Unplanned reoperations due to implant-related complications in older versus non-older patients following adult spinal deformity surgery: A retrospective cohort study using a multi-center database.

Abstract

Adult spinal deformity (ASD) surgery involves instrumentation, which can lead to implant-related complications (IRCs) and unplanned returns to the operating room (UPROR). Older patients often have risk factors like osteoporosis and multiple comorbidities, but research on how age-related factors affect IRCs and UPROR across age groups is limited. The aim of this study was to evaluate the characteristics of UPROR due to IRCs between older and non-older patients following ASD surgery. A retrospective analysis of patients (≥20 years) who underwent spinal fusion with instrumentation from 2010 to 2019 based on a multi-center database. Medical records were reviewed to identify ASD diagnoses and details of IRCs, including UPROR timing. UPROR timing was classified as early (<30 days), intermediate (30-90 days), and late (>90 days) postoperatively. Patients were stratified into older (≥65 years) and non-older (<65 years) groups to compare the characteristics of UPROR between the groups. IRCs occurred in 56 of 565 ASD cases (9.9 %) within 2 years postoperatively. UPROR was required in 38 patients (6.7 %), with implant breakage being the most frequent cause (23 cases), followed by screw malposition (14 cases). Screw-related complications predominated early, whereas implant breakage was most common in the late postoperative period. No significant differences in overall IRC or UPROR prevalence were observed between age groups. However, younger patients exhibited a higher rate of early UPROR (44.4 % vs. 20.0 % within 30 days). These findings highlight the distinct characteristics of IRCs between older and non-older patients, particularly in terms of UPROR timing. Understanding temporal patterns of these complications can inform surgical strategies and enhance patient outcomes by reducing UPROR.