Rotator Cuff Tears — Overview

Rotator cuff tears are among the most common causes of shoulder pain and disability in adults. They encompass a spectrum from partial-thickness tears to massive irreparable tears with secondary cuff tear arthropathy. Understanding the anatomy, pathophysiology, and current evidence-based management is essential for both the general orthopaedic surgeon and the shoulder specialist.

• Prevalence increases significantly with age — approximately 20% in the fifth decade, rising to over 50% by the eighth decade
• Many tears are asymptomatic — prevalence of asymptomatic tears mirrors that of symptomatic tears in population studies
• Supraspinatus is the most commonly torn tendon, followed by infraspinatus, then subscapularis
• Bilateral involvement occurs in up to 35% of cases — contralateral shoulder should always be assessed
• Risk factors: age, repetitive overhead activity, smoking, hyperlipidaemia, diabetes mellitus, dominant arm, and prior corticosteroid injections
• Tear progression: approximately 40% of partial tears progress to full-thickness tears over 5 years if untreated

The rotator cuff is formed by four muscles — supraspinatus, infraspinatus, teres minor, and subscapularis — which collectively provide dynamic stabilisation of the glenohumeral joint and act as force couples with the deltoid.

• Supraspinatus: initiates abduction; inserts on superior facet of greater tuberosity; most vulnerable to impingement between acromion and humeral head
• Infraspinatus & Teres Minor: external rotation; insert on middle and inferior facets of greater tuberosity; critical for posterior force couple
• Subscapularis: internal rotation; inserts on lesser tuberosity; tears often missed — check for increased external rotation and lift-off sign
• The rotator cable (thickened band of coracohumeral ligament running perpendicular to tendon fibres) redistributes load — a crescent tear within the cable may remain mechanically compensated
• Critical shoulder angle (CSA): angle between glenoid inclination and acromion tip on AP radiograph — CSA >35° associated with higher cuff tear rate; CSA <30° associated with glenohumeral OA
• Superior migration of humeral head occurs when the deltoid-cuff force couple is disrupted — leads to acromial erosion and eventual cuff tear arthropathy

Tears are classified by thickness, size, and chronicity. Several systems exist; the most clinically useful are summarised below.

Goutallier Classification (fatty infiltration on CT or MRI axial cuts, transposed to MRI by Fuchs):

Patte Classification grades retraction of the torn tendon (Stage 1: tendon at footprint; Stage 2: retracted to humeral head level; Stage 3: retracted to glenoid), which directly influences reparability and tendon tension at repair.

A focused clinical assessment distinguishes rotator cuff pathology from other causes of shoulder pain such as glenohumeral OA, AC joint pathology, cervical radiculopathy, and adhesive capsulitis.

• History: onset (acute traumatic vs insidious degenerative), dominant arm, occupation, overhead activity, prior injections, night pain, weakness vs pain-limited weakness
• Inspection: deltoid wasting, supraspinatus/infraspinatus fossa wasting, scapular dyskinesia
• Impingement tests: Neer sign, Hawkins-Kennedy — sensitive but not specific for cuff pathology

• Plain radiographs (AP, outlet, axillary): assess for subacromial narrowing (<7 mm suspicious), acromial morphology (Bigliani Type III hooked), acromioclavicular OA, calcific tendinopathy, superior humeral head migration, cuff tear arthropathy (Hamada classification)
• Ultrasound (USS): operator-dependent; high sensitivity and specificity for full-thickness tears (95% and 96% respectively); excellent for dynamic assessment and guided injection; less reliable for partial tears and subscapularis
• MRI (preferred): gold standard — assesses tear size, retraction (Patte), muscle bulk, and fatty infiltration (Goutallier); gadolinium arthrogram improves partial tear detection
• CT arthrogram: useful when MRI contraindicated; reliable for tear characterisation and bone assessment
• Critical Shoulder Angle (CSA): measure on true AP — calculated as angle between line along glenoid surface and line from inferior glenoid to acromion tip; CSA >35° is an independent predictor of cuff tear progression

Non-operative management is the first-line treatment for most rotator cuff tears, particularly in older patients with degenerative tears, low functional demands, and minimal fatty infiltration.

