The Importance of Lumbar Curve Flexibility and Apical Vertebral Rotation for the Prediction of Spontaneous Lumbar Curve Correction in Selective Thoracic Fusion for Lenke Type 1 and 2 C Curves: Retrospective Cohort Study with a Mean Follow-Up of More than 10 years

STUDY DESIGN

Retrospective analysis of a prospectively collected data.

OBJECTIVE

Lumbar flexibility(LF) is generally defined with preoperative side bending films;it is not clear what percentage of LF predicts the spontaneous lumbar curve correction (SLCC) at long term follow up. Aim of this study was to find out cut-off value of preoperative LF,apical vertebra rotation(AVR) and apical vertebral translation(AVT);which may predict more than 50%SLCC.

METHODS

Patients with Lenke 1C&2C curves,treated with posterior STF,with a minimum 10 years follow up were included.The patients who had more than 50% SLCC(Group A) or less than 50% (Group B) were compared in terms of LF,AVR and AVT to understand a cut-off value of those parameters.Statistically, Receiver Operating Characteristic(ROC) test was used.

RESULTS

Fifty five AIS patients (54F, 1M) with mean age 14 (11-17) were included to study.Thoracic curve correction rate was 75%;lumbar curve correction rate was 59% at the latest follow up.Group A included 45(82%) patients at the latest follow up.Three patients (5%) showed coronal decompensation at early postop and 2 of them became compensated at f/up.ROC analyses showed 69% flexibility as the cut-off value for SLCC (P < .01).The difference between groups in terms of preop mean AVRs was significant (P = .029) (Group A = 1.9; Group B = 2.4).

CONCLUSION

In Lenke 1C&2C curves,whenever LF on the preoperative bending x-ray is greater than 70% (P < .01)and AVR is equal or less than grade 2,STF provides satisfactory clinical and radiological SLCC with more than mean 10 years f/up.This flexibility rate and apical vertebral rotation can be helpful in decision making for successful STF.

How can postoperative shoulder imbalance be prevented in adolescent idiopathic scoliosis type 2?

Postoperative shoulder imbalance (PSI) is a common complication following adolescent idiopathic scolio- sis (AIS) surgery. There is little data available in literature on prediction of PSI. Prospectively collected data of AIS with thoracic curve (Lenke 2), operated in 2014-2018 at a single scoliosis-center, were analyzed retrospectively using X-rays of whole spine and traction films (TA): age, Cobb-angle of proximal (PC), major thoracic (MC) and lumbar curve (LC), shoulder height [mm], clavicle angle [°], T1-tilt [°], plumb line [mm]. Results as mean ± standard deviation. Change over time (postOP- FU) compared using t-test (≥=0.05). Correlation of preOP parameters and curve correction with PSI (|≥|15mm) was analyzed by correlation (Pearson)- and regression-classification-analysis. 32 AIS, average age of 14±1.3 yrs. FU 16 months (84%). Curve correction was 52.5% (PC), 70.1% (MC), 69.9% (LC), significant change in FU for PC (-2.4°, p>0.05), not for MC, LC (p=0.2, p=0.6). Shoulder height was negative if right- side up: 2.9±15.1mm (preOP), 5.5±15.0 mm (TA), 17.9±14.9mm (postOP), 17.4±8.4mm (FU). 28% had preOP shoulder imbalance, 69% postOP and 44% FU had PSI. Shoulder height on TA correlated to change preOP to FU (r=0.62) and preOP shoulder height (r=-0.85), clavicle angle had strong correlation (r=- 0.81). Regression-classification-analysis: correction of MC>62.4%, 81.5% of cases had PSI; with correction of MC>64.9% and LC>93.2%, 51.9% of cases had PSI. PSI is a common in Lenke2 AIS. In preOP planning TA, shoulder position and clavicle angle should be considered to prevent PSI. Correction of MC should be moderate, overcorrection of the LC avoided.

Global Spinal Realignment After Osteotomized Debridement in Active Lumbar Spinal Tuberculosis: Correlation with Patient-Reported Outcomes

OBJECTIVE

Osteotomized debridement (OD) has been proved to be highly effective in treating active thoracolumbar tuberculosis (TB); however, no research has investigated how OD affects spinal alignment. The goal of this study was to explore the global alignment compensatory mechanism after lumbar OD, as well as the correlation between spinopelvic parameters and patient-reported outcomes (PROs).

METHODS

Sixty-two patients with active lumbar spinal TB who underwent OD surgery were included. Spinopelvic parameters (C2-7 Cobb angle [C2-7 CA], sagittal vertical axis [SVA], proximal thoracic kyphosis, thoracic kyphosis, lumbar lordosis [LL], sacral slope [SS], pelvic tilt [PT], pelvic incidence [PI], spinosacral angle, and PI minus LL [PI-LL]) and PROs (Oswestry Disability Index [ODI] and Visual Analog Scale [VAS] score) were reviewed. The correlation between spinopelvic realignment and improved PROs was evaluated.

RESULTS

Compared with preoperative measurements, C2-7 CA, proximal thoracic kyphosis, thoracic kyphosis, LL, SS, and spinosacral angle significantly increased after OD, whereas SVA, PT, and PI-LL significantly decreased. ODI and VAS score significantly improved postoperatively. The improvement of VAS was observed to be correlated with variations of C2-7 CA, SVA, LL, and PI-LL. The improvement of ODI was found to be correlated with variations of SVA, LL, and PI-LL. The multiple stepwise regression analysis showed that LL was an independent predictor for ODI and VAS score.

CONCLUSIONS

The whole spine and pelvis are involved in realignment after lumbar spinal OD, which is closely related to PROs. More attention should be drawn to restoring an appropriate LL in lumbar TB surgery.

Correlation between Scoliosis Flexibility Degree on Preoperative Imaging with Postoperative Curve Correction and Mechanical Complications

(1) Background: In the preoperative planning stage of scoliosis surgery, it is routine to use radiographs obtained with and without traction to observe the curve flexibility in order to estimate curve correction, but its association with mechanical complications is not completely understood. (2) Methods: Retrospective cohort study of all patients undergoing infantile, congenital, neuromuscular or idiopathic adolescent scoliosis correction surgery at a single institution between 2015 and 2019, with a minimum follow-up of 24 months. Associations between qualitative variables were tested with the chi-square test. The association between qualitative and quantitative variables were tested with the Mann–Whitney test, and correlations between quantitative variables was tested with Spearman’s correlation. (3) Results: A total of 330 patients, 88 males and 242 females, with a mean age of 16.98 years at surgery, were included. The mean value of preoperative main curves, its flexibility and postoperative value were 54.44 degrees, 21.73 degrees and 18.08 degrees, respectively. (4) Conclusions: Preoperative spinal X-ray examination with traction or bending films is a reasonable option for assessing scoliotic curve flexibility, and patients with neuromuscular scoliosis who are not ambulatory can be informed of the increased risks of late mechanical complications.

Cost analysis comparison between anterior and posterior cervical spine approaches

Background

The costs of cervical spine surgery have steadily increased. We performed a 5-year propensity scoring-matched analysis of 276 patients undergoing anterior versus posterior cervical surgery at one institution.

Methods

We performed propensity score matching on financial data from 276 patients undergoing 1-3 level anterior versus posterior cervical fusions for degenerative disease (2015-2019).

Results

We found no significant difference between anterior versus posterior approaches for hospital costs ($42,529.63 vs. $45,110.52), net revenue ($40,877.25 vs. $34,036.01), or contribution margins ($14,230.19 vs. $6,312.54). Multivariate regression analysis showed variables significantly associated with the lower contribution margins included age (β = -392.3) and length of stay (LOS; β = -1151). Removing age/LOS from the analysis, contribution margins were significantly higher for the anterior versus posterior approach ($17,824.16 vs. $6,312.54, P = 0.01).

Conclusion

Anterior cervical surgery produced higher contribution margins compared to posterior approaches, most likely because posterior surgery was typically performed in older patients requiring longer LOS.

The Difference of Sagittal Correction of Adult Subaxial Cervical Spine Surgery According to Age: A Retrospective Study

Objective

At present, the true sagittal alignment of the cervical spine is uncertain, resulting in no standard reference for subaxial cervical surgery. So, we aimed to explore the age difference of normal cervical sagittal alignment and to further investigate the mid‐and long‐term changes of sagittal alignment after subaxial cervical spine surgery.

Materials and Methods

This was a retrospective study and 1223 asymptomatic volunteers and 79 patients undergoing subaxial cervical spine surgery were retrospectively reviewed in total. Asymptomatic volunteers and patients were divided into six subgroups: 20–29, 30–39, 40–49, 50–59, 60–69 and ≥70 groups. The age difference and trend with age of cervical sagittal parameters of asymptomatic volunteers were assessed by cervical lateral radiography and analyzed by ANOVA test, and the regression equation of C2‐7 Cobb was established via multiple linear regression. Based on the C2‐7 Cobb regression equations of different ages, the theoretical value, deviation value, loss value of the C2‐7 Cobb, and JOA recovery rate of patients were calculated, and the correlation among the loss value, deviation value of the C2‐7 Cobb, and JOA recovery rate of the 79 patients was evaluated by Pearson correlation analysis.

Results

For the asymptomatic volunteers, the C0‐2 Cobb decreased gradually with increasing age. The C2‐7 Cobb, C2‐7 SVA, T1S, NT, and TIA increased gradually with increasing age. The CBVA fluctuated with increasing age. T1S demonstrated a moderate correlation with C2‐7 Cobb (r = 0.60, p < 0.01); C0‐2 Cobb, C2‐7 SVA, CBVA, and TIA demonstrated a fair correlation with C2‐7 Cobb (r = −0.30, −0.33, 0.41, 0.40, p < 0.01); age demonstrated a poor correlation with C2‐7 Cobb (r = 0.19, p < 0.01). The regression equations of C2‐7 Cobb were established using C0‐2 Cobb, C2‐7 SVA, CBVA, and T1S. For the patients with subaxial cervical spine surgery, the loss of C2‐7 Cobb was moderately correlated with the deviation of C2‐7 Cobb (r = 0.33, p < 0.01).

Conclusion

The age difference of cervical sagittal alignment was obvious, and the C2‐7 Cobb increased with age especially. The closer the postoperative C2‐7 Cobb was to the theoretical value of corresponding age, the smaller the loss of correction angle was, and the better the mid‐ and long‐term outcomes. The personalized sagittal reconstruction should be performed according to age difference for subaxial cervical spine surgery.

