Pain at the Anterior Shoulder, Clavicle, and Sternoclavicular (SC) Joint

Schematic showing the proximity of major neurovascular structures to the SC joint - Textbook of Family Medicine 9e

Differential Diagnosis

1. Sternoclavicular Joint Dislocation / Subluxation (Traumatic)

• Grade I - Mild sprain of SC and costoclavicular ligaments; joint stable
• Grade II - Subluxation due to SC ligament and capsule disruption
• Grade III - True dislocation; complete rupture of both SC and costoclavicular ligaments

• Prominent, palpable medial end of clavicle displaced anteriorly
• Pain with any movement of the upper extremity
• Arm held in flexion at elbow, supported across trunk
• SC joint swollen and tender on palpation
• Crepitus may be present

• More painful than anterior
• Red-flag signs: hoarseness, dysphagia, dyspnea, venous congestion of the neck, cyanosis, upper limb paresthesias
• Can compress or lacerate great vessels, trachea, esophagus
• 25% of posterior dislocations have life-threatening complications

Red Flag: In younger patients (<25 years), apparent SC "dislocation" is often a Salter-Harris type I/II physeal injury through the medial clavicular epiphysis (which does not fuse until age 23-25). - Rockwood and Green's Fractures, p. 1092

2. Medial Clavicle Fracture

3. SC Joint Inflammatory Arthritis (Non-traumatic)

• Rheumatoid arthritis (RA)
• Psoriatic arthritis
• Ankylosing spondylitis
• Palmoplantar pustulosis (SAPHO syndrome)
• Septic arthritis (especially in IV drug users - Pseudomonas is common)

4. Septic Arthritis of the SC Joint

• IV drug users (Pseudomonas aeruginosa is common)
• Immunocompromised patients
• Patients with indwelling subclavian catheters

5. Condensing Osteitis of the Medial Clavicle

• Most common in women of late childbearing age
• Painful swelling over the medial one-third of the clavicle
• Radiographs show sclerosis; similar to condensing osteitis of the ilium/pubis
• Benign, idiopathic, self-limiting
• Also called aseptic enlarging osteosclerosis of the clavicle
• Firestein & Kelley's Textbook of Rheumatology; Rockwood and Green's Fractures

6. Friedrich's Disease (Osteonecrosis of the Medial Clavicle)

• Painful osteonecrosis of the sternal end of the clavicle
• Predominantly in women
• Rare but must be distinguished from infection and malignancy

7. Tietze's Syndrome

• Painful, non-suppurative swelling of the SC joint and adjacent sternochondral junctions
• Presents with localized tenderness and swelling at the SC joint / medial clavicle area
• Self-limiting

8. SC Hyperostosis (SAPHO Syndrome)

• Inflammatory condition causing new bone formation and potential ankylosis of the SC joint and medial ribs
• Associated with Japanese ethnicity and dermatologic lesions (palmoplantar pustulosis)
• Also classified under SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis)

9. Referred Pain / Cervical Spine Pathology

• About 5% of patients presenting with shoulder pain have an isolated cervical spine disorder as the cause
• The SC joint can refer pain to the neck and anterior chest
• Always examine the cervical spine in any shoulder pain patient
• Campbell's Operative Orthopaedics 15th Ed 2026

Physical Examination Approach

1. Inspection: Compare both shoulders - look for asymmetry, swelling, deformity, ecchymosis
2. Palpation: Systematically palpate the SC joint, clavicle, AC joint, and acromion - tenderness localizes the pathology
3. Range of motion: Active and passive; note painful arcs
4. Neurovascular exam: Both upper extremities - assess for brachial plexus or vascular compromise
5. Cervical spine: Examine to rule out referred pain
6. Airway/breathing assessment: If SC involvement - check for jugular venous distension, hoarseness, dyspnea (posterior dislocation warning signs)

Investigations

Summary Table

Updated Clinical Picture: Occupational Context - Sedentary Sewing Job

• Sustained forward head posture + protracted shoulders
• Chronic muscle overload of the neck, shoulder girdle, and pectoral muscles
• Narrowing of the costoclavicular and thoracic outlet spaces
• Microtrauma to SC joint ligaments from repetitive arm/shoulder cycling

Top Diagnoses in This Occupational Context

1. Costoclavicular Syndrome (a subtype of Thoracic Outlet Syndrome)

"Narrowing of the costoclavicular space is most common in persons with drooping shoulders, a flat back, retracted shoulders (from carrying heavy loads), a deformed first rib, or a previous clavicular fracture. Any narrowing of the costoclavicular space can be aggravated by lowering and retracting the shoulder girdle."

