How do you manage a fracture of the fifth metatarsal?

Management of Fifth Metatarsal Fractures

Fifth metatarsal fractures should be managed based on fracture location, displacement, and patient factors, with non-displaced fractures generally treated conservatively while displaced or unstable fractures may require surgical intervention.

Classification and Initial Assessment

• Fifth metatarsal fractures are among the most common foot fractures and require proper radiographic evaluation with three standard views (anteroposterior, lateral, and mortise) for accurate diagnosis 1, 2
• Classification by anatomical location is crucial for treatment planning:
  • Zone 1: Tuberosity/avulsion fractures (most common)
  • Zone 2: Jones fractures (at metaphyseal-diaphyseal junction)
  • Zone 3: Proximal diaphyseal fractures
  • Shaft fractures 3, 4

Treatment by Fracture Type

Zone 1 (Tuberosity/Avulsion) Fractures

• For non-displaced or minimally displaced (<2mm) tuberosity fractures:
  • Initial treatment with compressive dressing or elastic bandage 3, 5
  • Transition to a controlled ankle motion (CAM) walker boot or hard-soled shoe for 2-4 weeks 6, 7
  • Recent evidence shows symptomatic treatment with elastic bandage is non-inferior to cast immobilization in terms of patient-reported outcomes 5
  • CAM walker boots show faster radiographic healing (7.2 weeks) compared to hard-soled shoes (8.6 weeks), though clinical outcomes are similar 6
• For displaced (>2mm) tuberosity fractures or those involving >30% of the cubometatarsal joint:
  • Surgical fixation is indicated 4

Zone 2 (Jones Fractures)

• Higher risk of nonunion and complications
• Treatment depends on Torg classification:
  • Type I (acute): Consider 6-8 weeks in a non-weight-bearing cast
  • Type II (delayed union): Treatment based on patient activity level - surgical fixation for active patients
  • Type III (nonunion): Surgical fixation recommended
• Healing time can extend to 10-12 weeks 3, 4

Zone 3 and Shaft Fractures

• Non-displaced shaft fractures:
  • Initial treatment with posterior splint and weight-bearing restrictions
  • Followed by short leg walking cast or boot for 4-6 weeks 3
• Displaced shaft fractures (>3-4mm displacement or >10° angulation):
  • Surgical fixation with K-wires, plate, or screws 4

Rehabilitation and Follow-up

• Regular radiographic assessment to ensure proper healing and alignment 1
• Progressive weight-bearing as tolerated after initial immobilization period 3
• Early introduction of physical training and muscle strengthening followed by long-term balance training and fall prevention 2
• Special consideration for patients with diabetes or neuropathy:
  • More careful offloading to prevent complications
  • More vigilant monitoring for healing 1

Potential Complications

• Jones fractures have higher rates of delayed union, nonunion, and refracture due to the watershed blood supply in this region 4
• Displacement during treatment may necessitate surgical intervention 4
• Prolonged immobilization may lead to stiffness and muscle atrophy, requiring appropriate rehabilitation 2

Evidence-Based Treatment Selection

• For Zone 1 fractures, a soft dressing or elastic bandage allows faster return to pre-injury activity levels (average 33 days) compared to short leg casts (average 46 days) without compromising fracture union 7, 5
• For unstable fractures, CT imaging may be beneficial to evaluate the true extent of osseous injury and guide surgical planning 2
• Early fracture fixation provides the most effective pain relief when indicated 2