The Utility and Feasibility of Smart Glasses in Spine Surgery: Minimizing Radiation Exposure During Percutaneous Pedicle Screw Insertion.

OBJECTIVE: Spine surgeons are often at risk of radiation exposure due to intraoperative fluoroscopy, leading to health concerns such as carcinogenesis. This is due to the increasing use of percutaneous pedicle screw (PPS) in spinal surgeries, resulting from the widespread adoption of minimally invasive spine stabilization. This study aimed to elucidate the effectiveness of smart glasses (SG) in PPS insertion under fluoroscopy. METHODS: SG were used as an alternative screen for fluoroscopic images. Operators A (2-year experience in spine surgery) and B (9-year experience) inserted the PPS into the bilateral L1-5 pedicles of the lumbar model bone under fluoroscopic guidance, repeating this procedure twice with and without SG (groups SG and N-SG, respectively). Each vertebral body's insertion time, radiation dose, and radiation exposure time were measured, and the deviation in screw trajectories was evaluated. RESULTS: The groups SG and N-SG showed no significant difference in insertion time for the overall procedure and each operator. However, group SG had a significantly shorter radiation exposure time than group N-SG for the overall procedure (109.1 ± 43.5 seconds vs. 150.9 ± 38.7 seconds; p = 0.003) and operator A (100.0 ± 29.0 seconds vs. 157.9 ± 42.8 seconds; p = 0.003). The radiation dose was also significantly lower in group SG than in group N-SG for the overall procedure (1.3 ± 0.6 mGy vs. 1.7 ± 0.5 mGy; p = 0.023) and operator A (1.2 ± 0.4 mGy vs. 1.8 ± 0.5 mGy; p = 0.013). The 2 groups showed no significant difference in screw deviation. CONCLUSION: The application of SG in fluoroscopic imaging for PPS insertion holds potential as a useful method for reducing radiation exposure.

Clinical Characteristics, Surgical Outcomes, and Risk Factors for Emergency Surgery in Patients With Spinal Metastases: A Prospective Cohort Study.

OBJECTIVE: To elucidate the patient characteristics and outcomes of emergency surgery for spinal metastases and identify risk factors for emergency surgery. METHODS: We prospectively analyzed 216 patients with spinal metastases who underwent palliative surgery from 2015 to 2020. The Eastern Cooperative Oncology Group performance status, Barthel index, EuroQol-5 dimension (EQ5D), and neurological function were assessed at surgery and at 1, 3, and 6 months postoperatively. Multivariate analysis was performed to identify risk factors for emergency surgery. RESULTS: In total, 146 patients underwent nonemergency surgery and 70 patients underwent emergency surgery within 48 hours of diagnosis of a surgical indication. After propensity score matching, we compared 61 patients each who underwent nonemergency and emergency surgery. Regardless of matching, the median performance status and the mean Barthel index and EQ5D score showed a tendency toward worse outcomes in the emergency than nonemergency group both preoperatively and 1 month postoperatively, although the surgery greatly improved these values in both groups. The median survival time tended to be shorter in the emergency than nonemergency group. The multivariate analysis showed that lesions located at T3-10 (p = 0.002; odds ratio [OR], 2.92; 95% confidence interval [CI], 1.48-5.75) and Frankel grades A-C (p < 0.001; OR, 4.91; 95% CI, 2.45-9.86) were independent risk factors for emergency surgery. CONCLUSION: Among patients with spinal metastases, preoperative and postoperative subjective health values and postoperative survival are poorer in emergency than nonemergency surgery. Close attention to patients with T3-10 metastases is required to avoid poor outcomes after emergency surgery.

