“Guanhai Resort of HaiYan, JiaXing, Zhejiang Province, China” No abstract available

The Role of Type I Diabetes in Intervertebral Disc Degeneration Study Design. An experimental laboratory study. Objective. To investigate the pathogenesis of intervertebral disc degeneration (IDD) in a murine model of type 1 diabetes mellitus (DM), namely nonobese diabetic (NOD) mouse. Summary of Background Data. IDD is a leading contributor of low back pain, which represents one of the most disabling symptoms within the adult population. DM is a chronic metabolic disease currently affecting one in 10 adults in the United States. It is associated with an increased risk of developing IDD, but the underlying process remains poorly understood. Methods. Total disc glycosaminoglycan content, proteoglycan synthesis, aggrecan fragmentation, glucose transporter gene expression, and apoptosis were assessed in NOD mice and wild-type euglycemic control mice. Spinal structural and molecular changes were analyzed by micro-computed tomography, histological staining (Safranin-O and fast green), and quantitative immunofluorescence (anti-ADAMTS-4 and -5 antibodies). Results. Compared with euglycemic controls, NOD mice showed increased disc apoptosis and matrix aggrecan fragmentation. Disc glycosaminoglycan content and histological features of NOD mice did not significantly differ from those of euglycemic littermates. Conclusion. These data demonstrate that DM may contribute to IDD by increasing aggrecan degradation and promoting cell apoptosis, which may represent early indicators of the involvement of DM in the pathogenesis of IDD. Level of Evidence: N/A

Transport of Vancomycin and Cefepime Into Human Intervertebral Discs: Quantitative Analyses Study Design. Simulation of antibiotics transport into human intervertebral disc with intravenous infusion. Objective. The objective of this study was to quantitatively investigate antibiotic concentrations in the disc. Summary of Background Data. Intravenous infusion of antibiotics is typically used to treat intervertebral disc infection in clinics. However, it is difficult to evaluate the drug concentrations within discs in vivo. Methods. A computational model was used in this study. The variation of drug charge with pH was considered in the model. Thirty-minute infusions of two commonly used antibiotics in clinic—vancomycin and cefepime—were numerically investigated. Spatial and temporal concentration distributions of these drugs in both nondegenerated and moderately degenerated discs were calculated. Results. For intravenous infusion of 1 g vancomycin and 2 g cefepime in 30 minutes repeated every 12 hours, it was predicted that vancomycin concentration in the disc fluctuated between 17.0 and 31.0 times of its minimum inhibitory concentration (1 ug/mL) and cefepime concentration fluctuated between 1.1 and 4.2 times of its minimum inhibitory concentration (i.e., 8 ug/mL) in about 2 days. It was also found that vancomycin concentration in moderately degenerated disc was lower than that in the nondegenerated disc. Conclusion. This study provides quantitative guidance on selecting proper dosage for treating disc infection. The method used in this study could be used to provide quantitative information on transport of other antibiotics and drugs in discs as well. Level of Evidence: N/A

Endothelin-1 Activates the Notch Signaling Pathway and Promotes Tumorigenesis in Giant Cell Tumor of the Spine Study Design. Experimental study. Objective. To examine the role of endothelin-1 (ET-1) and the Notch signaling pathway in giant cell tumor (GCT) of the spine. Summary of Background Data. Previously published studies have shown that the Notch signaling pathway has a role in tumor invasion and that ET-1 is involved in tumor invasion and angiogenesis. However, the roles of both Notch signaling and ET-1 in GCT of the spine remain unknown. Methods. Expression of ET-1 in tissue samples from patients with spinal GCT, and adjacent normal tissue, were analyzed by immunohistochemistry and western blot. GCT stromal cells (GCTSCs) were isolated and ET-1 expression was demonstrated by immunofluorescence. Cell viability and cell migration of GCTSCs and human vascular endothelial cells following ET-1 treatment were assessed using the cell counting kit-8 assay and a transwell assay. Receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) mRNA expression was determined following ET-1 treatment of GCTSCs using quantitative real-time polymerase chain reaction. In GCTSCs treated with ET-1 and the ET-1 signaling antagonist, BQ-123, levels of cyclin D1, vascular endothelial growth factor, matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9), Jagged1, Hes1, Hey2, and Notch intracellular domain were examined by western blot. Results. Compared with normal adjacent tissue, ET-1 was highly expressed in GCT tissue. In GCTSCs studied in vitro, treatment with ET-1 significantly increased GCTSC and human vascular endothelial cells growth and migration and increased the expression of RANKL and OPG, meanwhile the ratio of RANKL/OPG was increased, in GCTSCs, it upregulated the production of cyclin D1, vascular endothelial growth factor, MMP-2, MMP-9, Jagged1, Hes1, Hey2, and Notch intracellular domain expression in a dose-dependent manner. Treatment with BQ-123 reversed these effects. Conclusion. In GCT of the spine, ET-1 showed increased expression. In cultured GCTSCs, ET-1 treatment activated the Notch signaling pathway. Level of Evidence: 2

