Episode 165.0 – Foot Fractures

Show Notes

Episode Produced by Audrey Bree Tse, MD

Background:

• Why do we care about Jones fractures?
  • Propensity for poor healing due to watershed area of blood supply
• Fifth metatarsal fractures account for 68% of metatarsal fractures in adults
• Proximal 5th metatarsal fractures are divided into 3 zones (93% zone 1, 4% zone 2, 3% zone 3)
• Zone 1 (pseudo-Jones):
  • Tuberosity avulsion fracture
  • Typically avulsion type injuries due to acute episode of forefoot supination with plantar flexion
  • Typical fracture pattern is transverse to slightly oblique
• Zone 2 (Jones fracture):
  • Fracture at the metaphyseal-diaphyseal junction of the fifth metatarsal
  • Typically acute episode of large adduction force applied to forefoot with the ankle plantar flexed
• Zone 3:
  • Proximal diaphyseal stress fracture
  • Typically results from a fatigue or stress mechanism

Clinical Presentation:

• History of acute or repetitive trauma to forefoot
• Fracture type / pattern closely related to injury location
• Foot often swollen, ecchymotic, very tender to fifth metatarsal +/- crepitus, inability to hear weight

Diagnosis:

• Clinical exam:
  • Evaluate skin integrity
  • Check neurovascular status
  • Evaluate toes/ feet/ ankles/ tib fib/ knees/ hips, involved tendon function, associated adjacent structures (Achilles, ankle ROM/ function, etc)
• 3 XR views: lateral, anteroposterior, 45* oblique
•  Acute stress fractures are typically not detected on the standard 3 views; therefore, repeat XRs 10-14d after onset of sx (may see radiolucent reabsorption gap around fracture)
• For more complex mid foot trauma, consider CT to r/o Lisfranc

Treatment:

• Consider classification of fracture, patient demographics & activity level when deciding on treatment
• Tertiary care centers that have access to Orthopedics/Podiatry services
  • Consider consultation for “true” Jones fractures, as some cases may be operatively managed acutely and/or for expedited follow-up to be arranged
• If working in community/rural locations: other than patients that present with “open” injuries, concerns for compartment syndrome (almost never), and “high-end”/professional athletes, there are generally no other circumstances that would require expedited transfer to a tertiary care center for immediate further evaluation.
• Less favorable outcomes associated with certain patient factors: female gender, DM, obesity

Surgical:

• Different modalities of surgery:
  • Intramedullary screw
  • Bone graft
  • Closed reduction and fixation with K-wire
  • ORIF (all +/- need for bone graft)
• Surgery likely recommended for displacement >10 degrees of plantar angulation or 3-4 mm of translation in any plane
• Indications for OR:
  • Neck and shaft fractures with >10 degrees plantar angulation or 3mm of displacement in any plane with insufficient closed reduction
  • Avulsion fractures (zone one) with >3 mm of displacement or comminuted
  • Zone two fractures: displaced zone two fractures require operative management.  For acute non displaced Jones fractures, consider early intramedullary screw fixation in athletes (studies have shown return to sport ~ 8 weeks, weight bearing within 1-2 weeks)
  • Zone three fractures (diaphyseal stress fractures) in athletes

Nonoperative:

• All non displaced fifth metatarsal fractures can be treated non operatively
• Non displaced zone 1 fractures: protected weight bearing/ symptomatic care in short leg walking cast, air-boot, posterior splint, or compression wrap/ rigid shoe until discomfort subsides
• Zone 2 and 3 fractures are more complex because they often result in prolonged healing time and potential for delayed/ nonunion
• Acute zone 2 fractures: nonweightbearing in short leg cast for 6-8 weeks
• Acute zone 3 fractures: nonweightbearing in short leg cast for up to 20 weeks
• With respect to athletes: repeat fracture after surgical treatment of Jones fracture can occur after healing and screw removal; thus it is recommended that the screw be left in until the end of the athlete’s career

References:

Bowes J, Buckley R. Fifth metatarsal fractures and current treatment. World J Orthop. 2016;7(12):793–800. Published 2016 Dec 18. doi:10.5312/wjo.v7.i12.793

Petrisor BA, Ekrol I, Court-Brown C.  The epidemiology of metatarsal fractures.  Foot Ankle Int.  2006 Mar; 27(3): 172-4.

Rammelt S, Heineck J, Zwipp H. Metatarsal fractures. Injury. 2004;35 Suppl 2:SB77–SB86.

Tham W, Sng S, Lum YM, Chee YH. A Look Back in Time: Sir Robert Jones, ‘Father of Modern Orthopaedics’. Malays Orthop J. 2014;8(3):37–41. doi:10.5704/MOJ.1411.009

Thomas JL, Davis BC. Three-wire fixation technique for displaced fifth metatarsal base fractures. J Foot Ankle Surg. 2011;50:776–779.

______________________

LISFRANC SHOW NOTES:

Intro:

• Can’t miss diagnoses: needs stat ortho
• 20% miss rate
• Can be dislocation, fracture, fracture dislocation, or ligamentous injury
• Jacques Lisfranc in Napoleonic Wars: performed transmetatarsal amputation for midfoot gangrene

Anatomy:

• Lisfranc ligament: 3 ligaments that run from the base of the second metatarsal to the medial cuneiform bone.  Helps attach the forefoot to the midfoot bones
• If ligament complex gets disrupted, can end up with chronic deformity and disability

Injury definitions:

• Dislocation: widening between base of 1st and 2nd metatarsal, or between cuneiforms
• Fracture dislocation: associated fracture, most commonly at the base of the proximal second metatarsal

Physical Exam:

• Pain and swelling in midfoot
• Pain elicited with passive abduction and pronation of the midfoot while holding heel steady
• Plantar ecchymosis
• r/o compartment syndrome
• Feel for DP pulse!

Diagnosis:

• XRs: AP, lateral, oblique, stress views with weight bearing
• Watch out for “fleck sign”
• Consider CT if pt cannot bear weight, or even if XR negative and high suspicion

Treatment:

• Ortho consult!

______________________

THANKS TO DANNY PURCELL, MD and MAY LI, MD