Orthopaedic Surgery - Rotator Cuff Injuries

Basics

The rotator cuff is composed of four tendons:

Supraspinatus

Infraspinatus

Teres minor

Subscapularis

Together, these tendons surround the humeral head and provide dynamic stabilization of the:

Glenohumeral joint.

Rotator Cuff Anatomy

The:

Subscapularis

inserts onto the:

Lesser tuberosity

and is the only rotator cuff tendon inserting primarily on the:

Anterior aspect of the humeral head.

The:

Supraspinatus

Infraspinatus

and

Teres minor

insert sequentially from anterior to posterior along the:

Greater tuberosity.

Innervation

The supraspinatus and infraspinatus are innervated by the:

Suprascapular nerve.

The teres minor is supplied by the:

Axillary nerve.

The subscapularis is supplied by the:

Upper and lower subscapular nerves.

Function

The principal role of the rotator cuff is to provide:

Dynamic stabilization of the humeral head within the glenoid.

The cuff compresses and centers the humeral head, producing a stable fulcrum that permits efficient:

Elevation

Rotation

and overall shoulder motion.

This function is especially important in the:

Coronal

and

Transverse planes.

Vascularity

The rotator cuff receives much of its blood supply from the:

Bursal surface.

The articular side is relatively less vascular.

A region of reduced vascularity near the supraspinatus insertion has historically been described as the:

Critical zone.

This area may contribute to susceptibility to:

Degenerative tearing.

Most Common Tendon Involved

The:

Supraspinatus tendon

is the most frequently torn component of the rotator cuff.

The:

Subscapularis

is also commonly involved, particularly in traumatic or combined tears.

Classification

Rotator cuff tears may be described according to:

Tendon involved

Partial- versus full-thickness involvement

Tear size

Tear shape

Amount of tendon retraction

Muscle atrophy

Fatty infiltration

Acute versus chronic onset

Partial-Thickness Tear

A partial-thickness tear involves only part of the tendon thickness.

It may occur on the:

Articular surface

Bursal surface

or within the tendon substance.

Full-Thickness Tear

A full-thickness tear extends through the entire tendon, creating communication between the:

Glenohumeral joint

and

Subacromial space.

Acute and Chronic Tears

Rotator cuff tears may be:

Acute traumatic

Chronic degenerative

or a combination of both.

A traumatic event may extend a previously asymptomatic:

Degenerative tear.

Epidemiology

Rotator cuff disease becomes increasingly common with:

Advancing age.

Sex

Traumatic tears have historically been reported more often in:

Men

whereas degenerative or nontraumatic tears have been reported more frequently in:

Women.

Mechanism

Among traumatic injuries, the most common mechanism is:

A fall.

Dominant Arm

The:

Dominant shoulder

is involved more frequently than the nondominant shoulder in both traumatic and degenerative rotator cuff disease.

Incidence

One population study reported an incidence of rotator cuff repair of approximately:

83 per 100,000 persons.

Patients aged:

65–74 years

have historically represented one of the most common age groups undergoing repair.

Prevalence

Cadaveric studies have reported approximately:

11.8% prevalence of full-thickness tears

and

18.5% prevalence of partial-thickness tears.

Age-Related Prevalence

The prevalence of both partial- and full-thickness tears increases with:

Age.

Asymptomatic tears are particularly common in older adults.

One MRI study found partial-thickness tears in approximately:

26% of asymptomatic patients older than 60 years

compared with approximately:

4% of patients younger than 40 years.

Asymptomatic Tears

A rotator cuff tear detected on imaging does not necessarily explain a patient’s pain.

Many older adults have:

Asymptomatic structural tears.

Clinical correlation is therefore essential.

Risk Factors

Important risk factors include:

Advancing age

Smoking

Pre-existing tendon degeneration

Large or medium-sized tears

Muscle fatty atrophy

Abnormal acromial morphology

Scapular dyskinesis

Smoking

Smoking may compromise:

Tendon vascularity

and

Healing capacity.

It has been associated with:

Rotator cuff tearing

Tear progression

and poorer healing after repair.

Tear Progression

Factors associated with progression include:

Smoking

and

Larger initial tear size.

