Image-Based Markers Predict Dynamic Instability in Lumbar Degenerative Spondylolisthesis

Abstract

Objective: To identify possible radiographic predictors markers of dynamic instability including disc height (DH), disc degeneration, and spondylosis in the setting of degenerative spondylolisthesis (DS). Methods: A retrospective review with prospectively collected data was performed on 125 patients with L4-5 DS who underwent decompression and fusion. Patients were divided into groups with dynamic instability and those without. Radiographs of the lumbar spine in neutral, flexion, and extension were used to determine degree of slip, DH, translational motion, angular motion, spondylotic changes, and lumbar lordosis. Magnetic resonance imaging (MRI) scans were reviewed to assess disc degeneration. Results: Thirty-one percent of the patients met criteria for dynamic instability. Significant correlations (p < 0.05) were found between preserved DH and dynamic instability; increased spondylotic changes and decreased translational motion; as well as advanced MRI-based disc degeneration scores with decreased angular motion, respectively. Six radiographic parameters were utilized to create a predictive model for dynamic instability, and a receiver operating characteristic curve was able to validate the predictive model (area = 0.891, standard error = 0.034, p < 0.001). Conclusion: In DS patients, preserved DH was significantly related to dynamic instability. This finding may represent a greater potential for slip progression over time in these patients. In contrast, disc degeneration on MRI, and spondylotic changes were inversely related to dynamic instability and may represent restabilization mechanisms that decrease the chance of future slip progression in DS.

Magnetic Resonance Imaging Proxies for Segmental Instability in Degenerative Lumbar Spondylolisthesis Patients

“…Similar to prior studies, 37 we found that maintenance of disk height is associated with instability. We assessed disk height as an index instead of a continuous variable to account for wedge-shaped disks and allowing comparison between patients to be more reliable.…”

“…Previous studies have investigated reliability of the measurement methods included in our study, and revealing excellent agreement in both intraobserver and interobserver reliability for facet effusion 7,10,35 and FJA, 34 translation 16,42 and DHI. 37 We therefore found a reliability study redundant.…”

The effect of sagittal alignment, coronal balance, and segmental stability on preoperative patient-reported outcomes in patients with degenerative lumbar spondylolisthesis

“…As reported by Kirkaldy-Willis, the accumulation of microscopic degenerative damage caused decreased intervertebral disc height and subluxation of the facet joints, which finally led to increased intervertebral instability [ 27 ]. Compared with the ratios ranging from 31 to 40% reported by previous studies [ 28 – 30 ], the proportion of unstable spondylolisthesis reached 58.4% in our study (Table 1 ). These discrepancies might be related to age and racial/ethnic composition.…”

Comparative Study between Transforaminal Lumbar Interbody Fusion and Posterolateral Fusion for Treatment of Spondylolisthesis: Clinical Outcomes and Spino-Pelvic Sagittal Balance Parameters

“…This defect mostly happens at levels L4-L5 and L5-S1. 3 In low-grade spondylolisthesis, the spino-pelvic parameters change to compensate for the variations of spine mobility. 4 Diminishing of the lumbar lordosis (LL) is followed by a reversed ratio of extensors/ flexors muscle power compared with normal controls.…”