Chronic cauda equina syndrome decompression surgery recovery is very "bad"? Based on patient self-assessment.

BACKGROUND: Symptoms of cauda equina syndrome (CES) secondary to degenerative lumbar spine diseases are sometimes mild and tend to be ignored by patients, resulting in delayed treatment. In addition, the long-term efficacy of surgery is unclear. OBJECTIVE: To determine the predictive factors of CES and post-operative recovery in patients with symptoms lasting > 3 months. METHODS: From January 2011 to December 2020, data of 45 patients with CES secondary to lumbar disk herniation/lumbar spinal stenosis were collected from a single center. The patients had bladder, bowel or sexual dysfunction and decreased perineal sensation that lasted for > 3 months. A 2-year post-operative follow-up was conducted to evaluate recovery outcomes, which were measured by validated self-assessment questionnaires conducted by telephone and online. RESULTS: Overall, 45 CES patients (57.8% female; mean age, 56 years) were included. The duration of pre-operative CES symptoms was 79.6 weeks (range, 13-730 weeks). The incidence of saddle anesthesia before decompression was 71.1% (n = 32), bladder dysfunction 84.4% (n = 38), bowel dysfunction 62.2% (n = 28) and sexual dysfunction 64.4% (n = 29). The overall recovery rate of CES after a 2-year follow-up was 64.4%. The rates of the residual symptoms at the last follow-up were as follows: saddle anesthesia 22.2%, bladder dysfunction 33.3%, bowel dysfunction 24.4% and sexual dysfunction 48.9%. Pre-operative saddle anesthesia, overactive bladder and sexual dysfunction were risk factors for poor prognosis after decompression. CONCLUSION: CES patients with symptoms lasting > 3 months may recover after surgery. Sexual dysfunction has a high residual rate and should not be ignored during diagnosis and treatment.

Effection of monoplanar pedicle screw on facet joint degeneration in thoracolumbar vertebral fractures.

BACKGROUND: This study aimed to compare the clinical outcomes and effect on instrument-related facet joints between fixed-axis pedicle screw (FAPS) and monoplanar pedicle screw (MPPS). METHODS: 816 pedicle screws of 204 patients with thoracolumbar vertebral fractures (TLVF) who underwent internal fixation surgery were analyzed in this retrospective study. All patients were divided into two groups (FAPS and MPPS). Preoperative, immediate postoperative, and 12-18-months postoperative CT and X-ray, and clinical data, including demographics, preoperative and immediate postoperative Visual Analogue Scale (VAS), blood loss (BL), operation time (OT) and hospital stay time (HST), were collected. Facet joint violation and degeneration grade were evaluated by CT according to Babu's criteria and Weishaupt's criteria respectively, and preoperative, immediate postoperative and 12-18-months postoperative anterior body compression index (ABCI) were measured by X-ray. RESULTS: Postoperative VAS of two groups was lower than preoperative VAS (p < 0.05). BL, OT, and HST were less in MPPS than FAPS, and the difference was statistically significant in BL and HST (p < 0.05) but no in OT (p > 0.05). Immediate postoperative and 12-18-months postoperative ABCI were significantly higher than preoperative (p < 0.05), and the difference of ABCI between immediate postoperative and 12-18-months postoperative were not significant in two groups (p > 0.05). Total violation rate (VR) was about 1.35% (11/816) and FAPS had a lower VR than MPPS, but no significant (p > 0.05). Weishaupt's criteria revealed that average class (AC) was 0.69 in FAPS and 0.67 in MPPS, and the distribution of degenerated facet joints in two groups did not differ preoperatively (p > 0.05). In 12-18 months postoperatively, AC was significantly higher in FAPS than in MPPS, and the distribution of degenerated facet joints in two groups was significantly different (p < 0.05). The comparison of cranial to caudal joints in two groups revealed that cranial joints had more severe degeneration than caudal joints. CONCLUSIONS: The findings suggested that both MPPS and FAPS were effective for patients with TLVF, but MPPS by percutaneous may be a better choice to avoid adjacent segment degeneration, especially the surgery-involved facet joints degeneration.

