Revision Surgery in Adult Spinal Deformity: Uncovering Key Predictors

Introduction: Adult spinal deformity (ASD) correction surgery aims to improve function, alleviate pain, and restore biomechanical alignment. However, the risk of revision surgery remains a significant concern, with reported rates ranging from 7% to 47% (Pitter, 2018). Identifying the key factors that lead to revision surgery is crucial for better preoperative planning and postoperative management, as well as reducing the likelihood of secondary procedures.

Methods: A retrospective review of 266 ASD surgeries performed at our tertiary care center between 2016 and 2023 was conducted. ASD was defined as surgeries with an upper instrumented vertebrae (UIV) at L2 or higher and a lower instrumented vertebrae (LIV) extending to the pelvis. Postoperative complications, including hardware failures (HF) such as screw and rod fractures or pullouts, proximal junctional kyphosis (PJK), proximal junctional failure (PJF), and the need for revision surgery, were analyzed. Only patients requiring revision surgery were included in the analysis.

Results: Of the 266 ASD patients, 37 (14%) required revision surgery (M: 24; F: 13). The mean age of the revision cohort was 64 years (±9.53). UIV distribution showed 20 (8%) patients at T4, 116 (44%) at T10, and 130 (48%) at L2. Hardware failure was the most common reason for revision, accounting for 26 cases (70%). Etiologies of HF included rod fractures (46%), screw pullout (27%), screw fractures (1%), and rod pullout (0.4%). Additionally, 12 patients (32%) with HF had associated PJK, while 3 patients (8%) experienced PJF. The average time to revision surgery was 20 months postoperatively.

Conclusion : Revision surgery remains a recognized risk following ASD correction, with hardware failure and symptomatic PJK being the most significant contributors. Understanding these key risk factors can improve surgical planning and patient outcomes, ultimately helping to reduce the revision surgery rate in ASD patients.