Etiology

Shoulder pathology
Rotator cuff disorders
Frozen shoulder
Glenohumeral joint osteoarthritis
Acromioclavicular joint disease
Instability disorders
Inflammatory arthritis
Septic arthritis
Paget’s disease
Avascular necrosis of the humeral head

Pathology outside the shoulder
Malignancy (1º or 2 bone or nearby malignancy, such as apical lung cancer)
Referred pain from the neck, heart, lungs or diaphragm
Polymyalgia rheumatica
Early herpes zoster (C5-T1 dermatomes)

Red Flags

Any history of trauma? Urgently refer, as may indicate rotator cuff tear or dislocation

Symptoms and signs
Trauma, pain and weakness, or sudden inability to actively raise the arm
Shoulder mass or swelling, lymphadenopathy, symptoms or signs of cancer
Red skin, painful joint, fever or the person is systemically unwell
Trauma leading to loss of rotation and abnormal shape
New symptoms of inflammation in several joints

Systemic symptoms: fever, night sweats, weight loss or new respiratory symptoms
Neurological lesion (unexplained wasting, significant motor or sensory deficit)ly

Initial assessment:

Condition
Acute rotator cuff tear
Malignancy
Septic arthritis
Shoulder dislocation
Inflammatory arthritis

Refer secondary care

Physiopathology

Rotator cuff disorders
Affects people aged 35-75yr, often with history of repetitive movements at shoulder height or heavy lifting activities.
Rotator cuff is the group of muscles and tendons that surround's and stabilise the shoulder.
Shoulder impingement between acromion and rotator cuff tendons causes rotator cuff tendinopathy and/or partial rotator cuff tear.
There can be night pain.
Consider subacromial corticosteroid/local anaesthetic injection
Secondary care options: surgery such as rotator cuff repair, subacromial decompression, or shoulder joint replacement

1. Pain experienced in the top and lateral side of shoulder (subacromial bursitis, supraspinatus tendinopathy).

2. Pain on abduction with the thumb down, which is worse against resistance

3. Painful arc 70-120 degrees of abduction

Check for traumatic rotator cuff tear (if confirmed, urgently refer to orthopaedics)

Trauma (dislocation or traction injury) + severe pain/weakness + positive ‘drop-arm test’ (unable to support the weight of the arm when it is abducted to 90 degrees).

Frozen Shoulder
Affects people aged 40-60yr. More common in women.
Primary (idiopathic) or secondary classification.
Secondary conditions include: trauma, rotator cuff disease, cardiovascular disease, hemiparesis, diabetes and thyroid dysfunction.
Progressive condition (pain followed by stiffness phases) with resolution by 18-24 months.
Pain can disturb sleep
Consider intra-articular (glenohumeral) corticosteroid/local anaesthetic injection

1. Gradual onset of pain in the deltoid region, with worsening shoulder stiffness

2. Global restriction of movement with a severe loss of passive external rotation

3. No crepitus on movement

Glenohumeral joint arthritis

Affects people>60y.
Previous trauma, chronic rotator cuff tear and systemic arthritis

1. Deep joint pain

2. Global restriction of movement with a severe loss of passive external rotation

3. X-ray (AP and axillary views) is needed to confirm the diagnosis and exclude other diagnosis such as avascular necrosis of humeral head

Consider intra-articular (glenohumeral) corticosteroid/local anaesthetic injection for acute/temporary symptom control (for example, if surgery is delayed)
Secondary care treatment options: arthroscopic debridement, biological glenoid resurfacing, hemiarthroplasty, total shoulder replacement

Acromioclavicular joint disorders

Acromioclavicular joint injuries
Affects people aged 20-50y (usually men)
Previous fall onto the shoulder

Acromioclavicular osteoarthritis
Affects people over 60y.
Previous acromioclavicular joint sprain.