The value of Hounsfield units in predicting cage subsidence after transforaminal lumbar interbody fusion.

BACKGROUND: Cage subsidence may occur following transforaminal lumbar interbody fusion (TLIF) and lead to nonunion, foraminal height loss and other complications. Low bone quality may be a risk factor for cage subsidence. Assessing bone quality through Hounsfield units (HU) from computed tomography has been proposed in recent years. However, there is a lack of literature evaluating the correlation between HU and cage subsidence after TLIF. METHODS: Two hundred and seventy-nine patients suffering from lumbar degenerative diseases from April, 2016 to August, 2018 were enrolled. All underwent one-level TLIF with a minimum of 1-year follow-up. Cage subsidence was defined as > 2 mm loss of disc height at the fusion level. The participants were divided into 2 groups: cage subsidence group (CS) and non-cage subsidence group (non-CS). Bone quality was determined by HU, bone mineral density of lumbar (BMD-l) and femoral (BMD-f) from dual-emission X-ray absorptiometry (DXA). HU of each vertebra from L1 to L4 (e.g., HU1 for HU of L1) and mean value of the four vertebrae (HUm) were calculated. Visual analog scale (VAS) of back/leg pain and Oswestry disability index (ODI) were used to report clinical outcomes. RESULTS: Cage subsidence occurred in 82 (29.4%) cases at follow-ups. Mean age was 50.8 ± 9.0 years with a median follow-up of 18 months (range from 12 to 40 months). A total of 90.3% patients presented fusion with similar fusion rate between the two groups. ODI and VAS in leg were better in non-CS group at last follow-ups. Using receiver operating characteristic curves (ROCs) to predict cage subsidence, HUm provided a larger area under the curve (AUC) than BMD-l (Z = 3.83, P <  0.01) and BMD-f (Z = 2.01, P = 0.02). AUC for HU4 was larger than BMD-f and close to HUm (Z = 0.22, P = 0.481). CONCLUSIONS: Cage subsidence may indicate worse clinical outcomes. HU value could be a more effective predictor of lumbar cage subsidence compared with T-score of DXA after TLIF.

Emissions of gaseous nitrous acid (HONO) from diesel trucks: Insights from real-driving emission experiments.

Nitrous acid (HONO) serves as a substantial contributor in the atmospheric chemistry of hydroxyl radicals (·OH). Despite its significance, the primary sources of atmospheric HONO, particularly diesel truck emissions, have not been thoroughly examined. This study investigated the factors influencing HONO emissions via on-road exhaust emission tests using a self-developed portable measurement system. The findings show that the HONO emissions measured during on-road testing are higher than those measured during chassis dynamometer testing, highlighting the need for on-road tests to capture HONO emissions. Emission standards and truck types greatly influence HONO emission factors (EFs), with stricter regulations leading to lower emissions. The average fuel consumption-based EFs for light-duty diesel trucks ranged from 0.93 g/kg for China III to 0.08 g/kg for China VI. For medium-duty diesel trucks, the EFs decrease from 1.43 g/kg for China III to 0.19 g/kg for China V. Moreover, the vehicle-specific power demonstrated a stronger correlation with HONO emissions. This research showed that HONO emissions were significantly higher without or before the optimal operation of the SCR device, and the device notably reduced HONO emissions. Future research should focus on the impact of various exhaust after-treatment systems and explore HONO conversion mechanisms.

Revisiting the estimation indicator for HONO emissions from light-duty vehicles.

