Rotator Cuff Tears

Rotator cuff tears are among the most common shoulder pathologies. They form a spectrum from the partial-thickness tear to the massive full-thickness defect involving several tendons, and they result from a combination of intrinsic tendon degeneration and extrinsic mechanical factors.

Who. Prevalence increases dramatically with age: tears are rare under 40 and common over 60. Many are asymptomatic, and up to 50% of individuals over 60 have a tear on imaging. Occupational and sports-related overhead activity increases the risk, and symptomatic tears often present with pain, weakness and functional limitation.

Why the cuff tears. The cause is multifactorial. Intrinsic factors lie in the tendon itself:

• Tendon degeneration - age-related collagen breakdown and decreased vascularity
• The hypovascular critical zone, 1cm medial to the insertion (see Anatomy)
• Genetics - a family history increases risk
• Smoking - impairs healing and increases tear size

Extrinsic factors act on it from outside:

• Subacromial impingement, with a type I (flat), II (curved) or III (hooked) acromion in Bigliani's classification
• Os acromiale, an unfused acromial apophysis causing impingement
• Trauma - acute on chronic, a fall on the outstretched hand
• Overuse - repetitive overhead activity in swimmers, painters and throwers

Natural history. Tear size tends to increase over time: in a randomised trial of tears up to 3cm treated with physiotherapy alone, 37% had enlarged by more than 5mm on ultrasound at 5 years, with an inferior outcome (Moosmayer 2014), and muscle atrophy and fatty infiltration progress alongside, often irreversibly. Functional deficits worsen as the tear progresses. Pain may nonetheless decrease over time even as the tear enlarges (the pseudoparalytic shoulder).

The cuff. Four muscles and their tendons arise from the scapula and insert on the humeral head, forming a circumferential cuff around the glenohumeral joint: supraspinatus superiorly, infraspinatus posterosuperiorly, teres minor posteroinferiorly and subscapularis anteriorly. The mnemonic is SITS, the cuff that sits on the humeral head and stabilises the glenohumeral joint. Supraspinatus is the most commonly torn tendon.

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The critical zone. Approximately 1cm medial to the supraspinatus insertion on the greater tuberosity lies a hypovascular area, the watershed between the osseous blood supply from the humeral circumflex arteries and the muscular supply from the suprascapular and thoracoacromial arteries. This critical zone is particularly prone to degeneration and tear formation. The arteries of the cuff are:

• Suprascapular artery - supraspinatus and infraspinatus
• Anterior humeral circumflex artery - anterior cuff and subscapularis
• Posterior humeral circumflex artery - posterior cuff
• Thoracoacromial artery - contributes to the anterior structures

The force couples. The cuff and the deltoid form force couples that stabilise the humeral head. In the coronal plane the deltoid elevates the arm and pulls the head superiorly, while infraspinatus, teres minor and subscapularis provide the opposing inferior force, compressing and depressing the head. In the transverse plane subscapularis anteriorly counterbalances infraspinatus and teres minor posteriorly.

A tear is described by four things: its size (Cofield), the depth of a partial tear (Ellman), the fatty infiltration of its muscle (Goutallier) and the retraction of its tendon (Patte). Size, muscle quality and retraction each carry a prognosis for repair.

Tear Size (Cofield)Partial vs Full-ThicknessFatty Infiltration (Goutallier)Retraction (Patte)

Cofield grades the tear by its maximum dimension in any plane.

Small

Dimension

Less than 1cm

Typical Repair

Single-row arthroscopic

Prognosis

Excellent healing

Medium

Dimension

1-3cm

Typical Repair

Double-row arthroscopic

Prognosis

Good healing potential

Large

Dimension

3-5cm

Typical Repair

Double-row with convergence

Prognosis

Guarded, longer rehab

Massive

Dimension

Greater than 5cm, or 2 or more complete tendons

Typical Repair

SCR or reverse TSA

Prognosis

Poor repair outcomes

Size	Dimension	Typical Repair	Prognosis
Small	Less than 1cm	Single-row arthroscopic	Excellent healing
Medium	1-3cm	Double-row arthroscopic	Good healing potential
Large	3-5cm	Double-row with convergence	Guarded, longer rehab
Massive	Greater than 5cm, or 2 or more complete tendons	SCR or reverse TSA	Poor repair outcomes

A massive tear is defined by either criterion, its size or the number of complete tendons involved. It has poor healing potential with standard repair and may require an alternative such as superior capsular reconstruction or reverse total shoulder arthroplasty.

Ellman classifies partial-thickness tears by location and by depth.

