|Beitragstitel||Factors Associated with Having an Indication for Surgery in Patients with Adult Spinal Deformity (ASD)|
The results of surgery for adult spinal deformity (ASD) are highly variable and suggest patient selection could be improved. Previous studies have investigated differences between groups of ASD patients receiving either surgery or conservative care, but not in relation to whether surgery was indicated or not; as such, patients refusing or unable to undergo surgery would have been grouped with those for whom no such indication existed, confounding the analyses. We sought to carry out a cross-sectional analysis of the presenting characteristics of patients with and without an indication for surgery, using data (N=937) from an international multicenter ASD database.
The treating surgeon documented whether there was an indication for surgery or not; this was the dependent variable in multiple logistic regression analysis. Baseline variables were grouped into demographics, medical history, health-related quality of life (HRQoL), radiological, and neurologic parameters, with significant variables in each block being entered into the final model. The model's predicted probability of an indication was compared with the actual status (indication/no indication) for each patient. The area under the Receiver Operating Characteristics (ROC) curve (AUC) indicated model accuracy.
316 patients had a degenerative (DEGEN) etiology and 621, an idiopathic (IDIO). For DEGEN, worse Oswestry Disability Index scores (p<0.0001) and a lower degree of maximal kyphosis (p=0.001) were the factors significantly associated with an indication for surgery. The corresponding variables for IDIO were lower age (p<0.0001), worse SRS self-image scores (p<0.0001), sagittal subluxation (p<0.0001), less lumbar lordosis (p<0.0001), a higher major Cobb angle (p=0.005), no prior fusion surgery (p=0.007), use of narcotics (p=0.041) and prior infiltrations (p=0.042). 81% DEGEN and 73% IDIO patients were correctly predicted, with ROC analysis showing good accuracy (DEGEN, AUC = 0.82; IDIO, AUC = 0.81; each p<0.0001).
For both etiologies, indicators of symptom severity (infiltration/medication use and/or HRQoL scores) and some radiographic parameters showed a strong statistical association with having an indication for surgery. Future studies of the model's prediction (indication/no indication) and the outcome of the actual treatment a patient receives (surgery/conservative) should reveal whether the predictors might help in selecting appropriate patients for surgery.