement (n ⫽ 25). Group II included patients with tendinous/ soft-tissue and osseous involvement (n ⫽ 5). For both groups, the inclusion criterion for arthroscopic treatment was the presence of persistent shoulder pain, refractory to conservative treatment, for at least 3 months. As confirmed by physical and radiologic examinations, none of the patients had an accompanying cause of pain such as symptomatic impingement syndrome, rotator cuff tear, acromioclavicular osteoarthritis, shoulder stiffness, and infection. The patients had different kinds of nonoperative treatment during their symptomatic preoperative period for a mean of 15 months (range, 3 to 84 months).
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FIGURE 2. Coronal T2-weighted magnetic resonance image of a 39-year old female patient with an intraosseous calcific deposit (arrow). The generalized bone marrow edema in the humeral head should be noted.
Radiologic Evaluation Preoperative radiographs (Fig 1) and magnetic resonance images (Fig 2) were obtained for all patients. Computed tomography (CT) scans were also available for all patients with osseous involvement (Fig 3). On radiographs, the size of the calcific deposit was measured, and its appearance was assessed according to the classification of the French Arthroscopy Society9: type A (dense, sharply delineated homogeneous appearance), type B (dense, sharply delineated, and multiple fragments), type
FIGURE 1. Preoperative radiograph of a patient with osseous involvement. The intraosseous calcification at the rotator cuff insertion (arrow) should be noted. The patient also has a large tendinous deposit.
C (more radiolucent, heterogeneous appearance), and type D (dystrophic calcifications at the tendon insertion). Radiographs were also taken on the first day after surgery and at the last follow-up to confirm the removal and absence of the deposit. Surgical Procedure All patients, under general anesthesia, were treated in the beach-chair position by the same experienced arthroscopic surgeon. The operation started with an arthroscopic inspection of the glenohumeral joint. The rotator cuff was probed percutaneously with a 20gauge spinal needle to localize the calcific deposit. Visible calcium material was carried to the joint when the needle perforated the deposit. A suture marker was then introduced from outside through the needle into the joint. Then the arthroscope was introduced to the subacromial space. Subacromial bursectomy and section of the coracoacromial ligament were performed, and the deposit was expressed out of the tendon, first with blunt instruments; the excision was completed with a curette and a synovial resector. A fluoroscopic control was performed at the end of the procedure to confirm complete removal of the deposit, and debridement was carried out until complete removal was achieved. After the removal of the deposit, the subsequent cavity in the tendon was closed with 1 or 2 side-to-side sutures.
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FIGURE 3. Computed tomography is the most sensitive imaging technique to detect tendinous, cortical, and intraosseous involvement. The arrows on the coronal (left) and axial (right) CT images show the extension of the calcification to the humeral cortex, as well as intraosseous calcification at the rotator cuff insertion.
Approach to osseous lesions: After the routine tendon debridement, the area of cortical bone erosion adjacent to the greater tuberosity was easily localized with the probe, and a small entrance hole was opened with the synovial resector and curette. The intraosseous calcific deposit was arthroscopically viewed through the hole and was expressed out of the osseous cavity (Figs 4 and 5). After the removal of the intraosseous deposit, the cavity wall was curetted. In 2 patients
with osseous involvement, the opening of the osseous cavity was closed again with a suture anchor (Corkscrew; Arthrex, Naples, FL), which was screwed down at the base of the deposit cavity (Fig 6).
FIGURE 4. The intraosseous calcific deposit (arrow) was arthroscopically viewed and was expressed out of the osseous cavity.
FIGURE 5. Before debridement and curettage, a sample of the deposit was taken with a grasper (arrow) for pathologic evaluation.
Pathology Evaluation Hematoxylin and eosin-stained slides were evaluated by an experienced pathologist. Material was reviewed for the presence and character of calcification, fibrosis, and chronic inflammation, as well as evidence of marrow involvement.
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data; Spearman correlation coefficients were used in the correlation analysis. The level of significance was set at P ⬍ .05. RESULTS
FIGURE 6. Postoperative radiograph of a patient with osseous involvement. After arthroscopic removal of the intraosseous deposit, the opening of the osseous cavity was closed again with a suture anchor (arrow), which was screwed down at the base of the deposit cavity.
Rehabilitation After surgery, all of the patients underwent an exercise and rehabilitation program. Follow-up Evaluation The patients were reviewed after a mean follow-up of 38 months (39.4 ⫾ 18 months in group I and 30.8 ⫾ 12 months in group II) by clinical and radiographic examination. Preoperative and postoperative clinical assessment of function was performed by the same physiotherapist, using the Constant scoring method. A 10-point visual analog scale was used in the evaluation of pain. The Constant and pain scores were gathered before the operation and at the last follow-up. Follow-up evaluation was blinded regarding the presence or absence of osseous involvement. Statistical Analysis NCSS 2007 software (NCSS, Kaysville, UT) was used in statistical analysis. In addition to the descriptive methods (median, range, mean, standard deviation), the Mann-Whitney U test was used to compare the unpaired samples, Wilcoxon test to compare paired samples, and 2 test to compare qualitative
The pure tendinous/soft-tissue involvement group (group I) consisted of 25 shoulders in 23 patients (14 women and 9 men; mean age, 49.6 ⫾ 11.4 years [range, 26 to 83 years]). In these patients the calcification was in the supraspinatus and/or infraspinatus tendons and there was no radiologic sign of osseous involvement. The time between the onset of symptoms and the time of surgery was 13 months on average (range, 6 to 36 months). The tendinous/soft-tissue and osseous involvement group (group II) consisted of 5 patients (4 women and 1 man; mean age, 42 ⫾ 10.9 years [range, 29 to 55 years]) with radiologic evidence of osseous involvement, in addition to classical tendinous calcification. The mean time between the first onset of symptoms and the time of surgery was 12 months (range, 3 to 84 months). Comparison of the demographic data of the 2 groups showed that they were homogeneous with regard to age (P ⫽ .16), gender distribution (P ⫽ .39), and follow-up time (P ⫽ .32). The groups were also homogeneous with regard to preoperative Constant score (median, 42 [range, 22 to 65] in group I and 40 [range, 25 to 55] in group II; P ⫽ .42) and pain score (mean, 6.5 ⫾ 1.4 in group I and 6.2 ⫾ 1.5 in group II; P ⫽ .67). There was no significant difference between the onset of symptoms and the time of surgery (mean, 13.4 ⫾ 8.3 months [range, 6 to 36 months] in group I and 24 ⫾ 33.7 months [range, 3 to 84 months] in group II; P ⫽ .98). The median number of preoperative local steroid injections was 2 (range, 1 to 3) in group I and 1 (range, 1 to 3) in group II (P ⫽ .47). The mean size of the soft-tissue calcification was significantly larger in group II (19.6 ⫾ 3.2 mm) than in group I (10.4 ⫾ 2.8 mm) (P ⫽ .001). However, there was no correlation between the size of the calcific deposit and the preoperative pain and Constant scores of the patients (P ⫽ .78 [r ⫽ ⫺0.05] and P ⫽ .99 [r ⫽ 0.002], respectively). The demographic data presented previously are summarized in Table 1. According to the classification of the French Arthroscopy Society,9 the appearance of the deposit was type A in 13 patients in the pure tendinous involvement group, type B in 8, and type C in 4. All 5 of the patients in the osseous involvement group showed a
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A. SEYAHI AND M. DEMIRHAN TABLE 1.
