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Background Context: Prior studies have hypothesized that degenerative cervical spondylolisthesis (DCS) may be influenced by loss of stability due to disc, facet joint or cervical alignment. Meanwhile, it is commonly believed that the facet joints and paraspinal muscles participate in maintaining cervical spine stability. However, the impact of paraspinal muscle morphology and detailed facet joint features on DCS requires further investigation., Purpose: To compare facet joint characteristics, disc degeneration and muscle morphology between patients with DCS and those without DCS., Study Design/setting: Retrospective cohort study., Patient Sample: Consecutive surgical patients with degenerative cervical spondylosis from June 2016 to August 2023 were recruited., Outcome Measures: DCS was assessed on X-ray based on the translation distance. Cervical facet joint degeneration (CFD), the facet joint angle on the axial plane (FA-A) and the facet joint angle on the sagittal plane (FA-S), and facet joint tropism (FT) were measured on computerized tomography (CT). Paraspinal muscle degeneration was assessed on magnetic resonance imaging (MRI) including by the adjusted cross-sectional area (aCSA), the functional aCSA, the fat infiltration ratio (FI%). The Pfirrmann grade of the cervical disc was also evaluated., Methods: Demographic and clinical data were compared in matched and unmatched cohorts. Disc degeneration, muscle degeneration and facet joint characteristics, including FA, FT and CFD, were compared between patients with and without DCS. Furthermore, the degree of CFD was compared with that of adjacent segments in both groups. Additionally, logistic regression was performed to determine independent risk factors for DCS. Finally, the receiver operating characteristic (ROC) curve, area under the curve (AUC) and cutoff value for the risk factors were calculated., Results: A total of 431 surgical patients were propensity score matched for age, sex and BMI, and 146 patients were included in the final analysis, with 73 patients in the DCS group and 73 patients in the non-DCS group. DCS patients exhibited more severe CFD at C4/5 (segment with spondylolisthesis). Additionally, DCS was generally associated with more severe CFD, a more horizontal FA-S, more FT and worse paraspinal muscle health but similar disc degeneration. In addition, anterior spondylolisthesis was related to more severe CFD and decreased functional aCSA of the flexors and extensors. Finally, more severe CFD, a more horizontal FA-S and a higher FI% on deep extensor were revealed to be risk factors for DCS, with cutoff values of 1.5, 44.5̊, and 37.1%, respectively., Conclusions: This study demonstrated that CFD, the FA and FT and parasipnal muscle degeneration were associated with DCS. And may provide novel insight into the pathogenesis and nature history of DCS and suggest the evolution of degeneration in the cervical spine., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background/context: Degenerative lumbar spondylolisthesis (DLS) is a prevalent spinal condition that can result in significant disability. DLS is thought to result from a combination of disc and facet joint degeneration, as well as various biological, biomechanical, and behavioral factors. One hypothesis is the progressive degeneration of segmental stabilizers, notably the paraspinal muscles, contributes to a vicious cycle of increasing slippage., Purpose: To examine the correlation between paraspinal muscle status on MRI and severity of slippage in patients with symptomatic DLS., Study Design/setting: Retrospective cross-sectional study at an academic tertiary care center., Patient Sample: Patients who underwent surgery for DLS at the L4/5 level between 2016-2018 were included. Those with multilevel DLS or insufficient imaging were excluded., Outcome Measures: The percentage of relative slippage (RS) at the L4/5 level evaluated on standing lateral radiographs. Muscle morphology measurements including functional cross-sectional area (fCSA), body height normalized functional cross-sectional area (HI) of Psoas, erector spinae (ES) and multifidus muscle (MF) and fatty infiltration (FI) of ES and MF were measured on axial MR. Disc degeneration and facet joint arthritis were classified according to Pfirrmann and Weishaupt, respectively., Methods: Descriptive and comparative statistics, univariable and multivariable linear regression models were utilized to examine the associations between RS and muscle parameters, adjusting for confounders sex, age, BMI, segmental degeneration, and back pain severity and symptom duration., Results: The study analyzed 138 out of 183 patients screened for eligibility. The median age of all patients was 69.5 years (IQR 62 to 73), average BMI was 29.1 (SD±5.1) and average preoperative ODI was 46.4 (SD±16.3). Patients with Meyerding-Grade 2 (M2, N=25) exhibited higher Pfirrmann scores, lower MF fCSA and MF HI , and lower BMI, but significantly more fatty infiltration in the MF and ES muscles compared to those with Meyerding Grade 1 (M1). Univariable linear regression showed that each cm 2 decrease in MF fCSA was associated with a 0.9%-point increase in RS (95% CI -1.4 to - 0.4, p<.001), and each cm 2 /m 2 decrease in MF HI was associated with an increase in