Gaseous nitrous acid (HONO), playing a crucial role in the generation of hydroxyl (OH) radicals and thus secondary pollution, lacks a source. Vehicular emission is a significant HONO source and is usually estimated by a traditional estimation indicator (RHONO/NOx = 0.8 %). Nevertheless, with more direct measurements for vehicular HONO emissions, RHONO/NOx values have been reported to vary over a wide range. In this study, we conducted the driving tests with a chassis dynamometer for ten light-duty gasoline vehicles. HONO emission factors have realized a significant reduction with the updating of emission standards, with emission factors of 0.40 mg/km, 0.13 mg/km, and 0.06 mg/km for China IV, China V, and China VI vehicles, respectively. Besides precursors, water content and exhaust temperature were found to be possible decisive factors for initiating HONO generation. Furthermore, by coupling NOx emissions and combustion efficiency, we modified the estimation indicator for vehicular HONO emissions and a better estimation effect has been verified. Additionally, we established a dynamic inventory of vehicular HONO emissions in Jinniu District in Chengdu and further found the traditional estimation indicator would overestimate HONO emissions by around 17 %. Our findings would help to advance a deeper understanding of vehicular HONO emissions and the modified estimation indicator would be beneficial in minimizing the uncertainties of the HONO budget in the troposphere.

Prevalence, distribution characteristic and risk factors of lumbar vertebral axial rotation in patients with lumbar disc herniation: a retrospective study.

This retrospective study aimed to investigate the impact of lumbar disc herniation (LDH) on vertebral axial rotation (VAR) in the lumbar spine, focusing on both close and distant neighboring vertebrae. A total of 516 patients with LDH and an equal number of healthy individuals were included in the study, matched for age and gender. The degree of axial rotation for each lumbar spine vertebra was assessed using the Nash-Moe index. The results revealed that the prevalence of VAR in the lumbar spine was significantly higher in the LDH group compared to the Control group (65.7% vs 46.7%, P < 0.001). Among the LDH group, the L2 vertebra had the highest frequency of VAR (49.5%), followed by L1 (45.1%), and then L3 to L5 (33.6%, 8.9%, 3.1%, respectively). A similar pattern was observed in the Control group (L2, 39.8%; L1, 34.6%; L3, 23.2%; L4, 3.1%; L5, 0.8%). Furthermore, the study found that disc herniation was associated with a higher incidence of VAR not only in close neighboring vertebrae but also in distant neighboring vertebrae. This indicates that the biomechanical influence of LDH extends beyond just the immediate adjacent vertebrae. To identify potential risk factors for VAR in LDH patients, multivariate analysis was performed. The results revealed that age was an independent risk factor for VAR (OR 1.022, 95% CI [1.011, 1.034], P < 0.001). However, the duration of symptoms and presence of back pain were not found to be significant risk factors for VAR.

How to assess the long-term recovery outcomes of patients with cauda equina syndrome before surgery: a retrospective cohort study.

BACKGROUND: Factors influencing recovery after decompression surgery for cauda equina syndrome (CES) are not completely identified. The authors aimed to investigate the most valuable predictors (MVPs) of poor postoperative recovery (PPR) in patients with CES and construct a nomogram for discerning those who will experience PPR. METHODS: Three hundred fifty-six patients with CES secondary to lumbar degenerative diseases treated at Xijing Hospital were randomly divided into training ( N =238) and validation ( N =118) cohorts at a 2:1 ratio. Moreover, 92 patients from the 970 th Hospital composed the testing cohort. Least Absolute Shrinkage and Selection Operator regression (LASSO) was used for selecting MVPs. The nomogram was developed by integrating coefficients of MVPs in the logistic regression, and its discrimination, calibration, and clinical utility were validated in all three cohorts. RESULTS: After 3 to 5 years of follow-up, the residual rates of bladder dysfunction, bowel dysfunction, sexual dysfunction, and saddle anesthesia were 41.9, 44.1, 63.7, and 29.0%, respectively. MVPs included stress urinary incontinence, overactive bladder, low stream, difficult defecation, fecal incontinence, and saddle anesthesia in order. The discriminatory ability of the nomogram was up to 0.896, 0.919, and 0.848 in the training, validation, and testing cohorts, respectively. Besides, the nomogram showed good calibration and clinical utility in all cohorts. Furthermore, the optimal cutoff value of the nomogram score for distinguishing those who will experience PPR was 148.02, above which postoperative outcomes tend to be poor. CONCLUSION: The first pretreatment nomogram for discerning CES patients who will experience PPR was developed and validated, which will aid clinicians in clinical decision-making.

