Evaluating thumb pain involves a thorough process that includes taking a detailed history, performing a physical examination, and potentially ordering imaging studies. This helps determine the underlying cause and guide appropriate treatment.
1. History:
- Onset and Duration: When did the pain start? How long has it lasted?
- Mechanism of Injury: Was there a specific injury (e.g., fall, sports injury)? What were the circumstances?
- Pain Characteristics: Describe the pain (sharp, dull, aching, throbbing). Where is the pain located? Does it radiate?
- Aggravating and Relieving Factors: What activities make the pain worse? What makes it better?
- Associated Symptoms: Any swelling, stiffness, numbness, tingling, or weakness?
- Past Medical History: Any relevant medical conditions (e.g., arthritis, diabetes) or previous thumb injuries?
- Occupation and Activities: What are your daily activities and work demands?
2. Physical Examination:
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Inspection: Look for swelling, bruising, redness, deformity, or any other visible abnormalities.
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Palpation: Gently feel different areas of the thumb and wrist to identify areas of tenderness.
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Range of Motion: Assess the active and passive range of motion of the thumb joints (CMC, MCP, IP). Note any pain or limitations.
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Strength Testing: Evaluate the strength of thumb abduction, adduction, flexion, and extension.
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Specific Tests: Several specific tests can help identify certain conditions:
- Grind Test: This test assesses for arthritis at the carpometacarpal (CMC) joint. The examiner grips the metacarpal bone of the thumb and moves it in a circular motion while applying gentle axial compression. A positive test elicits sharp pain and potentially crepitus at the CMC joint.
- Finkelstein's Test: This test assesses for De Quervain's tenosynovitis. The patient makes a fist with the thumb tucked inside. The examiner then ulnarly deviates the wrist (bends the wrist towards the little finger). A positive test elicits pain along the radial side of the wrist (thumb side).
- Ligament Stability Testing: Apply varus and valgus stress to the MCP and IP joints to assess the integrity of the collateral ligaments. Laxity or pain indicates a ligament sprain or tear.
- Thumb CMC Instability Test: This test assesses the stability of the CMC joint. The examiner stabilizes the trapezium and applies dorsal and palmar translation to the base of the metacarpal. Excessive movement or pain indicates ligamentous laxity.
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Neurovascular Examination: Assess sensation and circulation in the thumb and hand.
3. Imaging Studies (if indicated):
- X-rays: Used to evaluate for fractures, dislocations, arthritis, and other bony abnormalities.
- MRI: Used to evaluate soft tissues, such as ligaments, tendons, and cartilage. Helpful for diagnosing ligament tears, tendonitis, and other soft tissue injuries.
- Ultrasound: Can be used to evaluate tendons and ligaments.
- Nerve Conduction Studies (NCS) and Electromyography (EMG): May be performed if nerve compression is suspected (e.g., carpal tunnel syndrome).
Differential Diagnosis:
Based on the history, physical examination, and imaging studies, the following are some common causes of thumb pain:
- Arthritis: Osteoarthritis, rheumatoid arthritis
- De Quervain's Tenosynovitis: Inflammation of the tendons on the thumb side of the wrist.
- Ligament Sprains/Tears: UCL (ulnar collateral ligament) injury (Skier's Thumb), RCL (radial collateral ligament) injury.
- Fractures: Scaphoid fracture, Bennett's fracture, Rolando fracture.
- Tendonitis: Inflammation of the thumb tendons.
- Carpal Tunnel Syndrome: Compression of the median nerve at the wrist, which can cause pain, numbness, and tingling in the thumb and fingers.
- Trigger Thumb: Stenosing tenosynovitis of the flexor pollicis longus tendon.
By combining the information gathered through history, physical examination, and imaging (when necessary), a diagnosis can be reached, and an appropriate treatment plan can be developed.
