The rotator cuff consists of four muscles and their tendons. These surround the ball of the shoulder joint.
The muscles fine tune the movements of the shoulder joint and assist other large muscles in moving the arm.
The tendons run under the acromion (the prominent bone at the tip of the shoulder – part of the shoulder blade) where they are very vulnerable to being damaged. This can lead to a tear resulting in a painful, weak shoulder.
The tendon of the rotator cuff passes through a narrow space between the top of the arm bone and a prominent bone on the shoulder blade (the acromion). The tendon is very vulnerable to being pinched here when the arm is moved, especially above the head. Over time this pinching can lead to tears of the tendon; the chance of this increases as we get older.
When repeated tearing occurs, the fabric of the tendon becomes weakened and finally, like the cloth at the knees of old trousers, splits. This leads to pain, which can be severe. Weakness of the shoulder can occur, often with clicking and crunching on movement.
Other forms of treatment such as injection and physiotherapy are available, but sometimes it is necessary to repair the tendon. How well this does will depend upon the size of the tear. If we think about the trousers again, the bigger the split in the cloth, the more difficult is the repair and the more likely the repair is to re-tear. Your consultant will have discussed this with you.
What is rotator cuff injury?
The rotator cuff comprises a group of four muscles that function to stabilise and move the shoulder. Though the rotator cuff muscles are extremely important structures in the shoulder, they are also prone to tears and weakening.
A rotator cuff injury, which is fairly common, involves any type of irritation or damage to your rotator cuff muscles or tendons. The risk of injury increases with age, and is particularly common in the middle-aged.
Causes of rotator cuff injury
Normal wear and tear: As the tendon of the rotator cuff has poor blood supply, it tends to be prone to degeneration due to ageing. The degeneration can be aggravated by repetitive shoulder movements. Hence this condition typically occurs if you are above 40.
Repetitive movements: Athletes who regularly use overhead repetitive movements such as swimmers, rowers or tennis players are at higher risk of rotator cuff injuries. However, the injury can also happen through seemingly trivial activities like carrying a heavy load overhead or hanging clothes outside.
Trauma: The rotator cuff can also be damaged from a single traumatic injury such as a fall or a hard direct hit to the arm.
Heavy lifting or pulling: Lifting or pulling an object that is too heavy or lifting in the wrong way can cause strain or a tear to the rotator cuff muscle or tendon.
Poor posture: Slouching forward of the head and neck can cause the muscle or tendon to be pinched leading to inflammation.
Rotator cuff injury symptoms
Many people with underlying rotator cuff injury may often have no pain or limitation of motion though they may have inflammation or early injury to their rotator cuff resulting from degeneration from repeated usage. These symptoms often present only after an injury, like a fall, which causes a tear in the already injured rotator cuff.
When there is a tear in the rotator cuff, the most common symptom is pain in the shoulder especially when lifting the arm. Pain may be experienced when you reach up to comb the hair, or bend the arm back to wear a piece of clothing.
You can also experience weakness and tenderness in the shoulder, and pain when sleeping on the affected arm. The shoulder can also experience a loss of range of motion. With a large tear, there can be continuous pain and muscle weakness.
In the case of a complete tear of the rotator cuff, there is the likelihood that you may completely be unable to lift the arm.
Diagnosis of rotator cuff injury
The diagnosis of a rotator cuff tear is based on history and clinical examination. X-rays may be useful in determining if there are other contributing factors such as previous bony injury.
An ultrasound or MRI will show if a tear is present as it can identify all rotator tears from degeneration to partial or complete tears.
Rotator cuff injury treatment
Generally, pain relief medication would be the first line of treatment. A steroid injection can be given to relieve pain and inflammation.
Physiotherapy is recommended to increase shoulder muscle strength and improve flexibility.
Surgical options include arthroscopic or keyhole repair. The torn edge of the cuff is removed and mobilised. The tendons are reattached to the bone using absorbable or metal anchors using the latest technique available. Traditional open repair of the rotator cuff can also be performed. After surgery, patients are put in a sling or brace. Therapy starts the day after surgery.