Assessing radiological factors: the role of pelvic tilt in surgery for geriatric patients with degenerative spinal disorders

Adult Degenerative Spinal Disorders (ADSD) pose significant clinical challenges, especially among elderly population. Currently, the decision-making process regarding surgical intervention primarily relies on the severity of clinical symptoms. However, there is no well-established standard for determining which patients are appropriate candidates for surgery. In addition, there is a noticeable lack of research focusing on the radiological assessment of patients to determine the necessity for surgical intervention. Hence, this study aims to explore potential influencing factors for surgery in terms of radiological features. A retrospective analysis was conducted on 381 geriatric patients with ADSD. All patients underwent radiological assessments utilizing the EOS 2D/3D imaging system. We collected demographic information and a comprehensive set of 20 radiological features, including pelvic tilt (PT), sacral slope, thoracic kyphosis, pelvic incidence (PI), lumbar lordosis (LL), T1 pelvic angle, global tilt, pelvic shift, and the alignment of the C7 plumb line relative to the Center Sacral Vertical Line (CSVL). Logistic regression analysis was employed to identify risk factors associated with surgical intervention, while Restricted Cubic Spline (RCS) curve analysis was used to examine the relationship between risk factors and surgical decisions. The overall surgical intervention rate among the cohort was 29.4%. Subgroup analyses indicated that patients exhibiting higher PT (P < 0.001), higher PI (P = 0.007), greater PI-LL (P = 0.001), reduced lower lumbar lordosis (P = 0.048), elevated T1 pelvic angle (P < 0.001), increased global tilt (P < 0.001), and greater pelvic shift (P = 0.025) were more likely to pursue surgical treatment. Binary logistic regression confirmed these trends, and multinomial logistic regression revealed that PT remained significantly correlated with the decision to undergo surgery (Odds Ratio [OR] = 1.085, 95% Confidence Interval [CI]: 1.028–1.146, P = 0.003). When PT was classified into a binary variable based on the optimal threshold, patients with a PT exceeding 18.4 degree were 3.142 times (95% CI: 1.611–6.129) more likely to undergo surgery compared to those with PT at or below 18.4 degree (P < 0.001) after adjusting for potential confounding factors. In a four-class classification, patients with PT > 18.0 degree and ≦ 25.3 degree were 3.903 times (95% CI: 1.588–9.591) more likely, while those with PT > 25.3 degree were 4.987 times (95% CI: 1.472–16.893) more likely to require surgery compared to patients with PT ≦ 11.4 degree (P = 0.003 and P = 0.010 respectively) after adjusting for potential confounding factors. The RCS analysis demonstrated a significant association between PT and the predicted probability of surgery after adjusting for all other variables, but no non-linear relationships were identified, indicating that the association between PT and surgery was primarily linear across the different models analyzed. The findings of this study suggest that PT is a critical radiological factor associated with undergoing surgery in geriatric patients with ADSD. Higher degrees of PT significantly correlate with an increased likelihood of surgical intervention. These insights may assist clinicians in evaluating surgical options for patients with ADSD and underline the importance of radiological assessments in decision-making processes. This study was registered at the Chinese Clinical Trial Registry (Registration ID: ChiCTR2400090679, retrospectively registered).