Influence of a nerve injury proximal to the suprascapular nerve on healing of repaired rotator cuff tear

Effect of electroacupuncture combined with rehabilitation techniques on shoulder function in patients with rotator cuff injuries

BACKGROUND

The rotator cuff is located below the acromion and deltoid muscles and comprises multiple tendons that wrap around the humeral head, maintaining shoulder joint stability.

AIM

To explore the effect of electroacupuncture combined with rehabilitation techniques on shoulder function in patients with rotator cuff injuries.

METHODS

We selected 97 patients with rotator cuff injuries treated in the People's Hospital of Yuhuan from February 2020 to May 2023. Patients were grouped using the envelope method.

RESULTS

After treatment, the study group's treatment effective rate was 94.90% (46/49 patients), significantly higher than that in the control group (79.17%, 38/48 cases; P < 0.05). Before treatment, there was no difference in Constant Murley Score (CMS) scores, shoulder mobility, or 36-Item Short Form Health Survey (SF-36) scale scores (P > 0.05). Compared with those before treatment, the CMS scores (including pain, daily living ability, shoulder mobility, and muscle strength), all aspects of shoulder mobility (forward flexion, posterior extension, external rotation, internal rotation), and SF-36 scale scores (including physiological, psychological, emotional, physical, vitality, and health status) were higher in both groups after treatment and significantly higher in the study group (P < 0.05). There was no difference in the occurrence of complications between the two treatment groups (P > 0.05).

CONCLUSION

Electroacupuncture combined with rehabilitation techniques has a good treatment effect on patients with rotator cuff injuries, helps accelerate the recovery of shoulder function, improves the quality of life, and is highly safe.

Imaging and histological evaluation of the long head of the biceps tendon in the presence of different types of rotator cuff tears

BACKGROUND

A comparison of changes in the long head of the biceps tendon for different types of rotator cuff tears has not been previously performed. Furthermore, the correlation between the thickening and degeneration of the long head of the biceps tendon and the cause of these changes have not been fully clarified. We evaluated the relationship between degenerative changes in the long head of the biceps tendon and rotator cuff tears in a rat model using imaging and histology.

METHODS

Ninety-six 12-week-old Sprague-Dawley rats were divided into anterior (subscapularis tear), anterosuperior (subscapularis, supraspinatus, and infraspinatus tears), superior (supraspinatus and infraspinatus tears), and control groups. The long head of the biceps tendon was harvested at 4 or 12 weeks postoperatively. The cross-sectional areas of the intra- and extra-capsular components of the tendon were measured using micro-computed tomography, and the affected/normal ratio of the cross-sectional area was calculated. Masson's trichrome staining and Alcian blue staining were performed for histologic analysis, with degenerative changes described using the modified Bonar scale. The correlation between the affected/normal ratio and Bonar scores was evaluated.

RESULTS

The affected/normal ratio was higher for the anterior and anterosuperior groups than for the control group at 4 and 12 weeks. The ratio increased for the intra-articular portion in the superior group and for both the intra- and extra-articular portions in the anterior and anterosuperior groups. Degeneration considerably progressed in the anterior and anterosuperior groups compared with the control group from weeks 4 to 12 and was greater in the intra- than in the extra-articular portion. The ratio correlated with extracellular matrix score.

CONCLUSIONS

Subscapularis tears were associated with progressive thickening and degeneration of the long head of the biceps tendon at 4 and 12 weeks postoperatively, which was more significant in the intra- than in the extra-articular portion. Histologic evaluation indicated that the extracellular matrix likely caused these degenerative changes.

«Terrible triad» of the shoulder. Biomechanicalsemi-natural modeling andjustificationto rotator cuff restoration

The aim of this study: was determine the force of tension and deformation of axillary nerve in rupture rotator cuff and paresis of deltoid muscle of the shoulder joint. Material and methods: Semi-natural modelling based on the axial scans spiral computed tomography of the intact shoulder joint was performed to determine the degree of traction load on the axillary nerve with distal displacement shoulder head and tendon rupture which paresis of the deltoid muscle. Result: The values of deformations for axillary nerve being at the limit of tissue strength at distal displacement of humeral head of the model by 50 %, progressively increased with increasing distal displacement of humeral head to 100 % of its diameter, reaching values 1.7 times higher than the strength nervous tissue. Conclusion: The progressive changes occurring in the axillary nerve under the action of traction loads, and as a consequence of its ischemia, over time can lead not only to demyelination, but also to the defeat of the axons themselves atrophy of its fibers. In turn, deltoid muscle atrophy increases the traction load on the affected axillary nerve, which forms a vicious circle. The only possible option to "break" the vicious circle is restore the stabilizing structures damaged during the injury, among which one of the most important is the tendons of the rotator cuff of the shoulder. Surgical restoration of the integrity rotator cuff of the shoulder reduces the traction load acting on the axillary nerve, which in turn significantly improves the conditions for reinnervation of the deltoid muscle.