II. Pathophysiology
- Fifth Metatarsal has thinnest cortical thickness of any Metatarsal
III. Types: Based on landmarks along joint between 4th and 5th Metatarsals proximally
- Tuberosity Avulsion Fractures (Styloid Fractures, Pseudo-Jones Fracture, Zone 1)
- Proximal to the joint between 4th and 5th Metatarsals
- Mechanism: Lateral Ankle Sprain (inversion injury while foot plantar flexed)
- Typically heal without complications
- Metaphyseal-Diaphyseal Junction Fractures (Jones Fracture, Zone 2)
- Fracture line extends toward the joint between 4th and 5th Metatarsals
- Occurs 1.5 to 3 cm from the tip of the tip of the Metatarsal
- Mechanism: Sudden "cutting" motion side-to-side while the heel is off the ground
- Forceeful adduction to plantar flexed foot
- High risk area for non-healing Fractures
- Lies in the vascular watershed zone (at risk for poor healing, non-union)
- Fracture line extends toward the joint between 4th and 5th Metatarsals
- Diaphyseal Stress Fractures (Zone 3)
- Distal to the joint between 4th and 5th Metatarsals
- Mechanism: Recurrent Trauma such as jumping and pivoting in young athletes (Stress Fracture)
- Insidious pain onset with activity
- Highest risk area for non-healing Fractures
IV. Symptoms
- Distribution: Lateral Foot Pain
- Provocative: Walking
- Timing:
- Acute Fractures: Sudden onset
- Stress Fractures: Gradually progressive and increased with activity
V. Signs
- Localized swelling and Ecchymosis at the base of the fifth Metatarsal
VI. Imaging: XRay demonstrates Proximal Fifth Metatarsal Fracture
- See Proximal Fifth Metatarsal Fracture Grading Based on XRay
- See Types above for determining Fracture type
- Differential diagnosis on XRay of Proximal Fifth Metatarsal Fracture look-alikes
- Accessory bones (smooth, rounded densities surrounded by cortex)
- Styloid apophysis (children and teens)
VII. Management: Tuberosity Avulsion Fractures (Styloid Fractures)
- Indications for orthopedic referral
- Displaced tuberosity avulsion Fractures (>3 mm)
- Nonunion Fractures
- Cuboid-Metatarsal joint with >1-2 mm step-off
- Fracture fragment involves more than 60% of the Metatarsal-Cuboid joint surface
- Protocol for uncomplicated, non-displaced tuberosity avulsion Fractures
- Option 1
- Soft Bulky Dressing and weight bearing
- Option 2 (if pain despite Option 1)
- Hard soled shoe or cast boot and weight bearing (use for 5-6 weeks)
- Option 3 (if pain despite Option 2)
- Short leg walking boot or cast
- Option 1
- Protocol for minimally displaced tuberosity avulsion Fractures (<3 mm)
- Short leg walking boot or cast for 2 weeks
- Progressive ambulation and range of motion follow immobilization
- Reevaluation every 2 weeks and anticipate healing by 4-8 weeks
- Repeat XRay at 6-8 weeks to document healing (sooner if persistent pain on ambulation after 4 weeks)
- Course
- Anticipate asymptomatic by 3-6 weeks (pain may persist up to 8 weeks)
- Anticipate healed with union on XRay by 8 weeks
VIII. Management: Diaphyseal Fractures (Jones Fracture or Diaphyseal Stress Fractures)
- Indications for orthopedic referral
- See Fifth Metatarsal Fracture for absolute referral indications
- Consider Consultation in all patients given higher risk of non-union
- Athletes may also benefit from referral by decreasing duration of healing time
- Displacement >2mm
- Inadequate healing after immobilization for 12 weeks
- Non-union on xray
- Initial management
- Posterior splint
- Non-weight bearing
- Follow-up in 3-5 days
- Options: Non-displaced Jones Fracture (acute diaphyseal Fracture)
- Consider early surgical fixation in athletes
- Non-weight bearing short-leg cast or boot for 6-8 weeks
- Start weight bearing and PT if callus formation and no point tenderness at 6-8 weeks
- Continue non-weight bearing for additional 4 weeks and re-evaluate if inadequate healing
- Anticipate 6-10 weeks total of immobilization and up to 12 weeks for full healing
- Surgical repair may ultimately be needed in those managed with immobilization
- Options: Diaphyseal Stress Fracture Type I (early, See Torg Classification)
- Same management for Jones Fracture above
- Options: Diaphyseal Stress Fracture Type II (delayed, See Torg Classification)
- Early surgical fixation or
- Non-weight bearing cast for up to 20 weeks
- Options: Diaphyseal Stress Fracture Type III (nonunion, See Torg Classification)
- Surgical fixation or
- Non-weight bearing cast for up to 16 weeks and pulsed electromagnetic fields
- References
IX. References
- Feden and Kiel (2017) Crit Dec Emerg Med 31(11): 3-10
- Bica (2016) Am Fam Physician 93(3): 183-91 [PubMed]
- Hatch (2007) Am Fam Physician 76: 817-26 [PubMed]
- Quill (1995) Orthop Clin North Am 26:353-61 [PubMed]