6 Differences Between Frozen Shoulder and Rotator Cuff Tear That Change Treatment

Shoulder pain that stops you reaching a shelf or sleeping on one side gets a single label in most people's minds: something is wrong with the shoulder. But two of the most common causes, frozen shoulder and a rotator cuff tear, behave differently, respond to different treatments, and get worse with the wrong approach. The six distinctions below are the clinical ones that actually change what a doctor or physiotherapist does next.

Frozen shoulder, formally called adhesive capsulitis, tends to arrive without a clear trigger. The pain builds gradually over weeks, often beginning at night and without any fall, strain, or heavy lift to explain it. A rotator cuff tear usually has a story: a sudden wrench while catching something heavy, a fall on an outstretched arm, or years of overhead work that finally gave way. Acute tears have a precise moment. Degenerative tears in older adults can creep in slowly, but most people can point to a period of specific overuse rather than a blank.

In frozen shoulder, all directions of movement shrink. Reaching forward, lifting to the side, rotating the arm outward, rotating it behind the back, all of them become limited, and the limitation is roughly equal in active movement (what you do yourself) and passive movement (what someone else can move your arm through). This global restriction is the defining clinical feature. A rotator cuff tear restricts movement differently. Passive range, what a physiotherapist can move the arm through, is often preserved or only mildly reduced, while active movement, particularly lifting the arm out to the side against gravity, drops sharply. The shoulder can be moved; it simply cannot generate the force to move itself.

Frozen shoulder is primarily a stiffness problem. The joint capsule thickens and tightens, reducing the space the joint has to move through. Weakness, when present, is secondary, the muscles are not being used through their range and lose conditioning. A rotator cuff tear is primarily a strength and control problem. The tendons that stabilise and power the shoulder are partially or fully disrupted. A person with a significant tear often cannot hold the arm in certain positions against even light resistance, and specific tests, the empty-can test for the supraspinatus, the external rotation lag sign, isolate which part of the cuff is involved. Stiffness does not explain a positive lag sign. Weakness does not explain a globally frozen joint.

An X-ray rarely diagnoses either condition directly, but it rules out other causes such as arthritis or a fracture. Frozen shoulder is largely a clinical diagnosis: imaging is used to exclude other problems rather than to confirm the diagnosis. MRI changes in frozen shoulder, thickening of the joint capsule, reduced joint volume, are present but not always necessary to act on. A rotator cuff tear, particularly a full-thickness tear, is reliably visible on MRI or ultrasound. The size of the tear, which tendons are involved, and whether the muscle has begun to atrophy all show on imaging and directly shape the treatment decision. A partial tear managed conservatively is a different conversation from a complete supraspinatus tear in a working-age adult.

Frozen shoulder moves through three recognised stages: a painful freezing phase, a frozen phase where pain reduces but stiffness remains, and a thawing phase where range slowly returns. Physiotherapy in the freezing phase focuses on pain management and gentle range preservation, not aggressive stretching, which makes the inflammation worse. In the thawing phase, progressive stretching and capsular mobilisation are appropriate. The condition is self-limiting in most people, though it can take one to three years to fully resolve. A rotator cuff tear does not follow this arc. Physiotherapy for a partial tear focuses on strengthening the intact parts of the cuff to compensate and offload the damaged tendon. For a complete tear, physiotherapy may be tried first, but if strength and function do not recover, surgical repair becomes the realistic option, particularly in younger patients or those with a traumatic full-thickness tear. Stretching a frozen shoulder aggressively delays recovery. Stretching a rotator cuff tear without addressing the underlying structural damage achieves little.

Corticosteroid injections into the shoulder joint reduce inflammation and are effective in the early painful phase of frozen shoulder, buying time for the joint to move through its natural course. Hydrodilatation, injecting fluid into the joint capsule to stretch it, is a recognised option when the frozen phase is prolonged. Surgery for frozen shoulder, arthroscopic capsular release, is reserved for cases that do not resolve after 12 to 18 months of conservative management. For a rotator cuff tear, a corticosteroid injection may reduce pain enough to allow physiotherapy, but it does not repair tendon tissue. A full-thickness tear in a younger patient, or a tear that fails conservative treatment, typically requires surgical repair, either open or arthroscopic, followed by a structured rehabilitation programme that runs four to six months. The injection that helps a frozen shoulder is a temporary measure. The injection that helps a rotator cuff tear is a bridge to physiotherapy, not a treatment in itself. Knowing which condition is present determines whether the injection is the main tool or just the first step.