Subacromial Impingement Syndrome (SAIS)

Subacromial Impingement Syndrome (SAIS)

• SAIS isn't a valid diagnosis due to the lack of a clear anatomical cause.
• Imaging findings linked to SAIS are common even in people without symptoms.
• Orthopedic special tests, commonly performed for SAIS, lack validity.
• There's no solid connection between the shape of the acromion and rotator cuff tears.
• Surgery for SAIS has not proven to be more effective than rehabilitation.

Imaging for SAIS

• Imaging is unreliable for diagnosing SAIS as many asymptomatic individuals display shoulder abnormalities.
• Structural changes in the shoulder happen naturally as part of aging.
• What appears on imaging doesn't consistently correlate with a patient's symptoms.

Surgery vs. Rehab

• Research indicates surgery for SAIS offers no advantages over rehab in the long term (1-5 year follow-ups).

Rotator Cuff Related Pain Syndrome (RCRPS)

• RCRPS emphasizes factors like:
  • Tissue health
  • Movement and function
  • Psychosocial elements in shoulder pain assessment.

Biopsychosocial Model

• The biopsychosocial model reframes pain as a multifaceted experience, not solely structural.
• Treatment should prioritize enhancing function, strength, and movement, rather than correcting posture or addressing impingement.

Posture and SAIS

• There's no strong evidence that issues like kyphosis, rounded shoulders, or forward head posture directly cause shoulder pain.

Scapular Dyskinesia

• Scapular dyskinesia is a movement variation, not a diagnosis on its own.
• A definitive link between scapular dyskinesia and shoulder pain lacks strong evidence.

Muscle Imbalance

• It's unclear whether muscle issues are the cause of pain, or the result of it.

Treatment Focus

• Physical therapists should emphasize function over structure.
• Focus on improving strength and mobility with patients.
• Avoid language that induces fear.
• Prioritize rehabilitation over surgery for RCRPS.

RCRPS Definition

• RCRPS is defined as shoulder pain that develops gradually.
• It stems from the overuse or underuse of tendons, rather than impingement of the acromion.

Key Factor: RCRPS Development

• The development of RCRPS is caused by excessive load or sudden, high load after a period of underuse.
• The above factor can lead to tendinopathy.

Tendon Degeneration

• Tendon degeneration occurs in stages:
  • Reactive tendinopathy starts with early inflammation.
  • Tendon disrepair involves structural changes.
  • Degenerative tendinopathy then leads to chronic dysfunction.

Rotator Cuff Tendon

• Before the subacromial space narrows, the rotator cuff tendon thickens and pushes upwards, rather than the acromion pushing down.

Acromioplasty

• Acromioplasty is ineffective because it fails to address the underlying issue of tendon load imbalance.

Intrinsic Factors: RCRPS

• Intrinsic factors contributing to RCRPS encompass:
  • Tendon overload
  • Vascular changes leading to swelling
  • Age-related loss of elasticity.

Extrinsic Factors: RCRPS

• Extrinsic factors in RCRPS include:
  • Bony changes like osteophytes
  • Rotator cuff fatigue causing humeral head migration
  • Repetitive overhead activity leading to shear/compression forces.

Positive Predictors of PT Outcome

• Factors predicting positive outcomes in physical therapy include:
  • High patient expectations
  • Strong belief in personal pain management ability (self-efficacy)
  • Lower pain levels at rest
  • Being employed

Non-Predictors of PT Success

• Clinical examination findings or structural diagnoses do not predict PT success.

Psychology

• Fear and negative beliefs can worsen RCRPS symptoms.
• Emphasize reframing pain as manageable.

Shoulder Exam

• The first question to ask in a shoulder pain examination is, "Is this really a shoulder problem?".
• Rule out the cervical spine first.

RCRPS Symptoms

• Common RCRPS symptoms include:
  • Pain during overhead activities or reaching
  • Night pain, especially when lying on the affected shoulder.
  • Shoulder stiffness and weakness

ROM Findings

• Key ROM findings in RCRPS are:
  • Painful arc (60°-120° abduction)
  • Loss of external rotation
  • Pain during internal rotation stretch.

Strength Test Findings

• Key strength test findings in RCRPS are:
  • Pain with resisted external rotation, abduction, and flexion
  • Possible allodynia (pain from stimuli that usually don't cause pain).

Palpation

• Palpation may not be useful for diagnosis.
• Tenderness does not confirm specific pathology.

Special Tests

• The top 3 special tests for diagnosing RCRPS are:
  • Hawkins-Kennedy Test
  • Painful Arc
  • Infraspinatus Muscle Test

Special Test Accuracy

• If all 3 tests are positive, the likelihood ratio (+LR) is 10.56, suggesting high probability.
• If only 2 are positive, the +LR is 5.0, which is weaker evidence.

Internal Impingement

• Internal impingement primarily affects athletes, especially those involved in throwing and overhead sports.
• Pain is felt in the posterior shoulder during 90° abduction with external rotation.

Internal Impingement Cause

• Repetitive overload causes internal impingement.
• It leads to compression of the posterior rotator cuff.
• This occurs between the humeral head and glenoid.

Fear-Inducing Language

• Avoid fear-inducing language.
• Patients may develop fear-avoidance behaviors and movement restrictions.

PT Treatment: RCRPS

• Physical therapy treatment should focus on:
  • Gradual tendon loading
  • Pain education and promoting self-efficacy
  • Achieving functional goals rather than just correcting posture.