Patient Demographic Data
Group I: Pure Tendinous Involvement No. of Patients Total Female/male Age (yr) Symptomatic period (yr) No. of injections Follow-up (mo) Size of deposit (mm) Rehabilitation (wk) Pain score on visual analog scale Preoperatively Postoperatively Constant score Preoperatively Postoperatively
Median (Range)
Mean ⫾ SD
25 15/10
Group II: Tendinous and Osseous Involvement No. of Patients
Median (Range)
Mean ⫾ SD
P Value
5 4/1 48 (26-83) 0.8 (0.5-3) 2 (1-3) 38 (4-69) 10 (6-17) 4 (1-9) 7 (4-9) 0 (0-2) 42 (22-65) 100 (80-100)
49.6 ⫾ 11.4 1.1 ⫾ 0.7 39.4 ⫾ 18 10.4 ⫾ 2.8 4.7 ⫾ 1.6 6.5 ⫾ 1.36 0.2 ⫾ 0.5
42 ⫾ 10.9 2 ⫾ 2.8
40 (29-55) 1 (0.5-7) 1 (1-3) 29 (22-51) 20 (15-23) 4 (4-6)
30.8 ⫾ 11.9 19.6 ⫾ 3.2 4.8 ⫾ 1.1
.164 .977 .473 .316 .001* .835
6 (4-8) 0 (0-1)
6.2 ⫾ 1.5 0.4 ⫾ 0.6
.669 .263
40 (25-55) 100 (85-100)
.416 .854
NOTE. Both groups were homogeneous with regard to age, gender, preoperative pain score on visual analog scale and Constant score, length of symptomatic period, and follow-up time. *The mean size of the deposit was significantly larger in the osseous involvement group (P ⫽ .001).
dystrophic calcification pattern at the tendon insertion (type D). In 4 of these patients the appearance of the tendinous calcification was dense and multilobular, and in the remaining patient it was radiolucent and heterogeneous. Preoperatively on magnetic resonance imaging (MRI), there was intraosseous calcification in the greater tuberosity with adjacent bone edema in 4 of the patients, cortical bone erosion in all 5, and diffuse bone edema in the humeral head in 1. Complete removal of the calcific deposit was achieved in all patients but 1, who was in the pure tendinous involvement group and whose follow-up radiographic evaluation showed a 2-mm radiodense residual deposit. No rotator cuff tear was detected during arthroscopy. Specimens were available and calcifying tendinitis was pathologically confirmed in 11 cases with tendinous involvement and 4 cases with osseous involvement. Under the light microscope, calcific deposits appeared in all cases. Small granular calcification was the most common pattern, appearing in 8 cases in group I and 3 cases in group II. The remaining 3 cases in group I and 1 case in group II displayed large amorphous calcifications. Furthermore, all cases showed deposits of calcium crystals in the fibrocartilaginous matrix and cell-mediated resorption of the calcific deposit. The mean time for postoperative rehabilitation was 4.7 weeks (range, 1 to 9 weeks) in the patients with
pure tendinous calcification and 4.8 weeks (range, 4 to 6 weeks) in the patients with osseous involvement. The pain scores and functional Constant scores improved significantly after the operation in both groups (P ⫽ .043 for pain score and P ⫽ .0001 for Constant score in group I and P ⫽ .042 for pain score and P ⫽ .0001 for Constant score in group II). The median Constant score increased from 42 (range, 22 to 65) preoperatively to 100 (range, 80 to 100) postoperatively in group I and from 40 (range, 25 to 55) to 100 (range, 85 to 100) in group II. The mean pain score (minimum pain, 0; maximum pain, 10) was 6.5 ⫾ 1.4 (range, 4 to 9) before treatment and 0.2 ⫾ 0.5 (range, 0 to 2) at follow-up in group I, and it was 6.2 ⫾ 1.48 (range, 4 to 8) and 0.4 ⫾ 0.55 (range, 0 to 1), respectively, in group II. There was no significant difference between the final Constant (P ⫽ .85) and pain scores (P ⫽ .26) between the groups. DISCUSSION Our study suggested that the patients with osseous involvement benefited from the arthroscopic debridement as much as the patients with pure tendinous involvement. Calcifying tendinitis with osseous involvement is an important entity to recognize, and its diagnosis can be difficult to make. “Cortical erosion” and “periosteal reaction” are the main patterns of this pathology, and
CALCIFYING TENDINITIS OF ROTATOR CUFF they can mimic neoplastic diseases.1,2 Occasionally, the calcification can further extend into the adjacent bone, resulting in a “marrow extension or intraosseous calcification.” This bone marrow involvement can be mistaken for avascular necrosis of the humeral head or an infectious process, resulting in unnecessary investigation and treatment attempts.4,5 Because all of our patients had a primary diagnosis of calcifying tendinitis, the differential diagnosis for their osseous involvement had been straightforward. Osseous involvement in calcifying tendinitis was first reported by Hayes et al.15 with cortical erosions at the pectoralis major, gluteus maximus, and adductor magnus tendons. Since then, several case reports have described osseous involvement at different insertions. To our knowledge, until 2003, there were 5 case reports reporting 7 cases of osseous involvement around the shoulder.3,15-18 All of these calcifications were around the pectoralis major insertion. In 2003 Flemming et al.5 reported a retrospective review of 50 cases of osseous involvement in calcifying tendinitis, with 5 cases around the greater tuberosity. One of these five cases had an intraosseous calcification at the rotator cuff insertion; however, the exact number of cases with rotator cuff involvement is not stated in this study. In 2004 Chan et al.4 also reported a case of intraosseous calcification at the rotator cuff insertion. The pathogenesis of bone erosion is unclear. It is believed that active inflammation and local vascularization at the tendon insertion or mechanical effects of muscle traction may play a role.4,17 The pathologic evaluation of our intraosseous calcification specimens showed a similar pathology with the tendinous calcifications. Our results did not suggest any relation between osseous involvement and patient age, the longevity of complaints, and the number of preoperative local injections. The only parameter found to be significantly different between the groups was the mean size of the calcification, suggesting greater susceptibility to osseous involvement in patients with a larger deposit. The incidence of osseous involvement is unclear and might be more frequent than estimated. In our series 5 of 30 patients (17%), operated on consecutively, had osseous involvement. This suggests a high incidence of osseous involvement in the patients who underwent surgical treatment. Although direct radiography is still the most cost-effective method for the assessment of calcifying tendinitis, osseous involvement is probably underestimated with this modality. CT is the most sensitive imaging technique to detect tendinous, cortical, and intraosseous involvement. Although MRI may not show the tendinous calcification, it may be superior in detect-