Retear Risk After Repair

Risk factors for recurrent tearing include:

Older age

Large initial tear

Multiple tendon involvement

Fatty degeneration

Muscle atrophy

Diabetes mellitus

Smoking

Poor tissue quality

Inadequate postoperative protection

Acromial Morphology

Certain acromial shapes and spurs have historically been associated with rotator cuff disease.

These may contribute to:

Mechanical abrasion

or reflect the chronic degenerative process.

Scapular Dyskinesis

Abnormal scapular motion can alter:

Subacromial mechanics

and

Shoulder loading.

It may contribute to symptoms in patients with rotator cuff disease.

Genetics

Evidence suggests a:

Familial or genetic predisposition

to rotator cuff degeneration and tearing.

However, inheritance is complex and not explained by a single gene.

Etiology

Chronic tears usually develop through a combination of:

Age-related degeneration

Repetitive loading

Reduced vascularity

Intrinsic tendon degeneration

and possible:

Mechanical impingement.

Acute Tears

Acute tears may occur during:

Heavy lifting

Sudden eccentric loading

or after:

A fall or shoulder trauma.

In younger patients, a traumatic event is more likely to be a major contributing factor.

Shoulder Dislocation

A rotator cuff tear should be considered after shoulder dislocation, particularly in patients older than approximately:

60 years.

Persistent weakness after reduction should raise suspicion.

Associated Conditions

Rotator cuff injuries may occur with:

Shoulder dislocation

Acromioclavicular arthritis

Shoulder stiffness

Biceps tendinitis

Biceps instability or subluxation

Cervical radiculopathy

Diagnosis

Diagnosis is based on:

History

Physical examination

and selective use of:

Radiographs

Ultrasound

or

MRI.

Signs and Symptoms

Common symptoms include:

Shoulder pain

Night pain

Weakness

Difficulty with overhead activity

Loss of active motion

Pain Location

Pain is commonly described as:

Deep and lateral

over the deltoid region.

It may radiate toward the:

Elbow.

Pain extending below the elbow with neurologic features should raise concern for:

Cervical radiculopathy.

Night Pain

Night pain and difficulty sleeping on the affected shoulder are:

Common.

Weakness

Patients may notice weakness with:

Elevation

External rotation

or

Internal rotation

depending on the tendon involved.

Active Versus Passive Motion

A large tear may cause substantial loss of:

Active motion

while:

Passive motion remains relatively preserved.

This distinction helps differentiate rotator cuff dysfunction from:

Adhesive capsulitis.

Physical Examination

Inspection

Inspect the shoulder girdle for:

Muscle atrophy

particularly in the:

Supraspinatus fossa

and

Infraspinatus fossa.

Biceps Inspection

A distal bulge of the biceps muscle may indicate:

Long-head biceps rupture.

This classic appearance is known as a:

Popeye deformity.

Range of Motion

Assess both:

Active

and

Passive motion

in:

Forward elevation

Abduction

External rotation

Internal rotation

with the arm both at the side and, when tolerated, at:

90° of abduction.

Supraspinatus Testing

The:

Jobe test

or

Empty-can test

evaluates the supraspinatus.

Pain or weakness with resisted elevation in the scapular plane suggests:

Supraspinatus pathology.

Infraspinatus Testing

Weakness in external rotation with the arm at the side suggests:

Infraspinatus dysfunction.

An:

External rotation lag sign

may indicate a more substantial posterosuperior cuff tear.

Teres Minor Testing

External rotation weakness with the arm positioned at approximately:

90° of abduction

is more suggestive of:

Teres minor dysfunction.

Subscapularis Testing

Subscapularis function can be evaluated with:

Internal rotation strength testing

Lift-off test

Belly-press test

Bear-hug test

Internal rotation lag sign.

Excessive passive external rotation may also suggest:

Subscapularis insufficiency.

Cervical Spine Examination

If cervical involvement is suspected, examine:

Cervical range of motion

Upper-extremity reflexes

Sensation

Distal motor strength

and, when appropriate,

Hoffmann sign.

Imaging

Plain Radiographs

Standard shoulder radiographs should include at least:

Grashey AP view

Scapular Y view

Axillary view.

Radiographic Findings

Radiographs may identify:

Glenohumeral arthritis

Acromioclavicular arthritis

Calcific tendinitis

Acromial morphology

Superior migration of the humeral head

and chronic cuff-related changes.

Ultrasound

Diagnostic ultrasound can be highly accurate for:

Full-thickness

and many

Partial-thickness rotator cuff tears

when performed by an experienced examiner.

