In addition to the various cosmetic and medical applications of Botulinum toxin A (Botox), a new study reveals a potential benefit of Botox which may bring a new hope for patients who will undergo surgical repair of the rotator cuff.
The rotator cuff is a group of muscles and tendons that surround the shoulder joint; these muscles and their tendons provide stability to the shoulder and allow the shoulder to rotate. The rotator cuff injury is a major health issue because it is one of the most common causes of shoulder pain, in addition to the high costs of the treatment, which reached US$7 billion in the United States in the year 2000.
Rotator cuff disorders cause dull pain in the shoulder and decrease in the range of motion. They are commonly associated with careers and sports that require repetitive overhead motions such as carpentry, painting, basketball, tennis, and baseball; also with the same mechanism, orchestra conductors and drummers are commonly affected. These disorders include mild tears that can be managed by physiotherapy and medical care, whereas major injuries will require surgery known as rotator cuff repair.
A recent study published in the BMC Musculoskeletal Disorders assessed the effect of Botox injection into the supraspinatus muscle – one of the rotator cuff group muscles – after the surgical repair of the rotator cuff in a rat model. The study relied on the characteristics of botulinum toxin A (Botox) as a neurological toxin which causes a temporary muscular paralysis. Researchers performed surgical transection and repair of 82 supraspinatus tendons in rat models. After repair, each muscle was injected with Botox or saline for comparison purposes. Half of the shoulders were additionally treated with immobilization, and the other half were allowed free cage activity. The tendon healing quality was evaluated later on by histological examinations of the scarring zone and by biomechanical measurements of the repair site strength.
Researchers found that the tendon healing quality in the Botox injection group was better than that in the control groups and similar to the cast immobilization group; however, the combination of Botox injection and cast immobilization affected the surgical repair negatively. The avoidance of long-term immobilization in rats who underwent rotator cuff repair by injecting Botox into the muscles might be one of the potential benefits of this study; which leads to a minimal post-surgery stiffness and superior functional end results.
Written By: Andreh Kaba