Treatment of Tiny Avulsion Fracture at Base of Fifth Metacarpal
For a tiny avulsion fracture at the base of the fifth metacarpal, immediate rigid immobilization with a splint or cast is the recommended initial treatment, provided the fracture does not meet surgical criteria. 1
Initial Radiographic Assessment
Before any treatment, obtain 3-view radiographs (PA, lateral, and oblique) to assess fracture size, displacement, and joint subluxation. 1 The oblique view is particularly critical as it detects metacarpal fractures that may be missed on standard 2-view examination. 1
Determining Conservative vs. Surgical Management
The key decision point is whether surgical criteria are met:
Surgical Indications (Urgent Referral Required)
Refer immediately for surgical intervention if ANY of the following are present: 1
- Avulsion fracture involving ≥1/3 of the articular surface
- Palmar subluxation of the metacarpal base
- Interfragmentary gap >3mm
- Irreducible subluxation
- Open injury
- Intra-articular displacement with >2mm step-off
Conservative Management (For Fractures NOT Meeting Above Criteria)
Apply rigid immobilization immediately using a splint or cast that includes the affected metacarpal and adjacent joints. 1 Rigid immobilization is specifically preferred over removable splints for displaced fractures. 1
Immediate adjunctive measures: 1
- Apply ice-water mixture for 10-20 minutes with a thin towel barrier to reduce swelling
- Avoid heat application
- Do not attempt manual reduction before proper splinting
Early Mobilization Protocol
Begin active finger motion exercises of the PIP and MCP joints immediately while keeping the affected joint splinted to prevent stiffness. 1 This approach is supported by research showing that early mobilization provides good to excellent results in 94-95% of cases with no complications, compared to 85% success rates with prolonged immobilization. 2
Important caveat: Immobilization beyond 3-4 weeks is not necessary and should be avoided. 2
Follow-Up Imaging
If radiographs remain negative but clinical suspicion persists for additional injury, consider MRI without IV contrast to detect occult fractures. 1
Evidence Quality Note
The recommendation for conservative management of small avulsion fractures is strongly supported by network meta-analysis showing conservative treatment has the best outcomes (94.1% probability of lowest complication rates) compared to surgical options for fifth metacarpal fractures. 3 However, fractures of the base of the fifth metacarpal are inherently unstable, making accurate initial assessment of surgical criteria critical to avoid inadequate reduction that may result in pain, functional disability, and osteoarthritic changes. 4