What is the treatment for a 3rd metacarpal hairline oblique fracture?

Treatment of 3rd Metacarpal Hairline Oblique Fracture

For a 3rd metacarpal hairline oblique fracture, removable splinting with early active finger motion exercises is the recommended treatment approach, with immobilization typically lasting 3-4 weeks. 1

Initial Management

• Hairline oblique fractures of the 3rd metacarpal that are minimally displaced should be treated with removable splinting for 3-4 weeks 1
• Active finger motion exercises should be initiated immediately following diagnosis and treatment to prevent stiffness, which is one of the most common functionally disabling complications 1, 2
• Standard radiographic examination should include at least 3 views (posteroanterior, lateral, and 45° semipronated oblique) to properly visualize and confirm the fracture pattern 3, 1

Splinting Technique

• A hand-based functional splint allows for excellent maintenance of fracture reduction while preserving functional motion throughout treatment 4
• The splint should be positioned with fingers in full extension and metacarpophalangeal joint flexed at 60-90 degrees (position of function) 5
• This splinting technique allows for metacarpophalangeal joint, interphalangeal joint, and radiocarpal joint motion, minimizing stiffness 4

Follow-up Protocol

• Radiographic evaluation should be performed:
  • Initially to confirm diagnosis and fracture pattern
  • At approximately 3 weeks post-immobilization to assess healing
  • At the time of immobilization removal to confirm adequate healing 1
• Monitor for any changes in alignment during follow-up visits, though most patients (90%) show no change in alignment from start of splinting to end 4

Indications for Surgical Management

• Conservative management is appropriate for hairline fractures, but surgical intervention would be indicated if:
  • Significant displacement (>3mm) is present
  • Dorsal tilt >10° is observed
  • Intra-articular displacement is present
  • Open fracture or multiple unstable fractures exist 1, 5, 6

Potential Complications and How to Avoid Them

• Finger stiffness is the most common functionally disabling complication and can be minimized with early active motion exercises 3, 1
• Immobilization-related adverse events occur in approximately 14.7% of cases and may include skin irritation and muscle atrophy 1
• Avoid prolonged immobilization beyond the recommended 3-4 weeks to prevent stiffness and reduced function 1, 2
• Inadequate follow-up imaging may miss delayed displacement that requires intervention 1

Return to Activities

• Most patients with properly managed metacarpal fractures using a functional hand-based splint can continue working without missing days of work 4
• Early mobilization, especially with appropriate splinting, is critical to prevent stiffness and restore function 2