Rotator-cuff disease and impingement

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

History should define mechanism, speed of onset and the lost task. Ask about overhead work, throwing, heavy lifting, sleep on the affected side, dressing, hair care and reach behind the back. Immediate weakness after a fall differs from gradual activity pain. Record diabetes, smoking, dyslipidaemia, previous dislocation, neck symptoms, cancer history and systemic illness. Ask whether pain travels below the elbow or changes with neck, breathing or exertion. These details prevent a broad label of impingement from obscuring trauma, neurological disease or visceral referral.

Inspect for wasting, asymmetry and scapular dyskinesis. Examine the cervical spine and distal neurology, then compare active with passive movement. With preserved passive range, assess resisted abduction, external rotation and internal rotation, looking for pain and reproducible weakness. A painful arc can support a subacromial pattern but is not a stand-alone diagnosis. Recheck apparent weakness after suitable analgesia or altered test position because pain inhibition is common. Deltoid function and axillary sensation are essential after trauma or dislocation.

The language matters. Many people have more than one symptomatic tissue, and age-related bursitis, acromial shape or cuff defects may be incidental. Explain rotator-cuff-related or subacromial pain as a load-capacity problem rather than guaranteed mechanical trapping. This encourages graded use rather than fear and avoids promising that removal of a spur will solve pain. A scan should answer a management question, not merely provide an anatomical label.

Rehabilitation begins with tolerable range and isometric or low-load activation, then progresses external rotation, scaption, rowing, scapular control and the actual occupational or sporting task. Dose by technique, pain during exercise and the next-day response. Complete rest reduces capacity; equally, repeatedly provoking severe night pain can prevent progression. Agree a measurable baseline such as active elevation, ability to lift a known weight, sleep or work duty and reassess it at six to twelve weeks.

Medication is an adjunct. A topical NSAID can be tried when suitable; an oral NSAID requires ulcer, kidney, cardiovascular, anticoagulant and pregnancy review and should be time limited. A correctly targeted subacromial corticosteroid injection may reduce short-term pain enough to participate in exercise. Discuss transient flare, hyperglycaemia, skin change, rare infection and uncertain tendon effect. Lack of benefit should trigger diagnostic reconsideration rather than serial injections.

Ultrasound can define tendon continuity dynamically and is often sufficient for a focused cuff question, but operator dependence and incidental abnormalities require correlation. MRI adds muscle quality, retraction, marrow and broader joint anatomy when surgery or a complex alternative is being considered. Neither is the first test in routine atraumatic cuff pain. In an older adult after trauma, however, preserved passive range with persistent true weakness is a different scenario: early imaging and specialist review protect the option of timely repair.

Surgery is not the default consequence of a tear. Decisions incorporate trauma, symptom duration, functional demand, tear size, retraction, muscle quality, arthritis, comorbidity and the person's goals. Persistent subacromial pain without a repairable tear should not be offered decompression as though acromial contact alone explains symptoms. For selected symptomatic tears that fail non-operative care, specialist discussion may include repair, debridement, biceps procedures or, in cuff-tear arthropathy, arthroplasty.

Older adults need strength and falls assessment rather than age-based exclusion. Anticoagulation changes injection and operative bleeding planning but must not be stopped casually. During pregnancy, prioritise exercise and non-drug measures, use analgesia compatible with gestation and avoid systemic NSAIDs from 20 weeks unless specifically necessary, with avoidance in the final trimester. Diabetes increases cuff disease and post-injection hyperglycaemia; agree glucose monitoring and avoid injection when infection is possible.