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ing the marrow involvement as well as soft-tissue lesions such as rotator cuff tears. We think that CT and MRI should be requested in patients with calcifying tendinitis if there is a suspected osseous involvement, such as a superimposed opacity on plain radiographs, to detect the extension of the disease. Missing the diagnosis of osseous involvement can result in incomplete removal of the calcification. There was a dystrophic calcification pattern in all 5 of the patients with osseous involvement, denoted as type D according to the French Arthroscopy Society classification system.9 Because this classification does not address the pattern of the osseous involvement, we think that a new classification detailing the major patterns of osseous involvement (cortical erosion, periosteal reaction, marrow edema, or intraosseous calcification) may be helpful for subsequent series. For instance, they can be classified as a new type, i.e., “type E.” To our knowledge, all the previous reports addressed mainly the radiologic features and diagnostic challenges of osseous involvement in calcifying tendinitis. The data about the clinical course of this entity are limited to the results of a few cases with conservative follow-up and diagnostic biopsy. Fritz et al.18 reported 2 patients with cortical erosion around the shoulder, one of whom had resolution of his symptoms whereas the other continued to have residual chronic pain. The patient with intraosseous calcification of the rotator cuff who underwent an open biopsy was pain free at 6 months’ follow-up.4 Apart from the treatment aspect, our study was, to our knowledge, the first to confirm the intraosseous localization of the calcification by radiologic studies, arthroscopic view, and eventually, pathologic examination. There is still a debate about the necessity of complete removal of the deposit during operative treatment of calcifying tendinitis.6,7,19 Though successful in general, the results of previous series show variability, with a range of satisfaction rates (Table 2).6-10,12,13,20-25 This can be related to the extension of the disease and postoperative residual deposits. Jerosch et al.7 recommended removal of as much calcific deposit as possible. Recently, Porcellini et al.6 found a strong correlation between residual calcium deposits and persistent pain and recommended their complete removal. It has been hypothesized that osseous involvement may be an important cause of pain in patients with calcifying tendinitis.2 The main limitation of the study was the lack of a control group and the limited number of cases in the osseous involvement group. A prospective randomized controlled trial comparing operative and conservative
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TABLE 2.
Results of Previous Studies on Removal of Rotator Cuff Calcifications
Author Gschwend et al.22 Vebostad23 Ark et al.20 Molé et al.9 Rubenthaler and Wittenberg13 Tillander and Norlin10 Seil et al.12 Kayser et al.24
No. of Follow-up Excellent/Good Year Patients (mo) Results 1972 1975 1992 1993
31 43 23 112
26 43 26 21
76.9% 79% 91% 89%
1997
13
13
84.6%
1998 2006 2007
25 58 24
25 24 15
79% 94% 62.5%
treatment would also provide valuable information about the natural prognosis of osseous involvement in calcifying tendinitis. Another limitation of our study was the inclusion of patients who eventually underwent surgical treatment. Thus, as denoted in the text, the inferences should not be attributed to the whole population of patients with calcifying tendinitis. However, despite these limitations, we believe that this study adds to our understanding of the clinical importance of osseous involvement in calcifying tendinitis. CONCLUSIONS Arthroscopic removal of intraosseous and intratendinous deposits to treat calcifying tendinitis with osseous involvement seems to be as safe and effective a treatment method as the arthroscopic removal of intratendinous deposits in cases of tendinous involvement only. REFERENCES 1. Yang I, Hayes CV, Biermann JS. Calcific tendinitis of the gluteus medius tendon with bone marrow edema mimicking metastatic disease. Skeletal Radiol 2002;33:359-361. 2. Sakai T, Shimaoka Y, Sugimoto M, Koizumi T. Acute calcific tendinitis of the gluteus medius: A case report with serial magnetic resonance imaging findings. J Orthop Sci 2004;9:404-407. 3. Kraemer EJ, El-Khoury GY. Atypical calcific tendinitis with cortical erosions. Skeletal Radiol 2000;29:690-696. 4. Chan R, Kim DH, Millett PJ, Weissman BN. Calcifying tendinitis of the rotator cuff with cortical bone erosion. Skeletal Radiol 2004;33:596-599. 5. Flemming DJ, Murphey MD, Shekitka KM, Temple HT, Jelinek JJ, Kransdorf MJ. Osseous involvement in calcific tendinitis: A retrospective review of 50 cases. AJR Am J Roentgenol 2003;181:965-972. 6. Porcellini G, Paladini P, Campi F, Paganelli M. Arthroscopic treatment of calcifying tendinitis of the shoulder: Clinical and ultrasonographic follow-up findings at two to five years. J Shoulder Elbow Surg 2004;13:503-508.
