Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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A destructive or septic-appearing shoulder
A hot swollen shoulder with fever, systemic illness, recent surgery or injection, immunosuppression, bacteraemia risk or rapidly progressive loss of function must be treated as possible septic arthritis; major trauma, neurovascular compromise and acute cuff failure are additional emergencies.
Action: Arrange same-day hospital assessment, obtain blood cultures when febrile and aspirate an accessible effusion for cell count, Gram stain, culture and crystal assessment before antibiotics when safe; do not attribute the presentation to a visible calcium deposit or inject corticosteroid until infection has been reasonably excluded.
Synopsis
Recognise the different syndromes produced by basic calcium phosphate deposition, distinguish focal calcific periarthritis from infection and cuff disease, and use imaging, aspiration and staged conservative or procedural treatment safely.
Basic calcium phosphate includes hydroxyapatite and produces calcific tendinopathy, acute calcific periarthritis, destructive Milwaukee shoulder and crystal-associated osteoarthritis.
The usual presentation is severe focal shoulder pain from a resorbing rotator-cuff deposit, but deposits can be asymptomatic and may occur around other joints.
Routine polarised microscopy does not visualise basic calcium phosphate crystals; a negative crystal report therefore does not exclude the disorder.
Key red flags
Fever, rigors, hypotension, an acutely hot effusion or severe pain on passive movement requires urgent septic-arthritis assessment even when calcification is visible.
Milwaukee shoulder
An older person, often a woman, develops major painless or painful swelling, recurrent large haemorrhagic effusions, crepitus, instability and profound active-movement loss from cuff failure and rapid destruction.
Investigation priorities
01
Initial plain radiographFirst step
Confirm a peri-tendinous calcium deposit and assess bone, alignment and destructive change.
Management branches
First diagnostic stepMatch radiograph to phenotype
Focal atraumatic shoulder or periarticular pain suggests calcific disease without systemic instability.
Examine active and passive movement, cuff strength, focal tendon and bursal tenderness, neck and neurovascular status and sepsis or trauma features.
Request plain radiographs first and use ultrasound when the deposit, bursa or tendon must be localised or a tear or guided procedure is being considered.
First-line symptomatic careProtect briefly, then reload
A symptomatic deposit has no red flag or major tear and function can be managed conservatively.
Key medicines
Diclofenac 1.16% gelApply 2 to 4 g to the painful area three or four times daily, gently rubbing it in; use the smallest area and shortest duration needed and wash the hands afterwards unless they are treated.
NaproxenFor a severe inflammatory episode, a common off-label short course is 250 to 500 mg orally twice daily with food for 3 to 5 days, at the lowest effective dose; add a proton-pump inhibitor when gastrointestinal risk warrants it.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.