Key points

Cuff-related pain usually causes lateral upper-arm pain with overhead reach or lying on that side; active movement is painful or weak while passive glenohumeral range remains comparatively preserved.
Compare active and passive elevation, external rotation and internal rotation before provocative tests; no single painful-arc, Hawkins or empty-can manoeuvre proves one anatomical lesion.
True weakness that persists after analgesia, external-rotation lag, drop-arm behaviour or immediate loss after trauma raises the likelihood of a large or full-thickness tear.
First-line investigation for an uncomplicated atraumatic presentation is a structured clinical assessment; routine ultrasound or MRI does not improve initial conservative care.
Use radiographs after trauma or with marked stiffness, and request ultrasound or MRI only when the answer will alter referral, repair planning or evaluation of an alternative diagnosis.
First-line management is explanation, short-term modification of provocative load and a progressive exercise programme for cuff, scapular and functional capacity, usually reviewed over at least six to twelve weeks.
A single targeted subacromial corticosteroid injection may create short-term analgesia for rehabilitation, but it is not tendon repair and should not become an automatic repeated series.
Expedite shoulder review after acute traumatic functional loss; consider elective referral for persistent disability, objective weakness or diagnostic uncertainty after a well-supported rehabilitation course.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Age-related tendon change

Collagen disorganisation, reduced vascular response and cumulative loading make supraspinatus and neighbouring tendons less tolerant of demand; structural tears become common with age and may remain asymptomatic.

Load and movement exposure

Abrupt increases in overhead work, throwing, lifting or unaccustomed exercise can exceed current cuff and scapular capacity without requiring acromial abrasion as the sole explanation.

Traumatic failure

A fall, forced abduction or dislocation may rupture previously healthy or degenerative tendon, especially when the patient reports an immediate functional step-down rather than gradual soreness.

Biological modifiers

Smoking, diabetes, dyslipidaemia, obesity and previous shoulder injury are associated with poorer tendon quality, while prolonged unloading reduces muscle capacity and confidence.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Tendon load mismatch
Repeated tensile and compressive stress beyond recovery capacity alters tendon matrix and nociceptive signalling, producing pain that need not track the extent of imaging abnormality.
2
Force-couple disruption
Subscapularis, infraspinatus and teres minor balance deltoid pull to centre the humeral head; pain inhibition or a large tear weakens this dynamic control during elevation.
3
Subacromial pain generation
The cuff, bursa and adjacent tissues share a mechanically sensitive region, so the clinical syndrome is better understood as subacromial or cuff-related pain than a single structure being pinched.
4
Chronic tear progression
Some full-thickness defects enlarge with retraction, muscle atrophy and fatty infiltration, changes that can reduce repairability even though many degenerative tears remain stable or manageable without surgery.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Cuff-related pain pattern

Lateral deltoid-region pain during overhead reach, resisted abduction or external rotation, often worse at night on that side, occurs with substantially retained passive range.

Painful arc

Pain during mid-range active abduction that eases beyond the arc supports subacromial sensitivity but is neither sufficiently specific nor sensitive to stand alone.

Clinically important tear

Immediate post-traumatic functional loss, persistent external-rotation or abduction weakness and lag or drop signs are more concerning than pain alone.

Pain inhibition

Strength that improves when pain is reduced or the arm is positioned differently suggests inhibition; persistent deficit despite these measures deserves structural evaluation.

Referred presentation

A normal movement examination with exertional, pleuritic, cervical or constitutional features should prompt cardiac, pulmonary, neurological or malignant assessment.

Red flags requiring action

A sudden injury followed by inability to actively raise the arm despite preserved passive elevation suggests an acute substantial cuff tear and warrants expedited specialist assessment.
A hot swollen shoulder, fever, bacteraemic risk or severe pain with every small passive movement requires an emergency septic-joint pathway rather than injection.
Visible deformity, absent pulse, cool hand, delayed refill or new motor or sensory loss requires immediate fracture-dislocation and vascular assessment.
Unremitting night pain, weight loss, a mass, previous malignancy or pain not reproduced by shoulder movement requires investigation for tumour or referred disease.
Exertional chest pressure, breathlessness or diaphoresis must redirect assessment beyond the shoulder.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
First-line clinical localisationFirst stepFirst line
Why
Distinguish cuff-related pain from a stiff joint, acute tear, cervical lesion and urgent referred cause.
Interpretation and limitations
Preserved passive range with reproducible cuff pain supports the syndrome; true weakness, trauma or red flags changes the pathway immediately.
02
Plain radiographs
Why
Assess acute injury, marked passive restriction, prolonged atypical pain, calcific deposit or arthritis.
Interpretation and limitations
Use at least two orthogonal views after trauma; a normal image does not exclude tendon tear and an acromial spur does not establish causation.
03
Diagnostic ultrasound
Why
Answer a focused question about cuff continuity, biceps or bursal abnormality when the result will change referral.
Interpretation and limitations
Correlate side, symptoms, strength and tear dimensions because asymptomatic degenerative defects are frequent and accuracy is operator dependent.
04
MRI for complex or operative decisions
Why
Define tear retraction, muscle atrophy, fatty change, marrow and alternative intra-articular disease.
Interpretation and limitations
MRI is not routine first-line imaging; it becomes valuable for traumatic weakness, uncertain ultrasound or surgical planning.
05
Targeted blood and joint tests
Why
Investigate infection, inflammatory disease, polymyalgia or malignancy when clinical features suggest them.
Interpretation and limitations
Normal inflammatory markers cannot safely exclude an early septic joint; aspirate an accessible effusion urgently for culture and crystals when infection is suspected.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Adhesive capsulitis

