Fifth metatarsal fracture

Revision as of 04:34, 26 February 2019 by Rossdonaldson1 (talk | contribs) (Evaluation)

Background

  • Os peroneum is an accessory bone (ossicle) located at the lateral side of the tarsal cuboid, proximal to the base of 5th metatarsal, commonly mistaken for a fracture

Clinical Features

Dancer or tuberosity (styloid) avulsion fracture

  • Most common fracture at base of 5th metatarsal
  • Sx often mild, patients usually present with sprained ankle complaint
  • Occurs due to forced inversion foot/ankle while in plantar flexion

Jones or metaphyseal-diaphyseal junction fracture

  • Second most common fracture at base of 5th metatarsal
  • Abrupt onset of lateral foot pain, with no prior history of pain at that site, suggests acute injury and helps distinguish from stress injury
  • Occurs due to sudden change in direction with heel off the ground
  • Edema & ecchymosis usually present, may not be able to bear weight

Diaphyseal stress fracture

  • Occurs through repetitive microtrauma, usually in younger athletes
  • Important to identify given propensity for delayed union and nonunion
  • Usually present with history of months of pain, which is more intense during exercise or weight-bearing
    • always ask about persistent pain prior to acute event to help distinguish worsening stress fracture from acute fracture

Differential Diagnosis

Foot and Toe Fractures

Hindfoot

Midfoot

Forefoot

Evaluation

Workup

  • Plain radiographs are usually adequate

Diagnosis

5th Metatarsal fracture types
Jones fracture. Transverse fracture 2 cm from the base of the fifth metatarsal
  • Must distinguish Jones fracture from diaphyseal stress freacture:
    • Acute fracture will have narrow fracture line that appears sharp, normal thin cortex adjacent to fracture, and normal intramedullary canal
    • Stress fracture will demonstrate cortical thickening near fracture line, older stress fracture will demonstrate widened fracture line and intramedullary sclerosis

Management & Disposition

Tuberosity (Styloid) Avulsion Fracture

  • Refer to ortho if > 3mm displacement
  • Nondisplaced fracture usually require only symptomatic treatment, RICE
  • Walking boot (casting rarely necessary) and weight-bearing as tolerated, follow up in 1 week

Jones Fracture (non-displaced)

  • Posterior Ankle Splint, strict NWB, RICE, ortho follow up in 3-5 days
  • 50% of Jones fracture treated conservatively may result in nonunion or re-fracture
  • Conservative treatment failure usually due to poor vascular supply of bone and premature return to weight-bearing

Diaphyseal Stress Fracture

  • Strict NWB short-leg cast, RICE
  • Ortho referral for all stress fractures

Traumatic Diaphyseal Fracture

  • Posterior Ankle Splint, NWB, RICE, ortho/podiatry follow up in 3-5 days
  • Dorsal or Plantar displacement >10% or 3-4mm may require reduction in ED or at referral clinic while lateral/medial displacement usually heal well without reduction

See Also

References

Video