What are the treatment options for a fractured thumb and when should a patient be referred to an orthopedic specialist or hand surgeon?

Treatment Options and Referral Criteria for Thumb Fractures

Most thumb fractures can be managed conservatively with thumb spica immobilization for 3-6 weeks, but immediate orthopedic referral is mandatory when fracture displacement exceeds 3mm, articular involvement exceeds one-third of the joint surface, or when there is rotational deformity causing functional impairment. 1

Initial Assessment and Imaging

• Obtain at minimum 2-view radiographs (PA and lateral) of the thumb, though adding an oblique view increases diagnostic accuracy 1
• Specifically assess for fracture displacement (measure if >3mm), articular surface involvement (estimate percentage), and rotational alignment 1
• CT imaging should be considered when radiographs are equivocal or fracture pattern is unclear 2

Treatment Algorithm Based on Fracture Characteristics

Conservative Management Indications

Treat non-operatively with rigid thumb spica cast or splint when:

• Fracture displacement is <2-3mm 1
• Extra-articular fractures with angulation up to 30 degrees (compensatory motion at the carpometacarpal joint tolerates this deformity) 3
• Avulsion fractures at the ulnar base of proximal phalanx that are stable to lateral stress testing (even if displaced or rotated) 4

Immobilization protocol:

• Duration: 3-6 weeks in thumb spica cast or splint 1
• Follow-up radiographs at 10-14 days to confirm maintained position 1
• The thumb interphalangeal joint can remain mobile during treatment 4

Mandatory Orthopedic/Hand Surgery Referral

Refer immediately for surgical evaluation when:

• Fracture displacement >3mm 1
• Articular involvement >1/3 of joint surface 1
• Bennett fractures (intra-articular fracture-dislocation at thumb metacarpal base) - goal is <1mm articular step-off 3
• Rolando fractures (comminuted intra-articular base fractures) 3
• Avulsion fractures with lateral instability on stress testing 4
• Rotational deformity causing finger overlap or functional impairment 2
• Failed conservative treatment (persistent pain or loss of function) 1

Surgical Treatment Options (Specialist Decision)

• Bennett fractures: closed reduction with percutaneous Kirschner wire fixation 3
• Large Bennett fragments and Rolando fractures: open reduction and internal fixation for anatomic reduction 3
• Long oblique fractures: interfragmentary screws providing compression 2
• Severely comminuted fractures: external fixator with limited open reduction and bone grafting 3

Critical Pitfalls to Avoid

• Do not assume all displaced avulsion fractures require surgery - if the thumb is stable to lateral stress testing, non-operative treatment achieves 93% patient satisfaction despite 60% fibrous non-union rate 4
• Do not delay referral for intra-articular fractures - residual articular incongruity >1mm increases long-term posttraumatic arthritis risk 3
• Do not accept rotational deformity - this causes functional finger overlap and requires surgical correction 2
• Verify fracture position is maintained at 10-14 day follow-up, as severe deforming forces act to displace thumb base fractures into varus and shortened position 3

Post-Treatment Monitoring

• Serial radiographs to ensure proper healing and alignment 2
• Monitor specifically for pain relief and restoration of function 1
• Patients should achieve return to full work activities and sports participation with appropriate treatment 4