7. Jerosch J, Strauss M, Schmiel S. arthroscopic treatment of calcific tendinitis of the shoulder. J Shoulder Elbow Surg 1998;7:30-37. 8. Akpinar S, Ozkoc G, Hersekli MA, Ozala M, Tandogan YRN. Arthroscopic treatment of rotator cuff calcifying tendinitis. Acta Orthop Traumatol Turc 2002;36:413-416 (in Turkish). 9. Molé D, Kempf JF, Gleyze P, Rio B, Bonnomet F, Walch G. Results of endoscopic treatment of non-broken tendinopathies of the rotator cuff. 2. Calcifications of the rotator cuff. Rev Chir Orthop Reparatrice Appar Mot 1993;79:532-541 (in French). 10. Tillander BM, Norlin RO. Change of calcifications after arthroscopic subacromial decompression. J Shoulder Elbow Surg 1998;7:213-217. 11. 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 1998;14:540-542. 12. Seil R, Litzenburger H, Kohn D, Rupp S. Arthroscopic treatment of chronically painful calcifying tendinitis of the supraspinatus tendon. Arthroscopy 2006;22:521-527. 13. Rubenthaler F, Wittenberg RH. Intermediate-term follow-up of surgically managed tendinosis calcarea (calcifying subacromial syndrome – SAS) of the shoulder joint. Z Orthop Ihre Grenzgeb 1997;135:354-359. 14. Ifesanya A, Scheibel M. Arthroscopic treatment of calcifying tendonitis of subscapularis and supraspinatus tendon: A case report. Knee Surg Sports Traumatol Arthrosc 2007;15:14731477. 15. Hayes CW, Rosenthal DI, Plata MJ, Hudson TM. Calcific tendinitis in unusual sites associated with cortical bone erosion. AJR Am J Roentgenol 1987;149:967-970. 16. Chadwick CJ. Tendinitis of the pectoralis major insertion with humeral lesions: A report of two cases. J Bone Joint Surg Br 1989;71:816-818. 17. Durr HR, Lienemann A, Silbernagi H, Herlich A, Refior HJ. Acute calcific tendinitis of the pectoralis major insertion associated with cortical bone erosion. Eur Radiol 1997;7: 1215-1217. 18. Fritz P, Bardin T, Laredo JD, et al. Paradiaphyseal calcific tendinitis with cortical bone erosion. Arthritis Rheum 1994;37: 718-723. 19. Lorbach O, Kusma M, Pape D, Kohn D, Dienst M. Influence of deposit stage and failed ESWT on the surgical results of arthroscopic treatment of calcifying tendonitis of the shoulder. Knee Surg Sports Traumatol Arthrosc 2008;16:516-521. 20. Ark JW, Flock TJ, Flatow EL, Bigliani LU. Arthroscopic treatment of calcific tendinitis of the shoulder. Arthroscopy 1992;8:183-188. 21. Ellman H, Kay SP. Arthroscopic subacromial decompression for chronic impingement. J Bone Joint Surg Br 1991;73:395398. 22. Gschwend N, Patte D, Zippel J. Therapy of calcific tendinitis of the shoulder. Arch Orthop Unfallchir 1972;73:120-135 (in German). 23. Vebostad A. Calcific tendinitis in the shoulder region: A review of 43 operated shoulders. Acta Orthop Scand 1975;46: 205-210. 24. Kayser R, Hampf S, Seeber E, Heyde CE. Value of preoperative ultrasound marking of calcium deposits in patients who require surgical treatment of calcific tendonitis of the shoulder. Arthroscopy 2007;23:43-50. 25. Rubenthaler F, Ludwig J, Wiese M, Wittenberg RH. Prospective randomized surgical treatments for calcifying tendinopathy. Clin Orthop Relat Res 2003;(410):278-284.
Purpose: The purpose of this study was to evaluate the surgical outcome of arthroscopic removal of intraosseous deposits in calcifying tendinitis of the rotator cuff. Methods: We studied the results of arthroscopic treatment in 30 shoulders in 28 patients with calcifying tendinitis (mean age, 48.3 years; age range, 26 to 83 years), with a mean follow-up of 38 months. According to the localization of calcification, the patients were divided into 2 groups: those with pure tendinous/soft-tissue involvement (n ⫽ 25) (group I) and those with tendinous/soft-tissue and osseous involvement (n ⫽ 5) (group II). After routine tendon debridement, debridement and curettage of the bone lesion were also performed in patients with bone involvement. Clinical outcome was evaluated by use of the pain score on a visual analog scale and the Constant score, and a special inquiry was used for selfassessment. Results: The pain scores and functional Constant scores improved significantly after the operation in both groups (P ⫽ .043 for pain score and P ⫽ .0001 for Constant score in group I and P ⫽ .042 for pain score and P ⫽ .0001 for Constant score in group II). The median Constant score increased from 42 (range, 22 to 65) preoperatively to 100 (range, 80 to 100) postoperatively in group I and from 40 (range, 25 to 55) to 100 (range, 85 to 100) in group II. The mean pain score was 6.5 ⫾ 1.4 (range, 4 to 9) before treatment and 0.2 ⫾ 0.5 (range, 0 to 2) at follow-up in group I, and it was 6.2 ⫾ 1.48 (range, 4 to 8) and 0.4 ⫾ 0.55 (range, 0 to 1), respectively, in group II. There was no significant difference between the 2 groups in terms of the final Constant (P ⫽ .85) and pain scores (P ⫽ .26). Conclusions: Arthroscopic removal of intraosseous and intratendinous deposits to treat calcifying tendinitis with osseous involvement seems to be as safe and effective a treatment method as the arthroscopic removal of intratendinous deposits in cases of tendinous involvement only. Level of Evidence: Level IV, therapeutic case series. Key Words: Calcifying tendinitis—Bone erosion— Intraosseous calcification—Rotator cuff—Arthroscopy.
