Introduction. Unplanned reoperations (UROs) following corrective surgery for adult spinal deformity (ASD) present significant challenges for both patients and surgeons. Understanding the specific UROs types is crucial for improving patient outcomes and refining surgical strategies in ASD correction. Method. This retrospective analysis utilized data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database spanning from 2017 to 2021. Patient information was extracted using specific CPT codes related to posterior pedicle fixation. Result. In a cohort of 1088 patients undergoing posterior spinal deformity corrections, we examined various preoperative factors to discern their correlation with reoperation prevalence. Our analysis revealed no statistically significant differences in reoperation prevalence concerning gender (male: 4.0%, p=0.131) or ethnicity (Hispanic: 4.2%, p=0.192). Similarly, no notable associations were identified for diabetes mellitus, smoking status, dyspnea, history of severe COPD, hypertension, ASA classification, or functional health status before surgery, with reoperation prevalences ranging from 3.2% to 8.8% and p-values spanning from 0.146 to 0.744. Overall, the reoperation prevalence within the entire cohort stood at 5.2% (55 cases). In terms of the types of reoperations investigated, spinal-related procedures emerged as the most prevalent, accounting for 43.7% (24 cases), followed closely by wound site revisions at 23.6% (13 cases). Additionally, gastrointestinal-related procedures and various other miscellaneous interventions, such as uroscopy, demonstrated reoperation prevalences of 7.2% (4 cases) and 25.5% (14 cases), respectively. Conclusion. our findings highlight the diverse spectrum of reoperation procedures encountered following posterior spinal deformity corrections, with wound site revisions and spinal-related interventions being the most prevalent categories. These results emphasize the complexity of managing UROs in spinal surgery and the need for tailored approaches and infection/incision protocols to address the specific challenges associated with each type of reoperation

Currently, between 17% of patients undergoing surgery for adult spinal deformity experience severe instrumentation related problems such as screw pullout or proximal junctional failure necessitating revision surgery. Cables may be used to reinforce pedicle screw fixation as an additive measure or may provide less rigid fixation at the construct end levels in order to prevent junctional level problems. The purpose of this study is to provide insight into the maximum expected load during flexion in UHMWPE cable in constructs intended for correction of adult spine deformity (degenerative scoliosis) in the PoSTuRe first-in-man clinical trial. Following the concept of toppinoff, a new construct is proposed with screw/cable fixation of rods at the lower levels and standalone UHMWPE cables at the upper level (T11). A parametric FE model of the instrumented thoracolumbar spine, which has been previously validated, was used to represent the construct. Pedicle screws are modeled by assigning a rigid tie constraint between the rod and the lamina of the corresponding spinal level. Cables are modeled using linear elastic line elements, fixing the rod to the lamina medially at the cranial laminar end and laterally at the caudal laminar end. A Youngs modulus was assigned such that the stiffness of the line element was the same as that of the cable. An 8 Nm flexion moment was applied to the cranial endplate. The maximum value of the force in the wire (80 N) is found at the T11 (upper) level. At the other levels, forces in the cable are very small because most of the force is carried by the screw (T12) or because the wires are force shielded by the contralateral and adjacent level pedicle screws (L2, L3). The model provides first estimates of the forces that can be expected in the UHMWPE cables in constructs for kyphosis correction during movement. It is expected that this approach can help in defining the number of wires for optimal treatment