From the Guidelines
The best immobilization for a first metacarpal fracture is typically a thumb spica cast or splint, which immobilizes both the wrist and the thumb while leaving the other fingers free to move. For stable, non-displaced fractures, a removable thumb spica splint may be sufficient, while displaced or unstable fractures generally require a well-molded thumb spica cast. The immobilization should extend from below the elbow to the interphalangeal joint of the thumb, maintaining the thumb in a position of function with slight opposition. This position helps preserve the web space between the thumb and index finger, which is crucial for hand function. Key considerations for immobilization include:
- The type of fracture: non-displaced, displaced, or comminuted
- The stability of the fracture: stable or unstable
- The presence of any associated injuries: such as ligament sprains or nerve damage The immobilization period typically lasts 4-6 weeks, with radiographic follow-up at 1-2 weeks to ensure the fracture remains properly aligned, as simple immobilization is appropriate when fracture fragments are small, nonarticular; or minimally displaced 1. After the immobilization period, a gradual return to activities with physical therapy is recommended to restore strength and range of motion. This approach works well because it provides adequate stability to the fracture site while minimizing stiffness in the uninvolved joints, allowing for optimal healing and functional recovery. Some key points to consider when choosing an immobilization method include:
- The need for adequate stability and support to promote proper healing
- The importance of maintaining range of motion in uninvolved joints to prevent stiffness
- The potential for complications, such as nerve damage or infection, and the need for close monitoring and follow-up.
From the Research
Immobilization Options for First Metacarpal Fracture
- The best immobilization for a first metacarpal fracture can be achieved through various methods, including casting and orthosis management 2.
- A study from 1986 found that a modified thumb spica cast (MTSC) can be an effective form of immobilization for treating injuries of the metacarpophalangeal joint of the thumb, including fractures 3.
- The MTSC allows for full flexion and extension of the wrist, improving functional capabilities during immobilization, and has good patient acceptance 3.
- Another study from 2021 recommends the use of removable orthoses for immobilization of nonsurgical metacarpal fractures, as they have been shown to be effective in healing, patient satisfaction, and time to return to activity 2.
- However, the effectiveness of thumb immobilization in contributing to scaphoid fracture stability has been questioned, with one study finding no significant difference in fracture angulation or rotation between spica and short arm casts 4.
Comparison of Casting Methods
- A comparison of long arm thumb-spica versus Munster thumb-spica casts found that the latter may allow for some elbow motion during the long immobilization period, potentially playing a role in the conservative treatment of non-displaced scaphoid fractures 5.
- The application of a thumb spica cast is a valuable skill for family physicians to provide appropriate and definitive care for patients with scaphoid fractures 6.