Treatment for Mildly Displaced Comminuted Fracture of Distal Fifth Metatarsal
Surgical fixation is recommended for mildly displaced comminuted fractures of the distal fifth metatarsal to ensure proper healing, reduce time to union, and facilitate earlier return to normal activities. 1
Assessment and Classification
- Fractures with displacement >3mm or >10° dorsal tilt are considered significantly displaced and typically require surgical intervention 2, 3
- The presence of comminution (multiple fragments) increases the risk of displacement and malunion, which may affect functional outcomes 4
- Intraarticular extension is a critical factor that influences treatment decisions, as it can lead to joint incongruity and subsequent arthritis if not properly addressed 2
Treatment Options
Surgical Management (Recommended)
- Open reduction and internal fixation (ORIF) is indicated for comminuted distal fifth metatarsal fractures with any significant displacement 4
- Surgical treatment significantly decreases time to clinical union (8.2 vs 16.3 weeks), radiographic union (13.5 vs 25.2 weeks), and return to activity (12.9 vs 20.7 weeks) compared to conservative treatment 1
- Surgical management eliminates the risk of nonunion, which occurs in up to 35.5% of conservatively managed fifth metatarsal fractures 5
- For comminuted fractures, interlocking plates with screw diameter of 2.0-2.4mm are preferred to avoid soft tissue irritation 4
Conservative Management (Not Recommended for Displaced Fractures)
- Conservative management is not typically recommended for displaced comminuted fractures due to higher rates of delayed union and nonunion 5, 1
- If conservative management is chosen despite displacement, a rigid sole shoe may be preferable to a boot, as it results in shorter time to pain-free walking (4.6 vs 8.4 weeks) and return to normal footwear (6 vs 7.3 weeks) 6
- Patients treated with a rigid sole shoe report the treatment as less restrictive compared to those treated with a boot 6
Post-Operative Management
- Following surgical treatment, rest and elevation of the injured leg with local cooling is indicated 4
- Mobilization with partial weight bearing (20 kg) in foot orthosis or cast shoe for 6 weeks 4
- Active toe motion exercises should be initiated as soon as stability allows to prevent stiffness 2, 3
- Radiographic follow-up is recommended at approximately 3 weeks and at the time of immobilization removal to confirm adequate healing 2, 3
Potential Complications
- Delayed union, nonunion, and chronic pain may be long-term complications of fifth metatarsal fractures, particularly with conservative management 7
- Joint stiffness is one of the most functionally disabling adverse effects of foot fractures and can be minimized with early appropriate motion 2
- Immobilization-related complications occur in approximately 14.7% of cases and may include skin irritation and muscle atrophy 2, 3
Special Considerations
- For athletes and active individuals, surgical management is particularly beneficial as it significantly reduces time to return to full activity 1
- Even grossly displaced fractures of the fifth metatarsal shaft have good to excellent prognosis following surgical treatment with high union rates and rare complications 4
- The surgical approach typically involves a lateral incision centrally above the easily palpable fifth metatarsal shaft, taking care to avoid the glabrous skin of the sole 4