A Newly Established Cuproptosis-Associated Long Non-Coding RNA Signature for Predicting Prognosis and Indicating Immune Microenvironment Features in Soft Tissue Sarcoma

Cuproptosis, a new type of programmed cell death, is involved in the development and progression of malignancies. The study of cuproptosis-associated long non-coding RNAs (lncRNAs) in soft tissue sarcomas (STSs) is however limited. There is also uncertainty regarding the prognostic accuracy of cuproptosis-associated lncRNAs in STSs and their relationship to the tumor immune microenvironment. The aim of this study was to determine the prognostic significance of cuprotosis-associated lncRNAs in STSs and their relationship to the tumor immune microenvironment. Transcriptomic and clinical data from patients with STSs were obtained through The Cancer Genome Atlas (TCGA). Overall, 259 patients were randomly allocated to a training group or a testing group. In the training group, a cuproptosis-associated lncRNA signature was constructed, and the signature was verified in the testing group. On the basis of risk scores and clinical features, we later developed a hybrid nomogram. We also performed functional and tumor immune microenvironment analysis based on the cuproptosis-associated lncRNA signature. A signature of 5 cuproptosis-associated lncRNAs was created. Based on this signature, we categorized STS patients into high-risk and low-risk groups. The study showed that patients at high risk had a worse prognosis than those at low risk. A nomogram was then constructed combining clinical characteristics with the risk scores, and it was shown to have credible predictive power. Functional enrichment and tumor immune microenvironmental analyses showed that high-risk STSs tend to be immunologically sensitive tumors. In our study, we found a cuproptosis-associated lncRNAs signature, which serves as an independent prognostic indicator. Cuproptosis-associated lncRNAs may play a role in the tumor immune microenvironment, which might be a therapeutic target for patients with STSs.

A Comparison of Various Surgical Treatments for Degenerative Cervical Myelopathy: A Propensity Score Matched Analysis

STUDY DESIGN

Retrospective Cohort.

OBJECTIVE

To compare the short-term outcomes for Laminoplasty, Laminectomy/fusion, and ACDF.

METHODS

We utilized a prospectively-collected, multi-center national database with a propensity score matching algorithm to compare the short-term outcomes for laminoplasty, laminectomy/fusion, and multi-level (>3) ACDF (with and without corpectomy). Bivariate analyses involved both chi-square/fisher exact test and t-test/ANOVA on perioperative factors. Multivariate analyses were performed to determined independent risk factors for short term outcomes.

RESULTS

546 patients remained after propensity score matching, with 182 patients in each cohort. ACDF required the longest operative time 188 ± 79 versus laminectomy/fusion (169 ± 75, p = 0.017), and laminoplasty (167 ± 66, p = 0.004). ACDF required the shortest hospital stay (LOS ≥ 2: ACDF 56.6%, laminoplasty 89.6%, laminectomy/fusion 93.4%, p < 0.05). ACDF had lower overall complications (ACDF 3.9%, laminoplasty 7.7%, laminectomy/fusion 11.5%, p < 0.05), mortality (ACDF 0%, laminoplasty 0.55%, laminectomy/fusion 2.2%, p < 0.05), and unplanned readmissions (ACDF 4.4%, laminoplasty 4.4%, laminectomy/fusion 9.9%, p < 0.05). No significant differences were seen in the other outcomes including DVT/PT, acute renal failure, UTI, stroke, cardiac complications, or sepsis. In the multivariate analysis, laminectomy/fusion (OR 17, reference: ACDF) and laminoplasty (OR10, reference: ACDF) were strong independent risk factors for LOS ≥ 2 days. Laminectomy/fusion (OR 3.2, reference: ACDF) was an independent predictor for any adverse events 30-days after surgery.

CONCLUSIONS

Laminectomy/fusion carries the highest risk for morbidity, mortality, and unplanned readmissions in the short-term postoperative period. Laminoplasty and ACDF cases carry similar short-term complications risks. ACDF is significantly associated with the longest operative duration and shortest LOS without an increase in individual or overall complications, readmissions, or reoperations.

Post-operative tranexamic acid decreases chest tube drainage following vertebral body tethering surgery for scoliosis correction

PURPOSE

Anterior vertebral body tethering (VBT) is a non-fusion surgical treatment for Adolescent Idiopathic Scoliosis requiring chest tube(s) (CT). We sought to assess the efficacy of post-op intravenous tranexamic acid (IV TXA) in reducing CT drainage and retention.

METHODS

35 VBT patients received 24 h of post-op IV TXA (2 mg/kg/h) were compared to 49 who did not. Group comparisons were performed using Wilcoxon rank-sum and chi-squared tests. Multivariate linear regression analysis was used to assess the relationships between TXA and both CT drainage and retention time.

RESULTS

There were no group differences at baseline (Table). CTs placed for thoracic (T) and thoracolumbar (TL) curves were assessed separately. For TH CT, there was less total CT drainage in the TXA group (TXA 569.4 ± 337.4 mL vs. Non-TXA 782.5 ± 338.9 mL; p = 0.003) and shorter CT retention time (TXA 3.0 ± 1.3 vs. Non-TXA 3.9 ± 1.4 days; p = 0.003). For TL CT, there was less total CT drainage in the TXA group (TXA 206.8 ± 152.2 mL vs. Non-TXA 395.7 ± 196.1 mL; p = 0.003) and shorter CT retention time (TXA 1.7 ± 1.3 vs. Non-TXA 2.7 ± 1.0 days; p = 0.001). Following multivariate analysis, use of TXA was the only significant predictor of both drainage in T and TL CTs (p = 0.012 and p = 0.002, respectively) as well as T and TL CT retention time (p = 0.008 and p = 0.009, respectively). There were no differences in LOS (p = 0.863) or ICU stay (p = 0.290).

CONCLUSION

IV TXA results in a significant decrease in CT drainage and retention time. CT retention is decreased by 1 day for those that receive TXA.

LEVEL OF EVIDENCE

III.

Cacna2d2 inhibits axonal regeneration following surgical decompression in a rat model of cervical spondylotic myelopathy

Background

Cervical spondylotic myelopathy (CSM) is a clinically symptomatic condition due to spinal cord compression, leading to spinal cord dysfunction. Surgical decompression is the main treatment of CSM, but the mechanisms of axonal regeneration after surgical decompression are still fragmentary.

Methods

In a rat model of CSM, the cacna2d2 (α2δ2) expression levels in anterior horn of spinal cord were observed following compression and decompression by western blot and immunofluorescence. The expression levels of 5 hydroxytryptamine (5HT) and GAP43 were also analyzed by immunofluorescence. Furthermore, gabapentin intervention was performed for 4 weeks after decompression to analyze the changes of behaviors and anterior horn of spinal cords.

Results

Following decompression, the expression levels of α2δ2 in the anterior horn of spinal cord were decreased, but the expression levels of 5HT andGAP43 were increased. Compared with the vehicle treated rats, gabapentin treatment for 4 weeks ameliorated the behaviors of rats and improved the damaged anterior horn of spinal cord. Besides, inhibition of α2δ2 through gabapentin intervention enhanced the axonal regeneration in the anterior horn of damaged spinal cord.

Conclusions

Inhibition of α2δ2 could enhance axonal recovery in anterior horn of damaged spinal cord induced by CSM after surgical decompression, providing a potential method for promoting axon regeneration following surgery.

A Retrospective Comparative Study of Modified Percutaneous Endoscopic Transforaminal Discectomy and Open Lumbar Discectomy for Gluteal Pain Caused by Lumbar Disc Herniation

Introduction

This study aimed to demonstrate the safety and effectiveness of modified percutaneous endoscopic transforaminal discectomy (PETD) in the surgical management of single-segment lumbar disc herniation (LDH) gluteal pain and to determine whether it provides a better clinical outcome than open lumbar discectomy (OD).

Methods

A retrospective analysis of patients treated with modified PETD and OD for gluteal pain in LDH from January 2015 to December 2020 was conducted. Sample size was determined using a priori power analysis. Demographic information, surgical outcomes including procedure time (minutes), intraoperative blood loss (mL), hospital days, costs (RMB), fluoroscopy shots, recurrence and complications, etc., were recorded and analyzed. Prognostic outcomes were assessed using the visual analog scale (VAS), the Oswestry Disability Index (ODI), the Japanese Orthopedic Association Score (JOA) and modified MacNab criteria. The preoperative and postoperative VAS, ODI and JOA scores were recorded by two assistants. When the results were inconsistent, the scores were recorded again by the lead professor until all scores were consistently recorded in the data. MRI was used to assess radiological improvement and all patients received follow-ups for at least one year.

Results

The sample size required for the study was calculated by a priori analysis, and a total of 72 participants were required for the study to achieve 95% statistical test power. A total of 93 patients were included, 47 of whom underwent modified PETD, and 46 of whom underwent OD. In the modified PETD intragroup comparison, VAS scores ranged from 7.14 ± 0.89 preoperatively to 2.00 ± 0.58, 2.68 ± 0.70, 2.55 ± 0.69, 2.23 ± 0.81, and 1.85 ± 0.72 at 7 days, 1 month, 3 months, 6 months, and 12 months postoperatively. Patients showed significant pain relief postoperatively (P &lt; 0.01). According to the modified MacNab score, the excellent rate in the PETD group was 89.36%. There was no significant difference compared to the OD group (89.13%, P &gt; 0.05). Complication rates were lower (P &gt; 0.05) but recurrence rates were higher (P &gt; 0.05) in the modified PETD group than in the OD group. The modified PETD group had a faster operative time (P &lt; 0.01), shorter hospital stay (P &lt; 0.01), less intraoperative bleeding (P &lt; 0.01), and less financial burden to the patient (P &lt; 0.01) than the OD group. At 7 days postoperatively, the VAS score for low back pain was higher in the OD group than in the modified PETD group (P &lt; 0.01). The VAS and JOA scores at 1, 3, 6, and 12 months postoperatively were not significantly different between the modified PETD and OD groups (P &gt; 0.05), and the ODI was significantly different at 3 months postoperatively (P &lt; 0.05).

Conclusion

Modified PETD treatment is safe and effective for gluteal pain due to L4/5 disc herniation and has the advantages of a lower complication rate, faster postoperative recovery, shorter length of stay, fewer anesthesia risks and lower cost of the procedure compared with OD. However, modified PETD has a higher recurrence rate.

