Calcific Tendinitis of the Shoulder

Rotator cuff anatomy relevant to calcific tendinitis:

The supraspinatus tendon is most commonly affected (70-80% of cases), followed by infraspinatus (20%), teres minor, and subscapularis (rare).

The same crystal family - basic calcium phosphate (BCP), principally hydroxyapatite - that deposits reversibly in calcific tendinitis can, at the other extreme, drive a destructive arthropathy.

• Milwaukee shoulder is a BCP-crystal (hydroxyapatite) associated arthropathy seen typically in elderly women, characterised by a large, often blood-stained but non-inflammatory joint effusion, a massive rotator cuff tear and rapidly progressive glenohumeral destruction (cuff-tear arthropathy).
• BCP crystals are not birefringent under polarised light (unlike the negatively-birefringent urate of gout or the weakly-positively-birefringent CPPD of pseudogout), so they are easily missed - alizarin red staining or electron microscopy is needed to identify them.
• Management is largely supportive (analgesia, aspiration, activity modification); a reverse total shoulder arthroplasty is the reconstructive option for end-stage cuff-tear arthropathy, because the deficient cuff makes an anatomic replacement fail.

After barbotage:

• Sling for comfort only (24-48 hours)
• Ice, analgesia (NSAIDs)
• Resume normal activities as tolerated
• Physiotherapy for ROM and strengthening
• Review at 6-8 weeks with repeat imaging

After arthroscopic excision:

If rotator cuff repair performed:

• Standard cuff repair rehabilitation protocol
• No active elevation for 6 weeks
• Sling for 4-6 weeks

Prognostic Factors

Global epidemiology

• Radiographic calcific deposits are found in roughly 3-8% of adults, the majority asymptomatic.
• Peak incidence is in the 30-60 year age group, with a female predominance in most cohorts (around 60-65%).
• The supraspinatus is involved in the large majority of cases; bilateral disease occurs in roughly 10-20% and is a negative prognostic marker (Ogon et al, Arthritis Rheum 2009, PMID 19790063).
• Associations reported across populations include diabetes mellitus, thyroid disorders and a possible genetic/metabolic predisposition, although causation is unproven.

Registry and evidence notes

• Calcific tendinitis is a soft-tissue disorder, so it is not tracked by arthroplasty/implant registries (NJR, AJRR, AOANJRR). The strongest evidence base is from RCTs and meta-analyses rather than registries.
• Pooled RCT evidence (network meta-analysis, PMID 27554465) ranks US-guided needling plus subacromial corticosteroid as the preferred non-surgical option, with high-energy ESWT (PMID 14625334) a reasonable alternative.

High- vs limited-resource practice variation

• In well-resourced settings, ultrasound-guided barbotage and high-energy ESWT are widely available and used early for refractory deposits.
• Where musculoskeletal ultrasound or ESWT machines are scarce, management leans on plain radiographs, analgesia, physiotherapy, and image-free subacromial injection, reserving referral for arthroscopy in persistent cases.
• Across all settings the message is the same: counsel patients on the strongly self-limiting natural history before escalating to any intervention.