Anterior Atlantooccipital Transarticular Screw Fixation: A Cadaveric Study and Description of a Novel Technique Study Design. Retrospective analysis of collected data and operative experiment on human cadavers. Objective. To describe a novel technique of the anterior atlantooccipital (AC) transarticular screw fixation, and to analyze the pertinent anatomy with cadaveric and radiographic assessment of the feasibility, safety, and general applicability of this technique. Summary of Background Data. In some situations, the posterior AC fixation techniques may not be possible, or may require supplemental fixation, which include the congenital hypoplasia, absence of the bony elements, and even revision surgery. However, an anterior screw fixation technique may add stability to further attempts at obtaining an arthrodesis. Methods. A detailed description of the surgical technique was presented. Three-dimensional (3D) CT reconstruction of the cranioverteral region of 30 patients were performed to determine screw entry points, target points, and proposed screw trajectories. Following screw insertion in eight fresh frozen human cadaver spine specimens, dissection verified screw location relative to structures at risk. Results. The ideal entry point is located caudal to the C1 superior facet joint in line with the medial third of the C1 superior facet. The ideal screw is directed 41.7° posteriorly in the sagittal plane and 11.6° laterally in the coronal plane with a length around 30.4 mm. The feasibility of anterior AC screw fixation was 92% (35/38 cases). There is a risk of injury to the vertebral artery and the hypoglossal nerve. Conclusion. Anterior AC transarticular screw fixation is feasible and can be considered as a salvage technique or an alternative for the posterior AC fixation, as well as the supplement to the anterior occipitocervical fixation. Level of Evidence: 3

Short-term Outcomes Following Cervical Laminoplasty and Decompression and Fusion With Instrumentation Study Design. Retrospective review of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database years 2010 to 2015. Objective. Investigate which short-term outcomes differ for cervical laminoplasty and laminectomy and fusion surgeries. Summary of Background Data. Conflicting reports exist in spine literature regarding short-term outcomes following cervical laminoplasty and posterior laminectomy and fusion. The objective of this study was to compare the 30-day outcomes for these two treatment groups for multilevel cervical pathology. Methods. Patients who underwent cervical laminoplasty or posterior laminectomy and fusion were identified in National Surgical Quality Improvement Program (NSQIP) based on Current Procedural Terminology (CPT) code: laminoplasty 63,050 and 63,051, posterior cervical laminectomy 63,015 and 63,045, and instrumentation 22,842. Propensity-adjusted multivariate regressions assessed differences in postoperative length of stay, adverse events, discharge disposition, and readmission. Results. Three thousand seven hundred ninety-six patients were included: 2397 (63%) underwent cervical laminectomy and fusion and 1399 (37%) underwent cervical laminoplasty. Both groups were similar in age, sex, body mass index (BMI), American Society of Anesthesiologist Classification (ASA), Charleston Comorbidity Index (CCI), and had similar rates of malnutrition, chronic kidney disease, diabetes, chronic obstructive pulmonary disease, and history for steroid use. Age more than 70 and age less than 50 were not associated with one treatment group over the other (P > 0.05). Compared with laminoplasty patients, laminectomy and fusion patients had increased lengths of stay (LOS) (4.5 vs. 3.7 d, P < 0.01) and increased rates of adverse events (41.7% vs. 35.9%, P < 0.01), discharge to rehab (16.4% vs. 8.6%, P < 0.01), and skilled nursing facilities (12.2% vs. 9.7%, P = 0.02), and readmission (6.2% vs. 4.5%, P = 0.05). Both groups experienced similar rates of death, pulmonary embolus, deep vein thrombosis, deep and superficial surgical site infection, and reoperation (P > 0.05 for all). Conclusion. Posterior cervical laminectomy and fusion patients were found to have increased LOS, readmissions, and complications despite having similar pre-op demographics and comorbidities. Patients and surgeons should consider these risks when considering surgical treatment for cervical pathology. Level of Evidence: 3