FOXP4-AS1 Inhibits Papillary Thyroid Carcinoma Proliferation and Migration Through the AKT Signaling Pathway

Papillary thyroid carcinoma, also known as PTC, is one of the commonest malignancies in the endocrine system. Long non-coding RNAs (lncRNAs) in PTC could maintain proliferative signaling, induce therapeutic resistance, activate invasion and migration, and sustain stem cell-like characteristics. In this paper, results showed that lncRNA forkhead box P4 antisense RNA 1 (FOXP4-AS1) is downregulated in PTC tissues and cell lines. Patients in TCGA cohort with a higher FOXP4-AS1 expression showed a higher disease-free interval (DFI) rate, and the expression of FOXP4-AS1 is shown to be linked to the clinical stage, T stage, N stage, and extraglandular invasion condition of the TC patients. FOXP4-AS1 is localized in the cell cytoplasmic domain of PTC cells. Functionally, upregulated FOXP4-AS1 inhibited PTC cell proliferation, apoptosis, and migration, whereas it downregulated FOXP4-AS1-promoted progression of PTC. In vivo assay also confirmed the tumor inhibitory effect of FOXP4-AS1 in PTC growth. Mechanism analysis indicated that FOXP4-AS1 can play its functions by regulating the AKT signaling pathway, and AKT inhibitor treatment could attenuate the impact of FOXP4-AS1 on PTC progression. Furthermore, FOXP4-AS1 also negatively regulates the expression of its host gene FOXP4. Collectively, we showed that FOXP4-AS1 inhibited PTC progression although AKT signaling and FOXP4-AS1 plays a tumor-suppressor role in PTC tumorigenesis.

FOXP4-AS1 May be a Potential Prognostic Biomarker in Human Cancers: A Meta-Analysis and Bioinformatics Analysis

Background

Cancer is one of the leading causes of death worldwide. Early diagnosis can significantly lower cancer-related mortality. Studies have shown that the lncRNA Forkhead box P4 antisense RNA 1 (FOXP4-AS1) is aberrantly expressed in various solid tumors. A meta-analysis was performed to evaluate the correlation of FOXP4-AS1 with the prognosis of cancer patients and determine the clinical value of FOXP4-AS1 as a potential diagnostic marker.

Methods

Correlational studies from the Web of Science, Embase, OVID, Cochrane and PubMed databases were screened (up to April 1, 2021). Meta-analysis was performed using Stata SE12.0 software.

Results

Eleven original studies with 1,332 patients who were diagnosed with a solid cancer (nasopharyngeal carcinoma, hepatocellular carcinoma, colorectal cancer, gastric cancer, osteosarcoma, mantle cell lymphoma, prostate cancer, and pancreatic ductal adenocarcinoma) were included in the meta-analysis. High expression of FOXP4-AS1 was correlated with poor overall survival (OS) (HR = 1.77, 95% CI 1.29-2.44, P < 0.001) and shorter disease-free survival (DFS) (HR = 1.66, 95% CI 1.01-2.72, P = 0.044). Subgroup analysis based on sample size, follow-up time and Newcastle-Ottawa Scale (NOS) score revealed significant differences between FOXP4-AS1 levels and OS (P < 0.05). However, the expression level of FOXP4-AS1 was not significantly correlated with the OS of gastric cancer patients (P = 0.381). High expression of FOXP4-AS1 was predictive of a larger tumor size (OR = 3.82, 95% CI 2.3-6.3, P < 0.001).

Conclusions

Overexpression of FOXP4-AS1 correlates with poor prognosis of cancer patients, and is a potential prognostic biomarker and therapeutic target.

Systematic Review Registration

PROSPERO, identifier CRD42021245267.

Medium to Long-Term Clinical Outcomes of Spinal Metastasectomy

The prolonged survival of metastatic cancer patients highlights the importance of the local control of spinal metastases, which reduce patient performance status. This retrospective study examined the medium to long-term outcomes of spinal metastasectomy by evaluating 124 patients who underwent metastasectomy for isolated spinal metastases (2006-2018) with a postoperative follow-up for a minimum of 3 years. The findings present information on patient demographics (i.e., performance status, location of non-spinal metastases, and history of systemic therapy) and postoperative outcomes, including perioperative complications, disease progression of non-operated metastases, and additional excisional surgeries. Additionally, postoperative survival, local tumor control in the operated spine, and maintenance of spinal reconstruction without instrumentation failure were determined using Kaplan-Meier analyses. The primary malignancy was kidney and thyroid cancer in 51 and 14 patients, respectively, low-grade sarcoma and lung cancer in 13 patients, breast cancer in 12 patients, and other malignancies in 21 patients. The 3-year and 5-year survival rates were 70% and 60%, respectively. We found that patients with thyroid cancer had the best survival results, with local tumor recurrence and instrumentation failure at 10% and 22%, respectively. These findings suggest that for certain patients with isolated and removable spine metastases, metastasectomy can improve function and survival.

Instrumented Versus Noninstrumented Spinal Fusion for Degenerative Lumbar Spondylolisthesis: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

This systematic review compares radiographic and clinical outcomes between instrumented and noninstrumented posterolateral lumbar spine fusions for the treatment of degenerative lumbar spondylolisthesis.

SUMMARY OF BACKGROUND DATA

The optimal method of fusion for instability from degenerative lumbar spondylolisthesis remains to be an area of debate amongst spine surgeons. There are no prior comprehensive systematic review of comparative studies that compares outcomes between instrumented and noninstrumented posterolateral spine fusions for the treatment of degenerative lumbar spondylolisthesis.

MATERIALS AND METHODS

A systematic review was registered with PROSPERO and performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using the PubMed, SCOPUS, and Ovid MEDLINE databases. All level I-III comparative studies published in the English language investigating the clinical outcomes between instrumented and noninstrumented posterolateral spine fusions for the treatment of degenerative lumbar spondylolisthesis were included.

RESULTS

Seven studies (672 patients, 274 noninstrumented, 398 instrumented) were analyzed. One randomized study was level I evidence, 2 randomized studies were level II, and 4 nonrandomized studies were level III. Mean follow-up ranged from 1.4 to 5.9 years. Instrumented patients had a higher rate of solid fusion (87.6% vs. 77.1%, P=0.023) and a lower rate of definitive pseudarthrosis (5.3% vs. 19.9%, P<0.001). However, there was no difference in overall functional improvement at final follow-up between the 2 treatment groups (75.0% vs. 81.7%, P=0.258). In addition, there was no difference in reoperation or complication rates.

CONCLUSIONS

For the treatment of degenerative lumbar spondylolisthesis, there are significantly higher rates of fusion among patients undergoing instrumented posterolateral fusion compared with noninstrumented posterolateral fusion. However, there is no difference in overall functional improvement, pain-related outcome scores, reoperation rates, or complication rates between the 2 treatment groups.

LEVEL OF EVIDENCE

Level III-systematic review of level I-III studies.

Posterolateral Fusion Versus Posterior Lumbar Interbody Fusion: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

Arthrodesis has been a valid treatment option for spinal diseases, including spondylolisthesis and lumbar spinal stenosis. Posterolateral and posterior lumbar interbody fusion are amongst the most used fusion techniques. Previous reports comparing both methods have been contradictory. Thus, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to establish substantial evidence on which fusion method would achieve better outcomes.

METHODS

Major databases including PubMed, Embase, Web of Science and CENTRAL were searched to identify studies comparing outcomes of interest between posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF). We extracted data on clinical outcome, complication rate, revision rate, fusion rate, operation time, and blood loss. We calculated the mean differences (MDs) for continuous data with 95% confidence intervals (CIs) for each outcome and the odds ratio with 95% confidence intervals (CIs) for binary outcomes. P < 0.05 was considered significant.

RESULTS

We retrieved 8 studies meeting our inclusion criteria, with a total of 616 patients (308 PLF, 308 PLIF). The results of our analysis revealed that patients who underwent PLIF had significantly higher fusion rates. No statistically significant difference was identified in terms of clinical outcomes, complication rates, revision rates, operation time or blood loss.

CONCLUSIONS

This systematic review and meta-analysis provide a comparison between PLF and PLIF based on RCTs. Although PLIF had higher fusion rates, both fusion methods achieve similar clinical outcomes with equal complication rate, revision rate, operation time and blood loss at 1-year minimum follow-up.

Comparison of Endoscopic Discectomy Versus Non-Endoscopic Discectomy for Symptomatic Lumbar Disc Herniation: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review.

OBJECTIVE

The authors aimed to systematically compare the effectiveness and safety of endoscopic discectomy (ED) with non-endoscopic discectomy (NED) for treatment of symptomatic lumbar disc herniation (LDH).

METHODS

A systematic search was performed on PubMed, EMBASE, the Cochrane Library and China National Knowledge Infrastructure for randomized controlled trial from inception until August 13, 2020. Trials which investigated multiple operative approaches on lumbar disc herniation were identified without language restrictions.

RESULTS

In total, 25 trials involving 2258 patients with symptomatic LDH were included. Twenty trials performed the comparison between ED and NED. Five trials performed the comparison between percutaneous endoscopic transforaminal discectomy (PETD) and percutaneous endoscopic interlaminar discectomy (PEID). The operative time of micro-endoscopic discectomy (MED) was longer than open discectomy (OD). The length of hospital stay of percutaneous endoscopic lumbar discectomy (PELD) was shorter than fenestration discectomy (FD). Significant differences in intraoperative blood loss volumes were found between PELD with FD and MED with OD. The complication rate of PELD was lower than FD (PELD: 4.3%; FD: 14.6%) and the complication rate of full-endoscopic discectomy (FE) was lower than microscopic discectomy (MD) (FE: 13.4%; MD: 32.1%).

CONCLUSIONS

PELD and FE have the advantage of limiting intraoperative damages. ED and NED can be both considered sufficient to achieve good clinical outcomes. PETD and PEID are able to achieve similar results but the learning curve of PETD was steeper. More independent high-quality RCTs with sufficiently large sample sizes performing cost-effectiveness analyzes are needed.

Isthmic spondylolisthesis in adults… A review of the current literature

Isthmic spondylolisthesis can be defined as the anterior translation of a vertebral body relative to the one subjacent to it and secondary to an abnormality of the pars interarticularis. Isthmic spondylolisthesis is usually asymptomatic and discovered as an incidental radiographic finding. However, it can be symptomatic due to its biomechanical effects on the adjacent neural structures and patients may present with low back and/or radicular leg pain. Standing plain radiographs can be obtained to confirm the presence or assess the degree of isthmic spondylolisthesis. Computed tomography (CT) clearly shows the pars defect and provides a better assessment of the pathology. Magnetic resonance imaging (MRI) is indicated in patients with neurologic manifestations and can be used to assess the degree of foraminal or central stenosis. Conservative management including oral anti-inflammatory medication, physical therapy, and/or transforaminal epidural corticosteroid injections can be utilized initially. Surgery can be considered in the setting of persistent symptoms unrelieved with conservative management or significant neurologic compromise. Several surgical methods and techniques are available in the management of isthmic spondylolisthesis. There has been a significant national increase in the use of interbody fusion posteriorly for the management of isthmic spondylolisthesis. Reports have suggested that interbody fusion can be a cost-effective technique in selected patients with isthmic spondylolisthesis. Future studies are encouraged to further characterize the specific indications of various surgical modalities in patients with isthmic spondylolisthesis.

