Subaxial Lateral Mass Fracture

Background 

  • Associated disc 30% 

Classification (AO F) 

  • F1 – non displaced <40% 
  • F2 – non displaced >40% 
  • F3 – floating LM – disconnect the LM from body via fractured pedicle or lamina 
  • F4 – perched or disloacted 

Management 

  • Stable – non op 
  • Unstable – PSIF vs ACDF (ACDF if LM too comminuted to screw) 
  • Neuro (radicular) – PSIF 
  • *Val: fix all from the back because failure from the failure from anterior is higher 

Complications 

  • Late kyphotic 
  • Late instability 
  • Radiculopathy