Rate and Duration of Bone Union for Conservative Treatment in Pediatric Lumbar Spondylolysis.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To report the detailed bone fusion rates and duration of treatment in unilateral and bilateral cases of pediatric lumbar spondylolysis (LS). SUMMARY OF BACKGROUND DATA: Early diagnosis and optimal conservative management for LS are crucial for achieving bony healing without surgery. However, existing research on the conservative treatment of pediatric LS, particularly regarding bone union rates and treatment duration for each stage of bilateral spondylolysis, is limited. METHODS: We retrospectively analyzed 590 pediatric patients (522 boys and 68 girls) under 18 years of age diagnosed with LS and treated conservatively from 2015 to 2021. Diagnosis was based on computed tomography scans and magnetic resonance imaging findings, with stages classified as very early, early, progressive, or terminal. Patient background, sports history, level and stage of spondylolysis, presence of spina bifida occulta, bone union rate, duration of conservative treatment, and recurrence rate were retrospectively analyzed. RESULTS: The overall bone union rate was 81.9%, with a mean conservative treatment duration of 53.7 days. Unilateral LS cases showed decreased bone union rates with stage advancement (very early; 98.2%, early; 96.0%, progressive; 64.3%). Bilateral LS cases with progressive or terminal stage demonstrated low bone union rates (very early/very early; 100%, early/very early; 94.1%, progressive/very early; 66.7%, early/early; 82.9%, progressive/early; 32.3%, progressive/progressive; 23.7%, very early/terminal; 0%, early/terminal; 50.0%, progressive/terminal; 11.1%). The duration of conservative treatment extended as the stage of the main and contralateral lesions progressed, ranging from 39.1 days (very early/none) to 105 days (progressive/terminal). Recurrence rate after bone fusion was 16.6%, with no differences based on lesion stage. CONCLUSION: In this series of 590 patients, conservative treatment yielded high bone union rates for pediatric LS. However, union rates decreased with stage advancement, especially in bilateral cases. These findings provide valuable insights for prognosticating natural history and outcome regarding LS treatment, bone union and return to activity.

Preoperative Low Back Pain Affects Postoperative Patient Satisfaction Following Minimally Invasive Transforaminal Lumbar Interbody Fusion Surgery.

STUDY DESIGN: A single-center retrospective study. PURPOSE: To research the predictive factors associated with postoperative patient satisfaction 1 year after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), a minimally invasive procedure for lumbar degenerative disease. OVERVIEW OF LITERATURE: There have been reports of numerous variables influencing patient satisfaction with lumbar surgery; however, there have been few investigations on MIS are limited. METHODS: This study included 229 patients (107 men and 122 women; mean age, 68.9 years) who received one or two levels of MISTLIF, and the patient's age, gender, disease, paralysis, preoperative physical functions, duration of symptom(s), and surgery-associated factors (waiting for surgery, number of surgical levels, surgical time, and intraoperative blood loss) were studied. Radiographic characteristics and clinical outcomes such as Oswestry Disability Index (ODI) scores and Visual Analog Scale (VAS; 0-100) ODI scores for low back pain, leg pain, and numbness were studied. One year following surgery, patient satisfaction (defined as satisfaction for surgery and for present condition; 0-100) was assessed using VAS and its relationships with investigation factors were examined. RESULTS: The mean VAS scores of satisfaction for surgery and for present condition were 88.6 and 84.2, respectively. The results of multiple regression analysis showed that preoperative adverse factors of satisfaction for surgery were being elderly (ß =-0.17, p =0.023), high preoperative low back pain VAS scores (ß =-0.15, p =0.020), and postoperative adverse factors were high postoperative ODI scores (ß =-0.43, p <0.001). In addition, the preoperative adverse factor of satisfaction for present condition was high preoperative low back pain VAS scores (ß =-0.21, p =0.002), and postoperative adverse factors were high postoperative ODI scores (ß =-0.45, p <0.001) and high postoperative low back pain VAS scores (ß =-0.26, p =0.001). CONCLUSIONS: According to this study, significant preoperative low back pain and high postoperative ODI score after surgery are linked to patient unhappiness.

Clinical Characteristics and Surgical Outcomes of Metastatic Spine Tumors in the Very Elderly: A Prospective Cohort Study in a Super-Aged Society.

The number of advanced-age patients with spinal metastases is rising. This study was performed to clarify the characteristics and surgical outcomes of spinal metastases in advanced-age patients. We prospectively analyzed 216 patients with spinal metastases from 2015 to 2020 and divided them into three age groups: <70 years (n = 119), 70-79 years (n = 73), and ≥80 years (n = 24). Although there were no significant intergroup differences in preoperative characteristics and surgery-related factors except for age, patients aged ≥80 years tended to have a worse performance status (PS), Barthel index, and EuroQol-5 dimension (EQ-5D) before and after surgery than the other two groups. Although the median PS, mean Barthel index and mean EQ-5D greatly improved postoperatively in each group, the median PS and mean Barthel index at 6 months and the mean EQ-5D at 1 month postoperatively were significantly poorer in the ≥80-year group than the 70-79-year group. The rates of postoperative complications and re-deterioration of the EQ-5D were significantly higher in the oldest group than in the other two groups. Although surgery for spinal metastases improved the PS, Barthel index, and EQ-5D regardless of age, clinicians should be aware of the poorer outcomes and higher complication rates in advanced-age patients.

