What is the treatment for an avulsion fracture from the base of the middle phalanx of the third digit?

Treatment of Avulsion Fracture from the Base of Middle Phalanx of Third Digit

For avulsion fractures at the base of the middle phalanx, obtain standard 3-view radiographs immediately and refer for surgical fixation if the fracture involves >1/3 of the articular surface, shows >3mm displacement or interfragmentary gap, or demonstrates joint instability. 1

Initial Imaging Assessment

• Obtain standard 3-view radiographs (PA, lateral, and oblique views) as the initial imaging modality 1
• Add an internally rotated oblique projection in addition to the standard externally rotated oblique to increase diagnostic yield 1
• Consider CT without IV contrast if radiographs are equivocal to better evaluate intra-articular extension and displacement 1

Treatment Algorithm Based on Fracture Characteristics

Surgical Indications (Immediate Hand Surgery Referral Required)

Proceed with surgical fixation if ANY of the following criteria are met:

• Intra-articular extension with displacement >3mm or articular step-off 1
• Fractures involving more than one-third of the articular surface 1
• Interfragmentary gap >3mm 1
• Joint instability or incongruity on examination 1
• Palmar subluxation of the distal phalanx (>3mm interfragmentary gap or irreducible subluxation) 2

Surgical approach: Dynamic external fixation is preferred for unstable intra-articular fractures of the middle phalanx, with arthroscopic-assisted reduction useful for improved diagnostic accuracy 1. A single lag screw through a palmar approach has shown excellent results with full range of movement achieved within 3 weeks 3.

Conservative Management (Non-displaced, Stable Fractures Only)

Use conservative management ONLY if the fracture meets ALL of the following:

• No displacement (≤3mm) 1
• Involves <1/3 of articular surface 1
• Joint remains stable and congruent 1
• No interfragmentary gap >3mm 1

Conservative protocol:

• Apply removable splint immobilizing only the affected joint while allowing adjacent joint motion 4
• Initiate active finger motion exercises for non-immobilized joints immediately to prevent stiffness 4
• Avoid immobilizing joints unnecessarily, as this increases stiffness risk 4

Critical Management Pitfalls to Avoid

• Never use simple splinting for displaced intra-articular fractures - this leads to poor outcomes and post-traumatic arthritis 1
• Avoid excessive immobilization - this is the primary cause of joint stiffness, occurring in approximately 14.7% of cases 1
• Do not attempt conservative management for unstable fractures - all eight conservatively treated avulsion fractures in one series failed to unite and required subsequent surgery 3

Post-Treatment Protocol

For Surgical Cases:

• Initiate early active motion exercises as soon as stability allows to prevent stiffness 1
• Obtain radiographic follow-up at approximately 3 weeks post-surgery 1
• Perform additional radiographic evaluation at time of hardware removal to confirm adequate healing 1

For Conservative Cases:

• Radiographic follow-up at approximately 3 weeks post-immobilization 4
• Additional imaging at time of immobilization removal 4

Expected Complications and Their Prevention

• Joint stiffness is the most functionally disabling complication and can be minimized with early appropriate motion of non-immobilized joints 1, 4
• Post-traumatic arthritis develops when intra-articular fractures are not properly reduced, leading to joint incongruity 1, 4
• Immobilization-related complications (skin irritation, muscle atrophy) occur in approximately 14.7% of cases 1

The evidence strongly supports that surgical treatment producing good stability and congruity gives superior long-term results, and these should be the primary aims of treatment 5. The classification system divides these fractures into five types, with type-2 dorsal avulsions particularly requiring surgical attention to prevent boutonnière deformities 5, 6.