It also allows:

Dynamic assessment.

MRI

MRI is the primary advanced imaging study for evaluating:

Rotator cuff integrity

Tear size

Retraction

Muscle atrophy

Fatty infiltration

Biceps pathology

Associated labral or joint abnormalities.

CT Arthrography

CT arthrography may be used when MRI is contraindicated, such as in patients with:

Certain non-MRI-compatible implants

or other limitations.

Cervical Imaging

Cervical spine radiographs or more advanced imaging may be appropriate when:

Radiculopathy

or

Cervical stenosis

is suspected as a contributor to shoulder symptoms.

Pathological Findings

Histopathological examination is:

Not routinely required

for uncomplicated rotator cuff tears.

Degenerative tears generally demonstrate:

Collagen disorganization

Tendon degeneration

Reduced cellularity

and variable chronic changes.

Differential Diagnosis

Important alternatives include:

Calcific tendinitis

Suprascapular neuropathy

Acromioclavicular arthritis

SLAP tear

Biceps tendon subluxation

Glenohumeral arthritis

Adhesive capsulitis

Cervical stenosis or radiculopathy

Biceps tendon rupture

Symptomatic os acromiale

Parsonage–Turner syndrome

Calcific Tendinitis

Calcific tendinitis may produce severe shoulder pain and is often identifiable on:

Plain radiographs.

Suprascapular Neuropathy

Suprascapular nerve dysfunction may cause:

Weakness

Posterior shoulder pain

and

Supraspinatus or infraspinatus atrophy.

Possible causes include:

Paralabral cyst

or other compressive lesions.

Adhesive Capsulitis

Frozen shoulder differs from an isolated rotator cuff tear because both:

Active

and

Passive range of motion

are restricted.

Treatment

General Principles

Treatment depends on:

Age

Activity level

Acute versus chronic onset

Tear size

Tendon involved

Tissue quality

Degree of retraction

Muscle atrophy

Symptoms

Nonoperative Treatment

Partial-thickness tears and many chronic degenerative tears are initially treated with:

Activity modification

Physical therapy

Analgesics

and, when appropriate,

Subacromial corticosteroid injection.

Traumatic Tears

Acute traumatic tears, especially in:

Active patients

or those with substantial weakness, are treated more aggressively.

Early surgical consultation is often appropriate because prolonged delay may allow:

Retraction

Muscle atrophy

and

Fatty degeneration.

Activity

A short period of:

Sling use

may be appropriate after an acute injury or severe flare.

Prolonged immobilization should be avoided because it can contribute to:

Stiffness.

Activity Modification

Temporarily avoid:

Painful overhead activity

Heavy lifting

and repetitive loading that aggravates symptoms.

Activity may otherwise continue:

As tolerated.

Physical Therapy

The goals of therapy are to preserve:

Range of motion

Rotator cuff strength

Scapular mechanics

and

Periscapular strength.

Scapular Stabilization

Exercises commonly target:

Trapezius

Serratus anterior

Rhomboids

and other scapular stabilizers.

Improved scapular mechanics can reduce compensatory shoulder loading.

Anterior Deltoid Rehabilitation

Patients with chronic irreparable posterosuperior cuff tears may sometimes benefit from:

Anterior deltoid retraining.

This is most effective in carefully selected patients with preserved:

Deltoid function

and relatively isolated posterior cuff deficiency.

Home Exercise Program

After learning appropriate stretches and strengthening exercises with a therapist, patients should continue a:

Consistent home program.

Medication

First Line

Pain can be treated with:

NSAIDs

or

Acetaminophen.

Oral Corticosteroids

A short course of systemic corticosteroids is occasionally used for severe inflammatory symptoms, although routine repeated use is generally avoided because of:

Systemic adverse effects

and potential concerns regarding tendon health.

Subacromial Corticosteroid Injection

Subacromial injection may provide:

Temporary pain relief

and can assist rehabilitation.

It may also have diagnostic value when pain is substantially reduced after injection.

Repeated injections should be used cautiously because corticosteroids may adversely affect:

Tendon quality

and potentially influence healing.

Diabetes and Infection

Corticosteroid use requires caution in patients with:

Diabetes mellitus

and should generally be avoided when there is:

Active infection.

Opioids

Routine opioid treatment should be:

Avoided

for chronic rotator cuff pain.

