Summary

Rotator cuff tendinopathy encompasses a spectrum of pathology affecting the four rotator cuff tendons, ranging from acute tendonitis and subacromial bursitis to tendonosis (degeneration) and partial or full-thickness tears. It is the most common cause of shoulder pain in adults, characterized clinically by a "painful arc" of abduction and pain with overhead activities. The supraspinatus tendon is most frequently affected due to its vascular "critical zone" and anatomical position under the coracoacromial arch.

Key Facts

• Definition: Pathology of the rotator cuff tendons (SITS muscles) causing pain and dysfunction.
• Prevalence: Affects up to 30% of adults over 60; 3rd most common musculoskeletal complaint.
• Mortality/Morbidity: Significant morbidity (pain, sleep disturbance, work loss); no mortality.
• Key Management: First-line is physical therapy and activity modification (effective in 70-80%).
• Critical Threshold: Acute traumatic tears in young active patients require early surgical consideration.
• Key investigation: Ultrasound or MRI are diagnostic gold standards.

Clinical Pearls

The "Painful Arc": Classically, pain is worst between 60° and 120° of active abduction. This is where the tuberosity passes under the acromial arch, maximally compressing the inflamed tissues.

Night Pain: A hallmark of rotator cuff pathology is pain when lying on the affected side or a dull ache that wakes the patient at night. This correlates with bursitis and severe tendonosis.

Stiffness vs. Weakness: Differentiating true weakness (tear/neuropraxia) from pain-inhibition is crucial. Injecting local anesthetic (Impringement Test) can help—if strength returns when pain is gone, the cuff is likely intact.

Why This Matters Clinically

Shoulder pain is a leading cause of disability and sick leave. Misdiagnosis is common; distinguishing rotator cuff disease from frozen shoulder (adhesive capsulitis) or cervical radiculopathy is essential because the management pathways are completely different (active rehab vs. rest/surgery).

Structured Approach

General:

• Look: Wasting (shoulders from back), Winging, Swelling.
• Feel: AC Joint, Biceps tendon, Greater tuberosity.
• Move: Passive vs Active ROM. (Passive is full, Active is limited by pain/weakness).

Special Tests Profile

Natural History

• Partial Tears: Can heal or remain stable, but often progress to full tears over years.
• Full Thickness Tears: Do NOT heal spontaneously. Usually enlarge over time.
• Symptoms: 50% of asymptomatic tears become symptomatic within 3 years.

Outcomes with Treatment

Prognostic Factors

Good Prognosis:

• Small tear <1cm.
• Acute onset (better healing potential).
• Compliance with rehab.

Poor Prognosis:

• Smoking / Diabetes.
• Massive tear >3cm.
• Fatty atrophy of muscle (Goutallier stage 3/4) - Irreversible.
• Workmen's compensation claims (statistically poorer outcomes).

Key Guidelines

1. AAOS (American Academy of Orthopaedic Surgeons) 2019 — Management of Rotator Cuff Injuries. Strong evidence for physio; Weak evidence for PRP.
2. BESS (British Elbow & Shoulder Society) — Subacromial Shoulder Pain. Recommends exercise over surgery for isolated impingement.

Landmark Trials

CSAW Trial (Can Shoulder Arthroscopy Work?) (2018)

• Finding: Decompression surgery (SAD) was no better than placebo surgery or physiotherapy for simple impingement pain.
• Clinical Impact: Massive reduction in "bone shaving" surgeries; push for physio-first approach.

UKUFF Trial (2015)

• Finding: Open vs Arthroscopic repair had similar clinical outcomes, but arthroscopic had less pain/better cosmesis.
• Clinical Impact: Standardised arthroscopic approach.

Evidence Strength

What is the Rotator Cuff?

Imagine your shoulder is a golf ball sitting on a tee. The "rotator cuff" is a group of four small muscles that act like a sleeve, holding the ball firmly on the tee while the big muscles (like the deltoid) move the arm.

What is Tendinopathy?

It means the tendons of these muscles are worn, irritated, or torn. Think of it like a rope that is fraying. It often happens because the tendon gets pinched between the arm bone and the shoulder blade roof (impingement) when you lift your arm.

How is it treated?

Surgery is usually NOT the first step.

1. Rest & Move: Avoid heavy lifting, but keep the shoulder moving gently so it doesn't seize up.
2. Stronger Muscles: Physiotherapy is the most important treatment. By strengthening the other muscles, you make more space for the tendon to move without pinching.
3. Injections: A steroid shot can calm the inflammation down enough to let you do the exercises.

What to expect

• Shoulders are slow to heal. Expect 3-6 months of rehab.
• Night pain usually improves first.
• If you have a massive tear or an injury from an accident, surgery might be needed to stitch the tendon back.

When to seek help

• If you cannot lift your arm at all (drop arm).
• If you had a fall and now have weakness.
• If the pain wakes you up every single night despite painkillers.