Goro Sakurai

Incomplete tears of the subscapularis tendon associated with tears of the supraspinatus tendon: Cadaveric and clinical studies

This study was undertaken to evaluate incomplete tears of the subscapularis tendon that occur in conjunction with small or medium-sized tears of the supraspinatus tendon. Fifty-two shoulders were examined in 26 embalmed cadavers. The average age at the time of death was 76.3 years. Rotator cuff tears were observed in 32 (61.5%) shoulders. Six (11.5%) shoulders had massive rotator cuff tears and were excluded from the study, leaving 46 shoulders for study. Twenty shoulders had a tear of the supraspinatus tendon, and 17 had a tear of the subscapularis tendon. All tears of the subscapularis tendon were articular-side incomplete tears. On histologic examination most pathologic changes of the subscapularis tendon were observed on the articular side of the upper portion. Lesions of the long head of the biceps brachii were identified in 14 (30.4%) shoulders. A statistically significant correlation was found between tears of the subscapularis tendon and the presence of lesions of the long head of the biceps brachii (P=.0014). In addition, the results of preoperative magnetic resonance imaging of 15 patients (average age, 62.9 years) with a surgically confirmed diagnosis of incomplete tears of the subscapularis tendon in conjunction with tears of the supraspinatus tendon were also evaluated. Incomplete tears of the subscapularis tendon could be identified on magnetic resonance imaging as an area of high signal intensity on axial T2-weighted images in all 15 shoulders studied.

Electromyographic analysis of shoulder joint function of the biceps brachii muscle during isometric contraction.

Surface electromyography was performed for both heads of the biceps brachii in 11 healthy men while the muscles were under 30% maximum isometric shoulder flexion and abduction. Elbow related biceps activity was minimized by using a brace locked in neutral forearm rotation. Electromyographic activity was normalized as a percentage of maximal muscle contraction during 24 shoulder motions. Electromyographic activity was detected in all motions examined, suggesting that the biceps muscle acts as a flexor and an abductor of the shoulder. Both heads of the biceps muscle had higher activities during external rotation than during internal rotation for most motions. Activities of both heads increased with arm elevation, but showed little dependence on elbow position. The long head was still active during internal rotation of the shoulder. These findings also suggest that the biceps muscle is a flexor and an abductor of the shoulder, and that the long head can act as a humeral head stabilizer in superior and anterior directions. Muscle fatigue of the biceps and the deltoid muscle also was determined at 30% of maximum isometric flexion. All muscles had significantly decreased mean power frequency and turns count, and increased amplitude and integrated electromyography. The rate of decrease in mean power frequency was larger for the biceps than for the deltoid muscle, and the rate of increase in amplitude was larger for the long head of the biceps than for the short head or for the deltoid muscle. These findings suggest that the long head of the biceps must increase its mechanical output to keep the arm in elevation to a greater extent than do the short head and the deltoid muscle. This may be one of the causes of tendinitis or rupture of the long head.

Accuracy of the biceps tendon sheath injection: ultrasound-guided or unguided injection? A randomized controlled trial

BACKGROUND Patients often localize pain in the anterior shoulder; however, this patient-localized pain does not necessarily correlate to the location of disease. Unguided shoulder injections are common in clinical practice. The accuracy of unguided biceps tendon sheath injections has not been studied. Patient management may be aided by the knowledge of injection accuracy. This study compared the accuracy of ultrasound-guided biceps tendon sheath injection with unguided injection. MATERIALS AND METHODS The study comprised 30 patients (30 shoulders) with reported anterior shoulder pain who had a primary diagnosis of tenosynovitis or tendinitis of the biceps tendon, or both. Shoulders were randomly allocated into ultrasound-guided and unguided injection groups. Computed tomography (CT) imaging was performed immediately after a contrast agent was injected into the biceps tendon sheath. The locations of contrast seen on CT scan were classified into 3 types: only within the tendon sheath (type 1); inside the tendon, tendon sheath, and surrounding area (type 2); and only the area outside the tendon sheath (type 3). RESULTS Ultrasound-guided injections resulted in 86.7% type 1 and 13.3% type 2 locations. Unguided injections resulted in 26.7% type 1, 40.0% type 2, and 33.3% type 3 locations. The difference for each location type was significant (P < .05). CONCLUSION Injection into the tendon sheath of the long head of the biceps brachii can be more accurately performed using ultrasound guidance than by the blind method.