• Thieme Atlas of Anatomy (General Anatomy and Musculoskeletal System)

• Prolonged sitting rounds the thoracic spine and drops the shoulders forward and downward
• This narrows the space between the clavicle and first rib
• The neurovascular bundle (subclavian artery/vein + brachial plexus) gets compressed
• Results in anterior shoulder/clavicle aching, arm heaviness, and SC joint soreness

• Arm or hand tingling/numbness (especially ulnar distribution)
• Heaviness or fatigue in the arm after sewing for a while
• Venous swelling of the hand/forearm
• Pain that worsens as the day progresses (worse with prolonged sitting)
• Relief when lying down or elevating the arm

• Costoclavicular maneuver: Posterior rotation of the shoulders - reproduces symptoms
• Adson's test: Head rotated to affected side + deep inspiration - radial pulse diminishes
• EAST test (Elevated arm stress test): Arms raised 90°, open/close hands for 3 min - reproduces symptoms
• Harrison's Principles of Internal Medicine 22E (2025); Thieme Atlas of Anatomy

2. Myofascial Pain Syndrome - Trapezius / Levator Scapulae / Pectoralis Minor

"In the upper part of the trunk, a common trigger point cluster involves the muscles of the neck and shoulder area, including the trapezius, levator scapulae, and infraspinatus muscles."

• Roberts and Hedges' Clinical Procedures in Emergency Medicine

• Sustained isometric contraction of the upper trapezius (holding the arm up to sew)
• Pectoralis minor overactivity from protracted posture
• This overactivity of pectorals + weakness of upper trapezius leads to:
  • Subacromial impingement symptoms
  • Thoracic outlet syndrome symptoms
  • Anterior shoulder and SC joint referred pain

"Excessive depression of the scapula... weakness of the upper trapezius or overactivity of the pectorals and latissimus dorsi can lead to pain and symptoms of subacromial impingement or brachialgia and thoracic outlet syndrome."

• Rheumatology 2-Volume Set (Elsevier 2022)

3. SC Joint Stress / Overuse Subluxation

• Ligamentous laxity and microinstability at the SC joint
• Painful subluxation with palpable crepitus
• Localized SC joint tenderness

"The most common problem involves ligamentous injury and painful subluxation, which can be diagnosed by palpable instability and crepitus over the sternoclavicular joint."

• Firestein & Kelley's Textbook of Rheumatology

4. Thoracic Outlet Syndrome - Neurogenic Form

• Anterior shoulder + clavicular aching
• Radiating arm pain (often ulnar)
• Paresthesias in the hand

1. Interscalene space (scalene syndrome - cervical rib or muscle)
2. Costoclavicular space between clavicle and first rib - most relevant here
3. Sub-pectoralis minor space (hyperabduction syndrome)

• Thieme Atlas of Anatomy; Harrison's Principles of Internal Medicine 22E

5. SC Joint Osteoarthritis / Inflammatory Flare

• Degenerative OA of the SC joint (common in middle-aged to older patients)
• Appears as pseudosubluxation anteriorly on imaging
• Pain and stiffness worse after prolonged use, eases with rest

Revised Diagnostic Priority in This Patient

What to Look For in Examination

1. Posture assessment: Rounded shoulders? Forward head? Thoracic kyphosis?
2. SC joint palpation: Tenderness, swelling, crepitus, subluxation
3. Costoclavicular maneuver and Adson's test to reproduce symptoms
4. Trigger points: Upper trapezius, pectoralis minor, levator scapulae
5. Neurological screen: Sensation in medial forearm + hand (ulnar nerve territory)
6. Pulse comparison in provocative positions

Investigations

Management Principles

1. Ergonomic correction - raise the sewing table height, use armrests, support the forearms
2. Postural exercises - shoulder retraction, chin tucks, thoracic extension
3. Physiotherapy - trigger point release, scapular stabilization exercises
4. NSAIDs for pain control
5. Rest breaks every 30-45 minutes during work
6. Surgical decompression (first rib resection) only if conservative management fails over 3-6 months - Harrison's Principles of Internal Medicine 22E (2025)