Foraminal Stenosis

Before lumbosacral decompression surgery for radicular pain, selective nerve root block(SNRB) is a common procedure to identify the responsible compressed nerve root(RCNR) and predict surgical outcomes. However, the diagnostic accuracy of conventional SNRB is unsatisfactory, especially in terms of specificity. The main limitation is the uncontrolled distribution of anesthetics during injection: when anesthetics spread to surrounding soft tissues instead of acting directly on the RCNR, false-negative results may occur with persistent radicular pain; when anesthetics diffuse to two or more nerve roots including the RCNR, false-positive results may occur even if a normal nerve root is punctured, leading to misdiagnosis. This study aims to evaluate the diagnostic accuracy of a novel three-dimensional computed tomography multiplanar volume reconstruction (3D-CT MPVR) guided selective intraperineural nerve root block(SINRB) for identifying the RCNR in patients with lumbosacral radicular pain. The investigators hypothesize that this technique will achieve higher diagnostic specificity and overall accuracy than conventional SNRB, by ensuring anesthetics are delivered directly to the target nerve root. This improvement will help clinicians make more accurate surgical plans, achieve better targeted decompression, and ultimately improve postoperative pain relief and functional recovery for patients. The main research questions to be addressed in this study are: * What is the procedural success rate of SINRB? * Whether SINRB may cause clinically detectable nerve injury? * Whether sciatica is relieved after SINRB when only the responsible compressed nerve root is blocked? * Whether sciatica is relieved after SINRB when only a normal unaffected nerve root is blocked? Participants will: * Undergo one or two SINRB procedures and a single-level lumbar decompression surgery * Get assessment of pain, mobility disorder and neurological function

The overall purpose of the study is to investigate whether selective spinal nerve root blocks can improve diagnostics of radiculopathy due to lumbar disc herniation (LDH), foraminal stenosis (FS), and recess stenosis (RS), and hence identify the patients that will benefit from surgical intervention.