Articular-side

Description

Tear on undersurface (joint side)

Significance

Most common partial tear, often progresses

Bursal-side

Description

Tear on bursal surface

Significance

Associated with impingement

Intratendinous

Description

Within substance of tendon

Significance

Difficult to diagnose

Location	Description	Significance
Articular-side	Tear on undersurface (joint side)	Most common partial tear, often progresses
Bursal-side	Tear on bursal surface	Associated with impingement
Intratendinous	Within substance of tendon	Difficult to diagnose

• Grade 1: less than 3mm depth or less than 25% thickness
• Grade 2: 3-6mm depth or 25-50% thickness
• Grade 3: greater than 6mm depth or greater than 50% thickness

High-Grade Partial Tears

Partial tears greater than 50% thickness (Grade 3) have biomechanical properties similar to full-thickness tears and may benefit from repair, particularly if symptomatic after conservative management. The "50% rule" guides surgical decision-making.

Goutallier grades muscle quality on CT or MRI, and it is a critical prognostic indicator.

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0

Description

Normal muscle

Fat vs Muscle

No fat

Repair Prognosis

Excellent

1

Description

Some fatty streaks

Fat vs Muscle

Fatty streaks

Repair Prognosis

Good

2

Description

Moderate fatty infiltration

Fat vs Muscle

More muscle than fat

Repair Prognosis

Fair

3

Description

Advanced fatty change

Fat vs Muscle

Equal muscle and fat

Repair Prognosis

Poor

4

Description

Severe fatty degeneration

Fat vs Muscle

More fat than muscle

Repair Prognosis

Irreparable

Grade	Description	Fat vs Muscle	Repair Prognosis
0	Normal muscle	No fat	Excellent
1	Some fatty streaks	Fatty streaks	Good
2	Moderate fatty infiltration	More muscle than fat	Fair
3	Advanced fatty change	Equal muscle and fat	Poor
4	Severe fatty degeneration	More fat than muscle	Irreparable

Goutallier and Repair Outcomes

Goutallier Grade 3-4 fatty infiltration predicts poor outcomes with rotator cuff repair. Fatty change is largely irreversible even with successful tendon healing. These patients may be better candidates for conservative management, superior capsular reconstruction, or reverse total shoulder arthroplasty.

Patte stages the medial retraction of the torn tendon on coronal MRI.

Stage 1

Location of Tendon

Proximal stump close to its bony insertion (footprint)

Repairability

Easily repairable

Stage 2

Location of Tendon

Proximal stump at the level of the humeral head

Repairability

Repairable with mobilisation

Stage 3

Location of Tendon

Proximal stump at the level of the glenoid

Repairability

Difficult/irreparable

Stage	Location of Tendon	Repairability
Stage 1	Proximal stump close to its bony insertion (footprint)	Easily repairable
Stage 2	Proximal stump at the level of the humeral head	Repairable with mobilisation
Stage 3	Proximal stump at the level of the glenoid	Difficult/irreparable

The tangent sign is read on a sagittal MRI. It is positive when the supraspinatus muscle belly lies below the superior glenoid line, which means the muscle is atrophied. A positive sign indicates advanced muscle loss and is a poor prognostic indicator for repair.

History. Pain is anterolateral and often radiates to the deltoid insertion. Night pain is common, on lying on the shoulder, and disturbs sleep. The pain comes with overhead activity and with reaching behind the back. Establish whether the onset was acute and traumatic or insidious and degenerative.

Function. Weakness makes overhead activity and lifting difficult, and the patient struggles with tasks such as combing the hair or reaching for a wallet. Ask what the shoulder is costing them at work, in sport and in daily living.

Inspection and range. Look for wasting of the supraspinatus and infraspinatus fossae, asymmetry and scapular dyskinesis. Active motion is reduced more than passive, often limited by pain and weakness. Passive motion should be preserved; if it is limited, consider frozen shoulder or arthritis. A painful arc between 60 and 120 degrees of abduction indicates impingement.

Pseudoparalysis. Inability to elevate the arm actively despite full passive motion indicates a massive tear.

Tests for each tendon. Strength is tested tendon by tendon: supraspinatus with the empty-can or full-can test, external rotation against resistance at the side and at 90 degrees of abduction, and internal rotation with the belly-press and lift-off tests.

Impingement tests. Neer's sign, pain on passive forward flexion, indicates subacromial impingement. The Hawkins-Kennedy test is pain on internal rotation with the arm in 90 degrees of forward flexion. These tests are sensitive but not specific for rotator cuff tears.

Differential diagnosis. The table sets a cuff tear against the conditions that mimic it.

