Fixation of Chance fractures with cement-augmented pedicle screws reduces the risk of screw pullout in older patients: A retrospective comparative study

Abstract

Posterior fixation with pedicle screws and rods may be required when treating Chance fractures involving the posterior ligamentous complex. Only a few studies have evaluated the outcomes of older adults with Chance fractures. Given that bone mineral density decreases with increasing age, cement augmentation of pedicle screws may be critical in older patients. This study compared the postoperative outcomes of patients aged ≥ 65 with Chance fractures who underwent fixation with or without cement-augmented pedicle screws. This retrospective single-center comparative study included the data of patients enrolled between August 2014 and September 2022. The patients were divided into 3 groups according to whether cement augmentation was employed for pedicle screws. The Cobb angle was measured before and after surgery and at final follow-up. Refractures, adjacent fractures, implant removals, and screw pullouts were recorded. Twenty-one patients with a follow-up duration of ≥ 6 months were included, with 13 and 8 patients in the uncemented and cement-augmented screw groups, respectively. The mean Cobb angles significantly improved in both groups after surgery and the improvements were not different between groups. At final follow-up, the Cobb angle improvement in the uncemented screw group was significantly inferior to that in the cement-augmented screw group. The incidence of screw pullout was significantly higher in the uncemented screw group (69.2% vs 12.5%) and was especially higher in patients with a T-score greater than - 2.5 (87.5%). No between-group differences were noted in refracture, adjacent fracture, and implant removal rates. In patients aged ≥ 65 with Chance fractures, cement-augmented pedicle screws may help to reduce the risk of screw pullout. This effect was most notable in patients with a T-score greater than - 2.5, although this subgroup finding should be interpreted with caution.

Keywords: Chance fractures; cement-augmented pedicle screws; older patients; screw pullout; thoracolumbar fractures.