Management of Mildly Displaced Distal Third Scaphoid Fracture Without Spica Cast
Use a short-arm removable splint or standard short-arm cast (without thumb extension) for immobilization, as distal third scaphoid fractures are inherently stable and do not require thumb spica casting. 1
Initial Assessment and Classification
- Confirm the fracture is truly "mildly displaced" by measuring displacement on radiographs—displacement <1mm qualifies as stable and undisplaced, while >1mm indicates instability 2
- Obtain radial-ulnar deviation stress views or traction oblique views if standard films are equivocal about displacement 2
- Distal third (distal pole) scaphoid fractures have excellent blood supply and heal reliably with conservative management compared to waist or proximal pole fractures 1, 3
Recommended Immobilization Strategy
For truly minimally displaced distal third fractures (<1mm displacement):
- Apply a short-arm cast or removable splint that does not necessarily include the thumb, as distal pole fractures are stable injuries 4, 1
- Position the wrist in slight volar flexion and radial deviation, which provides optimal fracture alignment 2
- A traditional thumb spica cast is the gold standard for scaphoid waist fractures, but distal third fractures do not require this level of immobilization 1, 2
If displacement is >1mm (making it truly "displaced" rather than "mildly displaced"):
- Consider percutaneous screw fixation as the preferred treatment, as displaced scaphoid fractures have higher nonunion rates with casting alone 1, 5, 3
- If surgery is not feasible, attempt closed reduction with wrist flexion and radial deviation, then apply a long-arm cast initially 2
Duration and Follow-up
- Immobilize for approximately 6-8 weeks for distal third fractures, which heal faster than waist fractures 1
- Obtain radiographic follow-up at 3 weeks and at the time of immobilization removal to confirm adequate healing 4
- Initiate active finger motion exercises immediately to prevent stiffness, as finger motion does not adversely affect adequately stabilized fractures 4
Critical Pitfalls to Avoid
- Do not assume all scaphoid fractures require thumb spica casting—distal third fractures are the exception due to their stability and excellent vascularity 1, 2
- Avoid wrist extension positioning, which was traditionally used but has been replaced by volar flexion-radial deviation for better outcomes 2
- If you initially misclassify displacement and the fracture shows >1mm offset on repeat imaging, strongly consider surgical fixation rather than prolonged casting 2, 3
- Monitor for loss of reduction during the first 2-3 weeks; if reduction is lost, proceed to open reduction and internal fixation 2
Alternative: Surgical Management
Percutaneous screw fixation is a reasonable alternative even for minimally displaced distal third fractures in patients who cannot tolerate prolonged immobilization (athletes, manual laborers) 1, 5, 3