O
sseous involvement in calcifying tendinitis is a relatively new and not well-recognized entity. The condition has been characterized by erosion of the underlying cortex and bone marrow changes. Although it has been hypothesized that osseous involvement may be an important cause of pain, the actual clinical relevance of this pathology and its treatment options are not well known.1-5
From the Departments of Orthopaedic Surgery, VKV American Hospital (A.S.), and Istanbul Faculty of Medicine, Istanbul University (M.D.), Istanbul, Turkey. The authors report no conflict of interest. Address correspondence and reprint requests to Mehmet Demirhan, M.D., Department of Orthopaedic Surgery, Istanbul Faculty of Medicine, Istanbul University, Çapa, 34390 Aksaray, Istanbul, Turkey. E-mail: [email protected] © 2009 by the Arthroscopy Association of North America 0749-8063/09/2506-8506$36.00/0 doi:10.1016/j.arthro.2008.12.024
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In the absence of osseous involvement, arthroscopic removal of the calcific deposit is an effective treatment option for chronically painful calcifying tendinitis of the rotator cuff.6-14 In this study we report a series of patients with calcifying tendinitis of the rotator cuff with an unusual “intraosseous” extension. The purpose of the study was to evaluate the surgical outcome of arthroscopic removal of intraosseous deposits. We hypothesized that the patients with osseous involvement would benefit from the arthroscopic debridement as much as the patients with pure tendinous involvement.
METHODS Between September 2002 and June 2007, 30 shoulders in 28 patients with calcifying tendinitis underwent arthroscopic treatment at our institution. We
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 25, No 6 (June), 2009: pp 590-596
CALCIFYING TENDINITIS OF ROTATOR CUFF studied the results of arthroscopic treatment in these 28 patients, 10 men and 18 women, with a mean age of 48.3 years (range, 26 to 83 years). There were 21 right shoulders (70%) and 9 left shoulders (30%). According to the localization of calcification, the patients were divided into 2 groups. Group I included patients with pure tendinous/soft-tissue involvement (n ⫽ 25). Group II included patients with tendinous/ soft-tissue and osseous involvement (n ⫽ 5). For both groups, the inclusion criterion for arthroscopic treatment was the presence of persistent shoulder pain, refractory to conservative treatment, for at least 3 months. As confirmed by physical and radiologic examinations, none of the patients had an accompanying cause of pain such as symptomatic impingement syndrome, rotator cuff tear, acromioclavicular osteoarthritis, shoulder stiffness, and infection. The patients had different kinds of nonoperative treatment during their symptomatic preoperative period for a mean of 15 months (range, 3 to 84 months).
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FIGURE 2. Coronal T2-weighted magnetic resonance image of a 39-year old female patient with an intraosseous calcific deposit (arrow). The generalized bone marrow edema in the humeral head should be noted.
Radiologic Evaluation Preoperative radiographs (Fig 1) and magnetic resonance images (Fig 2) were obtained for all patients. Computed tomography (CT) scans were also available for all patients with osseous involvement (Fig 3). On radiographs, the size of the calcific deposit was measured, and its appearance was assessed according to the classification of the French Arthroscopy Society9: type A (dense, sharply delineated homogeneous appearance), type B (dense, sharply delineated, and multiple fragments), type
FIGURE 1. Preoperative radiograph of a patient with osseous involvement. The intraosseous calcification at the rotator cuff insertion (arrow) should be noted. The patient also has a large tendinous deposit.
C (more radiolucent, heterogeneous appearance), and type D (dystrophic calcifications at the tendon insertion). Radiographs were also taken on the first day after surgery and at the last follow-up to confirm the removal and absence of the deposit. Surgical Procedure All patients, under general anesthesia, were treated in the beach-chair position by the same experienced arthroscopic surgeon. The operation started with an arthroscopic inspection of the glenohumeral joint. The rotator cuff was probed percutaneously with a 20gauge spinal needle to localize the calcific deposit. Visible calcium material was carried to the joint when the needle perforated the deposit. A suture marker was then introduced from outside through the needle into the joint. Then the arthroscope was introduced to the subacromial space. Subacromial bursectomy and section of the coracoacromial ligament were performed, and the deposit was expressed out of the tendon, first with blunt instruments; the excision was completed with a curette and a synovial resector. A fluoroscopic control was performed at the end of the procedure to confirm complete removal of the deposit, and debridement was carried out until complete removal was achieved. After the removal of the deposit, the subsequent cavity in the tendon was closed with 1 or 2 side-to-side sutures.
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FIGURE 3. Computed tomography is the most sensitive imaging technique to detect tendinous, cortical, and intraosseous involvement. The arrows on the coronal (left) and axial (right) CT images show the extension of the calcification to the humeral cortex, as well as intraosseous calcification at the rotator cuff insertion.
Approach to osseous lesions: After the routine tendon debridement, the area of cortical bone erosion adjacent to the greater tuberosity was easily localized with the probe, and a small entrance hole was opened with the synovial resector and curette. The intraosseous calcific deposit was arthroscopically viewed through the hole and was expressed out of the osseous cavity (Figs 4 and 5). After the removal of the intraosseous deposit, the cavity wall was curetted. In 2 patients
with osseous involvement, the opening of the osseous cavity was closed again with a suture anchor (Corkscrew; Arthrex, Naples, FL), which was screwed down at the base of the deposit cavity (Fig 6).
FIGURE 4. The intraosseous calcific deposit (arrow) was arthroscopically viewed and was expressed out of the osseous cavity.
FIGURE 5. Before debridement and curettage, a sample of the deposit was taken with a grasper (arrow) for pathologic evaluation.
Pathology Evaluation Hematoxylin and eosin-stained slides were evaluated by an experienced pathologist. Material was reviewed for the presence and character of calcification, fibrosis, and chronic inflammation, as well as evidence of marrow involvement.
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data; Spearman correlation coefficients were used in the correlation analysis. The level of significance was set at P ⬍ .05. RESULTS
FIGURE 6. Postoperative radiograph of a patient with osseous involvement. After arthroscopic removal of the intraosseous deposit, the opening of the osseous cavity was closed again with a suture anchor (arrow), which was screwed down at the base of the deposit cavity.