Classification:
Grade I: Minor tear of the acromioclavicular (AC) ligament; coracoclavicular (CC) ligament intact.
Grade II: <50% vertical subluxation of the clavicle (complete rupture of AC and stretched CC ligaments).
Grade III: >50% vertical subluxation of the clavicle (complete rupture of both AC and CC ligaments).

Examination:

1. Tenderness over the AC joint

2. High arc pain

3. A positive cross-arm test: pain over AC joint and/or restriction of passive, horizontal movement of the arm adducted across the body when the elbow is extended.

4. Arrange X-ray (if history of trauma, conservative treatment unsuccessful, or diagnostic uncertainty)

5. Consider corticosteroid/local anaesthetic injection if severe pain

Instability disorders
Affects people <35yr.
Abnormal movement of the head of the humerus, causing either intermittent pain, ‘clicking’, subluxation or dislocation
Other symptoms may include: arm/hand weakness and/or numbness and tingling from proximal nerve traction.
Person feels as though the arm is ‘not completely within the joint’, particularly during certain activities or sports.
96% of shoulder dislocations are due to trauma (usually anterior rather than posterior dislocation) and can be complicated by axillary nerve injury, greater tuberosity fracture and rotator cuff tear.

Classification:

• traumatic structural instability

• atraumatic structural instability (young females with hypermobile joints)

• muscle patterning (poor posture)
  

History

• History of trauma and mechanism

• Shoulder: pain, stiffness, instability +/- dislocation

• Functional impairment and affect upon occupation and sporting activities

• Outside shoulder:
  MSK: other joint symptoms, neck pain
  Systemic features: fever, night sweats, weight loss, rash, respiratory or neurological symptoms
  Significant co-morbidities: diabetes, stroke, ischaemic heart disease, malignancy (such as breast or lung cancer), gastrointestinal or renal disease

• Previous history of musculoskeletal problems

• Family history of musculoskeletal problems

• Drugs (adverse drug side effects such as statin myopathy)

Examination of the shoulder

1. Compare both shoulders

2. Inspection: muscle wasting, swelling, deformity or bruising

3. Palpation: tenderness of bones (clavicle, proximal humerus, scapula) or joints (sternoclavicular, acromioclavicular, glenohumeral); crepitus on movement

4. Active and passive movements:
   Flexion, extension, abduction adduction, internal and external rotation
   Does movement elicit subjective shoulder instability?
   Arm abduction tests: thumb down, worse against resistance, painful arc 70-120 degrees
   Drop-arm test
   Cross-arm test
   Restrictive passive external rotation (frozen shoulder, glenohumeral osteoarthritis, avascular necrosis of humeral head, dislocation)

5. Examine for referred pain from other sites: neck, arms, axilla and chest.
   If neck movement reproduces pain, then assess neck for pathology (such as torticollis, cervical radiculopathy)

6. Neurological examination, if appropriate.

Investigations

Blood tests (such as FBC, ESR, CRP):
If suspect malignancy, polymyalgia rheumatica or inflammatory arthritis
Check for diabetes in people with frozen shoulder

X-ray indications:

• History of trauma +/- loss of abduction

• No improvement with conservative treatment or symptoms last more than four weeks

• Severe pain or restriction of movement (particularly if glenohumeral osteoarthritis or avascular necrosis is confirmed by X-ray)

• Suspected arthritis

• Presence of Red Flags

Management

Emergency/urgent orthopaedic assessment if acute trauma and any Red Flags

Patient information (Arthritis Research UK Shoulder Pain leaflet)

Analgesia (paracetamol, naproxen with PPI)

Physiotherapy referral

Consider corticosteroid/local anaesthetic injection (for rotator cuff, glenohumeral disorders, and AC joint disorders)

Referral to a specialised musculoskeletal clinic for further assessment (including shoulder ultrasound and MRI):

• If pain and function are not improving following conservative treatment for 3 months

• Pain is having significant impact on the person

• There is recurrent shoulder instability

• There is severe post-traumatic pain.