slippage by 2.2%-points (95% CI -3.7 to -0.7, p=.004). Each 1%-point rise in ES FI and MF FI corresponded to 0.17%- (95% CI 0.05-0.3, p=.01) and 0.20%-point (95% CI 0.1-0.3 p<.001) increases in relative slippage, respectively. Notably, after adjusting for confounders, each cm 2 increase in Psoas fCSA and cm 2 /m 2 in Psoas HI was associated with an increase in relative slippage by 0.3% (95% CI 0.1-0.6, p=.004) and 1.1%-points (95% CI 0.4-1.7, p=.001). While MF fCSA tended to be negatively associated with slippage, this did not reach statistical significance (p=.105). However, each 1%-point increase in MF FI and ES FI corresponded to increases of 0.15% points (95% CI 0.05-0.24, p=.002) and 0.14% points (95% CI 0.01-0.27, p=.03) in relative slippage, respectively., Conclusion: This study found a significant association between paraspinal muscle status and severity of slippage in DLS. Whereas higher degeneration of the ES and MF correlate with a higher degree of slippage, the opposite was found for the psoas. These findings suggest that progressive muscular imbalance between posterior and anterior paraspinal muscles could contribute to the progression of slippage in DLS., Competing Interests: Declaration of competing interest One or more of the authors declare financial or professional relationships on ICMJE-TSJ disclosure forms., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background Context: Vertebral endplate defects are often implicated in degenerative disc disorders, yet their connection to patient-reported symptoms remains unclear. COX-2 and PGE-2 are known for their roles in inflammation and pain, with EP-4 receptor involvement in pain signaling. Examining their expression in vertebral endplate tissues may provide insights into pathomechanism of low back pain., Purpose: To investigate the association between endplate defects and patient-reported symptoms and to further clarify the role of the COX-2/PGE-2/EP-4 axis in the pathogenesis of chronic low back pain., Study Design/setting: Retrospective study., Patient Sample: A total of 71 patients who had undergone single-level L4/5 or L5/S1 modified laminectomy decompression preserving proximal upper laminae and transforaminal lumbar interbody fusion surgery were included in this study, including 18 patients diagnosed with lumbar disc herniation, 19 with lumbar disc herniation accompanied by degenerative lumbar spinal stenosis, and 34 with degenerative spondylolisthesis., Outcome Measures: Demographic data, Pfirrmann grade, Modic changes, endplate defect score, visual analog scale (VAS) for back and leg pain, and Oswestry Disability Index (ODI) before surgery, 3-month and 6-month follow-up, and the percentage of immune-positive cells (COX-2, PGE-2, and EP-4) in endplate tissue sections., Methods: Patients were divided into defect and nondefect groups according to endplate morphology on lumbar MR. All intraoperative endplate specimens were immediately fixed in 10% formaldehyde, and then embedded in paraffin 3 days later for tissue sections. The outcome measures were compared between the defect group and nondefect group. Data were analyzed using independent t-tests and χ² tests. Pearson's rank correlation test was used to assess correlations between patient-reported symptoms and the percentage of immune-positive cells in the groups. Multivariable logistic regression models using the forward stepwise likelihood ratio method were used to identify the factors that were independently associated with endplate defects., Results: The age of Defect group was significantly higher than that of nondefect group (52.5±7.7 vs 57.2±9.1. p=.024). There were no significant differences in gender, diagnosis, BMI, comorbidities, or surgical level between the two groups. Modic changes (Type Ⅱ/Type Ⅲ) were more common in patients of Defect group than nondefect group (38.5% vs 11.1%, p<.001), and so was disc degeneration (Pfirrmann grade Ⅳ/Ⅴ) (69.2% vs 33.3%, p<.001). Defect group had significantly higher VAS-Back (6.5±2.0 vs 4.9±1.6, p<.001) and ODI scores (62.9±10.7 vs 45.2±14.8, p<.001) than nondefect group, while there was no significant differences between the two groups during the 3 and 6-month follow-up after surgery. Histologically, Defect group was characterized by upregulation of COX-2, PGE-2, and EP-4 in endplate tissue sections. Both in defect and nondefect groups, VAS-Back showed moderate positive correlations with the expressions of COX-2 (r=0.643; r=0.558, p both<.001), PGE-2 (r=0.611; r=0.640, p both<.001), and EP-4 (r=0.643; r=0.563, p both<.001). Multivariate regression analyses reveled that percentage of COX-2-positive cells was associated with endplate defects (OR=1.509, 95%CI [1.048-2.171], p=.027), as well as percentage of PGE-2-positive (OR=1.291, 95%CI [1.106-1.508], p=.001) and EP-4-positive cells (OR=1.284, 95%CI [1.048∼2.171], p=.003)., Conclusions: Patients with endplate defects had worse quality of life, more severe disc degeneration and Modic changes, and up-regulated COX-2/PGE-2/EP-4 axis expression in cartilage endplates in patients with defected endplates. Inflammatory factors may significantly contribute to the onset and progression of chronic low back pain in patients with endplate defects, consequently impacting patient-reported symptoms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Degenerative