Rehabilitation After surgery, all of the patients underwent an exercise and rehabilitation program. Follow-up Evaluation The patients were reviewed after a mean follow-up of 38 months (39.4 ⫾ 18 months in group I and 30.8 ⫾ 12 months in group II) by clinical and radiographic examination. Preoperative and postoperative clinical assessment of function was performed by the same physiotherapist, using the Constant scoring method. A 10-point visual analog scale was used in the evaluation of pain. The Constant and pain scores were gathered before the operation and at the last follow-up. Follow-up evaluation was blinded regarding the presence or absence of osseous involvement. Statistical Analysis NCSS 2007 software (NCSS, Kaysville, UT) was used in statistical analysis. In addition to the descriptive methods (median, range, mean, standard deviation), the Mann-Whitney U test was used to compare the unpaired samples, Wilcoxon test to compare paired samples, and 2 test to compare qualitative
The pure tendinous/soft-tissue involvement group (group I) consisted of 25 shoulders in 23 patients (14 women and 9 men; mean age, 49.6 ⫾ 11.4 years [range, 26 to 83 years]). In these patients the calcification was in the supraspinatus and/or infraspinatus tendons and there was no radiologic sign of osseous involvement. The time between the onset of symptoms and the time of surgery was 13 months on average (range, 6 to 36 months). The tendinous/soft-tissue and osseous involvement group (group II) consisted of 5 patients (4 women and 1 man; mean age, 42 ⫾ 10.9 years [range, 29 to 55 years]) with radiologic evidence of osseous involvement, in addition to classical tendinous calcification. The mean time between the first onset of symptoms and the time of surgery was 12 months (range, 3 to 84 months). Comparison of the demographic data of the 2 groups showed that they were homogeneous with regard to age (P ⫽ .16), gender distribution (P ⫽ .39), and follow-up time (P ⫽ .32). The groups were also homogeneous with regard to preoperative Constant score (median, 42 [range, 22 to 65] in group I and 40 [range, 25 to 55] in group II; P ⫽ .42) and pain score (mean, 6.5 ⫾ 1.4 in group I and 6.2 ⫾ 1.5 in group II; P ⫽ .67). There was no significant difference between the onset of symptoms and the time of surgery (mean, 13.4 ⫾ 8.3 months [range, 6 to 36 months] in group I and 24 ⫾ 33.7 months [range, 3 to 84 months] in group II; P ⫽ .98). The median number of preoperative local steroid injections was 2 (range, 1 to 3) in group I and 1 (range, 1 to 3) in group II (P ⫽ .47). The mean size of the soft-tissue calcification was significantly larger in group II (19.6 ⫾ 3.2 mm) than in group I (10.4 ⫾ 2.8 mm) (P ⫽ .001). However, there was no correlation between the size of the calcific deposit and the preoperative pain and Constant scores of the patients (P ⫽ .78 [r ⫽ ⫺0.05] and P ⫽ .99 [r ⫽ 0.002], respectively). The demographic data presented previously are summarized in Table 1. According to the classification of the French Arthroscopy Society,9 the appearance of the deposit was type A in 13 patients in the pure tendinous involvement group, type B in 8, and type C in 4. All 5 of the patients in the osseous involvement group showed a
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A. SEYAHI AND M. DEMIRHAN TABLE 1.
Patient Demographic Data
Group I: Pure Tendinous Involvement No. of Patients Total Female/male Age (yr) Symptomatic period (yr) No. of injections Follow-up (mo) Size of deposit (mm) Rehabilitation (wk) Pain score on visual analog scale Preoperatively Postoperatively Constant score Preoperatively Postoperatively
Median (Range)
Mean ⫾ SD
25 15/10
Group II: Tendinous and Osseous Involvement No. of Patients
Median (Range)
Mean ⫾ SD
P Value
5 4/1 48 (26-83) 0.8 (0.5-3) 2 (1-3) 38 (4-69) 10 (6-17) 4 (1-9) 7 (4-9) 0 (0-2) 42 (22-65) 100 (80-100)
49.6 ⫾ 11.4 1.1 ⫾ 0.7 39.4 ⫾ 18 10.4 ⫾ 2.8 4.7 ⫾ 1.6 6.5 ⫾ 1.36 0.2 ⫾ 0.5
42 ⫾ 10.9 2 ⫾ 2.8
40 (29-55) 1 (0.5-7) 1 (1-3) 29 (22-51) 20 (15-23) 4 (4-6)
30.8 ⫾ 11.9 19.6 ⫾ 3.2 4.8 ⫾ 1.1
.164 .977 .473 .316 .001* .835
6 (4-8) 0 (0-1)
6.2 ⫾ 1.5 0.4 ⫾ 0.6
.669 .263
40 (25-55) 100 (85-100)
.416 .854
NOTE. Both groups were homogeneous with regard to age, gender, preoperative pain score on visual analog scale and Constant score, length of symptomatic period, and follow-up time. *The mean size of the deposit was significantly larger in the osseous involvement group (P ⫽ .001).