Two-dimensional fluoroscopy-guided robot-assisted percutaneous endoscopic transforaminal discectomy: a retrospective cohort study

Percutaneous Endoscopic Transforaminal Discectomy (PETD) has been widely used for minimally invasive treatment of lumbar disc herniation (LDH), and percutaneous disc target puncture has a steep learning curve and high radiation exposure. Proper technology grafting can improve the surgical procedure and clinical outcomes. The changes brought by grafting surgical robots into PETD are worth investigating. A retrospective analysis was performed on the information of patients who received PETD in our hospital from March 2019 to July 2020. A total of 102 of patients who received 2D-guided robot-assisted PETD were included in Group A, and 102 of patients who received C-arm fluoroscopy-guided bare-handed PETD were included in Group B. The number of punctures, number of fluoroscopies, operation duration, intraoperative anxiety score, complications, and visual analogue scale (VAS) score and Oswestry disability index (ODI) before operation, on Day 1 after operation and at the last follow-up visit of the two groups were compared. All 204 patients received successful operations. Group A received 1.20±0.42 punctures, 10.49±2.16 fluoroscopies and 60.69±5.63 minutes of operation, significantly fewer than the 4.84±1.94 punctures, 17.41±3.23 fluoroscopies and 71.19±5.11 minutes of operation of Group B (all P<0.05), and Group A had significantly lower intraoperative anxiety scores and incidence of complications than Group B (both P<0.05). Both groups had comparable VAS and ODI scores on Day 1 after operation and at the last follow-up visit, which were both significantly higher than those before operation (P<0.05). 2D-guided robot-assisted PETD can enable precise planning of the puncture path, make it easier for operators to complete targeted punctures at pathogenic targets, reduce the number of punctures and fluoroscopies, shorten the operation duration to optimize the operation process, and reduce complications and alleviate intraoperative anxiety for better clinical results. Therefore it mayb be a better choice to assist PETD.

Proximal junctional fractures after long-segment instrumented fusion: comparisons between upper instrumented vertebrae and upper instrumented vertebrae + 1

Introduction

Proximal junctional failure (PJF) is a well-known complication after long-segment (at least 4 vertebral levels) instrumented fusion. The etiologies of PJF include degenerative processes or are fracture induced. The fracture type of PJF includes vertebral fractures developed at the upper instrumented vertebrae (UIV) or UIV + 1. The purpose of this study was to investigate clinical and radiographic features of these two subtypes of PJF and to analyze risk factors in these patients.

Method

In total, forty-two patients with PJF who underwent revision surgery were included. Twenty patients suffered fractures at the UIV, and the other 22 cases had fractures at UIV + 1. The weighted Charlson Comorbidity Index (CCI) and bone mineral density (BMD) T scores for these patients were recorded. Surgery-related data of index surgery and complications were collected. Radiographic parameters including pelvic tilt (PT), pelvic incidence (PI), sagittal vertical axis (SVA), lumbar lordosis (LL), and PI-LL were recorded in both groups before and after the revision surgery.

Result

Both groups had severe osteoporosis and comorbidities. The interval between the index surgery and revision surgery was shorter in the UIV group than in the UIV + 1 group (8.2 months vs. 35.9 months; p < 0.001). The analysis for radiographic parameters in UIV and UIV + 1 group demonstrated no significant change before and after the revision surgery. However, the preoperative radiographic analysis showed a larger PT (31.5° vs. 23.2°, p = 0.013), PI (53.7° vs. 45.3°, p = 0.035), and SVA (78.6° vs. 59.4°, p = 0.024) in the UIV group compared to the UIV + 1 group. The postoperative radiographic analysis showed a larger PI-LL (27.8° vs. 18.1°, p = 0.016) in the UIV group compared to the UIV + 1 group.

Conclusion

PJF in the UIV group tends to occur earlier than in the UIV + 1 group. Moreover, more severe global sagittal imbalances were found in the UIV group than in UIV + 1 group.

The Effect of Anterior Cervical Discectomy and Fusion Procedure Duration on Patient-Reported Outcome Measures

OBJECTIVE

To determine whether operative duration of anterior cervical discectomy and fusion (ACDF) significantly affects patient-reported outcome measures (PROMs) 90 days after surgery and at 1-year follow-up.

METHODS

Patients who underwent primary 1-level to 4-level ACDF were retrospectively identified. Demographic data and PROMs were collected through chart review. Patients were split into short, medium, and long tertiles based on procedure duration. PROM surveys were administered preoperatively as baseline measurements, at initial follow-up (between 60 and 120 days postoperatively), and at 1 year postoperatively. Outcomes included Neck Disability Index, Short-Form 12 Physical Component Score (PCS-12), Short-Form 12 Mental Component Score, visual analog scale (VAS) neck score, and VAS arm score.

RESULTS

Significant short-term improvements were found across all groups for all PROMs. All groups showed long-term improvements in Short-Form 12 Mental Component Score, PCS-12, Neck Disability Index, VAS neck score, and VAS arm score, with the exception of the medium-duration group in PCS-12 (P = 0.093). On multivariate analysis, short-duration procedures predicted better improvement in VAS neck score (β = -1.01; P = 0.012) and VAS arm score (β = -1.38; P = 0.002) compared with long-duration procedures, whereas medium-duration procedures resulted in better improvement in VAS arm score (β = -1.00; P = 0.011). Further, short and medium duration was a predictor of decreased length of hospital stay (β = -0.67, P = 0.001 and β = -0.59, P = 0.001, respectively) compared with long-duration procedures.

CONCLUSIONS

All groups improved after ACDF regardless of surgical duration. Further, surgical duration was not a predictor of differing improvement in physical function or disability.

Distal adding-on in adolescent idiopathic scoliosis results in diminished health-related quality of life at 10 years following posterior spinal fusion

PURPOSE

The purpose of this study was to investigate associations between the various definitions of adding-on identified in the literature and HRQoL at 10 years following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) to identify a clinically relevant definition.

METHODS

In this retrospective cohort study, patients with Lenke type 1 or 2 AIS with 10-year follow-up after PSF were identified in a multicenter registry. Adding-on was identified independently using 5 published definitions and expert spine surgeons' visual confirmation. Worsening of HRQoL was defined as a preoperative to 10-year postoperative decrease in SRS-22 domain score ≥ the minimal clinically important difference (MCID).

RESULTS

One hundred fifty patients were included, and 118 had HRQoL data available for the main analysis. Worsening pain was noted in 49 (41.5%) patients, appearance in 1 (0.8%), and activity in 70 (59.3%) from preoperative to postoperative. 4 of the 5 definitions of adding-on demonstrated no evidence of association with worsening HRQoL. By Cho's definition (either 1. ≥ 5° increase in Cobb angle AND increase in number of vertebrae in curve distally, or 2. ≥ 5° increase in angulation of 1st disc below LIV), adding-on (27 patients, 22.9%) was associated with an increased risk of worsening pain (59.3% vs. 36.3%, p = 0.033) and activity (77.8% vs. 53.8%, p = 0.026). There was no evidence of association with changes in appearance. Risk of worsening pain and activity was increased by 1.75 and 1.51 times (p = 0.023 and p = 0.002), respectively.

CONCLUSION

Cho's definition of adding-on was associated with worsening HRQoL at 10 years following PSF for Lenke type 1 and 2 AIS. Consistent use of this definition will allow us to compare studies and obtain meaningful information in this population.

LEVEL OF EVIDENCE

Level II.

Variation of cervical sagittal alignment parameters according to gender, pelvic incidence and age

PURPOSE

The aim was to describe radiographic cervical sagittal alignment variations according to age, gender and pelvic incidence (PI) and to investigate relationships with thoracic alignment.

METHODS

A total of 2599 individuals (5-93 years) without spinal deformity were studied. Cranial cervical parameters were: McGregor slope, occipita-C2 angle, McGregor-C2 lordosis and C1-C2 lordosis. Caudal cervical parameters were: C2-C7, cranial arch and caudal arch lordosis and C7- and T1-slope. A Bayesian inference compared parameter distributions. Correlations with spinopelvic and global alignment parameters were investigated.

RESULTS

Among cranial cervical parameters, variations of McGregor slope were non-significant. McGregor-C2 lordosis and C1-C2 lordosis were smaller in males and increased significantly during growth, whereas the occipito-C2 angle decreased (Pr > 0.95). The occipito-C2 angle was larger and McGregor-C2 lordosis was smaller in low PI (Pr > 0.95). Among caudal cervical parameters, C2-C7 lordosis and C7- and T1-slope were larger in males and increased after 50 years (Pr > 0.95). Lordosis changes were non-significant in the cranial arch, whereas values increased in the caudal arch after 35 years (Pr > 0.95). Caudal parameter differences were non-significant between PI groups. Strong correlations existed between C2-C7, caudal arch lordosis, C7-slope, T1-slope and thoracic kyphosis. The sagittal vertical axis C2 correlated with caudal arch lordosis and T1-slope (ρ > 0.5; Pr > 0.95).

CONCLUSION

Cervical alignment parameters vary according to age, gender and PI. In the cranial cervical spine, changes occur mainly during growth. In the caudal cervical spine, lordosis increases in the caudal arch, which is related to thoracic kyphosis increase with age. The caudal cervical arch acts as a compensatory segment by progressive extension, allowing horizontal gaze.

The Cellular Tumor Immune Microenvironment of Childhood Solid Cancers: Informing More Effective Immunotherapies

Common pediatric solid cancers fail to respond to standard immuno-oncology agents relying on preexisting adaptive antitumor immune responses. The adoptive transfer of tumor-antigen specific T cells, such as CAR-gene modified T cells, is an attractive strategy, but its efficacy has been limited. Evidence is accumulating that local barriers in the tumor microenvironment prevent the infiltration of T cells and impede therapeutic immune responses. A thorough understanding of the components of the functional compartment of the tumor microenvironment and their interaction could inform effective combination therapies and novel engineered therapeutics, driving immunotherapy towards its full potential in pediatric patients. This review summarizes current knowledge on the cellular composition and significance of the tumor microenvironment in common extracranial solid cancers of childhood and adolescence, such as embryonal tumors and bone and soft tissue sarcomas, with a focus on myeloid cell populations that are often present in abundance in these tumors. Strategies to (co)target immunosuppressive myeloid cell populations with pharmacological anticancer agents and with selective antagonists are presented, as well as novel concepts aiming to employ myeloid cells to cooperate with antitumor T cell responses.

