Superior articular process cross-sectional area is a new sensitive parameter for the diagnosis of lumbar central canal spinal stenosis

Abstract

PurposePrevious studies reported that hypertrophied superior articular process (SAP) was associated with an increased risk of lumbar foraminal stenosis. However, no study investigated the effect of SAP hypertrophy in lumbar central canal spinal stenosis (LCCSS). We hypothesized that the SAP cross-sectional area (SAPCSA) is the main morphologic feature in the diagnosis of LCCSS.Patients and methodsData regarding the SAPCSA were collected from 109 patients with LCCSS. All patients were enrolled after the LCCSS diagnosis was confirmed by an experienced, board-certified neuroradiologist. All patients had clinical manifestations compatible with LCCSS. A total of 120 subjects in the control group underwent lumbar spine MRI as part of non-symptomatic medical examination. T2-weighted axial images were obtained from the 2 groups. Using a picture archiving and communications system, we analyzed the CSA of the bone margin of SAP at the level of L4–L5 facet joint on MRI.ResultsThe average SAPCSA was 96.63±13.37 mm2 in the control group, and 123.59±14.18 mm2 in the LCCSS. The LCCSS group showed significantly higher levels of the SAPCSA (P<0.001) compared with the control one. Receiver operator characteristic (ROC) curve analysis was performed to determine the validity of the SAPCSA as a predictor of LCCSS. In the LCCSS group, the optimal cut-off-point was 110.71 mm2, with 83.5% sensitivity, 83.3% specificity, and area under the curve of 0.92 (95% CI: 0.88–0.95).ConclusionHigher SAPCSA values were associated with a higher possibility of LCCSS. These results are important in the evaluation of patients with LCCSS.

Preoperative Design for the Posterolateral Approach in Full-Endoscopic Spine Surgery for the Treatment of L5/S1 Lumbar Disc Herniation

“…To evaluate FJ hypertrophy, we measured the SAP area on axial T2-weighted MR imaging as described by An et al [7] FJ hypertrophy was defined as cases with areas greater than 111 mm 2 (Fig. 2A; case 6).…”

“…(A) Preoperative measurement of anatomical configurations The superior articular process area on axial T2-weighted magnetic resonance image was measured as described by An et al [7]. (yellow polygon).…”

“…To solve these problems, we calculated SAP cross-sectional area (mm 2 ) [7], entry angle, and entry distance for endoscope insertion, and determined the extent of the removal of SAP based on preoperative computed tomography (CT) and magnetic resonance (MR) images. Based on these calculations and determinations, we simulated the operative approach using omni-azimuth three-dimensional (3D) CT imaging of the corresponding facet joint (FJ) and neighboring structures.…”

Relative risk factors of nerve root sedimentation sign (Sedsign) in patients with severe central lumbar spinal stenosis (LSS)

“…The ligamentum avum and facet joint are the main structures that make up the posterior and lateral spinal canal walls, and has a protective effect on the spinal cord [22], which had been con rmed to be important roles in the development of LSS [23][24][25]. TLF and DFJ can induce a decrease in the central tube volume by compression from the behind a dural sac, which is the cause of LSS [26][27][28]. Therefore, we analyzed the TLF and DFJ between the two groups and found a signi cant difference for each of these parameters between the positive and negative groups.…”

Magnetic resonance imaging changes in multifidus and psoas muscles in patients with lumbar spinal stenosis

“…Computed tomography (CT) scanning allows accurate evaluation of the bone structures including vertebral bodies and facet joints [5]. When evaluating the spine, an SCCSA below 145 mm2 at the level of stenosis is radiologically accepted as spinal stenosis [6].…”