What is the appropriate history, physical examination, and initial management for a patient presenting with forearm pain?

Forearm Pain: Clinical Approach and Management

Initial Assessment and History

Start with plain radiographs (AP, lateral, and oblique views) as the mandatory first-line imaging for any patient presenting with forearm pain, regardless of mechanism of injury. 1, 2

Key Historical Elements to Elicit

• Mechanism of injury: Fall onto outstretched hand suggests possible fracture (radial head, olecranon, coronoid process); direct blow may indicate soft tissue injury or compartment syndrome 1, 3
• Timing and onset: Acute traumatic versus subacute/chronic overuse patterns guide differential diagnosis 4, 5
• Pain characteristics: Sharp, shooting pain during activity suggests brachioradialis muscle pain; pain out of proportion to examination findings is the hallmark of compartment syndrome 6, 3
• Functional limitations: Difficulty with gripping, opening doors, shaking hands, or using tools points toward brachioradialis or tendon pathology 6
• Occupational factors: Repetitive wrist extension (cycling, baseball catching) increases risk of ulnar neuropathy; repetitive forearm use suggests tendinopathy 4, 5

Critical Physical Examination Findings

• Passive stretch testing: Pain with passive wrist and digit extension is pathognomonic for compartment syndrome and requires emergent fasciotomy 3
• Palpation: Tenderness over lateral elbow extending through forearm to thumb/index finger suggests brachioradialis muscle pain 6
• Neurovascular assessment: Sensory changes in 4th and 5th digits indicate ulnar neuropathy; medial forearm dysesthesia suggests medial antebrachial cutaneous nerve injury 4, 7
• Elbow extension test: Inability to fully extend elbow while sitting with shoulders at 90° flexion predicts occult fracture in 12.8% of cases with normal radiographs 1, 2
• Joint effusion signs: Posterior and anterior fat pad elevation on exam or radiographs indicates occult fracture even without visible fracture line 2

Imaging Algorithm

Step 1: Plain Radiographs (Always First)

• Radiographs detect: Fractures, dislocations, avulsion injuries, joint effusions, and soft tissue calcifications in 62% of cases 8, 2, 9
• Standard views: AP, lateral, and oblique projections of the forearm and elbow 1, 2
• Comparison views: Consider contralateral elbow if subtle findings or pediatric patient 1

Step 2: If Radiographs Normal but Fracture Still Suspected

Order CT of elbow/forearm without IV contrast, which identifies occult fractures in 12.8% of patients with normal radiographs and positive elbow extension test 1, 2

• CT clarifies fracture morphology, fragment size, displacement, and angulation for surgical planning 1
• Particularly useful for radial head, coronoid process, and olecranon fractures 1, 2

Step 3: If Radiographs Normal but Soft Tissue Injury Suspected

Order MRI of elbow/forearm without IV contrast, which demonstrates 87.5% concordance with surgical findings for medial collateral ligament injuries and 90.9% for lateral collateral ligament injuries 1, 2

• MRI is superior for detecting tendon tears (biceps, triceps), ligament injuries, muscle tears, and hematomas 1, 2
• Provides excellent visualization of bone marrow edema and occult stress injuries 8

Step 4: If Mass or Lump Present

• Superficial/palpable masses: Add ultrasound after radiographs (94.1% sensitivity, 99.7% specificity) 9
• Deep or indeterminate masses: Proceed directly to MRI without and with IV contrast for tissue characterization and biopsy planning 9

Red Flags Requiring Urgent Action

Compartment Syndrome (Emergent Fasciotomy Required)

• Pain out of proportion to examination findings combined with pain on passive stretch of wrist/digits 3
• Mechanism: Osseofascial swelling causing decreased tissue perfusion and tissue necrosis 3
• Do not delay for imaging—this is a clinical diagnosis requiring immediate surgical decompression 3

Infection (Urgent Evaluation)

• Fever, spreading erythema, warmth, or systemic symptoms warrant evaluation for osteomyelitis or septic arthritis 8
• Rapid progression over hours to days suggests infectious process 8

Soft Tissue Sarcoma (Urgent Referral)

• Lump that is deep-seated, larger than 5 cm, or increasing in size requires referral to sarcoma specialist within 2 weeks 8
• Even with minor trauma history, unexplained masses warrant ultrasound to exclude malignancy 8, 9

Common Diagnoses and Management Pitfalls

Brachioradialis Muscle Pain (Frequently Misdiagnosed)

• Presentation: Sharp pain during activity, aching at rest from lateral elbow through forearm to thumb/index finger 6
• Triggers: Repetitive overuse, putting down cups, opening doors, handshaking, tool use 6
• Treatment: RICE protocol, stretching exercises, myofascial injection or botulinum toxin injection 6
• Pitfall: Often misdiagnosed as lateral epicondylitis, radial tunnel syndrome, or de Quervain's tenosynovitis 6

Occult Fractures

• Pitfall: Conventional radiography alone misses up to 30% of scaphoid fractures 4
• Solution: Use specialized views (PA in ulnar deviation, pronated oblique) and repeat radiographs in 10-14 days if initial films negative 4
• Joint effusion (fat pad elevation) on radiographs indicates occult fracture even without visible fracture line 2

Nerve Entrapment

• Ulnar neuropathy: Wrist discomfort with sensory changes in 4th and 5th digits; associated with repetitive wrist extension activities 4
• Medial antebrachial cutaneous nerve: Medial forearm pain and dysesthesia from repeated minor trauma 7
• Diagnosis: Electrodiagnostic testing identifies location and extent of nerve pathology 4, 7

Initial Management Framework

Conservative Treatment (Most Cases)

• RICE protocol: Rest, ice, compression, elevation for muscle strains and overuse injuries 6
• NSAIDs: For pain control in tendinopathy and muscle injuries 7
• Physical therapy: Stretching exercises for brachioradialis and other muscle-related pain 6
• Activity modification: Avoid repetitive motions and provocative activities 5

Injection Therapy

• Myofascial injection or botulinum toxin injection for refractory brachioradialis muscle pain 6
• Consider after failure of conservative measures for 4-6 weeks

Surgical Indications

• Immediate fasciotomy: Compartment syndrome with pain out of proportion and positive passive stretch test 3
• Fracture fixation: Complex fractures with significant displacement, angulation, or joint involvement identified on CT 1
• Ligament reconstruction: Gross instability with frank redislocation on stress testing 1