Preoperative Base Excess as a Predictor of Perioperative Complications in Patients with Nonidiopathic Scoliosis who Have High Risk Associated with General Anesthesia.

Introduction: Patients with nonidiopathic scoliosis often have a high risk associated with general anesthesia because of cardiac or pulmonary dysfunction secondary to underlying diseases. Base excess has been reported as a predictor in the management of trauma and cancer, although not yet in scoliosis. This study was performed to clarify the surgical outcomes and the association of perioperative complications with base excess in patients with nonidiopathic scoliosis who have a high risk associated with general anesthesia. Methods: Patients with nonidiopathic scoliosis who were referred to our institution from 2009 to 2020 because of their high risk associated with general anesthesia were retrospectively enrolled. High-risk factors for anesthesia were determined by a senior anesthesiologist and categorized into circulatory or pulmonary dysfunction. Perioperative complications were analyzed using the Clavien-Dindo classification; severe complications were defined as grade ≥III. We investigated high-risk factors for anesthesia, underlying diseases, preoperative and postoperative Cobb angle, surgery-related factors, base excess, and postoperative management. These variables were statistically compared between patients with and without complications. Results: Thirty-six patients (mean age, 17.9 years old; range, 11-40 years old) were enrolled (two patients declined surgery). High-risk factors were circulatory dysfunction in 16 patients and pulmonary dysfunction in 20 patients. The mean Cobb angle improved from 85.1° (36°-128°) preoperatively to 43.6° (9°-83°) postoperatively. Three intraoperative complications and 23 postoperative complications occurred in 20 (55.6%) patients. Severe complications occurred in 10 (27.8%) patients. All patients underwent postoperative intensive care unit management after posterior all-screw construction. A large preoperative Cobb angle (p=0.021) and base excess outliers (>3 or <-3 mEq/L) (p=0.005) were significant risk factors for complications. Conclusions: Patients with nonidiopathic scoliosis who have a high risk associated with general anesthesia have a higher complication rate. Preoperative large deformity and base excess (>3 or <-3 mEq/L) could be predictors of complications.

Anti-Inflammatory Effects of Adiponectin Receptor Agonist AdipoRon against Intervertebral Disc Degeneration.

Adiponectin, a hormone secreted by adipocytes, has anti-inflammatory effects and is involved in various physiological and pathological processes such as obesity, inflammatory diseases, and cartilage diseases. However, the function of adiponectin in intervertebral disc (IVD) degeneration is not well understood. This study aimed to elucidate the effects of AdipoRon, an agonist of adiponectin receptor, on human IVD nucleus pulposus (NP) cells, using a three-dimensional in vitro culturing system. This study also aimed to elucidate the effects of AdipoRon on rat tail IVD tissues using an in vivo puncture-induced IVD degeneration model. Analysis using quantitative polymerase chain reaction demonstrated the downregulation of gene expression of proinflammatory and catabolic factors by interleukin (IL)-1ß (10 ng/mL) in human IVD NP cells treated with AdipoRon (2 µM). Furthermore, western blotting showed AdipoRon-induced suppression of p65 phosphorylation (p < 0.01) under IL-1ß stimulation in the adenosine monophosphate-activated protein kinase (AMPK) pathway. Intradiscal administration of AdipoRon was effective in alleviating the radiologic height loss induced by annular puncture of rat tail IVD, histomorphological degeneration, production of extracellular matrix catabolic factors, and expression of proinflammatory cytokines. Therefore, AdipoRon could be a new therapeutic candidate for alleviating the early stage of IVD degeneration.

The Identification of Risk Factors for Symptomatic Spinal Metastasis Onset: A Prospective Cohort Study of 128 Asymptomatic Spinal Metastasis Patients.

