Introduction: The clinical-radiological dissociation in degenerative spinal stenosis (DSS) presents a significant challenge for surgical decision-making. This study aimed to investigate the predictive utility of preoperative health-related quality of life (HRQoL), as measured by the Short Form Health Survey-36 (SF-36), for determining postoperative outcomes following decompressive surgery in a geriatric cohort.

Methods: A prospective longitudinal study was conducted involving 108 patients (M = 73.2 years, SD = 5.3; 61.1% male) undergoing surgical intervention for DSS. Standardised clinical metrics, including the Visual Analogue Scale (VAS) for pain and the Oswestry Disability Index (ODI) for functional impairment, were recorded. Surgical success was operationalised using the Minimal Clinically Important Difference (MCID): reduction in VAS of at least 1 point, reduction in ODI of at least 1.5 points, or an increase in the total SF-36 score of at least 15 points. Predictive accuracy was assessed via Receiver Operating Characteristic (ROC) analysis and Spearman’s correlation (rs).

Results: Significant longitudinal improvements were observed across all clinical parameters post-surgery (p < .001). Mean ODI scores decreased from 3.15 to 2.19, VAS scores shifted from 2.51 to 1.60, and total SF-36 scores improved from 49.11 to 69.02. ROC analysis identified the preoperative SF-36 as a robust predictor of surgical success, yielding an area under the curve (AUC) of .951. Notably, anatomical severity (Schizas grade) did not correlate significantly with baseline functional status, further highlighting the clinical-radiological mismatch.

Conclusion: Preoperative HRQoL is a potent, independent predictor of surgical success in geriatric DSS patients. These findings support the integration of the SF-36 into routine preoperative assessments to enhance patient stratification and optimise therapeutic outcomes.