PT Emphasis

• Avoid emphasizing things like:
  • Postural "faults"
  • Scapular positioning
  • Structural diagnoses (e.g., acromial shape)

Rotator Cuff Tears

• Rotator cuff tears are the most common tendon injury in adults.
• They increase with age.

Occurrence of Rotator Cuff Tears with Age

• 50-60 years: ~10%
• 60-70 years: ~20%
• 70-80 years: ~30%
• 80+ years: ~50%

Rotator Cuff Tear Causes

• Rotator cuff tears are caused by:
  • Gradual (atraumatic) degeneration
  • Traumatic injury

Atraumatic Tears

• The primary cause of atraumatic rotator cuff tears is intrinsic tendon degeneration.
• This is due to aging, poor vascularity, and repetitive stress.

Traumatic Tears

• The most common cause of traumatic rotator cuff tears is a fall on an outstretched hand (FOOSH).
• Other causes include shoulder dislocation, or heavy lifting.

Intrinsic Factors: Tears

• Intrinsic factors contributing to rotator cuff tears include:
  • Poor tendon vascularity
  • Age-related degeneration
  • Altered tendon histology.

Extrinsic Factors: Tears

• Extrinsic factors contributing to rotator cuff tears include:
  • Repetitive overhead stress (work/sports)
  • Tensile, compressive, & shear overload
  • Bony changes reducing subacromial space.

Types of Rotator Cuff Tears

• Interstitial (fraying): Intact tendon with fiber fraying
• Partial Thickness: Bursal-side (near acromion) or Articular-side (near humeral head)
• Full Thickness: Complete tear through the tendon

Most Commonly Torn Muscle

• The supraspinatus muscle is most commonly torn.

Classifications: Full Thickness Tears

• Classifications are based on size/measurement and healing potential.
• Small tears are <1cm, medium tears are 1-3 cm, large tears are 3-5 cm, and massive tears are >5 cm.
• Healing potential can be classified as good or poor.

Rotator Cuff Tear Symptoms

• Symptoms include:
  • Gradual pain onset (if atraumatic)
  • Pain increases over time
  • Night pain is common
  • Pain interferes with ADLs.

Impairments

• Functional impairments include:
  • Weakness with arm elevation & external rotation
  • Shoulder shrug sign (compensatory upper trap activation)
  • Loss of flexion, abduction, external rotation

Special Tests: Diagnosing Tears

• Special tests include:
  • Painful Arc Test (pain 60°-120° abduction)
  • Drop Arm Test (unable to lower arm slowly from 90° abduction)
  • Infraspinatus Muscle Test (weakness in resisted ER).

Special Test Cluster

• Special test cluster:
  • 4/4 tests = +15.57 (high probability)
  • 2/4 tests = +3.57 (moderate probability)

Surgery

• Not all rotator cuff tears require surgery.
• Physical therapy is often as effective as surgery for small/moderate tears.

Rehab Considerations

• Key rehab considerations:
  • Gradual tendon loading
  • Pain education & movement reassurance
  • Avoid fear-based language (e.g., "your tendon is weak")
  • Focus on functional goals over isolated strength.

Rotator Cuff Tear Special Test Cluster

• Includes:
  • Age > 60 years old
  • Painful Arc Test (pain during 60°-120° abduction)
  • Drop Arm Test (unable to slowly lower arm from 90° abduction)
  • Infraspinatus Muscle Test (weakness/pain with resisted external rotation)

Rotator Cuff Surgery

• Rotator cuff surgery is recommended when:
  • Acute traumatic tears occur ( surgery is generally recommended within 1 year)
  • Significant weakness & functional loss is present
  • Conservative treatment has failed for ≥8 weeks

Early Surgery (Traumatic Tears)

• Early surgery for traumatic tears prevents tendon retraction.
• Retraction makes repair more difficult.

Open Repair

• Involves:
  • Large incision (3-6 inches)
  • Splitting the deltoid muscle.
  • Results in a longer recovery.

Mini-Open Repair

• A smaller incision (3-6 cm) is made.
• It is less invasive than an open repair.

Arthroscopic Repair

• Involves:
  • Smallest incisions (7-8 mm)
  • No deltoid splitting
  • Lower risk of stiffness/infection.

Most Common

• Today, arthroscopic repair is the most common surgical technique (96% of cases).

Failure Rate

• The failure rate for rotator cuff repairs:
  • 35% overall
  • 45% in patients >70 years old

Risk Factors: Surgical Failure

• Include:
  • Tear size (larger tears = lower healing rates)
  • Age (older patients = higher failure rates)
  • Diabetes (poor vascularity = slow healing)
  • Obesity (higher inflammation, poor tissue quality)
  • Fatty infiltration of the muscle
  • Pre-op ROM (better ROM = better outcomes)

Repaired Tendon

• It takes at least 12 weeks for the repaired tendon to reattach to the bone.

Tendon Over Time

• Repaired tendon strength over time:
  • 6 weeks: 19-30% of normal
  • 12 weeks: 29-50% of normal
  • 15 weeks: Bone healing nearly complete

Re-Tears

• Most re-tears occur between 3-6 months post-op.
• This occurs when patients feel "better" and return to activity too soon.

Post-Op Stiffness

• 7.6% of patients develop stiffness after rotator cuff surgery.

Post-Op Stiffness Concern

• Post-op stiffness is concerning when:
  • Flexion25% loss in multiple planes

Freezing Shoulder (FS) Movements

• The most affected movements are flexion, abduction, and external rotation.