Quality assessment of systematic reviews of surgical treatment of cervical spine degenerative diseases: an overview

OBJECTIVE

To gather all systematic reviews of surgical treatment of degenerative cervical diseases and assess their quality, conclusions and outcomes.

METHODS

A literature search for systematic reviews of surgical treatment of degenerative cervical diseases was conducted. Studies should have at least one surgical procedure as an intervention. Included studies were assessed for quality through Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) and Assessment of Multiple Systematic Reviews (AMSTAR) questionnaires. Quality of studies was rated accordingly to their final score as very poor (<30%), poor (30%-50%), fair (50%-70%), good (70%-90%), and excellent (>90%). If an article reported a conclusion addressing its primary objective with supportive statistical evidence for it, they were deemed to have an evidence-based conclusion.

RESULTS

A total of 65 systematic reviews were included. According to AMSTAR and PRISMA, 1.5% to 6.2% of studies were rated as excellent, while good studies counted for 21.5% to 47.7%. According to AMSTAR, most studies were of fair quality (46.2%), and 6.2% of very poor quality. Mean PRISMA score was 70.2%, meaning studies of good quality. For both tools, performing a meta-analysis significantly increased studies scores and quality. Cervical spondylosis studies reached highest scores among diseases analyzed. Authors stated conclusions for interventions compared in 70.7% of studies, and only two of them were not supported by statistical evidence.

CONCLUSION

Systematic reviews of surgical treatment of cervical degenerative diseases present "fair" to "good" quality in their majority, and most of the reported conclusions are supported by statistical evidence. Including a meta-analysis significantly increases the quality of a systematic review.

Can We Stop Distally at LSTV-1 for Adolescent Idiopathic Scoliosis With Lenke 1A/2A Curves?

STUDY DESIGN

A retrospective study.

OBJECTIVE

To determine in which case one level proximal to last substantially touching vertebra (LSTV-1) could be a valid lowest instrumented vertebra (LIV), in which case distal fusion should extend to last substantially touching vertebra (LSTV), and to identify risk factors for distal adding-on.

SUMMARY OF BACKGROUND DATA

Posterior thoracic fusion to save more lumbar mobile segments has become the mainstay of operative treatment for adolescent idiopathic scoliosis (AIS) with Lenke 1A/2A curves. Although previous studies have recommended selecting the LSTV as LIV, good outcomes could still be achieved in some cases when LSTV-1 was selected as LIV.

METHODS

Ninety-four patients were included in the study with a minimum of 2-year follow-up after posterior thoracic instrumentation, in which LSTV-1 was selected as LIV. Patients were identified with distal adding-on between first erect radiographs and 2-year follow-up based on previously defined parameters. Factors associated with the incidence of adding-on were analyzed.

RESULTS

The mean follow-up duration was 37.7 ± 15.8 months. Forty patients (42.6%) with LSTV-1 selected as LIV achieved good outcomes at the last follow-up. Several preoperative risk factors significantly associated with distal adding-on were identified, including lower Risser (P = 0.001), longer thoracic curve length (P = 0.005), larger rotation and deviation of LSTV-1 (P  < 0.001), and preoperative coronal imbalance (P = 0.013).

CONCLUSION

Skeletally immature patients with long thoracic curve, preoperative coronal imbalance, large rotation, and deviation of LSTV-1 are at increased risk of distal adding-on when selecting LSTV-1 as LIV. Under this condition, distal fusion level should extend to LSTV; while in other case, LSTV-1 could be a valid LIV.Level of Evidence: 4.

Relationship between TIA minus C0-7 angle and C2-7 SVA: analysis of 113 symptomatic patients

Background

Measurement of T1 slope (T1S) can be difficult due to the anatomical positioning of the shoulders. And thoracic inlet angle (TIA) was a morphological parameter and not changed by the position. We proposed a new parameter, TIA minus C0-7 angle (TIA-C07), to evaluate C2-7 SVA in order to overcome the T1S imperfection.

Methods

This was a retrospective radiological analysis of symptomatic subjects. The following cervical parameters were measured: Cervical lordosis angle (CL), C0-7 angle (C0-7), occiput-C2 lordosis angle (O-C2), C2-7 sagittal vertical axis (C2–7 SVA), TIA and TIA-C07. The Pearson correlation test was calculated, and the stepwise multiple regression analysis was conducted to determine the best predictor for C2-7 SVA. A paired sample t test was used to compare the predicted and measured C2-7 SVA.

Results

The mean age of 113 patients was 60.02 ± 9.67. The average O-C2, CL, C0-7, TIA, TIA-C07 and C2-C7 SVA was 29.24 ± 8.48°, 13.67 ± 11.22°, 42.91 ± 11.44°, 76.07 ± 9.54°, 33.16 ± 13.18° and 21.34 ± 11.42 mm. The predictive formula was founded: C2-7 SVA = 2.80 + 0.56 * (TIA—C07) (R = 0.645, R2 = 0.416). There was no statistical difference between the predicted and the measured C2-7 SVA (t = 0.085, P = 0.933).

Conclusions

TIA and C0-7 mismatch may significantly impact cervical alignment, and a greater T1A-C07 was related to a greater degree of C2-7 SVA. TIA-C07 may be a more important predictor for C2-7 SVA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05301-0.

Zooming in on Long Non-Coding RNAs in Ewing Sarcoma Pathogenesis

Ewing sarcoma (ES) is a rare aggressive cancer of bone and soft tissue that is mainly characterized by a reciprocal chromosomal translocation. As a result, about 90% of cases express the EWS-FLI1 fusion protein that has been shown to function as an aberrant transcription factor driving sarcomagenesis. ES is the second most common malignant bone tumor in children and young adults. Current treatment modalities include dose-intensified chemo- and radiotherapy, as well as surgery. Despite these strategies, patients who present with metastasis or relapse still have dismal prognosis, warranting a better understanding of treatment resistant-disease biology in order to generate better prognostic and therapeutic tools. Since the genomes of ES tumors are relatively quiet and stable, exploring the contributions of epigenetic mechanisms in the initiation and progression of the disease becomes inevitable. The search for novel biomarkers and potential therapeutic targets of cancer metastasis and chemotherapeutic drug resistance is increasingly focusing on long non-coding RNAs (lncRNAs). Recent advances in genome analysis by high throughput sequencing have immensely expanded and advanced our knowledge of lncRNAs. They are non-protein coding RNA species with multiple biological functions that have been shown to be dysregulated in many diseases and are emerging as crucial players in cancer development. Understanding the various roles of lncRNAs in tumorigenesis and metastasis would determine eclectic avenues to establish therapeutic and diagnostic targets. In ES, some lncRNAs have been implicated in cell proliferation, migration and invasion, features that make them suitable as relevant biomarkers and therapeutic targets. In this review, we comprehensively discuss known lncRNAs implicated in ES that could serve as potential biomarkers and therapeutic targets of the disease. Though some current reviews have discussed non-coding RNAs in ES, to our knowledge, this is the first review focusing exclusively on ES-associated lncRNAs.

An Analysis of the Risk Factors for Adding-on Phenomena After Posterior Hemivertebral Resection and Pedicle Screw Fixation for the Treatment of Congenital Scoliosis Caused by Hemivertebral Malformation

Objective

To retrospectively analyze the risk factors for adding-on phenomena (AOP) after posterior hemivertebral resection (PHR) and pedicle screw fixation for the treatment of congenital scoliosis (CS) caused by hemivertebral (HV) malformation.

Methods

Patients with CS who underwent surgery and were followed up for more than five years were included in this study. The d general data, such as gender, age, HV segment, Risser sign, and triangular cartilage, postoperative complications, and imaging data at different periods, including the standard anteroposterior and lateral x-rays of the total spine were collected.

Results

In total, 58 patients were included in this study, of which 10 experienced AOP and 48 did not. The results of the single-factor analysis showed that there were statistically significant differences between the patients with AOP and those without in terms of the HV direction, lowest instrumented vertebra (LIV)–upper instrumented vertebra (UIV) (P < 0.05), and postoperative trunk shift (P < 0.05). The results of the logistic regression analysis showed that the HV direction and the postoperative trunk displacement distance were the main risk factors for postoperative AOP. The area under the receiver operating characteristic curve was 0.842 (P < 0.001). The best cut-off value of the adding-on index as an indicator of the occurrence of AOP after surgery was 0.67. When the adding-on index was >0.67, the incidence of postoperative AOP was 90.0%, and the non-occurrence rate was 22.9%.

Conclusion

PHR and pedicle screw fixation is an effective way to treat HV malformation in CS. The HV direction, LIV–UIV, and postoperative TS are risk factors for AOP in patients with CS treated with PHR and pedicle screw fixation. The adding-on index has a high degree of accuracy for the prediction of the occurrence of AOP after PHR and pedicle screw fixation.

Differential Agnostic Effect Size Analysis of Lumbar Stenosis Surgeries

STUDY DESIGN

A meta-analysis of 89 randomized prospective, prospective, and retrospective studies on spinal endoscopic surgery outcomes.

OBJECTIVE

The study aimed to provide familiar Oswestry Disability Index (ODI), visual analog scale (VAS) back, and VAS leg effect size (ES) data following endoscopic decompression for sciatica-type back and leg pain due to lumbar herniated disc, foraminal, or lateral recess spinal stenosis.

BACKGROUND

Higher-grade objective clinical outcome ES data are more suitable than lower-grade clinical evidence, including cross-sectional retrospective study outcomes or expert opinion to underpin the ongoing debate on whether or not to replace some of the traditional open and with other forms of minimally invasive spinal decompression surgeries such as the endoscopic technique.

METHODS

A systematic search of PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials from 1 January 2000 to 31 December 2019 identified 89 eligible studies on lumbar endoscopic decompression surgery enrolling 23,290 patient samples using the ODI and VAS for back and leg pain used for the ES calculation.

RESULTS

There was an overall mean overall reduction of ODI of 46.25 (SD 6.10), VAS back decrease of 3.29 (SD 0.65), and VAS leg reduction of 5.77 (SD 0.66), respectively. Reference tables of familiar ODI, VAS back, and VAS leg show no significant impact of study design, follow-up, or patients' age on ES observed with these outcome instruments. There was no correlation of ES with long-term follow-up (P = 0.091). Spinal endoscopy produced an overall ODI ES of 0.92 extrapolated from 81 studies totaling 12,710 patient samples. Provided study comparisons to tubular retractor microdiscectomy and open laminectomy showed an ODI ES of 0.9 (2895 patients pooled from 16 studies) and 0.93 (1188 patients pooled from 5 studies). The corresponding VAS leg ES were 0.92 (12,631 endoscopy patients pooled from 81 studies), 0.92 (2348 microdiscectomy patients pooled from 15 studies), and 0.89 (1188 open laminectomy patients pooled from 5 studies).

