Spinal fractures in diffuse idiopathic skeletal hyperostosis: Advantages of percutaneous pedicle screw fixation

Purpose: To validate the effectiveness of percutaneous pedicle screw (PPS) fixation for spinal fractures associated with diffuse idiopathic skeletal hyperostosis (DISH) by comparing surgical outcomes for PPS fixation and conventional open posterior fixation. Patients with DISH are vulnerable to unstable spinal fractures caused by trivial trauma, and these fractures have high rates of delayed paralysis, postoperative complications, and mortality. Methods: This retrospective study assessed surgical outcomes for 16 patients with DISH (12 men; mean age 76.1 ± 9.4 years) who underwent PPS fixation for spinal fractures (pedicle screw (PS) group), and for a control group of 25 patients with DISH (18 men; mean age 77.9 ± 9.9 years) who underwent conventional open fixation (O group) at our affiliated hospitals from 2007 to 2017. We evaluated the preoperative physical condition (American Society of Anesthesiologists (ASA) classification), neurological status (Frankel grade), and improvement after surgery, fusion length, operating time, estimated blood loss, and perioperative complications. Results: Preoperatively, the PS group consisted of one ASA-1 patient, eight ASA-2 patients, six ASA-3 patients, and one ASA-4 patient; by Frankel grade, there were 2 grade B patients, 13 grade C, 4 grade D, and 6 grade E patients. The O group had 2 ASA-1 patients, 13 ASA-2, 9 ASA-3, and 1 ASA-4 patients. Frankel grades in the O group reflected severe neurological deficits, with 3 grade C patients, 2 grade D, and 11 grade E (p = 0.032) patients. The two groups had similar rates of neurological improvement (33.3% of PS and 40.0% of O patients; p = 0.410) and mean fusion length (PS 5.1 ± 0.8 segments; O 4.9 ± 1.2). The mean operating time and estimated blood loss were 168.1 ± 46.7 min and 133.9 ± 116.5 g, respectively, in the PS group, and 224.6 ± 49.8 min and 499.9 ± 368.5 g in the O group. Three O-group patients died of hypovolemic shock, respiratory failure, and pneumonia, respectively, within a year of surgery. Conclusion: Conventional open posterior fixation and PPS fixation for DISH-related spinal fractures were similar in fusion length and neurological improvement. However, PPS fixation was less invasive and had lower complication rates.