Rotator Cuff Injury

The rotator cuff

Four muscles make up the rotator cuff: the supraspinatus (most commonly injured), infraspinatus, teres minor and subscapularis. Their tendons form a cuff around the head of the upper arm bone (humerus). They keep the ball centered in the shallow socket while the larger deltoid muscle lifts the arm. A fluid sac (the subacromial bursa) lets the tendons glide under the bony roof of the shoulder (acromion).

Types of rotator cuff injury

Causes and risk factors

• Age: tendons degenerate with age; tears are present in many people over 60, often without symptoms.
• Repetitive overhead activity: painting, carpentry, swimming, tennis, baseball pitching, weightlifting.
• Injury: falling on an outstretched arm, lifting something heavy, or shoulder dislocation in people over 40.
• Bone spurs under the acromion.
• Smoking, diabetes and high cholesterol, which impair tendon health.
• Family history.

Symptoms

• a dull, deep ache in the shoulder, often spreading down the outer upper arm
• pain lifting the arm overhead or out to the side, or reaching behind your back
• pain at night, especially lying on the affected side
• weakness lifting or rotating the arm
• crackling (crepitus) with movement
• with large tears: inability to lift the arm, which may drop when lowered slowly

Weakness: tendon or nerve?

Weakness lifting the arm, even light objects above chest height, usually comes from a torn tendon or from pain inhibiting the muscles. It is a mechanical weakness, not a nerve problem. However, a pinched nerve in the neck (cervical radiculopathy) and, less often, entrapment of the suprascapular nerve can also cause shoulder weakness. Clues pointing to a nerve include neck pain, tingling or numbness down the arm, and muscle wasting. Doctors use examination, nerve studies and imaging to tell them apart.

Rotator cuff injury vs frozen shoulder

In frozen shoulder, the shoulder is stiff in all directions, and no one can move it further, even passively. In rotator cuff injury, someone else can usually lift your arm further than you can yourself.

Diagnosis

A doctor examines shoulder movement and strength in specific directions and performs tests such as the empty can test, drop arm test and impingement signs. They also examine the neck.

• X-ray: for bone spurs, arthritis and the position of the humeral head.
• Ultrasound: accurate for tears, quick and inexpensive.
• MRI: shows tears, tendon retraction and muscle quality, helpful for surgical planning.

Treatment

Non-surgical (first-line for most)

• Relative rest: avoid painful overhead activity; do not immobilize the shoulder completely.
• Ice or heat for pain.
• Pain relievers: acetaminophen (paracetamol) or NSAIDs such as ibuprofen. Follow the label dose; avoid NSAIDs if you have kidney problems, stomach ulcers or take blood thinners unless your doctor agrees.
• Physical therapy: the cornerstone. Programs restore movement, then strengthen the rotator cuff and shoulder blade muscles, and correct posture and technique. Many people improve within 6 to 12 weeks.
• Steroid injection into the subacromial space can relieve pain to allow therapy, but repeated injections may weaken tendons.

Surgery

Surgery may be recommended for:

• acute traumatic tears in active people, ideally repaired within weeks
• full-thickness tears with persistent pain and weakness after 3 to 6 months of therapy
• younger people with significant tears

Options include arthroscopic (keyhole) tendon repair, removal of bone spurs, and for massive irreparable tears, tendon transfers, superior capsule reconstruction or reverse shoulder replacement. Recovery takes 4 to 6 months or longer, with a sling for about 4 to 6 weeks and staged rehabilitation.

Preventing rotator cuff problems

• strengthen rotator cuff and shoulder blade muscles regularly
• warm up before sports and use correct technique
• take breaks from repetitive overhead work
• maintain good posture, avoiding a rounded shoulders position
• do not smoke

Frequently asked questions

How do I know if I tore my rotator cuff?

Signs include pain lifting the arm, night pain, weakness and difficulty reaching overhead or behind your back. A sudden injury followed by inability to lift the arm suggests a tear. Ultrasound or MRI confirms it.

Can a rotator cuff injury cause weakness, like not being able to lift light objects?

Yes. A rotator cuff tear can make it hard to lift even light objects above chest height because the tendon cannot hold the ball in the socket, or because pain inhibits the muscles. If you also have neck pain, numbness or tingling, a pinched nerve should be considered.

Can a rotator cuff tear heal without surgery?

Torn tendons do not fully heal on their own, but many people, especially older adults with degenerative tears, regain good function and pain relief with physical therapy. Surgery is considered for acute tears in active people or when therapy fails.

How long does a rotator cuff injury take to heal?

Tendinitis often improves in 6 to 12 weeks with therapy. Recovery after surgical repair usually takes 4 to 6 months, and full strength can take up to a year.

What is the difference between rotator cuff tendinitis and a tear?

Tendinitis is irritation or degeneration of the tendon, causing pain but usually preserved strength. A tear is a partial or complete break in the tendon, often with more weakness. Both can cause similar pain, so imaging helps distinguish them.