What is the next step in treatment for a 67-year-old with a fallen outstretched arm, experiencing pain and numbness over the thumb and first three fingers?

Management of Suspected Carpal Tunnel Syndrome After Fall on Outstretched Arm

The next step in treatment for this 67-year-old patient with suspected carpal tunnel syndrome after a fall on an outstretched arm should be immediate radiographic imaging with a 3-view wrist series (posteroanterior, lateral, and 45° semipronated oblique views) to rule out fracture before any other interventions. 1

Initial Assessment and Imaging

The patient's presentation with pain and numbness in the thumb and first three fingers after a fall on an outstretched arm raises concerns for both:

1. Possible wrist/distal radius fracture
2. Acute carpal tunnel syndrome (median nerve compression)

This pattern of numbness in the thumb and first three fingers is classic for median nerve involvement, which could be due to:

• Direct trauma to the nerve
• Compression from fracture fragments
• Swelling in the carpal tunnel after trauma

Imaging Protocol:

• Standard 3-view radiographic examination (posteroanterior, lateral, and 45° semipronated oblique views) 1
• If initial radiographs are negative but clinical suspicion remains high, consider CT scanning or MRI without contrast 1

Treatment Algorithm

If Fracture Present:

1. For stable, non-displaced fractures:

   • Functional splinting is preferred over complete immobilization 1
   • Early range of motion exercises under supervision 1

2. For unstable or displaced fractures:

   • Surgical intervention is indicated if:
     • Intra-articular fractures with >2mm step-off
     • Volar displacement of fragments
     • Interfragmentary gap >3mm
     • Postreduction radial shortening >3mm or dorsal tilt >10° 2, 1

If No Fracture but Persistent Neurological Symptoms:

1. Initial management:

   • Wrist splint in neutral position to reduce pressure in carpal tunnel
   • Cold application to reduce swelling and pain 2
   • Limit cold application to 20 minutes to prevent cold injury 2
   • Place a barrier between cold container and skin 2

2. Monitoring for progression:

   • If symptoms worsen or do not improve, urgent referral for nerve decompression may be necessary

Special Considerations

Nerve Injury Management:

• Most peripheral nerve injuries associated with closed fractures are neurapraxia (temporary loss of function) with excellent prognosis for spontaneous recovery 3, 4
• Immediate surgery for nerve symptoms is usually unwarranted in the acute setting due to difficulty accurately defining severity 3
• If symptoms persist beyond 3-4 months, nerve exploration may be indicated 3, 4

Complications to Monitor:

• Vascular compromise (pale or blue extremity requires immediate EMS activation) 2
• Complex regional pain syndrome
• Delayed carpal tunnel syndrome
• Malunion or nonunion if fracture present 1

Pitfalls to Avoid

1. Do not attempt to straighten the injured extremity if a fracture is suspected, as this may cause further injury 2

2. Do not delay imaging - underestimating the injury can lead to long-term hand/wrist impairment 1

3. Do not overlook nerve symptoms - persistent numbness requires close monitoring and may need specialist evaluation

4. Do not apply excessive compression which could worsen nerve compression symptoms

5. Do not immobilize for prolonged periods without a clear indication, as this can lead to stiffness and delayed recovery 1

By following this systematic approach with prompt imaging and appropriate management based on findings, you can optimize outcomes and minimize complications for this patient with suspected carpal tunnel syndrome after trauma.