Modic Changes Are Not Associated With Long-term Pain and Disability: A Cohort Study With 13-year Follow-up Study Design. A comparative cohort study with 13-year follow-up. Objective. To assess whether Modic changes (MCs) are associated with long-term physical disability, back pain, and sick leave. Summary of Background Data. Previous studies have shown a conflicting association of low back pain (LBP) with MCs and disc degeneration. The long-term prognosis of patients with MCs is unclear. Methods. In 2004 to 2005, patients aged 18 to 60 with daily LBP were enrolled in an randomized controlled trial study and lumbar magnetic resonance imaging (MRI) was performed. Patients completed numeric rating scales (0–10) for LBP and leg pain, Roland-Morris Disability Questionnaire (RMDQ), LBP Rating Scale for activity limitations (RS, 0–30), inflammatory pain pattern and sick leave days due to LBP at baseline and 13 years after the MRI. Patients were stratified based on the presence (+MC) or absence (−MC) of MCs on the MRI. Results. Of 204 cases with baseline MRI, 170 (83%) were available for follow-up; 67 (39%) with MCs and 103 (61%) without MCs. Demographics, smoking status, BMI, use of antibiotics, LBP, leg pain, and inflammatory pain pattern scores at baseline and at 13-year follow-up were similar between the two groups. Also, baseline RMDQ was similar between the +MC and −MC groups. At 13 years, the RMDQ score was statistically significant better in the +MC group (7.4) compared with the −MC group (9.6, P = 0.024). Sick leave days due to LBP were similar at baseline but less in the +MC group (9.0) compared with the −MC group (22.9 d, P = 0.003) at 13 years. Conclusion. MCs were not found to be negatively associated with long-term pain, disability, or sick leave. Rather, the study found that LBP patients with MCs had significantly less disability and sick-leave at long-term follow-up. We encourage further studies to elucidate these findings. Level of Evidence: 2

Sacropelvic Fixation With S2 Alar Iliac Screws May Prevent Sacroiliac Joint Pain After Multisegment Spinal Fusion Study Design. A retrospective study. Objective. To examine the postoperative incidence of sacroiliac joint pain (SIJP) at the lower fusion level following multisegment fusion. Summary of Background Data. Recently, multisegment fusion is being increasingly performed. While proximal junctional kyphosis (PJK) commonly develops following multisegment fusion, SIJP also commonly occurs following this surgery. In surgery for adult spinal deformity, fixation is often extended to the pelvis to include the sacroiliac joint. Therefore, the question of whether SIJP occurs in such cases is interesting. Here, we examined postoperative incidence of SIJP at the lower fusion level, including the incidence of PJK, and postoperative lumbopelvic alignment. Methods. Participants included 77 patients who underwent corrective fusion (≥3 segments). Patients were divided into three groups based on the lower fixation end: L5 (L5), S (sacrum), and P (pelvis). In the P group, an S2 alar iliac screw was used. Postoperative incidence of SIJP and PJK in each group was examined along with lumbopelvic parameters. Results. SIJP incidence was 16.7%, 26.1%, and 4.2% in the L5, S, and P groups, respectively, indicating the highest value in the S group and a significantly lower value in the P group. PJK incidence was 23.3%, 30.4%, and 29.2% in the L5, P, and S groups, respectively, with no significant differences. Regarding postoperative lumbopelvic parameters, there was no significant difference between the groups; however, lumbar lordosis tended to be better in the P group. Conclusion. SIJP incidence was extremely high with fixation to the sacrum, and in the group with fixation to the pelvis, there was hardly any SIJP. Sacropelvic fixation using S2 alar iliac screws could prevent SIJP onset following multisegment fusion. Level of Evidence: 3