dystrophic calcification pattern at the tendon insertion (type D). In 4 of these patients the appearance of the tendinous calcification was dense and multilobular, and in the remaining patient it was radiolucent and heterogeneous. Preoperatively on magnetic resonance imaging (MRI), there was intraosseous calcification in the greater tuberosity with adjacent bone edema in 4 of the patients, cortical bone erosion in all 5, and diffuse bone edema in the humeral head in 1. Complete removal of the calcific deposit was achieved in all patients but 1, who was in the pure tendinous involvement group and whose follow-up radiographic evaluation showed a 2-mm radiodense residual deposit. No rotator cuff tear was detected during arthroscopy. Specimens were available and calcifying tendinitis was pathologically confirmed in 11 cases with tendinous involvement and 4 cases with osseous involvement. Under the light microscope, calcific deposits appeared in all cases. Small granular calcification was the most common pattern, appearing in 8 cases in group I and 3 cases in group II. The remaining 3 cases in group I and 1 case in group II displayed large amorphous calcifications. Furthermore, all cases showed deposits of calcium crystals in the fibrocartilaginous matrix and cell-mediated resorption of the calcific deposit. The mean time for postoperative rehabilitation was 4.7 weeks (range, 1 to 9 weeks) in the patients with
pure tendinous calcification and 4.8 weeks (range, 4 to 6 weeks) in the patients with osseous involvement. The pain scores and functional Constant scores improved significantly after the operation in both groups (P ⫽ .043 for pain score and P ⫽ .0001 for Constant score in group I and P ⫽ .042 for pain score and P ⫽ .0001 for Constant score in group II). The median Constant score increased from 42 (range, 22 to 65) preoperatively to 100 (range, 80 to 100) postoperatively in group I and from 40 (range, 25 to 55) to 100 (range, 85 to 100) in group II. The mean pain score (minimum pain, 0; maximum pain, 10) was 6.5 ⫾ 1.4 (range, 4 to 9) before treatment and 0.2 ⫾ 0.5 (range, 0 to 2) at follow-up in group I, and it was 6.2 ⫾ 1.48 (range, 4 to 8) and 0.4 ⫾ 0.55 (range, 0 to 1), respectively, in group II. There was no significant difference between the final Constant (P ⫽ .85) and pain scores (P ⫽ .26) between the groups. DISCUSSION Our study suggested that the patients with osseous involvement benefited from the arthroscopic debridement as much as the patients with pure tendinous involvement. Calcifying tendinitis with osseous involvement is an important entity to recognize, and its diagnosis can be difficult to make. “Cortical erosion” and “periosteal reaction” are the main patterns of this pathology, and
CALCIFYING TENDINITIS OF ROTATOR CUFF they can mimic neoplastic diseases.1,2 Occasionally, the calcification can further extend into the adjacent bone, resulting in a “marrow extension or intraosseous calcification.” This bone marrow involvement can be mistaken for avascular necrosis of the humeral head or an infectious process, resulting in unnecessary investigation and treatment attempts.4,5 Because all of our patients had a primary diagnosis of calcifying tendinitis, the differential diagnosis for their osseous involvement had been straightforward. Osseous involvement in calcifying tendinitis was first reported by Hayes et al.15 with cortical erosions at the pectoralis major, gluteus maximus, and adductor magnus tendons. Since then, several case reports have described osseous involvement at different insertions. To our knowledge, until 2003, there were 5 case reports reporting 7 cases of osseous involvement around the shoulder.3,15-18 All of these calcifications were around the pectoralis major insertion. In 2003 Flemming et al.5 reported a retrospective review of 50 cases of osseous involvement in calcifying tendinitis, with 5 cases around the greater tuberosity. One of these five cases had an intraosseous calcification at the rotator cuff insertion; however, the exact number of cases with rotator cuff involvement is not stated in this study. In 2004 Chan et al.4 also reported a case of intraosseous calcification at the rotator cuff insertion. The pathogenesis of bone erosion is unclear. It is believed that active inflammation and local vascularization at the tendon insertion or mechanical effects of muscle traction may play a role.4,17 The pathologic evaluation of our intraosseous calcification specimens showed a similar pathology with the tendinous calcifications. Our results did not suggest any relation between osseous involvement and patient age, the longevity of complaints, and the number of preoperative local injections. The only parameter found to be significantly different between the groups was the mean size of the calcification, suggesting greater susceptibility to osseous involvement in patients with a larger deposit. The incidence of osseous involvement is unclear and might be more frequent than estimated. In our series 5 of 30 patients (17%), operated on consecutively, had osseous involvement. This suggests a high incidence of osseous involvement in the patients who underwent surgical treatment. Although direct radiography is still the most cost-effective method for the assessment of calcifying tendinitis, osseous involvement is probably underestimated with this modality. CT is the most sensitive imaging technique to detect tendinous, cortical, and intraosseous involvement. Although MRI may not show the tendinous calcification, it may be superior in detect-
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ing the marrow involvement as well as soft-tissue lesions such as rotator cuff tears. We think that CT and MRI should be requested in patients with calcifying tendinitis if there is a suspected osseous involvement, such as a superimposed opacity on plain radiographs, to detect the extension of the disease. Missing the diagnosis of osseous involvement can result in incomplete removal of the calcification. There was a dystrophic calcification pattern in all 5 of the patients with osseous involvement, denoted as type D according to the French Arthroscopy Society classification system.9 Because this classification does not address the pattern of the osseous involvement, we think that a new classification detailing the major patterns of osseous involvement (cortical erosion, periosteal reaction, marrow edema, or intraosseous calcification) may be helpful for subsequent series. For instance, they can be classified as a new type, i.e., “type E.” To our knowledge, all the previous reports addressed mainly the radiologic features and diagnostic challenges of osseous involvement in calcifying tendinitis. The data about the clinical course of this entity are limited to the results of a few cases with conservative follow-up and diagnostic biopsy. Fritz et al.18 reported 2 patients with cortical erosion around the shoulder, one of whom had resolution of his symptoms whereas the other continued to have residual chronic pain. The patient with intraosseous calcification of the rotator cuff who underwent an open biopsy was pain free at 6 months’ follow-up.4 Apart from the treatment aspect, our study was, to our knowledge, the first to confirm the intraosseous localization of the calcification by radiologic studies, arthroscopic view, and eventually, pathologic examination. There is still a debate about the necessity of complete removal of the deposit during operative treatment of calcifying tendinitis.6,7,19 Though successful in general, the results of previous series show variability, with a range of satisfaction rates (Table 2).6-10,12,13,20-25 This can be related to the extension of the disease and postoperative residual deposits. Jerosch et al.7 recommended removal of as much calcific deposit as possible. Recently, Porcellini et al.6 found a strong correlation between residual calcium deposits and persistent pain and recommended their complete removal. It has been hypothesized that osseous involvement may be an important cause of pain in patients with calcifying tendinitis.2 The main limitation of the study was the lack of a control group and the limited number of cases in the osseous involvement group. A prospective randomized controlled trial comparing operative and conservative
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TABLE 2.