Assessing the efficacy of famotidine and rebamipide in the treatment of gastric mucosal lesions in patients receiving long-term NSAID therapy (FORCE—famotidine or rebamipide in comparison by endoscopy)

BackgroundNonsteroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori infection are major causes of gastric mucosal lesions. In Japan, histamine-2 receptor antagonists are frequently prescribed, but the literature regarding their efficacy is limited. In this study, we compare the effects of famotidine and rebamipide on NSAID-associated gastric mucosal lesions using upper gastrointestinal endoscopy.MethodsThis study examined 112 patients taking NSAIDs for either gastric hemorrhage or erosion. Before treat-ment, the patients were assessed by endoscopy. Using blind randomization, patients were divided into two groups: group F (famotidine, 20 mg/day) and group R (rebamipide, 300 mg/day). Efficacy was examined 4 weeks later using endoscopy.ResultsAfter treatment, the Lanza score decreased significantly in group F (P < 0.001) but not in group R (P = 0.478). The change in the Lanza score in group F was significantly greater (P = 0.002) than that in group R.ConclusionsFamotidine was superior to rebamipide in treating NSAID-associated mucosal lesions.

In vivo microstructural analysis of the humeral greater tuberosity in patients with rotator cuff tears using multidetector row computed tomography

BackgroundIn arthroscopic surgery, the suture anchor technique has become popular for rotator cuff repair. Preoperative evaluation of the bone microstructure is of utmost importance because, especially in elderly patients, osteoporotic changes may cause anchor pullout, which results in failure of rotator cuff repair. Many groups have reported humeral microstructural analysis; however, most studies were experiments using porcine specimens or human cadavers. In this study, we used multidetector row computed tomography to successfully perform in vivo evaluation of the bone microstructure of the humeral greater tuberosity in patients with rotator cuff tears.MethodsTen patients were examined. Regions of interest were defined in six quadrants of the greater tuberosity (medial, lateral, and far lateral rows of the anterior and posterior areas). The local bone mineral density and the trabecular microstructural parameters, including the mean bone volume to total volume (BV/TV), trabecular thickness, trabecular separation, and structure model index (SMI), were measured using bone analysis software.ResultsThe BV/TV of the posteromedial region was highest and the SMI of the posteromedial region was lowest. These findings suggest that the bone quality of the posteromedial portion is the highest within the greater tuberosity.ConclusionBecause the bone quality may be correlated with the pullout strength of suture anchors, our method can help to understand the individual and regional variance in bone quality and may lead to the creation of personalized surgical protocols.

Ultrasound-guided arthroscope insertion and decompression of a supraspinous fossa cyst

A cyst arising in the scapular supraspinous fossa may cause shoulder pain; subsequently, enlargement of the cyst may result in severe compression of the adjacent suprascapular nerve, leading to muscle weakness and sensory disorder. Decompression of the nerve through cyst removal is effective in resolving these symptoms. However, treatment can also be performed less invasively through arthroscopy. Insertion of an arthroscope without visual guidance could cause tissue damage and, consequently, would become an invasive procedure itself. The use of ultrasonography to guide the scope to the cyst decreases the invasiveness of the procedure. Here, we present the case of a patient with a cyst arising in the scapular supraspinous fossa, in whom we could relatively readily and safely observe the cyst by advancing an arthroscope under ultrasonographic guidance. The suprascapular nerve was decompressed via cyst removal.