What is the recommended management for a 13-year-old with an isolated fifth metatarsal fracture?

Management of Fifth Metatarsal Fracture in a 13-Year-Old

Most fifth metatarsal fractures in adolescents should be treated conservatively with a short-leg walking cast for 3-6 weeks, with excellent outcomes expected, unless the fracture is a displaced intra-articular type or occurs at the metaphyseal-diaphyseal junction (Jones fracture), which may require surgical fixation in active adolescents. 1

Initial Assessment and Classification

The first critical step is determining the fracture location using the Lawrence and Botte classification system, as this directly impacts treatment strategy 2:

• Zone 1 (Tuberosity avulsion): Most common in pediatrics, involves the base/tuberosity 1, 2
• Zone 2 (Jones fracture): Metaphyseal-diaphyseal junction extending into fourth-fifth intermetatarsal joint 2
• Zone 3 (Proximal diaphyseal): Proximal shaft fractures 2
• Neck and shaft fractures: Distal to the proximal metaphysis 1

Obtain standard foot radiographs per Ottawa rules, which are validated for children over 5 years of age and have 99% sensitivity for fractures 3.

Treatment by Fracture Type

Zone 1 (Tuberosity Avulsion) Fractures

• Treat with short-leg walking cast for 3-6 weeks 1
• These fractures heal excellently due to robust blood supply 1, 2
• Early weight-bearing as tolerated is appropriate 1

Zone 2 and 3 (Jones and Proximal Diaphyseal) Fractures

These are high-risk stress fractures with increased rates of delayed union and nonunion 3, 2:

• For active adolescents: Consider early surgical fixation with intramedullary screw 1, 2

  • Allows faster return to activities and prevents refracture 1
  • Reduces risk of delayed union that occurs with conservative management 1, 2

• For less active patients: Conservative management is possible but carries higher risk of delayed healing 2

  • Requires non-weight-bearing cast initially 1
  • Expect prolonged healing time (8+ weeks) 4

Displaced Intra-articular Fractures

• Use non-weight-bearing cast for all angulated or displaced intra-articular injuries 1
• Displaced intra-articular fractures show significant delays in healing versus non-displaced fractures 1
• Displacement >3-4mm or angulation >10 degrees warrants reduction 5

Neck and Shaft Fractures

• Treat with walking cast 1
• These typically heal well with conservative management 1, 6
• Even significantly displaced spiral shaft fractures can be managed conservatively with excellent functional outcomes 6

Follow-up Imaging Strategy

Routine follow-up radiographs before 6-8 weeks do not alter management and are unnecessary 4:

• Initial radiographs establish diagnosis and fracture type 3
• Radiographs before 6-8 weeks rarely show healing and don't change treatment 4
• Only 29% of fractures show radiological union at final clinic visit, yet patients are successfully discharged based on clinical healing 4
• Displacement on follow-up films is rare (only 1% in one series) and can still be managed conservatively 4

Common Pitfalls to Avoid

• Do not miss Jones fractures (Zone 2): These require different management than simple tuberosity avulsions due to poor vascular supply at the metaphyseal-diaphyseal junction 2
• Do not confuse apophyseal variants with fractures: The apophysis at the fifth metatarsal base appears around age 9-11 and can mimic fracture 1
• Do not undertake unnecessary serial radiographs: Clinical healing guides discharge, not radiographic union 4
• Do not treat all fifth metatarsal fractures identically: Location determines prognosis and treatment 2

Expected Outcomes

• Zone 1 fractures: Excellent healing in 3-6 weeks 1, 2
• Zone 2/3 fractures treated conservatively: Average 8+ weeks to union with risk of delayed union 4, 2
• Zone 2/3 fractures treated surgically: Faster return to activity, reduced refracture risk 1, 2
• Pediatric fifth metatarsal fractures behave similarly to adult fractures and can be treated with the same principles 1