Background: Symptomatic spinal metastasis (SSM) decreases the activities of daily living (ADL) and quality of life of cancer patients. However, the risk factors for SSM onset remain unclear. This prospective cohort study aimed to statistically analyze the significant risk factors. Methods: From 2016 to 2018, 210 consecutive patients with spinal metastases were prospectively registered. Patients with SSM at the first consultation and those who were unable to be followed-up owing to poor general condition were excluded. The demographic factors (age, sex, primary cancer, performance status, and ADL), clinical factors (radiation therapy, chemotherapy, molecularly targeted drugs, and bone-modifying agents (BMAs)), and Spinal Neoplastic Instability Score (SINS) were evaluated. Multivariate analysis was performed to identify the risk factors for SSM onset. Furthermore, the threshold was calculated from the receiver operating characteristic curve using the Youden index. Results: Thirty-nine patients who presented with SSM at the first consultation and 43 patients who were unable to be followed-up owing to poor general condition were excluded. Finally, 128 asymptomatic patients were included. Thirty-seven patients (28.9%) developed SSM during the follow-up period. The total SINS (OR: 1.739; 95% CI: 1.345-2.250) was identified as the most significant factor. The cut-off value of the SINS was 9.5 (sensitivity: 67.6%; specificity: 83.5%). Twenty-five (62.5%) of the forty patients with a SINS ≥ 10 developed SSM within a mean of 5.5 months (95% CI: 1.17-9.83). Furthermore, all patients with a SINS ≥ 13 developed SSM (n = 5) within a mean of 1.37 months (95% CI: 0.0-3.01). Conclusions: This study identified the significant risk factors for SSM onset and the threshold of the SINS. If long-term survival is expected, patients with a SINS ≥ 10 should be considered for intervention to prevent SSM.

Survival Rate after Palliative Surgery Alone for Symptomatic Spinal Metastases: A Prospective Cohort Study.

The effect of spine surgery for symptomatic spinal metastases (SSM) on patient prognosis remains unclear. This study aimed to reveal the prognosis of patients with SSM after spine surgery. One hundred twenty-two patients with SSM were enrolled in this prospective cohort study. The patients who received chemotherapy after enrollment were excluded. The decision of surgery depended on patient's willingness; the final cohort comprised 31 and 24 patients in the surgery and non-surgery groups, respectively. The patients were evaluated by their performance status (PS), activities of daily living (ADL) and ambulatory status. Survival was evaluated by the Kaplan-Meier method. The PS, ADL and ambulation were significantly improved in the surgery group compared to non-surgery group. The median survival was significantly longer in the surgery group (5.17 months, 95% confidence interval (CI) 3.27 to 7.07) than in the non-surgery group (2.23 months, 95% CI 2.03 to 2.43; p = 0.003). Furthermore, the patients with a better PS, ADL and ambulatory status had a significantly longer survival. Surgery improved the PS, ADL, ambulation and survival of patients with SSM. In the management of SSM, spine surgery is not only palliative but may also prolong survival.

Protective Effects of Growth Differentiation Factor-6 on the Intervertebral Disc: An In Vitro and In Vivo Study.

Growth differentiation factors (GDFs) regulate homeostasis by amplifying extracellular matrix anabolism and inhibiting pro-inflammatory cytokine production in the intervertebral disc (IVD). The aim of this study was to elucidate the effects of GDF-6 on human IVD nucleus pulposus (NP) cells using a three-dimensional culturing system in vitro and on rat tail IVD tissues using a puncture model in vivo. In vitro, Western blotting showed decreased GDF-6 expression with age and degeneration severity in surgically collected human IVD tissues (n = 12). Then, in moderately degenerated human IVD NP cells treated with GDF-6 (100 ng/mL), immunofluorescence demonstrated an increased expression of matrix components including aggrecan and type II collagen. Quantitative polymerase chain reaction analysis also presented GDF-6-induced downregulation of pro-inflammatory tumor necrosis factor (TNF)-α (p = 0.014) and interleukin (IL)-6 (p = 0.016) gene expression stimulated by IL-1ß (10 ng/mL). Furthermore, in the mitogen-activated protein kinase pathway, Western blotting displayed GDF-6-induced suppression of p38 phosphorylation (p = 0.041) under IL-1ß stimulation. In vivo, intradiscal co-administration of GDF-6 and atelocollagen was effective in alleviating rat tail IVD annular puncture-induced radiologic height loss (p = 0.005), histomorphological degeneration (p < 0.001), matrix metabolism (aggrecan, p < 0.001; type II collagen, p = 0.001), and pro-inflammatory cytokine production (TNF-α, p < 0.001; IL-6, p < 0.001). Consequently, GDF-6 could be a therapeutic growth factor for degenerative IVD disease.