spondylolisthesis (DS) is one of the most common pathologies spine surgeons treat. While a number of potential factors have been identified, there is no current consensus on which variables most impact the decision to fuse vs. decompress alone in this population., Purpose: The purpose of this study was to describe current DS treatment practices and identify both the radiographic and clinical factors leading to the decision to fuse segments for one level DS., Study Design/setting: Descriptive cross-sectional survey., Patient Sample: Surveys were administered to members of Lumbar Spine Research Society and Society of Minimally Invasive Spine Surgery., Outcome Measures: Surgeon demographics and treatment practices were reported. Radiographic and clinical parameters were ranked by each surgeon with regards to their importance., Methods: The primary analysis was limited to completed surveys. Baseline characteristics were summarized. Clinical and radiographic parameters were ranked and compared. Ranking of each clinical and radiographic parameters was reported using best and worst rank, mean rank position, and percentiles. The most important, top 3 most important, and top 5 most important parameters were ordered given each parameter's ranking frequency., Results: 381 surveys were returned completed. With regards to fusion vs. decompression, 19.9% fuse all cases, 39.1% fuse > 75%, 17.8% fuse 50%-75%, and 23.2% fuse <25%. The most common decompressive technique was a partial laminotomy (51.4%), followed by full laminectomy (28.9%). 82.2% of respondents instrument all fusion cases. Instability (93.2%), spondylolisthesis grade (59.8%), and laterolisthesis (37.3%) were the most common radiographic factors impacting the decision to fuse. With regards to the clinical factors leading to fusion, mechanical low back pain (83.2%), activity level (58.3%), and neurogenic claudication (42.8%) were the top 3 clinical parameters., Conclusions: There is little consensus on the treatment of DS, with society members showing substantial variation in treatment patterns with the majority utilizing fusion for treatment. The most common radiographic parameters impacting treatment are instability, spondylolisthesis grade, and laterolisthesis while mechanical low back pain, activity level, and neurogenic claudication are the most common clinical parameters., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background Context: Patients with back pain predominance (BPP) have traditionally been thought to derive less predictable symptomatic relief from lumbar fusion surgery., Purpose: To compare postoperative clinical outcomes as well as degree of improvement in clinical outcome measures between patients with BPP and patients with leg pain predominance (LPP) undergoing open posterior lumbar fusion., Study Design: Retrospective cohort study., Patient Sample: Analysis of patients who underwent an open posterior lumbar fusion for low-grade (Meyerding Grade I or II) degenerative or isthmic spondylolisthesis from 2011 to 2018 was conducted. Surgery was indicated after failure of conservative treatment to address radiculopathy and/or neurogenic claudication. Patients were excluded if they were under 18 years of age at the time of surgery, had less than 6 months of follow-up, presented with a lumbar vertebral body fracture, tumor, or infection, or underwent a fusion surgery that extended to the thoracic spine, high-grade spondylolisthesis, or concomitant deformity., Outcome Measures: Radiographs obtained at preoperative, immediate postoperative, and final visits were evaluated for presence or absence of fusion. Patient-reported outcomes were recorded at preoperative and final clinic visits that included: visual analog scale (VAS) back/leg pain, and Oswestry disability index (ODI). Achievement of minimal clinically important difference (MCID) was analyzed, along with rates of postoperative complication and reoperation., Methods: Preoperative and final patient-reported outcomes were obtained. Achievement of MCID was evaluated using following thresholds: ODI 14.9, VAS-back pain 2.1, VAS-leg pain 2.8. For analysis, patients were divided into two groups based on predominant location of pain: predominantly VAS-back pain (BPP) and predominantly VAS-leg pain (LPP)., Results: One hundred forty-one patients met inclusion criteria. Of these, 71 had LPP, and 70 had BPP. Patients with preoperative LPP experienced greater improvements in VAS-leg (p<.001) compared to those with BPP, whereas patients with preoperative BPP experienced greater improvements in VAS-back (p=.011) postoperatively compared to those with LPP. There were no differences in the final clinical outcomes. Additionally, LPP achieved MCID for VAS-leg (p=.027) at significantly higher proportion than BPP and BPP achieved MCID for VAS-back (p=.050) at significantly higher proportion than LPP., Conclusions: Patients with low-grade spondylolisthesis who underwent an open posterior lumbar fusion had improvement in symptoms regardless of presentation with BPP or LPP. In properly indicated patients, posterior spinal fusion is effective for those with BPP in the setting of experiencing both leg and back pain, and clinicians can use this information for perioperative discussions and surgical decision-making., (Copyright © 2019. Published by Elsevier Inc.)

