Acute Rotator Cuff Tear ✅

Related Subjects: |Sprained Ankle |Achilles Tendon rupture |Acute Rotator Cuff Tear |Supraspinatus tendonitis

💪 An acute rotator cuff tear is disruption of one or more rotator cuff tendons, most often supraspinatus, but sometimes infraspinatus or subscapularis. Think of it when there is new pain plus objective weakness after trauma, heavy lifting, sudden traction, or shoulder dislocation.

📖 About

• The rotator cuff stabilises the humeral head and enables controlled shoulder movement.
• The four muscles are SITS: supraspinatus, infraspinatus, teres minor and subscapularis.
• Tears may be partial-thickness or full-thickness, and may involve one or multiple tendons.
• Acute tears are clinically important because early diagnosis can affect repairability and functional outcome.

📍 Tendon Involved

⚙️ Typical Mechanisms

• ⚡ Spontaneous rupture of a degenerative tendon under sudden stress, common in older adults.
• 🏋️‍♂️ Wrenching injury, sudden traction, fall onto an outstretched hand, or heavy lifting in younger/active patients.
• 🦴 After anterior shoulder dislocation, especially in patients over 40–60 years.
• 🔁 Acute-on-chronic tear: trauma unmasks a previously degenerative cuff.

🧩 Clinical Features

• Sudden shoulder pain after injury or loading.
• Difficulty lifting the arm above shoulder height.
• Night pain and inability to lie on the affected side.
• Painful arc, typically between 60–120° abduction.
• Objective weakness, especially abduction or external rotation.
• Passive range of movement may be relatively preserved compared with active movement.
• Pseudoparalysis: inability to actively elevate the arm despite preserved passive movement suggests a large tear.

🧪 Examination Tests

🖼️ Imaging — When Needed

📌 Imaging is not needed for every painful shoulder. It is most useful when there has been trauma, dislocation, marked weakness, suspected full-thickness tear, failed conservative treatment, or possible surgical referral.

🚩 When to Suspect a Clinically Significant Tear

• Marked weakness after a clear traumatic event.
• Inability to actively abduct/elevate the arm despite preserved passive movement.
• Persistent external rotation weakness or positive external rotation lag sign.
• Weakness after anterior shoulder dislocation, especially age over 40–60 years.
• Young or active patient with acute loss of function.
• Night pain plus objective weakness not improving over 1–2 weeks.

🏥 ED / MIU / UCC Management

• Assess pain, mechanism, deformity, range of movement and neurovascular status.
• If trauma/dislocation suspected, arrange plain X-ray.
• Provide analgesia: paracetamol ± NSAID if appropriate; consider short course stronger analgesia if severe.
• Use a broad arm sling initially for comfort, but avoid unnecessary prolonged immobilisation.
• Encourage early gentle active mobilisation within pain limits once fracture/dislocation has been excluded.
• Give pendular exercises and advice to avoid heavy lifting until reviewed.
• Safety-net for worsening pain, numbness, vascular symptoms, fever, increasing weakness or inability to function.

📅 Follow-Up / Referral

⚠️ Pitfalls & Complications

• Do not dismiss profound weakness as “just pain” after trauma.
• Missed acute full-thickness tears in younger active patients may become harder to repair if referral is delayed.
• After anterior shoulder dislocation in older adults, persistent weakness may be due to rotator cuff tear, axillary nerve injury, or both.
• Delayed mobilisation can contribute to adhesive capsulitis, especially in diabetes.
• Degenerative tears are common on imaging, including in asymptomatic older adults, so correlate imaging with symptoms and function.

💡 Revision Pearls

• 🌟 Classic clue = painful arc plus objective weakness on resisted abduction or external rotation.
• 🧪 USS is quick and common first-line cuff imaging; MRI is better for surgical planning or complex injury.
• 🦴 X-ray first after trauma/dislocation to exclude fracture or persistent dislocation.
• 🚨 Young active patient + acute weakness = early imaging and urgent shoulder referral.
• 👵 Older patient after dislocation + persistent weakness = think rotator cuff tear.

📚 References

• British Elbow and Shoulder Society / BOA: traumatic anterior shoulder instability pathway.
• NHS England Evidence-Based Interventions: shoulder imaging should be requested only when it will change management or is part of an agreed pathway.
• BMJ Best Practice: rotator cuff injury — diagnosis and treatment.