From the Guidelines
For a 4th metacarpal fracture, a simple immobilization method such as an ulnar gutter splint is typically recommended when fracture fragments are small, nonarticular, or minimally displaced. This approach is supported by the general principles of fracture management, which prioritize stability and immobilization to promote proper healing 1.
Key Considerations for Immobilization
- The splint should extend from the forearm to the hand, covering the ulnar side of the wrist and hand while immobilizing the 4th and 5th metacarpals and their corresponding fingers.
- The wrist should be positioned in slight extension (about 20-30 degrees), the metacarpophalangeal joints flexed at 70-90 degrees, and the interphalangeal joints in slight flexion to maintain proper hand function.
- The duration of immobilization may vary based on fracture severity and healing progress, but typically lasts for approximately 3-4 weeks for non-displaced fractures.
Additional Care Recommendations
- Elevating the hand above heart level and applying ice for the first 48-72 hours can help reduce swelling.
- Finger exercises for the unaffected digits should be performed regularly to prevent stiffness. The ulnar gutter splint is preferred for 4th metacarpal fractures because it effectively immobilizes the fracture site while allowing some functional use of the thumb and index finger, which helps maintain hand dexterity during the healing process 1.
From the Research
Types of Splints for 4th Metacarpal Fracture
- A hand-based functional splint can be used for non-operative treatment of 4th metacarpal fractures, allowing for maintenance of fracture reduction, early return to pre-injury activities, and low patient morbidity 2.
- Transverse fixation using Kirchner wires can also be effective in treating 4th metacarpal fractures, with improved functional outcomes and minimal complications 3.
- A thermoplastic splint with a thumb stabilizing component can be used as a surgical instrument to aid in open reduction and internal fixation of metacarpal fractures, including those of the 4th metacarpal 4.
- Non-operative treatment using a protocol of casting and outrigger can also be effective in treating isolated 4th metacarpal fractures, with no significant difference in functional outcome compared to operative treatment 5.
Characteristics of Splints for 4th Metacarpal Fracture
- The splint should allow for metacarpophalangeal joint, interphalangeal joint, and radiocarpal joint motion to maintain functional mobility 2.
- The splint can be custom fabricated preoperatively by a specialist hand therapist to ensure a proper fit and optimal support 4.
- Bioabsorbable screws can be used for internal fixation of proximal fractures of the 2nd and 4th metacarpal bones, offering a safe and feasible technique with several advantages over traditional metallic implants 6.