Background Context: T1 slope is a novel thoracic parameter used to assess cervical spine sagittal balance. Thoracic index (TI) parameters including T1 slope and cervical sagittal alignment parameters may play an important role in degenerative cervical spondylolisthesis (DCS). Current literature regarding the relationship between TI and cervical sagittal alignment parameters in patients with DCS is limited., Purpose: (1) To evaluate the T1 slope, cervical sagittal alignment, and thoracic inlet parameter in patients with DCS using kinematic magnetic resonance imaging (kMRI), and (2) to find a correlation between the T1 slope, TI, and other cervical sagittal parameters in patients with DCS., Design/setting: Retrospective kMRI study, Level III., Patient Sample: Fifty-two patients with DCS from 1,128 patients from a cervical kMRI database., Outcome Measures: T1 slope, C2-C7 angle, sagittal vertical axis C2-C7 (SVA C2-C7), cranial tilt, cervical tilt, neck tilt, and thoracic inlet angle (TIA)., Methods: Cervical spine kMRIs of 52 patients with DCS (mean age 51.7±standard deviation) were analyzed in neutral, flexion, and extension positions. Patients with DCS were divided into two groups: anterolisthesis (N=33) and retrolisthesis (N=19). Each listhesis group was subclassified into grade 1 (slip 2-3 mm) and grade 2 (slip>3 mm)., Results: Grade 2 retrolisthesis had the largest T1 slope followed by grade 1 retrolisthesis, grade 2 anterolisthesis, and grade 1 anterolisthesis. Significant differences were found between the anterolisthesis and the retrolisthesis groups in the neutral position (p=.025). The flexion position had the largest T1 slope and showed a significant difference with anterolisthesis in the neutral position (p=.041). Sagittal vertical axis C2-C7 showed strong correlation with cranial tilt in all DCS groups and all positions., Conclusions: In our study, T1 slope was larger in grade 2 DCS, and the retrolisthesis group had larger T1 slope than the anterolisthesis group. Presence of larger T1 slope was significantly correlated with larger cervical lordosis curvature. Furthermore, cranial tilt was strongly correlated with SVA C2-C7., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background Context: Magnetic resonance imaging (MRI) is often used in the evaluation of degenerative conditions of the cervical spine. However, the agreement of interpreting and reporting varying degenerative findings on cervical MRI has not been well assessed., Purpose: This study aimed to compare the inter-rater and intra-rater agreement of MRI findings between common degenerative findings of the cervical spine., Study Design: A retrospective diagnostic study was used as study design., Patient Sample: The sample consisted of 48 patients who underwent routine cervical spine MRI at our institution between January 2011 and June 2012., Outcome Measures: Reviewers evaluated each MRI study at each vertebral level for disc hydration, disc space height, central stenosis, foraminal stenosis, end plate changes, spondylolisthesis, and cord signal change., Methods: A panel of two orthopedic spine surgeons and four musculoskeletal radiologists independently reviewed 48 sets of T2-weighted axial and sagittal MRI sequences for a series of preselected criteria, and their findings were compared with those of the other panelists to determine inter-rater agreement. Each panelist also re-reviewed the first 10 studies to determine intra-rater agreement. Absolute inter-rater and intra-rater agreements were then calculated and compared for different findings. A modified analysis ignored disagreements between the least severe grades of findings to determine the inter-rater and intra-rater agreements of the most clinically important severity grades., Results: Absolute inter-rater agreement ranged from 54.6% to 95.0%. Disc hydration (54.6%), central stenosis (72.7%), and foraminal stenosis (73.1%) demonstrated the lowest inter-rater agreement, whereas spondylolisthesis (95.0%) and cord signal change (92.9%) demonstrated the highest agreement. The modified analysis found better inter-rater agreement, ranging from 80.9% to 95.0%. Absolute intra-rater agreement ranged from 74.2% to 94.7%. The modified analysis again found better agreement, ranging from 85.0% to 94.7%. As would be expected, overall intra-rater agreement (81.6%, 95% CI 78.9%-84.3%) was higher than inter-rater agreement (75.7%, 95% CI 74.4%-77.0%). The clinical specialty of the reviewer had no significant impact on inter- or intra-rater agreement., Conclusions: MRI findings play an important role in the management of patients with cervical spine conditions. For this reason, consistent descriptions of these findings are essential and physicians should be aware of the relative reliability of these findings. This systematic study developed standardized grading criteria and nomenclature for common clinically significant MRI findings in the cervical spine. Even in this optimized research setting, we found significant ranges in agreement across these MRI findings. In the clinical setting, inter- and intra-rater agreements may be lower, and the range of agreements between findings may be greater. Physicians should be aware of inconsistencies inherent in the interpretation of cervical MRI findings and should be aware that some findings demonstrate lower agreement than others., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Commentary on: Fu MC, Webb ML, Buerba RA, Neway WE, Brown JE, Trivedi M, et al. Comparison of agreement of cervical spine degenerative pathology findings in magnetic resonance imaging studies. Spine J 2016:16:42-8 (in this issue)., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background Context: Axial-loaded magnetic resonance imaging (MRI) can partially simulate the