• Structured physiotherapy: rotator cuff strengthening, periscapular stabilisation, posterior capsule stretching — minimum 3–6 months before considering surgery in non-acute tears
• Subacromial corticosteroid injection: provides short-term pain relief (6–12 weeks); does not improve long-term outcomes; repeated injections may impair tendon healing — limit to 2–3 per year
• NSAIDs: adjunct analgesia; limited evidence for tendon healing benefit
• Platelet-rich plasma (PRP): emerging evidence; some RCTs show benefit for partial tears — not yet standard of care
• MOON Shoulder Group data (Kuhn et al., 2013): 75% of patients with symptomatic full-thickness tears improved with non-operative management over 2 years; 25% required surgery — baseline predictors of failure include younger age, traumatic onset, and pseudoparalysis

Surgical repair is indicated when non-operative management fails, in acute traumatic tears in younger patients, or when there is progressive weakness, pseudoparalysis, or large/massive tears with good tissue quality.

Indications for Surgery:

• Failure of 3–6 months structured non-operative treatment
• Acute traumatic full-thickness tear in a patient under 60 years — early repair (within 3 months) gives superior outcomes
• Pseudoparalysis (inability to actively elevate arm) with repairable tear
• Large or massive tear with good tissue quality (Goutallier 0–2) in active patients
• Partial-thickness tear >50% tendon depth failing conservative treatment

Surgical Techniques:

• Arthroscopic repair: now standard of care — equivalent or superior outcomes to open repair; lower infection rate, faster rehabilitation, preserves deltoid
• Single-row vs double-row repair: double-row increases footprint contact area and initial fixation strength — most RCTs show no significant clinical outcome difference for small/medium tears; benefit more apparent in large tears
• Suture bridge (transosseous equivalent): provides maximal footprint coverage with medial row anchors and lateral row compression — reduces gap formation
• Acromioplasty: no longer routinely performed — evidence does not support improved outcomes when added to repair for non-outlet impingement
• Biologic augmentation: patch augmentation with dermal allograft or xenograft for high-risk repairs — emerging evidence; not yet routine

Re-tear rates following repair:

• Small tears: ~10–15%; large/massive tears: ~20–50%
• Re-tear does not necessarily correlate with poor clinical outcome — a structurally failed repair can still be clinically successful (scar tissue provides some function)
• Predictors of re-tear: advanced age, large tear size, Goutallier grade ≥3, diabetes, smoking

Massive irreparable tears (Goutallier ≥3, Patte Stage 3, >5 cm, involving ≥2 tendons) require alternative surgical strategies when primary repair is not feasible.

• Subscapularis tears are frequently underdiagnosed — always assess with bear hug, belly press, and lift-off; review MRI axial sequences specifically for upper subscapularis tears which can be subtle
• Pseudoparalysis vs pseudoparesis: pseudoparalysis = complete inability to actively elevate (<30°), usually from massive tear disrupting deltoid-cuff couple; pseudoparesis = pain-limited elevation — important distinction as pseudoparalysis may indicate surgical urgency
• Critical shoulder angle: measure on every shoulder plain film — CSA >35° is an independent risk factor for cuff tear; CSA <30° predicts glenohumeral OA; guides acromioplasty decision
• Hamada classification for cuff tear arthropathy: Stage 1 (acromiohumeral interval >6 mm) → Stage 5 (glenohumeral OA with acetabularisation) — guides arthroplasty planning
• Timing of repair in acute tears: retraction and fatty infiltration progress within weeks of acute tear — early repair within 6–8 weeks in young active patients with acute large tears is strongly recommended
• Lower trapezius transfer (Hartzler/Elhassan technique) is emerging as preferred option over latissimus dorsi for posterosuperior irreparable tears — better anatomical alignment as an external rotator, lower donor site morbidity
• SCR controversy: original Mihata results excellent; Western studies show more variable outcomes — likely relates to graft tensioning, size, and patient selection; dermal allograft performs better than fascia lata autograft in most series
• Biologics: PRP augmentation at repair site shows some promise in improving healing rates in meta-analyses, particularly for large tears — leukocyte-poor PRP may be superior; not yet standard of care but reasonable adjunct

• Goutallier grade ≥3 = poor prognosis for repair — consider alternative strategies
• Supraspinatus most commonly torn; subscapularis most commonly missed clinically
• Rotator cable: tears within the crescent may be mechanically compensated; tears involving the cable lead to greater functional loss
• Drop arm sign = massive cuff tear until proven otherwise
• External rotation lag sign = large posterosuperior tear (infraspinatus/teres minor)
• CSA >35° = high cuff tear risk; CSA <30° = high glenohumeral OA risk
• Re-tear after repair does not always equal poor clinical outcome — scar tissue can provide functional improvement
• Reverse shoulder arthroplasty is the gold standard for cuff tear arthropathy — deltoid powers elevation without rotator cuff
• Acromioplasty is no longer routinely recommended at time of cuff repair based on current evidence
• Acute traumatic full-thickness tear in patient under 60 — operate early (within 3 months); delay worsens fatty infiltration and outcomes