Adhesive Capsulitis (Frozen Shoulder) ✅

🧬 Pathophysiology (What’s actually happening?)

• Early disease involves synovial and capsular inflammation causing pain (often worse at night) and protective muscle spasm.
• Progression leads to capsular fibrosis and contracture, particularly affecting the rotator interval and coracohumeral ligament, reducing glenohumeral joint volume and causing a true mechanical restriction.
• Capsular pattern: external rotation is usually the most restricted movement, often followed by abduction and internal rotation.
• Diabetes association: people with diabetes have a substantially increased risk of frozen shoulder, and symptoms may be more prolonged, more severe, and more likely to affect both sides.

⏳ Natural history

Frozen shoulder is often described in painful (“freezing”), stiff (“frozen”), and recovery (“thawing”) phases, but in practice these stages overlap and are not always clearly separate.

🧠 Examination: what to look for

• Restriction of both active and passive ROM in a similar pattern is the key sign.
• External rotation is usually disproportionately reduced; compare both sides with elbows tucked in.
• Watch for scapulothoracic substitution (the patient hikes the scapula to fake glenohumeral movement).
• Focal tenderness over the greater tuberosity or marked weakness suggests rotator cuff pathology rather than pure adhesive capsulitis.
• Check the cervical spine, neurology, and distal upper limb because referred pain and radiculopathy can mimic shoulder pathology.

🚩 Red flags (do not miss these)

• Hot, red, acutely painful joint with fever or systemic upset → consider septic arthritis (same-day urgent assessment).
• Acute severe pain after trauma, deformity, or inability to move the arm → consider fracture or dislocation (urgent imaging/ED assessment).
• Unexplained mass, previous malignancy, constitutional symptoms, or unusual relentless pain → consider sinister pathology.
• True neurological deficit (motor weakness, sensory loss, wasting) → consider cervical/root/neurological pathology.
• Marked pain out of proportion with swelling, colour change, or allodynia after injury → consider CRPS.

🧩 Differentiating from look-alikes

• Rotator cuff tendinopathy/tear: painful arc and weakness; passive ROM is often relatively preserved early.
• Subacromial pain/impingement: pain with overhead activity; global passive restriction is less typical.
• Glenohumeral OA: older age, crepitus, stiffness, and radiographic degenerative change.
• Cervical radiculopathy: neck pain, paraesthesia, dermatomal symptoms, and pain reproduced by neck movement.

🧪 Investigations (UK practical approach)

• Frozen shoulder is usually a clinical diagnosis.
• X-ray is not routinely required in a classic presentation, but should be considered if there are atypical features, trauma, older age, severe restriction with diagnostic uncertainty, or failure to progress as expected.
• Blood tests are only needed if there are systemic features or concern about inflammatory arthritis, infection, or another diagnosis.
• Ultrasound or MRI are not routine in primary care; consider them if there is significant weakness suggesting rotator cuff tear, or ongoing diagnostic uncertainty.

🧭 Management: stage-based, primary care–friendly pathway

• Step 1: Explain + set expectations: recovery is often slow, and the aim of treatment is to improve pain and function rather than “force the shoulder free”.
• Step 2: Analgesia:
  • Paracetamol if appropriate.
  • Topical or oral NSAID if suitable, with gastroprotection where indicated.
  • Short course of stronger analgesia only if pain is preventing sleep or rehabilitation, with review.
• Step 3: Physiotherapy / home exercise:
  • Painful phase: gentle, pain-limited mobility; avoid aggressive stretching that flares symptoms.
  • Stiff/recovery phase: progressive stretching and strengthening guided by function.
• Step 4: Intra-articular corticosteroid injection:
  • Can be considered as part of non-operative treatment, especially for short-term symptom control when pain is prominent.
  • Often most useful earlier in the course when pain is limiting engagement with rehab.
  • Diabetes counselling: warn about transient hyperglycaemia after steroid injection and advise more frequent glucose monitoring if relevant.
• Step 5: Persistent limitation:
  • Hydrodilatation / hydrodistension can be considered in selected patients, usually alongside physiotherapy, but evidence continues to evolve.
  • Refer to MSK/orthopaedics if significant functional restriction persists despite a structured trial of conservative care, or if the diagnosis is uncertain.

🧘 Home exercise examples

• Pendulum swings: small circles with the arm relaxed.
• Table slides: slide the hand forwards on a table to gentle flexion.
• External rotation with stick: elbow tucked in, gentle outward rotation.
• Cross-body stretch: gentle posterior capsule stretch if tolerated.
• Rule of thumb: mild discomfort is acceptable; sharp pain that lingers suggests overloading.

🛠️ Procedural options

• Manipulation under anaesthesia (MUA): may improve range quickly, but carries risks including fracture, dislocation, and cuff injury.
• Arthroscopic capsular release: considered when prolonged symptoms and major functional restriction persist despite non-operative management.
• Choice is individual and depends on symptom severity, phase, diabetes, functional demands, and response to injection/rehabilitation.

🧑‍⚕️ When to refer

• Urgent / same-day: suspected infection, fracture, dislocation, or significant neurological deficit.
• Routine MSK/physio referral: suspected frozen shoulder causing functional impact.
• Specialist referral: persistent significant restriction despite structured conservative management, or diagnostic uncertainty.

🧠 Stroke/neurology link

• Post-stroke shoulder pain is often multifactorial: subluxation, spasticity, cuff pathology, CRPS, and secondary adhesive capsulitis may coexist.
• Prevention includes safe handling, arm support, positioning, and early guided range-of-movement work.
• If global passive restriction develops, treat as possible adhesive capsulitis with pain control and gentle ROM.

🧠 Extra Teaching Pearls

• External rotation is the canary: marked ER loss strongly suggests capsular contracture.
• Match treatment to the dominant problem: pain early, stiffness later.
• Steroid injection is not just analgesia; it can create a window for rehabilitation.

Case examples (continued)

• 🏃‍♂️ Case 4 – Age 44: Night pain, difficulty with bra fastening/back-pocket movements, and marked loss of external rotation with equal active/passive restriction. Diagnosis: Early adhesive capsulitis. Management: Education, analgesia, consider intra-articular steroid, then gentle physiotherapy. Teaching point: Injection is most useful when pain is the main barrier to movement and rehab.
• 🛌 Case 5 – Age 61: Nine months of progressive stiffness, less pain now, cannot reach overhead or wash hair; X-ray unremarkable. Diagnosis: Stiff-phase adhesive capsulitis. Management: Structured rehab; consider hydrodilatation or specialist review if progress stalls. Teaching point: Once stiffness dominates, recovery depends more on function-led rehabilitation than on analgesia alone.
• 🩸 Case 6 – Age 55: Type 1 diabetes, bilateral stiffness, poor sleep, and slow progress. Diagnosis: Diabetic-associated adhesive capsulitis. Management: Realistic timelines, glucose advice around steroid use, consider staged escalation if disability remains high. Teaching point: Diabetes is a major risk factor for more persistent and bilateral disease.

🌟 Mini-algorithm: Night pain + global passive restriction (especially ER) → exclude red flags and major alternative diagnoses → treat pain + begin gentle rehab → consider intra-articular steroid for short-term symptom control → progress exercises as stiffness becomes dominant → consider hydrodilatation or specialist referral if severe functional limitation persists.

📚 References

• NICE CKS – Shoulder pain: Frozen shoulder management
• NICE CKS – Shoulder pain: Diagnosis
• NICE CKS – Shoulder pain: Initial management and red flags
• British Elbow and Shoulder Society (BESS) patient care pathway: Frozen shoulder, 2025
• NHS – Frozen shoulder