lumbar spine in patients in a standing position and potentially provides additional imaging findings that cannot be obtained with conventional MRI in the clinical assessment of patients with degenerative lumbar disease. Previous studies have shown that axial-loaded MRI demonstrates a significant reduction in the size of the dural sac compared with conventional MRI. However, there has been no study to compare the degree of olisthesis among conventional MRI, axial-loaded MRI, and upright X-ray imaging in patients with degenerative spondylolisthesis (DS)., Purpose: The purpose of the study is to determine whether axial-loaded MRI can demonstrate similar positional changes in lumbar olisthesis as those detected on upright lateral X-ray in patients with DS., Study Design: This is an imaging cohort study., Patient Sample: A total of 43 consecutive patients with DS exhibiting olisthesis of 3 mm or more on X-ray images in the standing position were prospectively evaluated in this study., Outcome Measures: The degree of olisthesis, intraclass correlation coefficient (ICC), and percentage of patients exhibiting olisthesis of 3 mm or more on MRI., Methods: The degree of olisthesis was measured on conventional MRI, axial-loaded MRI, and lateral X-ray imaging performed in the upright position. The degree of olisthesis was compared among the three imaging techniques. The ICC values for the measurements of olisthesis between X-ray studies and conventional and axial-loaded MRI were calculated and compared. The percentage of patients exhibiting olisthesis of 3 mm or more was compared between conventional MRI and axial-loaded MRI., Results: The degree of olisthesis on axial-loaded MRI (5.9±2.5 mm) was significantly greater than that observed on conventional MRI (4.4±2.4 mm) (p<.05) although the degrees on conventional and axial-loaded MRI were significantly smaller than that on upright X-ray images (7.1±2.8 mm) (p<.05). The ICC between axial-loaded MRI and X-ray imaging (0.75, 95% confidence interval: 0.58-0.85) was considerably greater than that observed between conventional MRI and X-ray imaging (0.40, 95% confidence interval: 0.11-0.62). The percentage of patients exhibiting olisthesis of 3 mm or more was significantly higher on axial-loaded MRI (91%) than on conventional MRI (63%) (p<.01)., Conclusions: Axial-loaded MRI demonstrates a significantly larger degree of olisthesis than conventional MRI. In addition, the degree of olisthesis on axial-loaded MRI was found to be more strongly correlated with that observed on X-ray studies in the upright position. Furthermore, the use of axial-loaded MRI significantly reduced the misdiagnosis of olisthesis of 3 mm or more that was detected on X-ray imaging. These results suggest that axial-loaded MRI may be superior to identify the olisthesis of the lumbar spine and show the degrees of olisthesis correlated to those detected on upright X-ray imaging. Further studies should be needed to clarify the actual value of these findings on axial-loaded MRI and provide the evidence to support its clinical significance in the assessment of patients with DS., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background Context: Degenerative spondylolisthesis is a common pathologic condition that leads to lumbar instability and significant clinical symptoms. The effect of this pathology on adjacent lumbar motion segments, however, has not yet been studied., Purpose: To characterize the motion characteristics of lumbar degenerative spondylolisthesis at both the diseased and adjacent levels in patients with low-grade, single-level lumbar degenerative spondylolisthesis using kinetic magnetic resonance imaging (kMRI)., Study Design: Retrospective study of patient kMRIs., Patient Sample: One-hundred twelve patient MRIs with low-grade, single-level lumbar spondylolisthesis were included., Outcome Measures: Angular and translational motion., Methods: This study compared 112 patients diagnosed with low-grade (Grade 1 or 2), single-level lumbar degenerative spondylolisthesis at L3-L4, L4-L5, or L5-S1 with 296 control patients without spondylolisthesis. Angular and translational motion were measured using patient kMRIs. The level of slip was graded according to the Meyerding classification system, and disc degeneration was classified according to the Pfirrmann system. Instability was defined as translational motion greater than 4 mm., Results: Lumbar hypomobility was often present regardless of the level of degenerative spondylolisthesis. A slip at L3-L4 resulted in the largest decrease in lumbar range of motion. Instability at the diseased level was most common at L3-L4 (36%), followed by L5-S1 (31%) and L4-L5 (30%). Instability at the adjacent segments was most frequent at L4-L5 (49%), followed by L5-S1 (34%) and L3-L4 (23%). Patients with stable spondylolisthesis generally had decreased angular motion at all lumbar levels. Translational motion at the diseased level was consistently increased. Disc degeneration was significantly greater at the level of slip for the L3-L4 and L4-L5 spondylolisthesis groups and equal to the control group in the L5-S1 group. There was no significant difference in disc degeneration at adjacent segments in L3-L4 and L4-L5 degenerative spondylolisthesis patients, but there was a significant decrease with an L5-S1 slip., Conclusions: There were a similar percentage of patients in each degenerative spondylolisthesis group with lumbar instability. Angular motion decreased at the diseased level with L3-L4 and L5-S1 spondylolisthesis, but increased with L4-L5 spondylolisthesis. Translational motion, however, increased at the diseased level in all three groups. There was compensatory hypermobility at adjacent levels in patients with unstable spondylolisthesis at L3-L4 and L4-L5, but not