Intervertebral disc viability after burst fractures of the thoracic and lumbar spine treated with pedicle screw fixation and direct end-plate restoration

BACKGROUND CONTEXT: Controversies persist for the best treatment of burst fractures of the thoracolumbar spine. Anterior corpectomy and discectomy followed by reconstruction with intervertebral cage and posterior fixation, for example, are based mainly on the widespread assumption that intervertebral discs involved in burst-type fractures, typically, do not survive the traumatic event and will degenerate irrevocably.

PURPOSE: To evaluate whether intervertebral discs, located adjacent to traumatic burst fractures and treated with pedicle screw fixation and direct end-plate restoration, survive the traumatic event or irrevocably progress to severe disc degeneration.

STUDY DESIGN: Prospective trial.

PATIENT SAMPLE: Twenty adult patients with traumatic burst fractures of the thoracolumbar spine and treated with pedicle screw fixation and direct end-plate reduction were included.

OUTCOME MEASURES: Disc degeneration according to the Pfirrmann classification.

METHODS: Magnetic resonance imaging scans were obtained preoperatively, 1 month after surgery and 1 month after pedicle screw removal 12 to 18 months after index surgery. Degeneration of the intervertebral discs adjacent to the fracture was assessed using the Pfirrmann classification. Grade 1/2/3 was defined as mild-to-moderate degeneration of the intervertebral disc (MDID), whereas Grade 4/5 was defined as severe-to-endstage degeneration of the intervertebral disc (SDID). Repeated measure analysis was performed to detect significant differences between MDID and SDID scores.

RESULTS: A total of 19 patients (38 discs) were fully documented and available for study. All discs showed MDID preoperatively, and while five discs (13%) progressed to SDID at 12 to 18 months posttrauma, the other discs did not show progression of degeneration.

CONCLUSIONS: Intervertebral discs adjacent to traumatic burst fractures treated with pedicle screw instrumentation and direct end-plate restoration do not routinely seem to progress to severe degeneration at 12 to 18 months postinjury.