Surgery

Surgery may be indicated for:

Acute traumatic full-thickness tears

Persistent pain despite appropriate nonoperative care

Progressive weakness

Functional loss

Large or enlarging tears in selected patients.

Arthroscopic Repair

Most contemporary repairs are performed:

Arthroscopically.

This allows treatment of:

Tendon tears

Biceps pathology

Labral lesions

and other associated abnormalities.

Open Repair

Open and mini-open repair remain valid options.

Historically, open and arthroscopic repairs have demonstrated:

Comparable functional outcomes

when appropriately performed.

Tendon Repair

The goal is to restore the torn tendon to its:

Anatomic footprint on the greater or lesser tuberosity

with stable fixation that permits biological healing.

Graft Augmentation

Biologic or structural grafts may occasionally be used when:

Tendon tissue is deficient

or the tear cannot be repaired primarily.

Outcomes vary according to:

Indication

Graft type

and

Tissue quality.

Tendon Transfer

An irreparable tear in a younger or more active patient may occasionally be treated with a:

Tendon transfer.

Examples depend on the tear pattern and may include transfers designed to restore:

External rotation

or

Anterior cuff function.

Reverse Shoulder Arthroplasty

Reverse total shoulder arthroplasty is a salvage option for:

Massive irreparable rotator cuff tears

particularly when associated with:

Pseudoparalysis

or

Cuff tear arthropathy.

Rotator Cuff Tear Arthropathy

Long-standing massive cuff failure may result in:

Superior migration of the humeral head

Glenohumeral cartilage degeneration

and

Altered shoulder biomechanics.

This condition is termed:

Rotator cuff tear arthropathy.

Follow-Up

Patients treated either nonoperatively or surgically require periodic reassessment.

Monitoring should include:

Pain

Range of motion

Strength

Functional improvement

Response to therapy.

Prognosis

Many patients with chronic degenerative tears achieve acceptable function with:

Nonoperative treatment.

However, structural tears may enlarge over time.

Tear Progression

One historical series reported enlargement of tear size in approximately:

47% of patients.

Progression risk is influenced by:

Initial tear size

Age

Smoking

and

Tendon quality.

Prognosis After Repair

Successful repair can substantially improve:

Pain

Strength

Shoulder function.

Healing is less reliable in patients with:

Advanced age

Large or massive tears

Muscle atrophy

Fatty infiltration

Diabetes

Smoking

Multiple tendon involvement.

Retear

Structural failure after repair is not uncommon.

Large tears have historically been associated with retear rates around:

40% or higher

depending on the population and imaging criteria used.

A structural retear does not always correlate directly with:

Poor clinical function.

Complications

Stiffness

Postoperative shoulder stiffness is a relatively common complication.

It may also develop after prolonged nonoperative immobilization.

Recurrent Tear

The repaired tendon may:

Fail to heal

or

Rerupt.

Infection

Deep infection after rotator cuff surgery is:

Uncommon.

Nerve Injury

Iatrogenic injury to the:

Axillary

Suprascapular

or other nerves is rare but possible.

Deltoid Dysfunction

Open surgical approaches can rarely result in:

Deltoid injury or dysfunction.

Tear Enlargement

With nonoperative treatment, a degenerative tear may progressively:

Increase in size

and develop greater:

Retraction

Muscle atrophy

or

Fatty infiltration.

Patient Monitoring

Patients treated conservatively should be monitored for:

Persistent pain

Progressive weakness

Loss of motion

Declining function.

Postoperative Monitoring

After repair, follow-up should assess:

Wound healing

Pain control

Passive range of motion

Progressive active motion

Strength recovery

and adherence to the:

Rehabilitation protocol.

Key Principle

Rotator cuff injuries range from asymptomatic degenerative partial tears to acute traumatic full-thickness ruptures.

The rotator cuff functions primarily as a:

Dynamic stabilizer that centers the humeral head within the glenoid and provides a stable fulcrum for shoulder motion.

The most commonly involved tendon is the:

Supraspinatus.

Chronic and partial tears are commonly treated initially with:

Activity modification, physical therapy, and analgesic or anti-inflammatory treatment, whereas acute traumatic tears, persistent functional weakness, and selected large or irreparable tears may require:

Repair, reconstruction, tendon transfer, or reverse shoulder arthroplasty.