at L5-S1., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background Context: Characteristic changes of the facet joints, including synovial cysts, facet joint hypertrophy, and facet joint effusions, on magnetic resonance imaging (MRI) and computed tomography have been associated with lumbar degenerative spondylolisthesis. The cervical facets have not been examined for associations with cervical degenerative spondylolisthesis similar to those seen in the lumbar spine., Purpose: To define abnormalities of the facet joints seen on supine MRI that correlate with cervical spondylolisthesis seen on upright radiographs., Study Design: Retrospective radiographic review of consecutive patients with a universally applied standard., Patient Sample: A total of 204 consecutive patients from a single institution, with both an MRI and upright radiographs, were reviewed., Outcome Measures: Sagittal plane displacement on upright lateral radiographs was compared with MRI. The total area of the facet joint and the amount of facet joint asymmetry were measured on an axial MRI., Methods: The data were analyzed to determine a significant association between the cervical degenerative spondylolisthesis and the following: facet joint asymmetry, increased total area of the facet joint, and age., Results: Degenerative spondylolisthesis was seen in 26 patients at C3-C4 and in 27 patients at C4-C5. Upright radiographs identified significantly more degenerative spondylolisthesis than MRIs at levels C3-C4 and C4-C5, 26 versus 6 (p<.001) at C3-C4 and 27 versus 11 (p<.001) at C4-C5. Patients with degenerative spondylolisthesis were more likely to be older, have a larger total facet area, and more facet asymmetry at C3-C4 and C4-C5 (p<.05)., Conclusions: Supine MRIs underestimate sagittal displacement compared with upright lateral radiographs. Asymmetric facet hypertrophy at C3-C4 and C4-C5 is associated with degenerative spondylolisthesis on upright lateral films even in the absence of anterolisthesis on supine MRIs., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background Context: Lumbar degenerative spondylolisthesis (DS), typically characterized by the forward slippage of the superior vertebra of a lumbar motion segment, is a common spinal pathological condition in elderly individuals. Significant deformation and volume changes of the spinal canal can occur because of the vertebral slippage, but few data have been reported on these anatomic variations in DS patients. Whether to restore normal anatomy, such as reduction of the slippage and restoration of disc height, is still not clear in surgery., Purpose: This study was designed to determine the volume change of the spinal canal and detect specific anatomic factors affecting the spinal canal volume in DS patients., Study Design/setting: A case-control study., Methods: Nine asymptomatic volunteers (mean age 54.4) and 9 patients with L4/L5 DS (mean age 73.4) were recruited. All patients had intermittent claudication and different extent low back pain, and two patients also had leg pain. L4/L5 vertebral motion segment unit of each subject was reconstructed using three-dimensional computed tomography or magnetic resonance images in a solid modeling software. In vivo lumbar vertebral motion during functional postures (supine, standing upright, flexion, and extension) was determined using a dual fluoroscopic imaging technique. The volume of the spinal canal was measured at each functional posture. Various anatomic parameters (disc height, cross-sectional area of the canal, left-right diameter of the canal, anterior-posterior diameter of the canal, slippage, posture, intervertebral disc angle [DA], etc.) that may potentially affect the canal volume were also measured, and their correlations with the volume change of spinal canal were analyzed. This study was funded by a 2-year, $275,000 grant from the National Institutes of Health., Results: On average, spinal canal volume was larger at supine and flexion postures than at stand and extension postures in both the DS and the asymptomatic groups. Spinal canal volume of the DS patients were significantly lower than that of the asymptomatic subjects under all the four postures (p<.05). Correlation analysis showed that spinal canal volume was strongly affected by the posterior disc height (Pearson correlation coefficient γb=0.822) and the slippage percentage (γb=-0.593) and moderately affected by the anterior disc height (γb=0.300) and the DA (γb=-0.237)., Conclusions: The volume of spinal canal is affected by multiple factors. Increased spinal canal volume at supine and flexion positions may explain the clinical observations of relief of symptoms at these postures in DS patients. The data also suggest that reduction of slipped vertebral body, decrease of DA, intervertebral distraction, and decompression could all be effective to increase the canal volume of DS patients thus to relieve clinical symptoms., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background Context: Dural ectasia in the lumbosacral spine is a common feature of Marfan syndrome and is associated with low back pain and surgical complications, but its natural history is unknown., Purpose: To evaluate the natural history of dural ectasia in adults with Marfan syndrome by determining if, over time, symptoms associated with dural ectasia worsen, dural ectasia imaging findings worsen, or spondylolisthesis/spondylolysis develops or worsens., Study Design: Prospective cohort study., Patient Sample: For our prospective follow-up study, we enrolled 20 patients with Marfan syndrome and dural ectasia who, from 1998 through 1999, had undergone magnetic resonance imaging (MRI) and computed tomography (CT) of the lumbosacral spine and had completed the Oswestry Disability Index (ODI) questionnaire. Of the 20, five did not meet the inclusion criterion of a completed 2009 ODI questionnaire and were excluded. The remaining 15 patients (mean age, 49.6 years; mean follow-up, 10.5 years) formed our study group., Outcome Measures: The ODI, MRI-based qualitative and quantitative measurements, CT-based quantitative measurements., Methods: We performed matched-pair analyses via Student t test and Wilcoxon signed-rank test of the ODI scores (15 pairs), dural volume of L5-S2 (eight pairs), dural sac ratio (DSR) of L4-S2 (nine pairs), development/progression of spondolysthesis/spondylolysis (11 pairs), and Fattori qualitative grading of dural ectasia size (10 pairs). Significance was set at p<.05., Results: We found no statistical differences in the 1998/1999 and 2009 ODI scores (25.8 vs. 22.2 points), dural volume (70.4 vs. 73.9 cm(3)), or DSR (0.68, 0.78, 2.04, and 58.1 vs. 0.69, 0.83, 2.30, and 70.20). There was also no development or progression of spondylolisthesis/spondylolysis and no increase in dural ectasia size., Conclusions: During this 10-year period, the natural history of dural ectasia in adults with Marfan syndrome was not associated with a significant increase in ODI scores, dural ectasia size, or with the development/progression of spondylolisthesis or spondylolysis., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background Context: Minimal access surgery is becoming more popular for spinal fusion because of a lower theoretical risk of complications and shorter postoperative recovery period, compared with the traditional open approach. The lateral approach uses retroperitoneal transpsoas access to the vertebra, obviating the need for an approach surgeon and minimizing muscular disruption, thus allowing a quicker recovery. Initial reports of the lateral transpsoas procedure described few complications. However, a number of complications have subsequently been documented. To our knowledge, there has not been a description of an incisional hernia after this approach., Purpose: To report the rare complication of an incisional hernia after a minimal access lateral transpsoas approach for lumbar interbody fusion., Study Design: Case report., Methods: We reviewed the hospital charts, radiographs, and intraoperative photographs of a patient who underwent a minimally invasive lateral approach lumbar spine fusion with a subsequent incisional hernia that necessitated laparoscopic repair., Results: A 75-year-old woman with a history of low back and left lower extremity pain with radiographic evidence of foraminal stenosis and degenerative spondylolisthesis underwent a successful L4-L5 discectomy with an extreme lateral interbody fusion via a retroperitoneal transpsoas approach. This was supplemented with a posterior minimally invasive surgery instrumented fusion from L4 to L5. The patient reported significant improvement in symptoms on initial follow-up, however, complained of a prominence over her incision 4 weeks later. An incisional hernia was diagnosed and subsequently repaired laparoscopically, from which the patient recovered uneventfully., Conclusions: Postoperative incisional hernia after extreme lateral interbody fusion is a complication that has not been previously described in the literature but is one that spine surgeons must recognize. This case may prompt surgeons to use a more posterior approach to avoid this complication. Additionally, direct repair of the transversalis fascia is critical to avoiding this complication., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background Context: Traumatic spondyloptosis of the cervical spine is usually associated with a complete, or rarely a partial, neurological deficit. Traumatic spondyloptosis with bipedicular fracture of the C3 vertebra is uncommon. To the best of the authors' knowledge, there is no report in the literature of bipedicular fracture of C3 with spondyloptosis of C3 over C4 with no neurological deficit. Literature is not clear about the role of preoperative traction in neurologically intact patients, and most authors advise both anterior and posterior fixation for cervical spondyloptosis., Purpose: To report a case of C3-C4 spondyloptosis with C1 and C2 posterior arch fractures with no neurological deficit and its management strategy and underline the fact that closed reduction and limited anterior fusion can preserve the motion segment of cervical spine at other fractured levels and give a stable cervical column with good long-term results., Study Design: A case report with review of the literature., Methods: A 35-year-old man fell from a height with hyperextension-compression injury to the cervical spine. The patient suffered fracture of the posterior elements of C1-C3 along with spondyloptosis of C3 over C4 without any neurological deficit. The patient was treated with an awake nasotracheal intubation with gradual cervical traction under fluoroscopic guidance to acceptable alignment followed by anterior cervical fusion at C3-C4., Results: At 24 months' follow-up, the C3-C4 level fused completely with fracture healing at C1 and C2. The patient remained asymptomatic with normal neurological examination and near complete cervical motion. The patient returned to his preinjury job and recreational activities., Conclusions: A case of C3-C4 spondyloptosis with associated C1-C2 posterior arch fracture is reported. The patient can present without neurological deficit if associated with a fracture of the posterior elements. Spondyloptosis without neurological deficit can be treated with gradual reduction under fluoroscopic guidance. A limited anterior-only fusion at the spondyloptosis level can provide good long-term results with preservation of other motion segments., (Copyright 2010 Elsevier Inc. All rights reserved.)