The change of Roussouly classification after posterior lumbar fusion surgery.

Background: Roussouly classification is an important morphologic classification which can help to determine high local stress zones of the spine. Different lumbar morphologies of Roussouly type suggest different biomechanics leading to degenerative evolution. This study aimed both to describe the change of the Roussouly classification of the human spine after posterior lumbar fusion surgery and to explore the influencing factors of postoperative Roussouly type. Methods: The study is a retrospective case-control study on preoperative and postoperative Roussouly types. A total of 167 patients with lumbar degenerative disease who had undergone short-level transforaminal lumbar interbody fusion surgery between January 2014 and December 2017 in the Department of Orthopedic Surgery, First Affiliated Hospital, Air Force Medical University, were recruited. Preoperative and postoperative general data including gender, age, follow-up time, Oswestry disability index (ODI) score, visual analogue scale (VAS) score, diagnosis, and surgical segment were recorded. Clinical parameters including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), and sagittal vertical axis (SVA) were measured using Surgimap software, and the Roussouly classification was assessed. Results: This study included 86 male patients and 81 female patients with a mean age of 52.0±12.4 [14-88] years. The mean follow-up time for these patients was 11.5±6.9 months. The value of sagittal alignment parameters changed after the posterior lumbar fusion surgery, except for the PI value (P=0.591). Roussouly classification changed after surgery. The preoperative Roussouly values of preoperative PI, SS, and LL were significantly different in patients of 4 postoperative Roussouly types. Conclusions: The Roussouly classification changes after posterior lumbar fusion surgery. This change is independent of gender, age, follow-up time, and the number of surgical segments. The preoperative Roussouly type and PI value are essential in predicting one's postoperative Roussouly type.

Ultrasound-Guided Transversus Abdominis Plane Block in Treating Abdominal Skin Tension Pain After Kyphosis Surgery: A Pilot Study in Enhanced Recovery After Surgery Setting.

BACKGROUND: The postsurgical management of patients with ankylosing spondylitis is often only focused on the incision pain, and the pain caused by abdominal skin traction is paid little attention. OBJECTIVES: To explore the effectiveness of ultrasound-guided transversus abdominis plane block (TAPB) in treating abdominal skin tension pain after kyphosis surgery. STUDY DESIGN: Randomized controlled trial. SETTING: This prospective study consecutively enrolled patients scheduled to undergo kyphosis correction surgery at the Department of Orthopedics of Xijing Hospital from March 2021 to December 2021. METHODS: The patients were randomized 1:1 to the TAPB and control groups. The Visual Analog Scale (VAS) for abdominal pain, Bruggrmann Comfort Scale (BCS), abdominal skin tension blisters, bed rest duration, length of hospitalization, and the use of patient-controlled analgesia pumps (PCAPs) were compared. The primary endpoint was pain alleviation at 24 hours after surgery. RESULTS: Thirty-one patients were enrolled, without differences between the 2 groups regarding age, body mass index, preoperative kyphosis severity, operation duration, and blood loss. The TAPB group (n = 16) had lower abdominal VAS scores than the control group (n = 15) at 2, 4, 6, 8, and 12 hours after surgery (P < 0.05). The TAPB group had higher BCS scores than the control group at 4, 6, 8, and 12 hours after surgery (P < 0.05). The TAPB group used PCAPs less frequently than the control group after surgery (P < 0.001). The incidence of tension blisters in the TAPB group was numerically lower than that of the control group, but the difference was not statistically significant (18.8% vs 33.3%, P > 0.05). LIMITATIONS: The sample size of this study is small and a single-center study, there might be data bias. CONCLUSIONS: In the first 24 hours after severe kyphosis surgery, TAPB can reduce the pain from abdominal skin tension and increase the comfort scores, but its effects on tension blisters remain to be further studied.

Associations between facet tropism and vertebral rotation in patients with degenerative lumbar disease.