Global restriction of both active and passive movement, particularly external rotation with the elbow at the side, favours capsular contracture over isolated cuff pain.

Glenohumeral osteoarthritis

Deep joint pain, crepitus and passive restriction can resemble a stiff painful cuff; radiographs demonstrate joint-space loss, osteophytes and subchondral change.

Cervical radiculopathy

Neck-provoked pain extending below the elbow, dermatomal sensory change, altered reflexes or myotomal weakness points to a cervical source rather than primary tendon disease.

Acromioclavicular disease

Focal superior tenderness and pain with cross-body adduction localise symptoms to the acromioclavicular joint instead of the lateral cuff region.

Calcific tendinopathy

Abrupt extreme atraumatic pain and guarding may occur during deposit resorption; a radiographic calcification supports the diagnosis only when its location matches symptoms.

Additional chapter-specific clues

Alternative stiff shoulder

Restriction of passive external rotation and elevation redirects assessment toward adhesive capsulitis, arthritis, fracture or joint infection.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01First-lineLocalise and begin active careFirst stepFirst lineAtraumatic cuff-pattern pain is present without substantial weakness, passive restriction or systemic red flags.

1Explain the load-capacity model and identify work, sleep and activity goals before attaching significance to imaging findings.
2Modify the most provocative load temporarily while maintaining general use and beginning progressive cuff and scapular exercise.
3Offer a short suitable analgesic strategy and provide return advice for fever, deformity, neurological change or sudden weakness.
4EscalationReview a measurable functional outcome after six to twelve weeks and check technique, adherence and competing diagnoses before escalation.

02Stepwise imagingAsk a question before ordering a scanTrauma, objective weakness, passive stiffness, atypical pain or failed supported rehabilitation makes anatomy actionable.

1Obtain orthogonal radiographs first after injury or when joint disease, calcification or tumour is plausible.
2Choose ultrasound for an isolated tendon-continuity question or MRI when retraction, muscle quality, marrow or multiple structures matter.
3Interpret the report alongside onset, side, strength and goals, recognising that a degenerative tear may not be the pain generator.
4Send imaging with a focused referral rather than repeating scans when the treatment decision is already clear.

03UrgentProtect a repairable traumatic tearA defined injury produces immediate loss of active elevation or persistent true external-rotation or abduction weakness.

1Exclude fracture and unreduced dislocation, provide analgesia and record active versus passive movement plus complete neurovascular status.
2Arrange expedited ultrasound or MRI according to the local acute shoulder pathway and contact an appropriate shoulder service.
3Do not require months of routine physiotherapy before the tear is characterised when delay may permit retraction and muscle change.
4Use a supported sling briefly for comfort only when needed, preserving elbow, wrist and hand movement while awaiting the plan.

04Persistent disabilityReassess before elective escalationEscalationPain, weakness or work limitation remains substantial after an adequate, adhered-to exercise programme.

1Re-examine passive range, cervical neurology, strength and the specific task that remains limited.
2Review whether one targeted injection would enable rehabilitation or whether imaging is now needed for a repair decision.
3Refer when a symptomatic tear, persistent objective deficit or diagnostic uncertainty requires specialist discussion.
4Continue active conditioning and safe analgesia while avoiding repeated passive procedures with no durable functional gain.