CONCLUSION

Successful clinical outcomes can be achieved with various lumbar surgeries. ESs with endoscopic spinal surgery are on par with those found with open laminectomy and microsurgical decompression.

CLINICAL RELEVANCE

This article is a meta-analysis on the benefit overlap between lumbar endoscopy, microsurgical decompression, laminectomy, and lumbar decompression fusion.

Rapidly Progressive Classic Adamantinoma of the Spine: Case Report and Literature Review

Adamantinoma is a locally aggressive or malignant tumor, accounting for <0.5% of all primary bone tumors. The tumor usually progresses slowly, with a relatively promising prognosis. Primary or metastatic spinal adamantinoma of bone are rarer. Only four cases have been documented till date. We present two cases of aggressive spinal adamantinoma whose microphotography and radiographic appearance were unusual, with extensive involvement of multiple segments and rapid progression. Case 1 was a 36-year-old woman, presenting with back pain, progressive numbness and motor weakness, who was diagnosed with metastatic adamantinoma in the T2, T7, L2, and L4. She underwent spondylectomy three times to resect these lesions, respectively. Case 2 was a 68-year-old male with complaints of severe left back pain. MRI revealed destructive changes in T1-T4. He underwent posterior decompression (T1-T3), partial vertebrectomy (T2), fixation and fusion (C5-C7, T4-T6). The pathology of two patients was metastatic spinal adamantinoma, whose primary lesions were from tibia and femoral adamantinoma, respectively. Rapid squamous progression was observed in specimens of T2 and T7 lesions of Case 1 in two months. Twenty-five months after surgery, Case 1 developed paralysis, but she refused to receive further examination and treatment. Two months after surgery, Case 2 presented with an upper back pain again. The MRI revealed an increase in osseous destruction and paravertebral mass size. He was administered radiotherapy, with his upper back pain partially relieved. The biological behavior of classic adamantinoma is highly unpredictable, often exhibiting more aggressive behavior upon recurrence or metastasis. The pathological diagnosis of adamantinoma should be confirmed by preoperative biopsy. En bloc resection with a wide margin is the preferred treatment for primary spinal adamantinoma. Radiation therapy can partially relieve the pain.

Efficacy and safety of anterior cervical discectomy and fusion (ACDF) through mini-incision and posterior laminoplasty (LAMP) for treatment of long-level cervical spondylosis: a retrospective cohort study

BACKGROUND

The efficacy and safety of anterior cervical discectomy and fusion (ACDF) through mini-incision and posterior laminoplasty for long-level cervical spondylosis were investigated.

METHOD

From January 2018 to September 2019, clinical patients data with 3-4 segments (C3-7) cervical spondylotic radiculopathy, cervical spondylotic myelopathy, or mixed cervical spondylosis who received ACDF (42 cases) throughwith mini-incision or LAMP (36 cases) treatment were retrospectively collected and analyzed. The operative time, bleeding volume, incisive length, and hospital stay were recorded. Moreover, the intervertebral height, functional segment height, cervical lordosis, cervical hyperextension and hyperflexion range-of-motion (ROM) and ROM in all directions of the cervical spine before and after the operation were measured. Additionally, all relevant postoperative complications were also recorded. Then, the therapeutic effects of both surgical methods were investigated.

RESULTS

Patients in the ACDF group had less bleeding, shorter incision, and fewer hospitalization days than the LAMP group. There was no significant difference in JOA, VAS score of the upper limb, NDI score after surgery between two groups. Postoperative intervertebral height and functional segment height in the ACDF group were significantly higher than those before the operation, and postoperative functional segment height of the ACDF group was significantly higher than that of the LAMP group. Moreover, the postoperative cervical lordosis angle in the ACDF group was significantly larger than the LAMP group. There was no significant difference between preoperative and postoperative ROM in all directions of the cervical spine for the two groups.

CONCLUSIONS

Both ACDF through mini-incision and LAMP are effective treatments for long-level cervical spondylosis. However, ACDF through mini-incision shows minor trauma, less bleeding, fast recovery, and it is beneficial for cervical lordosis reconstruction.

Microendoscopic decompression of conjoined lumbosacral nerve roots

Nerve root morphological variability is often incompletely appreciated on preoperative imaging and can complicate intraoperative decision-making. This case demonstrates the utility of spinal endoscopy in the visualisation and manipulation of conjoined nerve roots and includes procedural images to promote better understanding and awareness of this anatomical anomaly. A woman in her 50s presented with 1 year of progressive left S1 radiculopathy refractory to non-operative modalities. History and examination were notable for S1 dermatomal paresthesias, positive ipsilateral straight leg raise and grade 4/5 gastrocnemius strength. MRI demonstrated an L5-S1 left paracentral disc herniation causing severe lateral recess stenosis. Endoscopic decompression revealed conjoined lumbosacral nerve roots. Laminotomies and discectomy provided circumferential decompression. The patient experienced immediate and sustained relief of her preoperative radiculopathy as manifested in patient-reported outcome measures. Evolving endoscopic spine platforms provide novel visualisation of nerve root anomalies yielding new insight on safe and effective decompressive techniques.

Can Postoperative Distal Adding-On be Predicted in Lenke Type 1B and 1C Curves with Intraoperative Radiographs?

STUDY DESIGN

A retrospective study of consecutive collected data.

OBJECTIVE

To investigate risk factors for postoperative distal adding-on (DA) in Lenke Type 1B and 1C curves using intraoperative radiographs.

SUMMARY OF BACKGROUND DATA

In adolescent idiopathic scoliosis (AIS), DA radiographic complication can negatively affect postoperative clinical results. However, few studies have focused on assessing risk factors for DA using intraoperative radiographs.

METHODS

We retrospectively evaluated 69 AIS patients with Lenke Type 1B or 1C curves who underwent posterior selective thoracic fusion. We divided patients into DA and non-DA groups based on radiograph data at 2-year follow-up using Wang et al (Spine 2011) definition of DA. We compared coronal radiographic parameters, including relative positions of end vertebra (EV), stable vertebra (SV), neutral vertebra (NV), and last touching vertebra (LTV) to lowest instrumented vertebra (LIV), and intraoperative radiographic parameters, between the two groups.

RESULTS

DA was present in 13 patients (18.8%) at 2-year follow-up. The mean LIV-EV, LIV-NV, LIV-SV, and LIV-LTV relative positions were significantly smaller in the DA group than in the non-DA group. Multivariate analysis showed that LIV-LTV was significantly associated with DA (DA: -0.2 ± 0.7, non-DA: 0.6 ± 0.7). Intraoperative radiographs showed that the mean angulation of the first disc below the LIV after final adjustment was significantly larger in the DA group (2.3° ± 1.1°) than in the non-DA group (0.9° ± 0.7°). Patients whose angulation of the first disc below the LIV was more than 3° were significantly associated with DA.

CONCLUSION

The LIV selected at more cranial to the LTV may be a risk factor for postoperative DA in Lenke Type 1B and 1C curves. Moreover, it was suggested that LIV extension might be considered when the first disc's angulation below the LIV is >3° in intraoperative radiographs.Level of Evidence: 3.

Better Functional Recovery After Single-Level Compared With Two-Level Posterolateral Lumbar Fusion

Background

Multiple studies describe the outcomes of patients undergoing single-level and multilevel posterolateral lumbar fusion (PLF). However, a comparison of outcomes between single-level and two-level PLF is lacking. The aim of this prospective cohort study was to compare outcomes between single-level and two-level instrumented PLF.

Methods

A total of 42 patients were enrolled at nine US centers between October 2015 and June 2017. Data included radiologic outcomes, visual analog scale (VAS) Back and Leg Pain, disability per the Oswestry Disability Index (ODI), and health-related quality of life (QoL) per 36-Item Short Form Survey version 2.0 (SF-36v2) at six weeks and three, six, 12, and 24 months.

Results

Twelve-month and 24-month follow-ups were completed by 38 (90.5%) and 32 (76.2%) subjects, respectively. The average age was 67 years, and 54.8% were female. Twenty-six received single-level PLF, and 16 received two-level PLF. In the single-level group, there was one reoperation, two postoperative infections, and one dural tear. In the two-level group, there was one postoperative infection. The surgeon computed tomography (CT)-based evaluation of fusion rate was 67.6% (25/37) at 12-month follow-up and 94.1% (32/34) at 24-month follow-up. The third-party evaluation of fusion rate was 52.8% (19/36) at six months, 81.1% (30/37) at 12 months, and 86.5% (32/37) at 24 months. There was a tendency toward a higher fusion rate in single-level compared with two-level PLF. The ODI, SF-36v2 Mental Component Score (MCS), and VAS Back Pain and Leg Pain outcomes improved by the first follow-up visit in both the single-level and two-level groups. Improvement in the ODI was 5.86 (95% confidence interval (CI): 0.03-11.69) points greater in the single-level group compared with the two-level group.

Conclusions

Compared with the two-level PLF subjects, single-level PLF subjects had better functional outcomes and reported higher satisfaction with the outcome of surgery but showed similar fusion, pain, and generic health-related quality of life outcomes. Both single-level and two-level PLF subjects demonstrated high fusion rates in association with improvements in pain, functional, and quality of life outcomes, as well as high satisfaction levels.

Spontaneous Osseous Fusion after Remodeling Therapy for Chronic Atlantoaxial Rotatory Fixation and Recovery Mechanism of Rotatory Range of Motion of the Cervical Spine

We aimed to investigate the risk factors of spontaneous osseous fusion (SOF) of the atlantoaxial joint after closed reduction under general anesthesia followed by halo fixation (remodeling therapy) for chronic atlantoaxial rotatory fixation, and to elucidate the recovery mechanism of the rotatory range of motion (ROM) after halo removal. Twelve patients who underwent remodeling therapy were retrospectively reviewed. Five patients with SOF were categorized as the fusion group and seven patients without SOF as the non-fusion group. Three dimensional CT was used to detect direct osseous contact (DOC) of facet joints before and during halo fixation, while dynamic CT at neutral and maximally rotated head positions was performed to measure rotatory ROM after halo removal. The duration from onset to initial visit was significantly longer (3.2 vs. 5.7 months, p = 0.04), incidence of DOC during halo fixation was higher (0/7 [0%] vs. 4/5 [80%], p = 0.004), and segmental rotatory ROM of Occiput/C1 (Oc/C1) at final follow-up was larger (9.8 vs. 20.1 degrees, p = 0.003) in the fusion group. Long duration from the onset to the initial visit might induce irreversible damage to the articular surface of the affected facet, which was confirmed as DOC during halo fixation and resulted in SOF. Long duration from the onset to the initial visit and DOC during halo fixation could be used to suggest the risk for SOF. Nonetheless, rotatory ROM of Oc/C1 increased to compensate for SOF.

