Arthroskopische Rekonstruktion der Rotatorenmanschette

High-intensity interval training improves fatty infiltration in the rotator cuff through the β3 adrenergic receptor in mice

Aims

Rotator cuff muscle atrophy and fatty infiltration affect the clinical outcomes of rotator cuff tear patients. However, there is no effective treatment for fatty infiltration at this time. High-intensity interval training (HIIT) helps to activate beige adipose tissue. The goal of this study was to test the role of HIIT in improving muscle quality in a rotator cuff tear model via the β3 adrenergic receptor (β3AR).

Methods

Three-month-old C57BL/6 J mice underwent a unilateral rotator cuff injury procedure. Mice were forced to run on a treadmill with the HIIT programme during the first to sixth weeks or seventh to 12th weeks after tendon tear surgery. To study the role of β3AR, SR59230A, a selective β3AR antagonist, was administered to mice ten minutes before each exercise through intraperitoneal injection. Supraspinatus muscle, interscapular brown fat, and inguinal subcutaneous white fat were harvested at the end of the 12th week after tendon tear and analyzed biomechanically, histologically, and biochemically.

Results

Histological analysis of supraspinatus muscle showed that HIIT improved muscle atrophy, fatty infiltration, and contractile force compared to the no exercise group. In the HIIT groups, supraspinatus muscle, interscapular brown fat, and inguinal subcutaneous white fat showed increased expression of tyrosine hydroxylase and uncoupling protein 1, and upregulated the β3AR thermogenesis pathway. However, the effect of HIIT was not present in mice injected with SR59230A, suggesting that HIIT affected muscles via β3AR.

Conclusion

HIIT improved supraspinatus muscle quality and function after rotator cuff tears by activating systemic sympathetic nerve fibre near adipocytes and β3AR.

[Surgical treatment of anterosuperior impingement of the shoulder]

OBJECTIVE

Therapy of intraarticular lesions and elimination of structural risk factors for those suffering from clinical manifest anterosuperiorer impingement (ASI) of the shoulder. This includes as a maximum version the arthroscopic repair of supraspinatus (SST) and subscapularis tendon (SCT) tears with subsequent subpectoral tenodesis of the long head of the biceps tendon (LBT) and arthroscopic coracoplasty.

INDICATIONS

Clinical manifest anterosuperiorer impingement of the shoulder with anterior shoulder pain, failed conservative treatment and clear intraarticular damage in radiological imaging. This involves in detail lesions of the SST, SCT and damage to the LBT.

CONTRAINDICATIONS

Lack of structural intraarticular lesions or massive osteoarthritis. Persistent dysfunction of active and passive glenohumeral and scapulathoracal motion, due to neurologic deficits or stiff shoulder. A hypertrophic or deformed healed coracoid process is seen as a structural risk factor for suffering from ASI and should be addressed surgically when causing impingement.

SURGICAL TECHNIQUE

Arthroscopic tenotomy of the LBT with subsequent repair of the SST and SCT. Arthroscopic coracoplasty if indicated and subpectoral tenodesis of the long head of the biceps.

POSTOPERATIVE MANAGEMENT

No biceps activity and intermittent immobilization in sling for 6 weeks. Limitation of abduction, flexion and external rotation for 6 weeks depending on rotator cuff tendon repair. Start of sport-specific training after 3 months, over-head sports 6 months postoperatively.

RESULTS

The arthroscopic repair of anterosuperior rotator cuff tears provides reliable results for improvement in function, decreases in pain and improvement in shoulder scores. The overall rate of adverse events is low.

Surgical referral criteria for degenerative rotator cuff tears: a Delphi questionnaire study

Selecting the most appropriate patients to refer for surgery is crucial for high-quality and efficient clinical care. However, there are no specific referral criteria to guide the referral of appropriate patients for rotator cuff repair surgery. The aim of the present study was to design robust surgical referral criteria for patients with degenerative rotator cuff tears using consensus methodology. A two-round Delphi questionnaire was undertaken with a nationally representative sample of 41 specialist shoulder surgeons experienced in rotator cuff repair. Surgical referral criteria for degenerative rotator cuff tear were developed where consensus of at least 70% agreement was achieved. The initial questionnaire consisted of 24 items. Consensus was reached on 14 items, including: severity of pain, functional limitation, the identification of fat atrophy, agreement that a course of physiotherapy should be attempted before surgical referral, and exclusion for those with an active frozen shoulder. However, there was no consensus with regard to the dimensions of the tear. The surgical referral criteria developed were novel and promising for patients with degenerative rotator cuff tears, and further research is required to examine their efficacy.

Rotator cuff repair fluid extravasation characteristics are influenced by repair technique

BACKGROUND

This study evaluates rotator cuff repair fluid extravasation characteristics for different rotator cuff repair techniques.

METHODS

Eight fresh-frozen cadaveric shoulders were dissected free of soft tissues, with the glenohumeral joint capsule and rotator cuff muscles being left intact. A custom fluid infusion device was used to deliver fluid at constant pressure into the glenohumeral joint. The shoulders were tested in conditions of (1) intact rotator cuff, (2) supraspinatus tear, (3) repaired supraspinatus tear with a single-row technique, and (4) repaired supraspinatus tear with a double-row suture bridge technique.

RESULTS

The volume per minute of saline solution extravasation for single-row repair and double-row suture bridge repair was 48.53 mL/min and 11.73 mL/min, respectively, at 2 psi; 73.3 _ 24.1 mL/min and 24.5 _ 19.7 mL/min, respectively, at 3 psi; and 95.2 _ 22.6 mL/min and 39.2 _ 23.8 mL/min, respectively, at 4 psi. There was a statistically significant greater fluid extravasation for the single-row repair compared with the double-row suture bridge repair at all 3 pressures tested (P < .05).

CONCLUSION

Single-row rotator cuff repair exposes the healing zone to greater extravasation of fluid compared with double-row suture bridge repair. Therefore, double-row repair potentially enhances rotator cuff healing.

LEVEL OF EVIDENCE

Controlled laboratory study.