What is the appropriate treatment for a young to middle-aged adult with a history of recent trauma and possible conditions like osteoporosis or previous fractures who has been diagnosed with a Bennett fracture?

Bennett Fracture Treatment

For a young to middle-aged adult with a Bennett fracture, surgical treatment with open reduction and internal fixation using screws, K-wires, or mini-plates is the definitive approach, as adequate reduction and maintenance of reduction are essential to prevent post-traumatic osteoarthritis and preserve first carpometacarpal joint function. 1

Immediate Assessment and Diagnosis

• Mechanism of injury: Typically results from axial trauma to a partially flexed thumb, fall on extended/abducted thumb, or impact to clenched fist 2, 1
• Clinical presentation: Pain, swelling, and loss of function at the base of the thumb with visible deformity 1
• Fracture pattern: Intra-articular fracture separating the palmar ulnar fragment (which remains attached to the volar ligament) from the metacarpal shaft, which displaces dorsally, proximally, and radially due to pull of abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis, and adductor pollicis 2
• Imaging: Standard radiographs including AP, lateral, and oblique views of the thumb to assess fracture displacement and joint congruity 1

Treatment Decision Algorithm

Surgical intervention is recommended for Bennett fractures due to inherent instability, regardless of initial displacement. 1, 3 The fracture is unstable by nature, and inadequate treatment leads to osteoarthritis, weakness, and loss of function 1.

Surgical Options (Choose Based on Fracture Pattern):

1. Interfragmentary screws (Herbert, AO, TwinFix): Preferred for larger fragments with adequate bone stock for screw purchase 3

2. Titanium mini T-plate: Suitable for comminuted or small fragments where screw fixation alone is insufficient 3

3. Percutaneous K-wire fixation: Option for minimally displaced fractures or when open reduction is contraindicated, though requires wire removal at 5-7 weeks 3

4. Open reduction internal fixation (ORIF): Use minimal 2-3 cm radiopalmar curving incision approach 3

Conservative Treatment (Limited Role):

• Only consider if displacement is less than 1-2 mm after closed reduction and patient cannot tolerate surgery 4
• Requires 5 weeks immobilization followed by 4-8 weeks physical therapy 4
• Critical caveat: Even 1 mm displacement warrants surgical treatment to prevent long-term complications 3

Surgical Timing and Technique

• Operate at the earliest possible time after injury, ideally within days 3
• Achieve anatomic reduction with less than 1 mm articular step-off 3, 4
• The key to successful outcome is adequate reduction and maintenance of reduction 1
• Hardware removal: K-wires require removal at 5-7 weeks; screws and plates can remain permanently 3

Postoperative Rehabilitation

• Begin physical rehabilitation as soon as possible after surgical stabilization 3
• Full recovery of function typically achieved between 4-8 weeks 3
• Early mobilization prevents stiffness while allowing fracture healing 3

Expected Outcomes and Complications

Primary concern: Post-traumatic osteoarthritis occurs in approximately 9% of patients overall 5

Secondary complications:

• Pain: 13% of patients 5
• Reoperation rate: 2% 5
• Infection: rare (less than 1%) 5
• Nonunion: essentially zero with appropriate treatment 5

Important caveat: Degenerative changes may develop radiographically but do not necessarily correlate with poor hand function if anatomic reduction was achieved 4

Special Considerations for Osteoporosis Context

While the provided evidence focuses primarily on osteoporotic hip and vertebral fractures 6, Bennett fractures are not classified as osteoporotic (fragility) fractures 6. They are traumatic fractures requiring significant external force and occur in the hand, which is specifically excluded from osteoporotic fracture definitions 6.

However, if the patient has documented osteoporosis:

• Ensure adequate calcium intake (1000-1200 mg/day) and vitamin D (800 IU/day) to support fracture healing 6
• Consider bone density evaluation if not previously performed 6
• Address any underlying metabolic bone disease that could impair healing 6

Critical Pitfalls to Avoid

• Do not accept any articular displacement: Even 1 mm requires surgical correction 3
• Do not delay surgery: Early intervention prevents complications and improves outcomes 3
• Do not rely on closed reduction alone: The fracture is inherently unstable and will redisplace 1
• Refer to hand surgeon: Due to technical complexity and importance of anatomic reduction 1