Evaluating flexibility and predicting curve correction using fulcrum-bending radiographs in Lenke type 2 adolescent idiopathic scoliosis

BACKGROUND

Fulcrum-bending (FB) correction is considered to provide the best estimation of main thoracic (MT) curve flexibility and postoperative correction in surgical treatment for adolescent idiopathic scoliosis (AIS). However, few studies evaluated the usefulness of FB radiographs for proximal thoracic (PT) curve. We aimed to perform flexibility assessments using both active side-bending (SB) and FB radiographs and evaluate surgical outcomes after posterior spinal fusion (PSF) for Lenke type 2 AIS.

METHODS

This study included 38 consecutive patients with Lenke type 2 AIS who underwent PSF using a pedicle screw construct with a minimum 2-year follow-up. Radiographic parameters, including correction rate, SB and FB flexibility, and FB correction index (FBCI: [correction rate/FB flexibility] × 100), were evaluated preoperatively, immediately after surgery, and at the 2-year follow-up. The clinical outcomes were preoperatively evaluated using the Scoliosis Research Outcomes Instrument-22 and at the follow-up.

RESULTS

All scoliosis curves significantly improved and shoulder balance shifted toward left shoulder elevation (all comparisons, p < 0.0001). There were significant differences between the SB and FB corrections in the PT and MT curves (p < 0.0001). The magnitudes of the discrepancies between the SB and FB corrections in the PT and MT curves were 11.2° ± 5.2° and 11.6° ± 7.2°, respectively. FB correction did not differ from postoperative Cobb angles correction immediately after surgery or at the 2-year follow-up; the mean FBCIs in the PT and MT curves were 98.8% and 105.5%, respectively. The self-image domain SRS-22 scores had significantly increased at the 2-year follow-up (p < 0.0001).

CONCLUSIONS

There were significant differences between the SB and FB corrections, and FB correction tended to approximate the postoperative curve correction (FBCI = 100%) for PT and MT curves in patients with Lenke type 2 AIS. FB flexibility is more reliable than SB flexibility in evaluating actual curve flexibility even for the PT curve.

Risk factors for the development of DJK in AIS patients undergoing posterior spinal instrumentation and fusion

PURPOSE

Typically, selection of lowest instrumented vertebra (LIV) in Adolescent Idiopathic Scoliosis (AIS) is based on the coronal radiograph; however, increasing evidence suggests that fusions proximal to the stable sagittal vertebrae (SSV) on the lateral radiograph can result in distal junctional kyphosis (DJK). The purpose of this study is to compare rates of DJK in patients with AIS that have a discordance between the Lowest Touched Vertebra (LTV) and the SSV and to identify risk factors for developing DJK.

METHODS

Patients with AIS Lenke type 1, 2 and 3 curves treated with a posterior spinal fusion were separated into two groups. Group 1 had SSV that was proximal to the LTV whereas group 2 had SSV that was distal to the LTV. Comparisons were made for patients that were fused to the SSV(a), LTV(b) or between(c). Distal junctional angle (DJA) > 5° and increasing kyphosis at the end of the fusion construct were evaluated as risk factors for DJK.

RESULTS

The rate of DJK was 0.0% in group 1a, 1b, and 1c compared to 4.3%, 18.5% and 10.0% in groups 2a, 2b and 2c, respectively(p < 0.001). The rate of DJK was 22.9% when the distal junctional angle(DJA) > 5° versus 1.4% when the DJA < 5°(p < 0.001).

CONCLUSION

There was a low risk for progression of DJK when the SSV was proximal to the LTV, however, those with SSV distal to the LTV represent a high-risk group. Importantly, the development of DJK occurred almost exclusively in patients with LIV at the thoracolumbar junction which demonstrates that surgeons need to be cautious when ending fusions at T11, T12, and L1 in patients at high risk for DJK. Furthermore, having a distal junctional angle 5° or greater increased the risk of developing DJK by roughly 16-fold. At a minimum of 5-year follow-up, the development of DJK did not appear to adversely impact SRS outcomes or revision rates.

circ‑LRP6 contributes to osteosarcoma progression by regulating the miR‑141‑3p/HDAC4/HMGB1 axis

Circular RNA-lipoprotein receptor 6 (circ-LRP6) serves a role in promoting the tumorigenesis of retinoblastoma, esophageal squamous cell cancer and oral squamous cell carcinoma; however, whether circ-LRP6 demonstrates the same effect in osteosarcoma (OS) is yet to be fully elucidated. The present study aimed to analyze the expression, role and potential molecular mechanism of circ-LRP6 in OS. The expression levels of circ-LRP6, microRNA (miR)-141-3p, histone deacetylase 4 (HDAC4) and high mobility group protein 1 (HMGB1) were evaluated by reverse transcription- quantitative PCR in OS tissues and cell lines. Cell Counting Kit-8, Transwell and Matrigel assays were conducted to evaluate cell proliferation, migration and invasion, respectively. Western blotting was also performed to determine HDAC4 and HMGB1 protein expression levels. Bioinformatics and dual-luciferase reporter assays were used to predict and analyze the interactions between circ-LRP6 and miR-141-3p, miR-141-3p and HDAC4, as well as between miR-141-3p and HMGB1. Additionally, RNA immunoprecipitation was performed to verify the association between circ-LRP6 and miR-141-3p. The results confirmed that circ-LRP6 was highly expressed in OS tissues and cell lines. In addition, circ-LRP6 negatively regulated the expression of miR-141-3p and, in turn, miR-141-3p negatively regulated HDAC4 and HMGB1 expression. Functional assays revealed that circ-LRP6 knockdown inhibited the proliferation, migration and invasion of OS cells, whereas the inhibition of miR-141-3p or the overexpression of either HDAC4 or HMGB1 partly reversed the inhibitory effect of circ-LRP6 knockdown. In summary, the present study determined that circ-LRP6 knockdown inhibited the proliferation, migration and invasion of OS cells by regulating the miR-141-3p/HDAC4/HMGB1 axis.

Cost-effectiveness of full endoscopic versus open discectomy for sciatica

OBJECTIVE

To assess the costs and cost-effectiveness of percutaneous transforaminal endoscopic discectomy (PTED) compared with open microdiscectomy among patients with sciatica.

METHODS

This economic evaluation was conducted alongside a 12-month multicentre randomised controlled trial with a non-inferiority design, in which patients were randomised to PTED or open microdiscectomy. Patients were aged from 18 to 70 years and had at least 6 weeks of radiating leg pain caused by lumbar disc herniation. Effect measures included leg pain and quality-adjusted life years (QALYs), as derived using the EQ-5D-5L. Costs were measured from a societal perspective. Missing data were multiply imputed, bootstrapping was used to estimate statistical uncertainty, and various sensitivity analyses were conducted to determine the robustness.

RESULTS

Of the 613 patients enrolled, 304 were randomised to PTED and 309 to open microdiscectomy. Statistically significant differences in leg pain and QALYs were found in favour of PTED at 12 months follow-up (leg pain: 6.9; 95% CI 1.3 to 12.6; QALYs: 0.040; 95% CI 0.007 to 0.074). Surgery costs were higher for PTED than for open microdiscectomy (ie, €4500/patient vs €4095/patient). All other disaggregate costs as well as total societal costs were lower for PTED than for open microdiscectomy. Cost-effectiveness acceptability curves indicated that the probability of PTED being less costly and more effective (ie, dominant) compared with open microdiscectomy was 99.4% for leg pain and 99.2% for QALYs.

CONCLUSIONS

Our results suggest that PTED is more cost-effective from the societal perspective compared with open microdiscectomy for patients with sciatica.

TRIAL REGISTRATION NUMBER

NCT02602093.

Surgical Predictors for Prevention of Postoperative Shoulder Imbalance in Lenke Type 2A Adolescent Idiopathic Scoliosis

STUDY DESIGN

Multicenter, retrospective cohort study.

OBJECTIVE

The aim of this study was to investigate the occurrence and surgical predictors of postoperative shoulder imbalance (PSI) in Lenke type 2A adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Although several studies have investigated the factors influencing PSI in Lenke type 2 curves, no studies have analyzed PSI-related factors considering upper instrumented vertebra (UIV) and lumbar modifier type simultaneously.

METHODS

Patients with Lenke Type 2A AIS treated by spinal fusion were retrospectively identified and their data were extracted from six spine centers in Japan. Inclusion criteria were age between 10 and 20 years at surgery, UIV = T2, major curve 40° to 90°, and follow-up for 24 to 30 months after surgery. We analyzed patient characteristics, surgical characteristics, and preoperative and immediate-postoperative radiographic parameters. We defined patients with lower instrumented vertebra (LIV) equal or proximal to the last touching vertebra (LTV) as selective thoracic fusion (STF-LTV) and patients with LIV distal to the LTV as non-STF-LTV. t Tests, Mann-Whitney U test, χ2 tests, Fisher exact tests, and multivariate logistic regression were used for statistical analyses.

RESULTS

Among the 99 consecutive patients with a mean follow-up of 25.6 months, PSI was seen in 27 (27.3%) patients immediately after and in 17 (17.2%) patients at 24 to 30 months. The univariate analysis revealed that the significant risk factors of PSI were preoperative radiographical shoulder height, non-STF-LTV, and high main thoracic curve (MTC) correction (immediate-postoperative MTC correction rate: ≥70%), with PSI incidence of 40.0%. The multivariate logistic regression analysis indicated that interaction term of non-STF-LTV and high MTC correction was an independent risk factor for PSI (non-STF-LTV and high MTC correction, odds ratio: 5.167, 95% confidence interval: 1.470-18.159, P = 0.010).

CONCLUSION

To prevent PSI in Lenke Type 2A AIS patients, surgeons should avoid the combination of non-STF-LTV and high MTC correction in those surgeries with UIV as T2.Level of Evidence: 4.

MicroRNA let-7 and viral infections: focus on mechanisms of action

MicroRNAs (miRNAs) are fundamental post-transcriptional modulators of several critical cellular processes, a number of which are involved in host defense mechanisms. In particular, miRNA let-7 functions as an essential regulator of the function and differentiation of both innate and adaptive immune cells. Let-7 is involved in several human diseases, including cancer and viral infections. Several viral infections have found ways to dysregulate the expression of miRNAs. Extracellular vesicles (EV) are membrane-bound lipid structures released from many types of human cells that can transport proteins, lipids, mRNAs, and miRNAs, including let-7. After their release, EVs are taken up by the recipient cells and their contents released into the cytoplasm. Let-7-loaded EVs have been suggested to affect cellular pathways and biological targets in the recipient cells, and can modulate viral replication, the host antiviral response, and the action of cancer-related viruses. In the present review, we summarize the available knowledge concerning the expression of let-7 family members, functions, target genes, and mechanistic involvement in viral pathogenesis and host defense. This may provide insight into the development of new therapeutic strategies to manage viral infections.

