“Patient-specific” rods in the management of adult spinal deformity. One-year radiographic results of a prospective study about 86 patients

Abstract

IntroductionBased on global knowledge regarding sagittal alignment, preoperative planning is a crucial point in the management of adult spinal deformity (ASD). Patient-specific rods (PSR) have been recently developed in order to change preoperative planning into a postoperative reality. The aim of this study was therefore to analyze the 1-year radiographic results of prospective ASD cohorts managed using PSR. MethodsIn this prospective study, all patients managed for an ASD using PSR since 2014 and with a minimal follow-up of 1-year were included. Radiographic parameters were evaluated pre and postoperatively and patients were stratified according to their final sagittal alignment status (A: aligned vs. MA: malaligned) according to the age-related Schwab classification. Statistical analyses were performed using the Student's-t-test in order to compare groups. ResultsEighty-six patients were included in the study, with a mean age of 57.2 years. At one-year follow-up, mean sagittal vertical axis and pelvic incidence-lumbar lordosis mismatch were significantly improved. Twenty-two patients were aligned on both sagittal and coronal planes, 52 patients were still considered as malaligned in the sagittal plane, 3 were still malaligned in the coronal plane and 9 patients were malaligned in both planes (vs. 42 patients preoperatively). At final follow-up, the rate of mechanical complications was 18%. ConclusionBased on our results, patient-specific rods can represent a useful supplementary tool in the management of ASD and transform preoperative planning into a postoperative reality. Corrections rates are comparable to other series in the literature with conventional rods, and fewer complications have been reported. However, further studies will be required in order to confirm these results.