Results of Previous Studies on Removal of Rotator Cuff Calcifications
Author Gschwend et al.22 Vebostad23 Ark et al.20 Molé et al.9 Rubenthaler and Wittenberg13 Tillander and Norlin10 Seil et al.12 Kayser et al.24
No. of Follow-up Excellent/Good Year Patients (mo) Results 1972 1975 1992 1993
31 43 23 112
26 43 26 21
76.9% 79% 91% 89%
1997
13
13
84.6%
1998 2006 2007
25 58 24
25 24 15
79% 94% 62.5%
treatment would also provide valuable information about the natural prognosis of osseous involvement in calcifying tendinitis. Another limitation of our study was the inclusion of patients who eventually underwent surgical treatment. Thus, as denoted in the text, the inferences should not be attributed to the whole population of patients with calcifying tendinitis. However, despite these limitations, we believe that this study adds to our understanding of the clinical importance of osseous involvement in calcifying tendinitis. CONCLUSIONS Arthroscopic removal of intraosseous and intratendinous deposits to treat calcifying tendinitis with osseous involvement seems to be as safe and effective a treatment method as the arthroscopic removal of intratendinous deposits in cases of tendinous involvement only. REFERENCES 1. Yang I, Hayes CV, Biermann JS. Calcific tendinitis of the gluteus medius tendon with bone marrow edema mimicking metastatic disease. Skeletal Radiol 2002;33:359-361. 2. Sakai T, Shimaoka Y, Sugimoto M, Koizumi T. Acute calcific tendinitis of the gluteus medius: A case report with serial magnetic resonance imaging findings. J Orthop Sci 2004;9:404-407. 3. Kraemer EJ, El-Khoury GY. Atypical calcific tendinitis with cortical erosions. Skeletal Radiol 2000;29:690-696. 4. Chan R, Kim DH, Millett PJ, Weissman BN. Calcifying tendinitis of the rotator cuff with cortical bone erosion. Skeletal Radiol 2004;33:596-599. 5. Flemming DJ, Murphey MD, Shekitka KM, Temple HT, Jelinek JJ, Kransdorf MJ. Osseous involvement in calcific tendinitis: A retrospective review of 50 cases. AJR Am J Roentgenol 2003;181:965-972. 6. Porcellini G, Paladini P, Campi F, Paganelli M. Arthroscopic treatment of calcifying tendinitis of the shoulder: Clinical and ultrasonographic follow-up findings at two to five years. J Shoulder Elbow Surg 2004;13:503-508.
7. Jerosch J, Strauss M, Schmiel S. arthroscopic treatment of calcific tendinitis of the shoulder. J Shoulder Elbow Surg 1998;7:30-37. 8. Akpinar S, Ozkoc G, Hersekli MA, Ozala M, Tandogan YRN. Arthroscopic treatment of rotator cuff calcifying tendinitis. Acta Orthop Traumatol Turc 2002;36:413-416 (in Turkish). 9. Molé D, Kempf JF, Gleyze P, Rio B, Bonnomet F, Walch G. Results of endoscopic treatment of non-broken tendinopathies of the rotator cuff. 2. Calcifications of the rotator cuff. Rev Chir Orthop Reparatrice Appar Mot 1993;79:532-541 (in French). 10. Tillander BM, Norlin RO. Change of calcifications after arthroscopic subacromial decompression. J Shoulder Elbow Surg 1998;7:213-217. 11. 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 1998;14:540-542. 12. Seil R, Litzenburger H, Kohn D, Rupp S. Arthroscopic treatment of chronically painful calcifying tendinitis of the supraspinatus tendon. Arthroscopy 2006;22:521-527. 13. Rubenthaler F, Wittenberg RH. Intermediate-term follow-up of surgically managed tendinosis calcarea (calcifying subacromial syndrome – SAS) of the shoulder joint. Z Orthop Ihre Grenzgeb 1997;135:354-359. 14. Ifesanya A, Scheibel M. Arthroscopic treatment of calcifying tendonitis of subscapularis and supraspinatus tendon: A case report. Knee Surg Sports Traumatol Arthrosc 2007;15:14731477. 15. Hayes CW, Rosenthal DI, Plata MJ, Hudson TM. Calcific tendinitis in unusual sites associated with cortical bone erosion. AJR Am J Roentgenol 1987;149:967-970. 16. Chadwick CJ. Tendinitis of the pectoralis major insertion with humeral lesions: A report of two cases. J Bone Joint Surg Br 1989;71:816-818. 17. Durr HR, Lienemann A, Silbernagi H, Herlich A, Refior HJ. Acute calcific tendinitis of the pectoralis major insertion associated with cortical bone erosion. Eur Radiol 1997;7: 1215-1217. 18. Fritz P, Bardin T, Laredo JD, et al. Paradiaphyseal calcific tendinitis with cortical bone erosion. Arthritis Rheum 1994;37: 718-723. 19. Lorbach O, Kusma M, Pape D, Kohn D, Dienst M. Influence of deposit stage and failed ESWT on the surgical results of arthroscopic treatment of calcifying tendonitis of the shoulder. Knee Surg Sports Traumatol Arthrosc 2008;16:516-521. 20. Ark JW, Flock TJ, Flatow EL, Bigliani LU. Arthroscopic treatment of calcific tendinitis of the shoulder. Arthroscopy 1992;8:183-188. 21. Ellman H, Kay SP. Arthroscopic subacromial decompression for chronic impingement. J Bone Joint Surg Br 1991;73:395398. 22. Gschwend N, Patte D, Zippel J. Therapy of calcific tendinitis of the shoulder. Arch Orthop Unfallchir 1972;73:120-135 (in German). 23. Vebostad A. Calcific tendinitis in the shoulder region: A review of 43 operated shoulders. Acta Orthop Scand 1975;46: 205-210. 24. Kayser R, Hampf S, Seeber E, Heyde CE. Value of preoperative ultrasound marking of calcium deposits in patients who require surgical treatment of calcific tendonitis of the shoulder. Arthroscopy 2007;23:43-50. 25. Rubenthaler F, Ludwig J, Wiese M, Wittenberg RH. Prospective randomized surgical treatments for calcifying tendinopathy. Clin Orthop Relat Res 2003;(410):278-284.