Treatment of Distal 5th Metatarsal Fractures: Displaced vs Non-Displaced
For non-displaced distal 5th metatarsal fractures, conservative management with immobilization in a cast boot or pneumatic walking boot for 6 weeks with weight-bearing as tolerated is appropriate, while displaced fractures (>2-3mm displacement or >10° angulation) require surgical fixation to prevent nonunion and ensure timely healing. 1, 2, 3
Non-Displaced Fractures: Conservative Management
Conservative treatment is the standard approach for minimally displaced or non-displaced distal 5th metatarsal shaft fractures. 1, 2
- Immobilize with a below-knee cast or pneumatic walking boot for 6 weeks 2, 3
- Allow weight-bearing as tolerated in stable orthosis or cast shoe 2
- Obtain radiographic follow-up at approximately 3 weeks and at immobilization removal to confirm adequate healing 4, 5
- Initiate active toe motion exercises immediately to prevent stiffness 4, 5
Critical Caveat for Conservative Management
The major pitfall of conservative treatment is the 35.5% risk of asymptomatic nonunion, though patients typically remain pain-free at one year. 3 This is significantly higher than the 0% nonunion rate seen with surgical management, making displacement thresholds crucial for treatment decisions 3.
Displaced Fractures: Surgical Indications
Surgical fixation is indicated when specific displacement or angulation thresholds are exceeded. 1, 2, 3
Absolute Surgical Thresholds:
- Displacement >2-3mm 1, 3
- Angulation >10° 1, 2
- Involvement of >30% of the cubometatarsal joint (for tuberosity fractures) 1
- Open fractures 2
Surgical Technique Selection by Fracture Pattern:
For grossly displaced, shortened, or multifragment fractures: Open reduction with plate fixation using 2.0-2.4mm interlocking plates is the method of choice 2. This approach allows anatomic reconstruction under longitudinal traction with interfragmentary lag screws for compression when fragments are large enough 2.
For long spiral shaft fractures: Screw fixation alone may be used as an alternative 2.
For transverse or subcapital fractures: Percutaneous antegrade or retrograde medullary wiring with two Kirschner wires should be considered 2.
Post-Surgical Protocol:
- Rest, elevation, and local cooling immediately post-operatively 2
- Partial weight-bearing (20kg) in foot orthosis or cast shoe for 6 weeks 2
- Mean radiographic healing time of 7.73 weeks with overall complication rate of 6.25% 6
Outcomes Comparison
Surgical management eliminates the risk of nonunion (0% vs 35.5%) and ensures timely return to activity, though both groups achieve symptom resolution by one year. 3 The mean displacement at injury in surgically treated cases averages 3.20mm with 5.89° angulation, resulting in minimal postoperative complications including 1.56% nonunion, 3.13% delayed union, and no malunions 6.
Clinical Decision Algorithm
Use the 2mm displacement threshold as your surgical decision point: 3
- <2mm displacement + <10° angulation → Conservative management with close radiographic monitoring 1, 2
- ≥2mm displacement OR ≥10° angulation → Surgical fixation 1, 3
- Active athletes or patients requiring rapid return to function → Consider surgery even for borderline cases 7, 6
The key distinction is that while both approaches ultimately achieve pain-free outcomes, surgical management provides more predictable healing, eliminates nonunion risk, and allows faster return to pre-injury activity levels 3, 6.