Sagittal Alignment Profile Following Selective Thoracolumbar/Lumbar Fusion in Patients With Lenke Type 5C Adolescent Idiopathic Scoliosis Study Design. A retrospective case series. Objective. This study aimed to report the sagittal outcome measures in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS) undergoing thoracolumbar/lumbar (TL/L) fusion surgery. Summary of Background Data. Previous studies have demonstrated coronal correction of Lenke type 5C AIS by selective TL/L fusion surgery. However, little is known about the sagittal influence of selective TL/L curve correction in Lenke type 5C AIS. Methods. Thirty-nine patients with Lenke type 5C AIS underwent selective posterior TL/L curves fusion (mean age, 15.9 ± 2.1 yrs). Preoperative and postoperative radiographic and clinical parameters were analyzed at a minimum 2-year follow-up period. Radiographic parameters were compared between patients with Lenke sagittal modifier normal (Group N) to those with Lenke sagittal modifier minus (Group M). Results. The main TL/L Cobb angle was 46.3° ± 7.7° preoperatively and 20.7° ± 5.3° (P < 0.0001) at 2-year follow-up. Also, thoracic kyphosis (TK) (T1–12) angle was 29.0° ± 11.3° preoperatively and 36.4° ± 10.3° at follow-up (P < 0.001), and TK (T5–12) angle was 18.1° ± 10.2° preoperatively and 25.9° ± 8.9° at follow-up (P < 0.001). The cervical lordosis (CL) was 9.6° ± 11.6° preoperatively and 6.1° ± 10.9° at follow-up (P = 0.037). Compared with the Lenke sagittal modifier groups, preoperative TK (T1–12), TK (T5–12), thoracolumbar kyphosis (TLK), and CL were significantly different from both the groups; and after the surgery, no significant differences in these parameters were observed between the two groups. Conclusion. After the selective TL/L posterior fusion surgery in patients with Lenke type 5C AIS, the sagittal alignment profile, including TK, TLK, C7 sagittal vertical axis, T1 slope, and CL, was significantly changed. With regard to the sagittal aspect, selective TL/L surgery was more likely to affect Group M than Group N. Level of Evidence: 4

Magnetically Controlled Growing Rods in Treatment of Early-Onset Scoliosis: A Single Center Study With a Minimum of 2-Year-Follow up and Preliminary Results After Converting Surgery Study Design. Case series. Objective. To evaluate complications and radiographic parameters after magnetically controlled growing rod (MCGR) index surgery (IS), during lengthening and following converting surgery (CS) with a minimum of 2-year follow up (FU). Summary of Background Data. MCGR are maintaining skeletal growth in treatment of early onset scoliosis (EOS). There is no data regarding correction potential after CS available. Methods. Twenty-four cases were included. Two patients with rib and pelvic hook fixation instead of pedicle screws and three patients with previous spinal surgery were excluded from radiographic analysis. Results. Twenty-one patients received grade 3 or 4 in Classification of Early-Onset-Scoliosis (C-EOS) for main curve severity. The kyphotic modifiers (–) were given to seven and (+) to seven patients. Mean age at IS was 10.5 ± 2.4 years with a mean FU time of 42.3 ± 11.3 months. Deformity correction was only achieved during IS (46%) and CS (36%). During MCGR treatment a 5° loss of correction seen, while 25 mm of T1–S1 length was gained during the lengthening period. An overall average lengthening of 1.6 mm per lengthening procedure was achieved. Possibility to gain length during distractions decreases over time. No major failure of the distraction mechanism was observed, only 16 lengthening procedures failed within a total of 264 lengthening procedures. A total of 19 revision surgeries in 10 patients were observed. Four patients received more than one revision surgery. Conclusion. Applying MCGR results in a revision rate of 0.23 per patient and per one FU year, while making further lengthening procedures obsolete compared with conventional growing rod techniques. Correction of major curve is possible during IS und CS. The law of diminishing returns applies during the period of lengthening. Level of Evidence: 4