Impact of oxidized LDL/LOX-1 system on ligamentum flavum hypertrophy

BACKGROUND

Patients with lumbar spinal canal stenosis (LSS) often have peripheral arterial disease and aortic disease based on atherosclerosis. Oxidized LDL, which is clinically involved in the development of atherosclerosis, may also influence LF hypertrophy, but the function of the oxidized low-density lipoprotein (LDL)/lectin-type oxidized LDL receptor 1 (LOX-1) system in LF hypertrophy is unknown. We aimed to elucidate the potential involvement of oxidized LDL/LOX-1 system in ligamentum flavum (LF) hypertrophy.

METHODS

A total of 43 samples were collected from LF tissues of the patients who underwent posterior lumbar spinal surgery. Immunohistochemistry for LOX-1 was performed using human LF samples. We treated the cells in vitro with inflammatory cytokines TNF-α and IL-1β, oxidized LDL, and simvastatin. The expressions of LOX-1 and LF hypertrophy markers including type I collagen, Type III collagen, and COX-2 were assessed by real-time RT-PCR and immunocytochemistry. Phosphorylation of MAPKs and NF-κb was evaluated by Western blot after treatment with TNF-α, IL-1β, oxidized LDL, and simvastatin.

RESULTS

A significant weak correlation was observed between the number of positive cells of LOX-1 and cross-sectional area of LF on preoperative axial magnetic resonance imaging. In functional analysis, simvastatin treatment neutralized the oxidized LDL-mediated induction of mRNA expressions of LF hypertrophy markers. Western blot analysis showed that oxidized LDL as well as TNF-α and IL-1β activated the signaling of MAPKs and NF-κb in LF cells, and that simvastatin treatment reduced the phosphorylation of all signaling. The TNF-α and IL-1β treatments increased both mRNA and protein expression of LOX-1 in LF cells.

CONCLUSION

We found a link between the oxidized LDL/LOX-1 system and LF hypertrophy. In addition, our in vitro analysis indicate that oxidized LDL may affect LF hypertrophy through signaling of MAPKs. Our results suggest that the oxidized LDL/LOX-1 system may be a potential therapeutic target for LSS.

Risk factors for postoperative coronal decompensation in adult lumbar scoliosis after posterior correction with osteotomy

INTRODUCTION

To determine potential risk factors for postoperative coronal imbalance following posterior osteotomy for adult scoliosis.

MATERIALS AND METHODS

A total of 74 patients underwent osteotomy for rigid adult lumbar scoliosis. A group of 20 patients with postoperative coronal imbalance was identified. Clinical data and surgical strategies were compared to determine the risk factors, including age, gender, etiology, Cobb angle, preoperative coronal balance distance, direction of preoperative imbalance, T1 tilt, tilt of upper instrumented vertebra (UIV), UIV translation, location of UIV (T6 above or below), fusion to L5 or S1, lower instrumented vertebra (LIV) tilt, LIV rotation, screw density, osteotomy procedure (PSO or SPOs) and use of iliac screws.

RESULTS

Comparison between patients with and without postoperative coronal imbalance showed that postoperative coronal imbalance occurred in older patients and those with degenerative scoliosis as the etiology, UIV above T6, preoperative LIV rotation, preoperative LIV tilt and preoperative coronal imbalance towards the convex side and who underwent Smith-Petersen osteotomy. All seven parameters were included in the logistic regression analysis. UIV above T6 (P = 0.010), LIV rotation (P = 0.012) and preoperative coronal imbalance towards the convex side (P = 0.005) were identified as risk factors for postoperative coronal imbalance after osteotomy.

CONCLUSIONS

Patients with preoperative coronal imbalance towards the convex side (UIV above T6) and LIV rotation were more likely to develop coronal imbalance than those without risk factors. Older patients and those with degenerative scoliosis were also at a relatively higher risk of postoperative coronal imbalance.

Risk Factors of Postoperative Shoulder Imbalance in Adolescent Idiopathic Scoliosis: The Role of Sagittal Spinopelvic Parameters and Upper Instrumented Vertebrae Selection

STUDY DESIGN

This is a retrospective study.

OBJECTIVE

To determine (1) the independent risk factors of postoperative shoulder imbalance (PSI) after adolescent idiopathic scoliosis (AIS) correction surgery; and (2) whether the level of upper instrumented vertebrae (UIV) affects postoperative shoulder balance.

SUMMARY OF BACKGROUND DATA

PSI is an important outcome of AIS correction surgery as it influences a patient's appearance and satisfaction. However, risk factors for PSI remain controversial and there are currently no studies evaluating the effect of sagittal spinopelvic parameters on PSI. Previous studies on the relationship between the level of UIV and PSI have also reported conflicting results.

MATERIALS AND METHODS

Sixty-nine AIS patients undergoing correction surgery at a single institution were retrospectively reviewed. Radiographic parameters were measured on anteroposterior and lateral x-rays preoperatively, immediate postoperatively, and 12 months postoperatively. At 1 year follow-up, patients were divided into 2 groups based on their radiographic shoulder height (RSH): (1) PSI group (RSH ≥20 mm) and (2) non-PSI group (RSH <20 mm).

RESULTS

On multivariate regression analysis, a lower postoperative main thoracic curve (MTC) [odds ratio (OR): 0.702, 95% confidence interval (CI): 0.519-0.949, P=0.022], greater percentage correction of MTC (OR: 1.526, 95% CI: 1.049-2.220, P=0.027) and higher postoperative sacral slope (OR: 1.364, 95% CI: 1.014-1.834, P=0.040) were identified as independent risk factors of PSI. When preoperative, postoperative, and absolute change in shoulder parameters were compared across the level of UIV, no significant differences were found regardless of the radiographic shoulder parameter analyzed.

CONCLUSIONS

Lower postoperative MTC, greater percentage correction of MTC and higher postoperative sacral slope were independent risk factors of PSI. Shoulder balance and symmetry were not affected by the level of UIV selected. Relative curve correction is a more important consideration than UIV to avoid PSI after AIS correction surgery.

LEVEL OF EVIDENCE

III.

Ball Tip Technique for S2AI Screw Placement in Sacropelvic Fixation: A Comparative Study with Conventional Freehand Technique

OBJECTIVE

To evaluate the efficiency of the ball tip technique for S2AI screw placement and introduce this technique.

METHODS

Sixty-three patients who underwent pelvic fixation with S2AI screws were retrospectively reviewed. They were 29 males and 34 females with an average age of 59.6 ± 12.5 years. Among these patients, 35 patients (14 males and 21 females with an average age of 58.8 ± 11.3 years) received ball tip technique and 28 patients (15 males and 13 females with an average age of 63.7 ± 12.6 years) received conventional freehand technique. Ball tip technique was used in ball tip technique group. After a pedicle probe just penetrated the sacroiliac joint, a ball-tipped probe consisting of a ball shaped metal tip with a flexible shaft was malleted to make a guide track within ilium. This ball-tipped probe could bend automatically away from the cortex and forward through the cancellous bone when the tip met the cortical lamina of ilium, which can avoid penetration. After repeating the procedures, a guide hole was gradually formed. S2AI screw was inserted along the guide hole after tapping. In the conventional freehand group, S2AI screw was placed according to the conventional method. Postoperative computed tomography (CT) was used to assess the accuracy of screws. The time cost of screw insertion and screw-related complications were recorded. Independent t-test was used to compare the time cost between ball tip group and conventional freehand group. A chi-square test was used to compare the accuracies of the ball tip group with the conventional group.

RESULTS

There were 35 patients (70 S2AI screws) in ball tip group and 28 patients (56 S2AI screws) in conventional freehand group. No screw-related complication occurred in all patients. Time costs were 9.8 ± 4.5 mins in ball tip group and 20.2.0 + 8.6 mins in conventional freehand group, respectively (P < 0.05). Four screws penetrated iliac cortex in the ball tip group vs 10 screws in conventional freehand group (5.7% vs 17.9%) (P < 0.05).

CONCLUSIONS

The ball tip technique enhances the accuracy of screw placement and has less time cost compared with conventional freehand technique.

Anterior vs Posterior Approach in Multilevel Cervical Spondylotic Myelopathy: A Nationwide Propensity-Matched Analysis of Complications, Outcomes, and Narcotic Use

BACKGROUND

There is unclear evidence regarding the optimal surgical approach for multilevel cervical spondylotic myelopathy (CSM). The objective of this study was to compare complications, outcomes, and narcotic use in anterior discectomy and fusion (ACDF) vs posterior decompression and fusion (PCDF) in CSM patients.

STUDY DESIGN

Registry-based retrospective cohort analysis.

METHODS

Patients undergoing 3-level ACDF or PCDF for CSM between 2007 and 2017 were identified from the Humana Claims Database using relevant procedure codes. Propensity score-matched groups were compared in regards to complications, outcomes, and narcotic use.

RESULTS

Propensity score matching generated equal cohorts of 6124 patients. The posterior fusion group had a higher rate of urinary tract infection (OR 2.47, P < 0.0001), deep vein thrombosis (OR 1.90, P < 0.0001), and pulmonary embolism (OR 1.75, P < 0.0001). In regards to 30-day outcomes, the posterior approach demonstrated higher rates of stroke (OR 1.68, P < 0.0001), wound dehiscence (OR 5.59, P < 0.0001), Surgical site infection (SSI) (OR 4.76, P < 0.0001), wound revision surgery (OR 3.02, P < 0.0001), and all-cause readmission (OR 2.01, P < 0.0001). One-year outcomes revealed higher rates of pseudarthrosis (4.7% vs 2.0%, OR 2.43, P < 0.0001) and revision or extension surgery (OR 2.33, P < 0.0001) in the posterior fusion cohort. These patients also demonstrated significantly higher mean morphine milligram equivalent used at 30 days (OR 1.19, P < 0.0001), as well as 60 (OR 1.20, P < 0.0001), 90 (OR 1.21, P < 0.0001), and 120 (OR 1.21, P < 0.0001) days.

CONCLUSIONS

This nationwide propensity-matched analysis of multilevel CSM patients found the posterior approach to be associated with increased rates of inpatient complications, wound complications, 30-day readmission, 1-year pseudarthrosis, and 1-year revision or extension surgery. These patients also demonstrated higher levels of narcotic use up to 120 days after surgery.

CLINICAL RELEVANCE

The posterior approach for treatment of CSM may be associated with increased rates of short- and long-term complications in addition to increased narcotic consumption in comparison to the anterior approach.