The Buttress Technique, A New Maneuver to Prevent Subsidence After Thoracic and Lumbar Corpectomy

Thoracolumbar corpectomy is an essential tool for restoration of anterior and middle column support. However, subsidence remains a problematic complication. This may be partly mitigated by using wide footprint rectangular endcaps that rest on the peripheral and stronger bone of the vertebral endplate.

In this study, we describe a new technique, named the "buttress technique" that may further reduce subsidence. A 75-year-old woman presented to the emergency department with 2 weeks of falls and severe back pain. She was dependent on a walker, and was found to have a T11 burst fracture with retropulsion and cord compression. An all-posterior transpedicular corpectomy was performed using an expandable cage with large-footprint rectangular endcaps. The buttress technique was used. First, fenestrated pedicle screws above the corpectomy cage are angled caudally such that the tips of the screws are just deep to the surface of the endplate in contact with the corpectomy cage. The pedicle screws below the cage are similarly angled cranially. Second, cement augmentation of the fenestrated screws helps create a more solid endplate and further reduces the chance of subsidence. A case is presented with imaging and no subsidence at 10-month follow-up. A case series of 21 patients is reported with average follow-up of 19 months (range 8-41 months, 1 deceased at 5 months from cancer-related causes) in which all patients demonstrated grade zero subsidence, with average change in defect height of 5.5%.

The buttress technique may reduce subsidence after thoracolumbar corpectomy.