What is the treatment for an oblique, non-displaced fracture of the 4th metacarpal bone diaphysis?

Treatment for Oblique Non-Displaced Fracture of 4th Metacarpal Bone Diaphysis

Conservative treatment with functional taping or a hand-based splint is the recommended approach for an oblique, non-displaced fracture of the 4th metacarpal bone diaphysis, allowing for early mobilization and faster functional recovery. 1, 2

Initial Assessment and Imaging

• Initial evaluation should include 3-view radiographs of the hand (posteroanterior, lateral, and 45° semipronated oblique) to confirm the diagnosis and assess fracture characteristics 3
• Ensure there is no malrotation, angulation greater than 30 degrees, or shortening greater than 5mm, which would require surgical intervention 4
• Confirm the fracture is truly non-displaced, as displacement may necessitate different management approaches 4

Treatment Algorithm

Conservative Management (Recommended for Non-Displaced Oblique Fractures)

1. Functional Treatment Options:

   • Buddy taping (taping the injured finger to an adjacent uninjured finger) for 4 weeks 1
   • Hand-based functional splint that allows metacarpophalangeal joint, interphalangeal joint, and radiocarpal joint motion for approximately 24 days 5

2. Alternative Option (Less Preferred):

   • Short-term cast immobilization (if needed for pain control) with the fingers in extended position and metacarpophalangeal joint flexed 60-90 degrees, but only for a brief period until swelling subsides 4
   • Transition to functional treatment as soon as possible 4

Expected Outcomes and Follow-up

• Clinical and radiographic assessments should be performed at approximately day 15, then at 1 month, 2 months, and 6 months post-fracture 1
• Most fractures show radiographic healing by 2 months 1
• Functional recovery is significantly faster with functional taping compared to cast immobilization 2
• Range of motion typically returns to 90% of the contralateral side after 2 months 1
• Grip and pinch strength may be approximately 33% less than the contralateral side at 2 months but continues to improve 1

Advantages of Functional Treatment

• Allows for excellent maintenance of fracture reduction 5
• Enables early or immediate return to pre-injury activities 5
• Maintains functional motion throughout treatment period 5
• Results in lower patient morbidity and faster recovery 2, 5
• Most patients can continue working without missing days 5

Potential Complications and Monitoring

• Secondary displacement occurs in approximately 11% of cases but usually remains within acceptable limits 1
• Monitor for any signs of malrotation, which would require surgical intervention 4
• Watch for excessive angulation (>30 degrees) which may require reassessment and possible surgical management 4

Special Considerations

• For oblique fractures of the metacarpal diaphysis, functional treatment is particularly appropriate as these fractures tend to be more stable than transverse fractures 1
• Long oblique or spiral fractures typically have less initial volar tilt (average 11.5°) compared to short oblique or transverse fractures (average 26°) 1
• If the fracture shows signs of instability during follow-up, reassessment and possible conversion to surgical management may be necessary 4