Influence of the Preoperative Duration of Symptoms on Patients' Clinical Outcomes after Minimally Invasive Surgery-Transforaminal Lumbar Interbody Fusion for Degenerative Lumbar Spinal Diseases.

Background and Objectives: The impact of the duration of symptoms (DOS) on postoperative clinical outcomes of patients with degenerative lumbar spinal diseases is important for determining the optimal timing of surgical intervention; however, the timing remains controversial. This prospective case−control study aimed to investigate the influence of the preoperative DOS on surgical outcomes in minimally invasive surgery-transforaminal lumbar interbody fusion (MIS-TLIF). Materials and Methods: Patients who underwent single-level TLIF for lumbar degenerative diseases between 2017 and 2018 were reviewed. Only patients with full clinical data during the 1-year follow-up period were included. The patients were divided into two groups (DOS < 12 months, group S; DOS ≥ 12 months, group L). The clinical outcomes, including the Oswestry disability index (ODI) and visual analog scale (VAS) for lower back pain, leg pain, and numbness, were investigated preoperatively and at 1, 3, and 6 months, as well as 1 year, after surgery. Furthermore, postoperative patient satisfaction 1 year after surgery was also surveyed. Results: A total of 163 patients were assessed: 60 in group S and 103 in group L. No differences in baseline characteristics and clinical outcomes were found. The ODI and VAS significantly improved from the baseline to each follow-up period (all p < 0.01). Group S had significantly lower ODI scores at 3 months (p = 0.019) and 6 months (p = 0.022). In addition, group S had significantly lower VAS scores for leg pain at 3 months (p = 0.027). In a comparison between both groups, only the patients with cauda equina symptoms showed that ODI and leg pain VAS scores at 3 months after surgery were significantly lower in group S (19.9 ± 9.1 vs. 14.1 ± 12.5; p = 0.037, 7.4 ± 13.9 vs. 14.7 ± 23.1; p = 0.032, respectively). However, the clinical outcomes were not significantly different between both groups 1 year after surgery. Patient satisfaction was also not significantly different between both groups. Conclusions: Patients with a shorter DOS tended to have a significantly slower recovery; however, clinical outcomes 1 year after surgery were good, regardless of the DOS.

Complications of Posterior Fusion for Atlantoaxial Instability in Children With Down Syndrome.

OBJECTIVE: To clarify the complications of posterior fusion for atlantoaxial instability (AAI) in children with Down syndrome and to discuss the significance of surgical intervention. METHODS: Twenty pediatric patients with Down syndrome underwent posterior fusion for AAI between February 2000 and September 2018 (age, 6.1 ± 1.9 years). C1-2 or C1-3 fusion and occipitocervical fusion were performed in 14 and 6 patients, respectively. The past medical history, operation time, estimated blood loss (EBL), duration of Halo vest immobilization, postoperative follow-up period, and intra- and perioperative complications were examined. RESULTS: The operation time was 257.9 ± 55.6 minutes, and the EBL was 101.6 ± 77.9 mL. Complications related to the operation occurred in 6 patients (30.0%). They included 1 major complication (5.0%): hydrocephalus at 3 months postoperatively, possibly related to an intraoperative dural tear. Other surgery-related complications included 3 cases of superficial infections, 1 case of bone graft donor site deep infection, 1 case of C2 pedicle fracture, 1 case of Halo ring dislocation, 1 case of pseudoarthrosis that required revision surgery, and 1 case of temporary neurological deficit after Halo removal at 2 months postoperatively. Complications unrelated to the operation included 2 cases of respiratory infections and 1 case of implant loosening due to a fall at 9 months postoperatively. CONCLUSION: The complication rate of upper cervical fusion in patients with Down syndrome remained high; however, major complications decreased substantially. Improved intra- and perioperative management facilitates successful surgical intervention for upper cervical instability in pediatric patients with Down syndrome.