Background Context: Degenerative spondylolisthesis has been well described as a disorder of the lumbar spine. Few authors have suggested that a similar disorder occurs in the cervical spine. To our knowledge, the present study represents the largest series of patients with long-term follow-up who were managed surgically for the treatment of degenerative spondylolisthesis of the cervical spine., Purpose: To describe the clinical presentation and radiographic findings associated with degenerative cervical spondylolisthesis, and to report the long-term results of surgically managed patients., Study Design: Analysis of 58 patients treated with anterior cervical decompression and fusion for degenerative spondylolisthesis of the cervical spine., Patient Sample: From 1974 to 2003, 58 patients were identified as having degenerative spondylolisthesis of the cervical spine occurring in the absence of trauma, systemic inflammatory arthropathy, or congenital abnormality. These patients were identified from a database of approximately 500 patients with degenerative cervical spine disorders treated by the senior one of us., Outcome Measures: Patient outcomes were evaluated with regard to neurologic improvement (Nurick grade myelopathy) and osseous fusion., Methods: The records of 58 patients were reviewed. The average follow-up period was 6.9 years (range, 2-24 years). Seventy-two cervical levels demonstrated spondylolisthesis. In all cases, there was radiographic evidence of facet degeneration and subluxation. All patients were treated with anterior cervical decompression and arthrodesis with iliac crest structural graft. This most commonly involved corpectomy of the caudal vertebrae. Three patients required additional posterior facet fusion., Results: Fifty-eight patients demonstrated 72 levels of involvement. The C4-C5 level was most frequently involved (43%). Two radiographically distinct types of listhesis were observed based on the amount of disc degeneration and the degree of spondylosis at adjacent levels. The average neurologic improvement was 1.5 Nurick grades. The overall fusion rate was 92%. Three patients were treated with combined anterior-posterior arthrodesis. The prevalence of myelopathy and instability pattern was greater in the listheses occurring adjacent to spondylotic levels., Conclusions: Degenerative spondylolisthesis is relatively common in the cervical spine. Common to all cases is facet arthropathy and neurologic compression. Anterior cervical decompression and arthrodesis appears to yield excellent union rates and neurological improvement in those patients having cervical degenerative spondylolisthesis and significant neurological sequelae who have failed nonoperative treatments.

Background Context: One traditional treatment for spondylolisthesis is fusion. However, for high-grade spondylolisthesis and spondyloptosis, posterior fusion has had high rates of nonunion, progression, and persistent physical deformity. Thus, some surgeons have recommended reduction and instrumentation. One such technique (Gaines procedure) entails a two-stage procedure: L5 vertebrectomy anteriorly, followed by resection of the L5 posterior elements and instrumented reduction of L4 onto S1. However, to our knowledge, there is no report of reversing the fusion and deformity reduction in a symptomatic patient with previous solid fusion of the spondyloptosis at L5-S1., Purpose: To present the first reported revision via the Gaines procedure for failed fusion secondary to spondyloptosis., Study Design: Patient report., Methods: A 24-year-old woman, who had undergone multiple procedures for L5-S1 spondylolisthesis and a final fusion and instrumentation attempt, presented with continued urinary retention, leg and back pain, and inability to stand. She subsequently underwent posterior hardware removal, followed by anterior L5 vertebral body resection. In the second stage, she had posterior osteotomy of the previous L5-S1 fusion, resection of the posterior elements of L5, and reduction and instrumentation of L4 to S1., Results: At the 2-year follow-up, she had full resolution of symptoms, full return of motor strength, and resolution of urinary retention., Conclusions: The Gaines procedure has been performed successfully in patients without previous fusions at the level of spondylolisthesis or spondyloptosis. Patients for whom the traditional posterior fusion fails still may be candidates for this procedure, albeit at increased risk of neurologic injury.

Background Context: The association between scoliosis and spondylolisthesis is well documented, but criteria and methods for managing the deformity in patients with debilitating pain are not clear., Purpose: To describe correction of scoliosis by internal fixation of the spondylolisthesis., Study Design: Case report of a patient with scoliosis developing in association with spondylolisthesis., Methods: A 17-year-old female presented with a 6-month history of back and leg pain. No spinal curvature was noted in radiographs taken at the onset of symptoms. Significant curvature appeared during the 6-month history of pain in association with an L5-S1 spondylolisthesis. The spondylolisthesis was repaired with posterior pedicle screw instrumentation., Results: The pain and the spinal curvature almost completely resolved after surgery, and the outcome remained excellent 14 months after surgery., Conclusion: In the properly diagnosed patient, surgical repair of the spondylolisthesis can relieve pain and correct spinal curvature.