How is a shoulder tear classified and treated?

Shoulder Tear Classification and Treatment

Classification of Rotator Cuff Tears

Rotator cuff tears are classified into three main categories: partial-thickness tears (subdivided by location), full-thickness tears, and tendinosis without tear. 1

Partial-Thickness Tears

• Articular surface tears are the most common type of partial-thickness tears, occurring on the inferior (undersurface) of the tendon 1
• Bursal surface tears occur superiorly on the top surface of the tendon 1
• Intrasubstance tears occur within the tendon substance itself 1
• Snyder's arthroscopic classification grades partial tears as A1-4 (articular surface) or B1-4 (bursal surface) based on extent, with higher numbers indicating greater involvement 2

Full-Thickness Tears

• Complete disruption of the tendon from inferior to superior surface, demonstrating increased signal intensity on all MRI sequences 1
• Can be partial-width (not extending across entire tendon width) or complete-width 3
• Classified as C1-4 in Snyder's system based on tear size and retraction 2
• Associated findings include tendon retraction, muscle atrophy, and fatty infiltration—critical factors determining surgical candidacy and prognosis 1

Tendinosis/Tendinopathy

• Signal intensity abnormality without focal disruption, indicating chronic degeneration or inflammation 1
• Characterized by tendinous enlargement and heterogeneous signal pattern with diffuse increased T1 signal intensity 1

Diagnostic Imaging Approach

Initial Evaluation

• Plain radiographs should be obtained first for all acute shoulder pain, including at minimum a Grashey projection and either axillary lateral or scapular Y view 1
• Radiographs identify fractures, dislocations, and osseous abnormalities but cannot visualize soft tissue tears 1

Advanced Imaging Selection

For suspected full-thickness tears: MRI without contrast, MR arthrography, and ultrasound are equally appropriate (rating 9/9) depending on local expertise. 1

• MRI without contrast has 94% sensitivity and 93% specificity for full-thickness tears 4
• Ultrasound has 92% sensitivity and 93% specificity for full-thickness tears, with the advantage of lower cost and faster procedure 1, 4
• MR arthrography is preferred when distinguishing between full-thickness and partial-thickness tears is uncertain, particularly for articular surface tears 1

For suspected partial-thickness tears: MR arthrography (rating 9/9) is superior to MRI or ultrasound. 1

• MR arthrography has increased sensitivity for detecting partial-thickness articular surface tears compared to conventional MRI 1
• Both MRI and ultrasound may have poor sensitivity for partial-thickness tears 4
• Ultrasound has conflicting evidence and variable interobserver agreement for partial-thickness tears 1

For patients under 35 years with suspected labral tears: MR arthrography (rating 9/9) is the preferred modality. 1

Treatment Algorithm

Conservative Management (First-Line for All Tears)

Structured physical therapy for 3-6 months is the cornerstone of initial treatment for both partial-thickness and small full-thickness tears. 3, 5

• Focus on rotator cuff strengthening, scapular stabilization, and range of motion exercises 3
• Conservative treatment can be effective even for full-thickness tears 5
• Note that 10% of rotator cuff tears are asymptomatic and present only with morphologic changes 1

Adjunctive Treatments

• Subacromial corticosteroid injection may be used as an adjunct for localized inflammation 3
• For patients with concurrent polymyalgia rheumatica, ensure appropriate systemic glucocorticoid therapy (prednisone 12.5-25 mg daily), but avoid doses exceeding 30 mg daily as this impairs tendon healing 3

Surgical Referral Indications

Refer to orthopedic surgery if no improvement in pain or function after 3-6 months of structured physical therapy. 3, 5

• Surgical repair aims for tendon-to-bone healing, which correlates with improved long-term outcomes 3
• Factors favoring surgery include: younger age, physically demanding occupation, involvement of 2 or more tendons, and rotator cable lesions 5
• Surgical options include arthroscopic, mini-open, or open repair depending on tear characteristics and tissue quality 1

Special Considerations for Irreparable Tears

• Partial repairs can reliably improve pain and potentially reverse pseudoparalysis 5
• Address concomitant biceps pathology when present 5
• Reverse shoulder arthroplasty is reserved for painful pseudoparalysis with associated arthropathy 5

Critical Pitfalls to Avoid

• Do not rely solely on physical examination for diagnosis—clinical tests have overlapping symptoms between different shoulder conditions and are less accurate than imaging 6, 7
• Do not assume MRI is always superior to ultrasound for full-thickness tears—they have equivalent diagnostic performance when local ultrasound expertise is available 1, 4
• Do not skip MR arthrography when partial-thickness tears are suspected, as conventional MRI and ultrasound have significantly lower sensitivity 1, 4
• Assess for tendon retraction, muscle atrophy, and fatty infiltration on imaging, as these findings determine surgical approach and prognosis 1