Splinting for Middle Finger Proximal Phalanx Fracture
For a middle finger proximal phalanx fracture, use a rigid dorsopalmar splint that immobilizes the wrist in 30 degrees of dorsiflexion and the metacarpophalangeal (MCP) joint in 70-90 degrees of flexion (intrinsic plus position), while allowing immediate active motion of the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints. 1, 2
Splint Configuration and Positioning
The optimal splint is a two-component thermoplastic or plaster splint system that provides:
- Wrist immobilization in 30 degrees of dorsiflexion 2
- MCP joint immobilization in 70-90 degrees of flexion 2, 3
- Free PIP and DIP joint motion to prevent stiffness 2, 3
This "intrinsic plus position" creates tension in the extensor aponeurosis, which covers two-thirds of the proximal phalanx and provides firm fracture stabilization without rigid immobilization of all joints 2.
Rationale for Dynamic Treatment
The evidence strongly supports dynamic (functional) treatment over static immobilization:
- Simultaneous healing and motion recovery: Dynamic treatment achieves bone healing and full active motion at the same time, not in succession 2, 3
- Superior outcomes: In a series of 78 proximal phalanx fractures treated dynamically, 86% achieved full range of motion, with all fractures consolidating without delayed union or pseudarthrosis 2
- Prevention of stiffness: Active motion exercises during immobilization prevent the most functionally disabling complication of hand fractures—finger stiffness 1
Initial Assessment Requirements
Before splinting, obtain:
- Three-view radiographs (PA, lateral, and oblique) to detect displacement, angulation, and articular involvement 1
- Internally rotated oblique projection in addition to standard views increases diagnostic yield for phalangeal fractures 1
Treatment Algorithm Based on Fracture Pattern
For Non-Displaced or Minimally Displaced Fractures (<10 degrees angulation):
- Apply the dorsopalmar splint as described above 4, 2
- Begin immediate active PIP and DIP motion exercises 1, 2
For Displaced Fractures with Significant Angulation (>10 degrees):
- Reduction may be required before splinting 4
- Consider traction splint systems that utilize the stabilizing effect of soft tissues (Zancolli complex) while enabling movement 5
For Fractures with Malrotation or Significant Displacement:
- These often require surgical referral rather than conservative splinting alone 4
Active Motion Protocol
Critical component: Begin active finger motion exercises immediately for the PIP and DIP joints 1, 2:
- Active motion does not adversely affect adequately stabilized fractures 1
- Prevents rotational and axial deformities 2
- Prevents interphalangeal joint stiffness that can be very difficult to treat after fracture healing 1
Duration and Follow-Up
- Splint duration: Continue rigid splinting for 3-4 weeks with the MCP joint immobilized 1
- Radiographic follow-up: Obtain at approximately 3 weeks and at cessation of immobilization 1
- Full consolidation: Typically achieved by 6 weeks with dynamic treatment 3
Common Pitfalls to Avoid
- Over-immobilization: Rigid splinting of all finger joints leads to unnecessary stiffness and poor functional outcomes 1
- Inadequate initial radiographs: Two views are insufficient; always obtain three views including oblique projections 1
- Static immobilization: Traditional plaster casting of all joints results in limitation of interphalangeal joint mobility requiring prolonged therapy 2
- Delayed motion: Waiting until after fracture healing to begin motion exercises significantly increases stiffness risk 1
Alternative Splint Systems
For specific fracture patterns, consider:
- Buddy taping: Appropriate for stable, minimally angulated fractures as an adjunct to the dorsopalmar splint 4
- Reversed extension splints: Can be used for dorsally angulated proximal phalanx fractures 6
- Custom-molded thermoplastic splints: Allow removal for dressing changes and radiologic evaluations while maintaining fracture stability 3