A 35-year-old man sustains a burst fracture of L1 following a fall from height. CT scan shows 40% canal compromise and 30° kyphosis. Neurological examination reveals bilateral lower limb weakness (grade 3/5) and bladder dysfunction. According to the Denis three-column theory, which columns are disrupted in a burst fracture?
- A Middle and posterior columns only
- B Anterior column only
- C Anterior and middle columns ✓
- D All three columns — anterior, middle, and posterior
Correct answer: C. Anterior and middle columns
Explanation
Denis classified spinal stability using three columns: anterior (anterior half of vertebral body and disc), middle (posterior half of vertebral body and posterior longitudinal ligament), and posterior (posterior elements). A burst fracture disrupts the anterior and middle columns due to axial compressive forces causing the nucleus pulposus to explode the vertebral body, driving bone fragments into the canal. This makes it unstable, and surgical decompression with posterior pedicle screw fixation is indicated for neurological compromise and significant canal narrowing.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.