BACKGROUND: Vertebral rotation and facet tropism are very common in various lumbar degenerative diseases. Facet tropism means the presence of asymmetric angles on both sides of the facet joints. Studies have shown that facet tropism contributes to lumbar degenerative disease, and also inevitably leads to the asymmetry of movement and the imbalance of force, which may be possible to rotate the vertebral body. The aim of this study was to explore the correlation between lumbar vertebral rotation and facet tropism in patients with lumbar degenerative diseases. METHODS: A total of 198 patients with lumbar degenerative diseases from 2018 to 2019 were enrolled. Five hundred and seventy vertebral rotation angles and 1140 facet angles were measured. The vertebral bodies are divided into non-rotation group (Group A) and rotation group (Group B) with the vertebral rotation angle of 3° as the boundary. The information including gender, age, BMI (body mass index), bone mineral density, history of smoking, drinking, hypertension, diabetes, diagnosis, segment distribution, and degree of facet degeneration were also counted. Using inter-class correlation coefficients (ICC) to test the reliability of measurement results. Univariate and multivariate logistic regression analysis were used to analyze the relationship between vertebral rotation and facet tropism. RESULTS: The consistency of the ICC within the groups of the observers is above 0.8, with good agreement. The results of univariate analysis showed that facet tropism was significantly different between group A and group B (OR (odds ratio) = 3.30, 95% CI = 2.03-5.35, P < 0.0001). Other significant factors were included as adjustment variables into the multivariate regression model. Three models were analyzed separately (Model 1: non-adjusted. Model 2: adjust for age; facet degeneration; Model 3: adjust for age; disease distribution; segment distribution; facet degeneration). The results showed that after adjusting the confounders, the correlation between facet tropism and vertebral rotation did not change (Model 1: OR = 3.30, 95% CI = 2.03-5.35, P < 0.0001; Model 2: adjusted OR = 2.87, 95% CI = 1.66-4.97, P = 0.0002, Model 3: adjusted OR = 2.84, 95% CI = 1.56-5.17, P = 0.0006). CONCLUSION: Current research demonstrates that there is an association between vertebral rotation and facet tropism, suggesting that vertebral rotation may also have a certain degree of correlation with lumbar degenerative diseases.

Robot-assisted orthopedic surgery in the treatment of adult degenerative scoliosis: a preliminary clinical report.

STUDY DESIGN: A single-institution, retrospective cohort study. OBJECTIVE: To compare the accuracy and short-term clinical outcomes of pedicle screw placement between robot-assisted (RA) and freehand (FH) technique in the treatment of adult degenerative scoliosis (ADS). METHODS: From February 2018 to October 2019, 97 adult patients with degenerative scoliosis admitted to our department were retrospectively reviewed. Thirty-one patients received robot-assisted pedicle screw placement (RA group), and 66 patients underwent freehand pedicle screw placement (FH group). Patient demographics and short-term clinical outcomes were recorded and compared between two groups. Gertzbein-Robbins grading system was adopted to evaluate the accuracy of pedicle screw placement by means of postoperative CT scan. Short-term clinical outcomes consist of operative time, intraoperative blood loss, length of hospital stay (LOS), radiological parameters, Scoliosis Research Society-22 (SRS-22) scores before the operation, 6 months after operation, adverse events, and revisions. RESULTS: The accuracy of screw placement was higher than that of the FH group (clinically acceptable 98.7% vs. 92.2%; P< 0.001). Intraoperative blood loss of the RA group was less than those in the FH group (499 vs. 573 ml; P < 0.001). Operative time (283.1 vs. 291.9 min; P = 0.31) and length of stay (12.8 vs. 13.7 days; P = 0.36) were compared between RA and FH groups. In terms of radiological parameters, both of groups were improved postoperatively. The SRS-22 scores at 6 months after operation from both groups were better than those before operation. For surgery-related complication, one case had pressure sores in the RA group while two cases developed dural tears in the FH group. No revision was required in both groups. CONCLUSION: Combined with other surgical correction modalities, robot-assisted pedicle screw fixation is an effective and safe method of treating degenerative scoliosis. Due to its satisfactory surgical outcomes such as higher accuracy and less trauma, it provides a good alternative for clinical practice. LEVEL OF EVIDENCE: 3.