How to manage left shoulder laxity in a young adult or adolescent, possibly with Postural Orthostatic Tachycardia Syndrome (POTS), who can subluxate their shoulder?

Management of Left Shoulder Laxity with Voluntary Subluxation

Start with a structured conservative rehabilitation program focusing on rotator cuff and scapular stabilizer strengthening, avoiding overhead activities and voluntary subluxation maneuvers, with surgery reserved only for cases with persistent pain or functional limitation after 3-6 months of dedicated physical therapy. 1, 2, 3

Initial Assessment Priorities

Document the exact nature of the instability:

• Determine if the subluxation is voluntary (patient-initiated) versus involuntary (occurs during activities), as voluntary instability with no pain is a contraindication to surgery 4
• Assess for generalized joint laxity using the Beighton criteria, as multidirectional instability commonly coexists with systemic hypermobility 5
• Perform the sulcus sign test to evaluate inferior capsular laxity and apprehension testing for directional instability 6
• Rule out POTS-related connective tissue disorders (Ehlers-Danlos syndrome), which fundamentally changes the treatment approach toward lifelong conservative management 5

Key examination findings to document:

• Focal weakness with decreased range of motion during abduction with external or internal rotation suggests underlying rotator cuff dysfunction 1, 7
• Scapular dyskinesis assessment is mandatory, as poor scapular coordination is both cause and effect of shoulder instability 7

Conservative Management Protocol (First-Line Treatment)

Phase 1: Immediate Restrictions (Weeks 0-6)

• Absolutely prohibit voluntary subluxation maneuvers, as repetitive voluntary instability episodes cause progressive capsular stretching and labral damage 4, 5
• Complete rest from overhead activities and any movements that reproduce the subluxation 1, 3
• Implement gentle stretching focusing on posterior shoulder muscles to restore balanced capsular tension 1, 3
• Begin rotator cuff isometric strengthening exercises in neutral positions 2, 3
• Use analgesics (acetaminophen or ibuprofen) only if pain is present 2

Phase 2: Progressive Strengthening (Weeks 6-12)

• Advance to isotonic rotator cuff strengthening with emphasis on external rotators and supraspinatus, as preseason weakness correlates with injury requiring surgery 1
• Implement scapular stabilization exercises targeting serratus anterior and lower trapezius 1, 7
• Begin core and lower extremity strengthening to address kinetic chain deficits 1
• Avoid overhead pulley exercises entirely, as they encourage uncontrolled abduction and worsen instability 7, 3

Phase 3: Advanced Strengthening (Weeks 12-16)

• Progress to plyometric exercises and endurance training 1
• Initiate proprioceptive training to enhance dynamic muscular restraints 6
• Gradually return to functional activities only after achieving pain-free motion and full strength 1

Critical Management Principles

The "Thrower's Paradox" applies here: the shoulder must maintain enough laxity for normal motion but sufficient stability to prevent symptomatic subluxation 1. In patients with voluntary instability and generalized laxity, this balance is inherently compromised and requires lifelong attention to dynamic stabilizers rather than surgical tightening 4, 5.

Conservative treatment succeeds in the majority of cases when patients comply with activity modification and strengthening protocols 4, 5. The key is addressing the underlying dynamic instability through muscular control rather than attempting to surgically correct physiologic laxity 5.

Imaging Recommendations

Obtain plain radiographs first (AP, Grashey, axillary views) to assess bony morphology and rule out glenoid dysplasia or humeral head abnormalities 7

MR arthrography is indicated only if:

• Pain persists despite 3-6 months of conservative therapy 1
• Clinical suspicion exists for labral tear (positive O'Brien's sign) 6
• Surgical planning is being considered 1

MR arthrography has 65% sensitivity for labral tears in clinically unstable shoulders (lower than the 86-100% reported in general shoulder pain populations), so negative imaging does not rule out pathology 1.

Surgical Considerations

Surgery is indicated ONLY when:

• Persistent pain interferes with daily activities after 3-6 months of dedicated conservative therapy 4, 5
• Recurrent involuntary subluxations cause functional limitation despite rehabilitation 8
• Patient demonstrates compliance with conservative measures and cessation of voluntary subluxation 4

Surgery is contraindicated when:

• Instability is painless and voluntary 4
• Generalized ligamentous laxity is present without specific traumatic pathology 5
• Patient continues voluntary subluxation behaviors 4

Surgical options when indicated:

• Arthroscopic capsular plication for unidirectional instability without significant bone loss 8, 5
• Open capsular shift for multidirectional instability with inferior capsular redundancy 4, 5
• Both techniques show equivalent outcomes in high-demand populations when properly selected 8

Common Pitfalls to Avoid

Do not operate on voluntary, painless instability, as outcomes are universally poor and patients continue subluxation behaviors postoperatively 4. Pain is the principal indicator for surgical intervention 4.

Do not overlook POTS and associated connective tissue disorders, as these patients have systemic collagen abnormalities that predispose to surgical failure and require lifelong conservative management 5.

Do not allow aggressive passive range-of-motion exercises, as evidence supporting aggressive stretching is lacking and can worsen capsular laxity 3.

Do not proceed to surgery without documenting 3-6 months of supervised, compliant conservative therapy, as most patients respond to appropriate rehabilitation 4, 5.