Isolated bursal-side infraspinatus tear diagnosed by computed tomography bursography: a case series

A 59-year-old Asian woman with no previous history of trauma presented with 2-year history of severe shoulder pain. She underwent conservative management with steroidal injection and physiotherapy for at least 3 months at the referral hospital. On physical examination at the first visit to our institute, there was tenderness over the greater tubercle, and Neer’s test and Hawkins–Kennedy test elicited pain. Radiographs showed a subacromial spur (Fig. 1), and T2-weighted MRI with field strength of 1.5 T demonstrated a normal rotator cuff. Based on these findings, shoulder impingement syndrome was diagnosed, and the patient was managed conservatively with combinations of nonsteroid antiinflammatory medication, a steroid injection into the subacromial space, and physical therapy. However, no improvement was noted after 1 month, and the patient reported her shoulder pain as intolerable. Arthrography was performed using contrast mixed with lidocaine. The image showed no leakage, and the lidocaine did not alleviate the shoulder pain. Therefore, bursography was performed, and the image showed pooling of the contrast medium in a tendon area of the rotator cuff (Fig. 2). In addition, the shoulder pain was relieved. CT bursography clearly revealed a longitudinal infraspinatus tear (Fig. 3a–d). This lesion could not be identified on the MRI obtained 1 month earlier (Fig. 3a–d). Subsequent arthroscopy identified the bursal-side infraspinatus tear (Fig. 4a), and the torn flap was trimmed after subacromial decompression (Fig. 4b). At 2 years postoperatively, the patient remained free of shoulder pain.

A 59-year-old Asian woman presented with 1-month history of shoulder pain. She did not report any history of trauma. Examination revealed tenderness over the greater tubercle, and pain was elicited on performing Neer’s test. A marked subacromial spur could be seen on radiographs (Fig. 5), and a T2-weighted MRI with field strength of 1.5 T demonstrated a normal rotator cuff. Accordingly, shoulder impingement syndrome was diagnosed, and she was treated conservatively for 6 months. However, symptoms did not improve with conservative treatment, and the patient requested surgical treatment. Her preoperative arthrogram with contrast and lidocaine showed no findings of note and did not relieve her shoulder pain. Hence, bursography was performed, showing pooling of the contrast medium in a tendon area of the rotator cuff (Fig. 6), and the patient reported alleviation of the shoulder pain. CT bursography revealed a longitudinal infraspinatus tear (Fig. 7a–d). Fat-suppressed T2-weighted MRI with a field strength of 1.5 T was performed within 1 month after the CT. Although the MRI images suggested a bursal-side PTRCT, the longitudinal lesion was difficult to identify (Fig. 7a–d). The patient underwent arthroscopy, which confirmed the bursal-side infraspinatus tear (Fig. 8a, b). The torn flap was trimmed after subacromial decompression. The patient’s shoulder remained pain-free 1 year later.

A 71-year-old Asian woman presented with 3-year history of shoulder pain. She reported no history of trauma. Slight tenderness over the greater tubercle was found on physical examination, and Neer’s test and Hawkins–Kennedy test elicited pain. Plain radiographs showed no abnormal findings, and there was no apparent subacromial spur (Fig. 9). In addition, a T2-weighted MRI with a field strength of 1.5 T demonstrated a normal rotator cuff. She was diagnosed with shoulder impingement syndrome and managed conservatively for 10 months; however, her shoulder pain was refractory to conservative treatment. At 10 months, an arthrogram showed no abnormal findings and did not relieve her shoulder pain. Therefore, bursography was performed. Bursography showed pooling of the contrast medium in a tendon area of the rotator cuff (Fig. 10), and the shoulder pain was relieved. A longitudinal infraspinatus tear (Fig. 11a–d) was visualized on CT bursography. Although a fat-suppressed T2-weighted MRI (field strength, 1.5 T) was repeated within 1 month following the CT, the findings were suggestive of subacromial bursitis (Fig. 11a–d). We suspected a bursal-side infraspinatus tear; however, the patient declined surgical treatment. Her shoulder pain persisted at the 2-year follow-up.

The patient is placed in supine position on the fluoroscopy table. Shoulder arthrography is performed first using 7–8 ml of contrast mixed with lidocaine. This contrast medium contains 10 ml 60% meglumine sodium amidotrizoate and 10 ml 2% lidocaine. If no leakage is observed on arthrography and it provides no pain relief, then subacromial bursography is performed.

The injection site for subacromial bursography is located one fingerbreadth distal to the anterolateral corner of the acromion. A 22-gauge, 32- or 70-mm needle is inserted until the tip of the needle contacts the undersurface of the acromion process [6]. When pressure is felt on the plunger of the syringe, the syringe and needle are withdrawn slowly until a sudden drop in pressure is noted, signifying that the needle tip is inside the subacromial bursa [6, 7]. Next, 3–4 ml of the same contrast mixture is injected into the bursa. Anteroposterior radiographs of the shoulder in internal, external, and neutral rotation are made. Whether the shoulder pain is relieved or not must be recorded.

Subacromial bursography was performed in each of the presented cases by a single orthopedist (Y.O.) with 3 years of experience in shoulder arthrography and bursography.