Radiographs come first. The standard shoulder series is three AP views, in neutral, internal and external rotation, with a scapular Y and an axillary lateral. On them, assess:

• Acromiohumeral distance - normal is greater than 7mm; less than 7mm suggests a massive tear
• Superior migration of the humeral head (chronic massive tear)
• Acromial morphology (Bigliani type) and os acromiale
• Greater tuberosity cysts, sclerosis and osteophytes
• Glenohumeral and acromioclavicular arthritis

MRI is described as the gold standard for rotator cuff assessment. It shows the tear itself - its presence, size (anteroposterior and mediolateral), location, whether it is partial or full thickness, and whether a partial tear is articular or bursal-sided - and the tendon and muscle behind it:

• Tendon retraction (Patte stage)
• Muscle atrophy (the tangent sign on the sagittal view)
• Fatty infiltration (Goutallier grade)
• Associated pathology: labral tears, biceps pathology and bone marrow oedema, and paralabral or intramuscular cysts, which can track along the cuff and are a clue to underlying tendon pathology

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Ultrasound is dynamic, cheaper than MRI and useful for guided injection. It matches MRI for full-thickness tears but is less accurate for partial tears and for muscle quality. It has long been called operator-dependent, though pooled accuracy was similar whether a trained radiologist, a sonographer or an orthopaedic surgeon performed it.

CT arthrography is less commonly used but helpful in specific scenarios: when the patient cannot have MRI (pacemaker, metallic implants), and when bone quality needs assessing for revision surgery or arthroplasty planning. Goutallier grading of fatty infiltration is possible on it.

How accurate each test is. A systematic review and meta-analysis of ultrasound, MRI and MR arthrography in rotator cuff disorders (DOI) found that for full-thickness tears all three achieved sensitivity and specificity over 0.90. For partial-thickness tears and tendinopathy, specificity stayed above 0.90 but sensitivity fell to 0.67-0.83, and that drop applies to MRI as much as to ultrasound.

The missed partial tear. The error runs towards under-diagnosis. A normal MRI does not exclude a partial-thickness tear; on these figures roughly one in five to one in three is missed. If the history and examination point to a partial articular-sided tear and the scan is read as normal, the scan has not settled the question.

MR arthrography is the practical next step. It outperforms both non-contrast MRI and ultrasound for partial-thickness and labral tears, because joint distension demonstrates an articular-sided defect that a plain scan can miss.

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Predicting a poor repair. On MRI, these findings predict poor repair outcomes:

1. Goutallier Grade 3-4 fatty infiltration
2. Patte Stage 3 retraction
3. A positive tangent sign
4. Massive tear size
5. Acromiohumeral distance less than 7mm (chronic massive tear with superior migration)

The decision. Treatment follows the patient's age and demands, the tear and the state of its muscle, as the quick guide sets out.

A rotator cuff repair is fundamentally a tendon-to-bone (enthesis) healing problem. The repaired interface heals with disorganised fibrovascular scar rather than a true graduated enthesis, which is why re-tear remains the commonest complication even with mechanically strong constructs.

Strategies that augment the biology of healing, as distinct from the construct itself, aim to lower the re-tear rate.

Re-tear is the most common complication, and its rate climbs with the size of the tear: in the UKUFF trial, failure to heal at 12 months was small 34%, medium 32%, large 53% and massive 73%. The other factors that predict it:

• Fatty infiltration - Goutallier 3-4 dramatically increases re-tear
• Age over 65 years
• Smoking, which impairs healing and doubles the re-tear rate
• Diabetes, through poor tissue quality and delayed healing
• Repair technique - single-row has a higher re-tear rate than double-row in medium-large tears

Stiffness is prevented by starting passive range of motion within the first week, progressing to active-assisted motion at 6 weeks and avoiding prolonged immobilisation. Diabetic patients are at the highest risk and warrant an aggressive physiotherapy protocol.

Because re-tear is the dominant complication, it is worth knowing how repair integrity is graded and where repairs fail. Postoperative integrity on MRI (or ultrasound) is described by the Sugaya classification, and the anatomical pattern of failure by the Cho classification.

Types I-II are regarded as intact, type III as thinned but continuous, and types IV-V as re-tear.

Rehabilitation follows one of two protocols. A small-medium repair follows the standard timeline; a large or massive repair is tenuous and follows a more protective protocol.

Outcome by tear size. Healing and function both fall as the tear gets bigger. The healing rates below are from the UKUFF trial: 217 repairs imaged by MRI or ultrasound at 12 months, 56% healed overall (Rashid 2017).

Prognostic factors. Each factor has a favourable and an unfavourable end.

Global Epidemiology

The population prevalence figures above are from Yamamoto et al (DOI).

Major Guidelines - Side by Side

Registry and High-Level Evidence

• Rotator cuff repair is a soft-tissue procedure and is not captured by the major arthroplasty joint registries (NJR, AJRR, AOANJRR, SHAR). The evidence base therefore rests on RCTs and meta-analyses (e.g. single- vs double-row, DOI) and large prospective cohorts (MOON).
• Reverse total shoulder arthroplasty for cuff-tear arthropathy is registry-tracked: national arthroplasty registries (NJR, AOANJRR, AJRR, Nordic registries) report rising reverse-TSA volumes and implant survival, complementing survivorship series such as Guery et al (DOI).

Global Practice Variation

Consent and Documentation (Universal)