J. Ozaki

Fatty degeneration in the supraspinatus muscle after rotator cuff tear

We studied the relationship between fatty degeneration in the supraspinatus muscle after rotator cuff tear and muscle atrophy and tendon retraction in 41 cadaveric shoulders. Eighteen shoulders had a supraspinatus tendon tear. Transverse sections of the supraspinatus muscle were made at the proximal end of the scapular notch. The tendon fiber areas were stained red and the muscle fiber areas were stained yellow by the van Gieson method. Areas of fatty degeneration were stained orange-red by the Sudan three method. These areas were measured with a computer color image analysis system. There were many areas of the fatty degenerative change in the supraspinatus muscles associated with a cuff tear, mainly around the tendon fibers and the vessels. The fatty degeneration in the supraspinatus muscle after cuff tear was found to have a strong association with the degree of retraction of the tendon fibers rather than the reduction of muscle volume.

Bone mineral density of the shoulder joint in frozen shoulder.

Abstract The purpose of this study was to evaluate the osteopenia in several parts of the shoulder joint in a series of individuals suffering from frozen shoulder and to elucidate the pathogenesis. The bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DEXA). In 30 cases of frozen shoulder, 16 men and 14 women, BMD of the head of the humerus, greater tubercle of the humerus, surgical neck of the humerus, and neck of the scapula was evaluated. The average age of the male patients was 58.4 years and of the women, 59.5 years. At the neck of the scapula, there were no significant differences in any of the cases. However, there was a marked decrease in BMD at the proximal end of the humerus on the affected side of women. In contrast, men showed no significant difference between the affected and unaffected shoulders, suggesting that the degree of osteopenia remains low compared with women. Although frozen shoulder is a disease which may occur in both men and women, the loss of bone was conspicuous only in women. This may be due to the involvement of female hormones in alterations of bone in frozen shoulder, as in cases of osteoporosis, in addition to the originally low bone density in women. The degree of osteopenia of the proximal humerus with frozen shoulder was not correlated with the duration of the disease, range of motion of the shoulder joint, or patient’s age.

Surgical treatment for posterior ossifications of the glenoid in baseball players.

Seven baseball pitchers with symptomatic posterior glenoid osteophytes were operated on between 1982 and 1988 and were followed for an average of 5.2 years. Five and two patients had ossifications on the posteroinferior glenoid rim and on the infraglenoid tubercle, respectively. Ossifications on the posteroinferior glenoid rim were associated with posterior glenohumeral impingement, posterior glenoid labrum tears, and axillary neuropathy. Ossifications on the infraglenoid tubercle were associated with axillary nerve entrapment by the osteophytes and the thickened long head of the triceps muscle. Histologic study showed the coexistence of reactive new bone formation and bone necrosis. Preoperative and postoperative pain, sensory loss, muscle strength, and throwing distance were assessed. After surgical resection of the osteophytes and release of the axillary nerve entrapment, improvement in all parameters was observed in all patients.

Neurohistology of the subacromial bursa in rotator cuff tear

This study was undertaken to identify and quantitate neural elements in the human subacromial bursa. Biopsy specimens of subacromial bursae were obtained from patients with rotator cuff tears and from cadavers of patients with no history of shoulder disorder (controls). We used a modified gold chloride method to characterize neural elements within the subacromial bursa. The population of intrabursal neural elements was calculated by computerized image analysis. The subacromial bursa demonstrated an extensive neural network: four morphological types of mechanoreceptors and many free nerve endings were identified. In general, there was an inverse relationship between the population density of neural elements and the extent of cuff tear. The population density of neural elements of the subacromial bursa associated with massive cuff tear was significantly lower than that observed in control shoulders. With regard to clinical symptoms, a significant correlation was established between the population density of neural elements in the subacromial bursa and shoulder pain at rest. Our investigation strongly suggests that the subacromial bursa is intimately involved in the perception of shoulder pain, providing an anatomical basis for afferent neural input in proprioceptive reflex ares.

The changes occurring after the Putti-Platt procedure using magnetic resonance imaging.

Abstract The purpose of this study is to evaluate the magnetic resonance imaging (MRI) following Putti-Platt procedure for recurrent anterior dislocation of the shoulder. Six shoulders of six patients who had received Putti-Platt procedure were evaluated by the MRI before and after operation. After the Putti-Platt procedure the subscapularis tendon was thickened and an increased signal area on T2-weighted images were observed in four patients. The area of subscapularis tendons after operation was increased maximally 3.46-fold and the volume was increased on average 1.51-fold. The course of subscapularis muscle fiber before operation was described as a mild arc, but changed to a straight line after the procedure in five patients. The findings in this study suggest that the Putti-Platt procedure leads to a remarkable increase in strength of subscapularis tendon and an improvement of laxity of subscapularis muscle. In conclusion, there is a good possibility that this procedure will increase the stability of the glenohumeral joint and be a successful treatment for recurrent anterior dislocation of the shoulder.