Key medicines and prescribing safety3 treatments · regimens, roles and cautions

Offers local pain reduction that may improve sleep and participation in graded loading without routine systemic exposure.

Topical diclofenac gel

For 1.16% diclofenac gel, apply 2–4 g to the painful lateral shoulder per application, repeating three or four times a day for a brief trial within the licensed daily maximum.

Avoid damaged skin and NSAID hypersensitivity, account for concurrent oral NSAIDs and systemic adverse effects, and seek pregnancy-specific advice; NSAIDs are contraindicated in the final trimester.

Provides brief systemic analgesia when topical treatment is inadequate and pain prevents useful movement or sleep.

Naproxen with gastroprotection when suitable

Use naproxen 250–500 mg orally twice daily with or after food for the shortest effective course; add omeprazole 20 mg orally once daily while treatment continues when gastroprotection is indicated.

Check peptic ulcer, kidney function, heart failure, hypertension, cardiovascular risk, frailty, anticoagulants and antiplatelets; avoid combined NSAIDs and apply MHRA pregnancy restrictions from 20 weeks.

Can reduce symptoms for a limited period when pain blocks rehabilitation; it does not heal a torn tendon.

Subacromial corticosteroid injection

Under a trained local injection protocol, give one accurately placed dose such as triamcinolone acetonide 20–40 mg into the subacromial bursa, then pair the analgesic window with a defined exercise progression.

Exclude skin, bursal or joint infection, use aseptic technique, review anticoagulation without unplanned interruption, warn about flare, skin atrophy and rare infection, and arrange glucose monitoring in diabetes.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Irreparable tear evolution

Delayed assessment of an acute large tear can permit retraction, atrophy and fatty replacement, narrowing later reconstructive options in a functionally demanding patient.

Secondary stiffness

Pain-driven immobility may create capsular restriction and extend disability even when tendon irritability begins to settle.

Cuff-tear arthropathy

Long-standing massive deficiency can allow superior humeral migration, altered joint mechanics and destructive glenohumeral arthritis with loss of elevation.

Treatment harm

Repeated injections can expose tendon, skin and glucose control to harm, while prolonged opioid or NSAID use adds systemic toxicity without rebuilding shoulder capacity.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Record active elevation, external-rotation strength, sleep disruption and one meaningful work or self-care task at baseline and each review.
Progress resistance according to movement quality and next-day response, not pain-free perfection during every repetition.
Revisit cervical, joint and referred causes if the pattern changes, passive range falls or rehabilitation produces no plausible trajectory.
For a documented tear, monitor functional strength and specialist decisions; new pseudoparalysis or rapid decline warrants faster review.
Review NSAID benefit and gastrointestinal, renal, cardiovascular and blood-pressure safety, stopping treatment when it no longer enables function.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Passive range separates pathways

A cuff can fail while the examiner still elevates the arm; fixed passive loss directs attention to capsule, cartilage, bone or infection.

Impingement is not a verbatim mechanism

Subacromial pain reflects several load-sensitive tissues and biological factors, so rehabilitation targets capacity rather than simply avoiding an imagined pinch.

Acute and degenerative tears differ

A chronic incidental tear may be managed non-operatively, whereas immediate weakness after trauma can be time sensitive even in an older tendon.

Repairability changes over time

Retraction and muscle fatty change can accumulate, which is why a suspected acute large tear should not wait through a routine prolonged pathway.

11Common pitfallsFrequent interpretation and management errors.

01
Calling any positive provocative manoeuvre impingement without comparing active and passive range or examining the neck.
02
Treating an age-related ultrasound tear as proof that surgery is necessary or that it explains all pain.
03
Requiring a long conservative trial after a traumatic onset with immediate and persistent true weakness.
04
Using complete rest, repeated injections or analgesic escalation without a progressive functional loading plan.
05
Injecting through infected skin or when septic arthritis has not been excluded.
06
Prescribing systemic NSAIDs without renal, gastrointestinal, cardiovascular and pregnancy review.