The predictive value of preoperative paraspinal muscle morphometry on complications after lumbar surgery: a systematic review.

PURPOSE: The effect of paraspinal muscles atrophy and fat infiltration (FI) on the complications of spinal surgery has not been established. METHODS: A review of the literature was conducted from a search of the PubMed, EMBASE, and Web of Science databases from inception through January 2021. The literature was searched and assessed by independent reviewers based on criteria that included an assessment of preoperative paraspinal muscle morphology in addition to measuring its relationship to surgical complications. All relevant papers were assessed for risk of bias according to the modified Newcastle Ottawa Scale and the Joanna Briggs Institute Critical Appraisal Tools. A narrative synthesis was conducted. RESULTS: The initial search yielded 5632 studies, of which 16 studies were included in the analysis. All included studies were at a low risk of bias. There existed strong evidence that the atrophy and FI of paraspinal muscles had an association with the development of bone nonunion (two high quality studies), pedicle screw loosening (two high quality studies), adjacent segment degeneration (three high quality studies) and proximal junctional kyphosis (five high quality studies) after lumbar surgery. Besides, there is also limited evidence for association between atrophy and FI of paraspinal extensor muscles and less local and global curve improvement. CONCLUSIONS: Strong evidence was found for an association between preoperative paraspinal muscle degeneration and multiple postoperative complications after lumbar surgery. However, the findings should be interpreted with caution due to the small quantity of the available literature and high heterogeneity among studies.

Long-term degradation characteristics of cyanide in closed monofills and its effects on the environment and human health: Evidence from nine landfill sites in northen China.

Cyanide residues weighing many millions of tons are disposed of in cyanide residue monofills (CRMs) worldwide. The degradation characteristics of cyanide in the anoxic environments of closed landfills may have been overestimated, leading to an underestimation of the long-term risk of cyanide residue landfills. To study the effect, a total of 387 cyanide residue samples were collected for analysis from nine closed CRMs in northen China that have been closed for more than 10 years. The study shows that the probability of achieving the target cyanide concentration (5 mg/L) in the nine sites was only 2.9%. And there is no significant reduction in the overall concentrations compared to the pre-closure period. The effectiveness of the CRM containment barrier needs to be maintained for at least 220 years to allow cyanide concentrations to degrade to harmless levels. Nine CRMs sites, except for CRMs A and B, had a low short-term risk, but in the long term exposure concentrations can exceed the groundwater Class III water quality limit by a factor of 1.64-30, posing a risk of groundwater contamination. This study reveals the risk of cyanide residue degradation in CRMs and its long-term evolution, providing theoretical support for site management and risk control.

Evaluating the Reproducibility of the Walking Test for Intermittent Claudication Associated with Lumbar Spinal Stenosis.

STUDY DESIGN: This is a multicenter, prospective study. PURPOSE: This study aimed to evaluate the reproducibility of the walking test for patients with lumbar spinal stenosis (LSS). OVERVIEW OF LITERATURE: Walking test is one of the useful procedures to investigate cauda equina syndrome with lumbar spinal stenosis. One the other hands, there were few studies to investigate the reproducibility of this test. METHODS: In this study, we prospectively examined 70 LSS patients with intermittent claudication symptoms at a multicenter outpatient clinic. A walking test was administered at baseline and week 4 to assess patients' walking distance and lower limb pain and numbness. Immediately after the walking test, patients were asked to use the Visual Analog Scale (VAS) to rate their pain and numbness in the front, back, outside, inside, and hip of the lower legs. The reproducibility of the walking test was evaluated using Cohen's κ analysis and intraclass correlation coefficients (ICCs). Meanwhile, the Swiss Spinal Stenosis (SSS) Questionnaire was used to evaluate the severity of the stenosis. RESULTS: The walking distance ICC at baseline and at week 4 remained unchanged at 0.7, with acceptable interobserver reliabilities for lower limb pain and numbness in both legs. The average VAS score for lower leg pain was 23.2±25.2 mm at baseline and 27.4±28.8 mm at week 4, while the corresponding average VAS score for numbness was 23.4±26.7 mm at baseline and 24.8±25.2 mm at week 4. The ICC score was 0.7 for leg pain and 0.7 for numbness. The mean SSS was 30.2±5.5 at baseline and 29.2±5.2 at week 4, and there was no significant difference in the severity. CONCLUSIONS: The walking test for LSS has acceptable reproducibility.

Sagittal plane analysis of the spine and pelvis in degenerative lumbar scoliosis.

BACKGROUND: Previous studies have reported the normative values of pelvic sagittal parameters, but no study has analyzed the sagittal spino-pelvic alignment in degenerative lumbar scoliosis (DLS) and its role in the pathogenesis. METHODS: Retrospective analysis was applied to 104 patients with DLS, together with 100 cases of asymptomatic young adults as a control group and another control group consisting of 145 cases with cervical spondylosis. The coronal and sagittal parameters were measured on the anteroposterior and lateral radiograph of the whole spine in the DLS group as well as in the two control groups. RESULTS: Statistical analysis showed that the DLS group had a higher pelvic incidence (PI) value (50.5° ± 10.2°), than the normal control group (with PI 47.2° ± 8.8°) and the cervical spondylosis group (46.9° ± 9.1°). In DLS group, there were 38 cases (36.5%) complicated with degenerative lumbar spondylolisthesis, who had higher PI values than patients without it. Besides, the lumbar lordosis (LL) and sacral slope (SS) of DLS group were lower; the scoliosis Cobb's angle was correlated with pelvic tilt (PT); thoracic kyphosis was correlated with LL, SS, and PT; and LL was correlated with other sagittal parameters. CONCLUSION: Patients with DLS may have a higher PI, which may impact the pathogenesis of DLS. A high PI value is probably associated with the high prevalence of degenerative lumbar spondylolisthesis among DLS patients. In DLS patients, the lumbar spine maintains the ability of regulating the sagittal balance, and the regulation depends more on thoracic curve.