Surgical Management of Hip-Spine Syndrome: A Systematic Review of the Literature.

BACKGROUND: Hip-spine syndrome (HSS) was first described in 1983 to describe the symptomatology resulting from concomitant lumbar degenerative stenosis and hip osteoarthritis. Numerous studies have sought to understand the underlying pathology and appropriate management of this syndrome. The purpose of this article is to review the literature for the specific imaging characteristics and the optimal surgical treatment of HSS. METHODS: A systematic review was conducted via an electronic database search through PubMed to identify all publications related to HSS. All publications that contained data on patients who underwent surgical treatment for HSS and reported patient-reported outcome measures or radiographic data were included. Exclusion criteria consisted of publications in a language other than English, review articles, and technique articles. RESULTS: Fifteen articles that focused on the surgical management of HSS were identified. Of these 15 articles, 8 reported radiographic outcomes, with most reporting no significant change in spinopelvic parameters before and after surgery. Thirteen articles reported clinical outcomes, with 8 of those 13 articles identifying patient-reported outcome measures to be significantly improved following surgery. CONCLUSIONS: The data on the surgical management of HSS remains sparse. While there is some evidence that total hip arthroplasty in patients who previously underwent spinal fusion may have higher complication rates, there remains debate regarding which surgical problem to address first, the hip or the spine.

Durability of stand-alone anterolateral interbody fusion in staged minimally invasive circumferential scoliosis surgery with delayed posterior instrumentation due to medical necessity.

PURPOSE: Circumferential minimally invasive scoliosis surgeries are often staged, wherein anterior and/or lateral lumbar interbody fusion is followed by percutaneous posterior fixation days later. This study examines the impact on outcomes when posterior augmentation was delayed due to unexpected medical issues following the first stage, anterolateral procedure. METHODS: A retrospective review was conducted of all patients undergoing minimally invasive circumferential deformity corrections from 2006 to 2019. Patients in whom planned posterior fixation was postponed due to medical necessity or safety concerns were identified. Perioperative surgical metrics and radiographic parameters were collected. RESULTS: Three of the six patients initially scheduled for circumferential fusion never underwent posterior augmentation due to symptomatic improvement (2.3, 5, and 10.7 years of follow-up). The other three underwent posterior fixation once medically optimized after an average interval of 4.7 months (range 3.2-7.8 months) due to persistent symptoms. It was also observed that the average coronal malalignment in the postoperative period was 5.1 cm in the group requiring further fixation and only 1.6 cm in the group which did not. CONCLUSION: In select cases, the indirect decompression and stability conferred by minimally invasive anterolateral arthrodesis alone may afford adequate pain relief to delay or even avoid posterior fixation in patients with adult spinal deformity.

Graft subsidence and reoperation after lateral lumbar interbody fusion: a propensity score-matched and cost analysis of polyetheretherketone versus 3D-printed porous titanium interbodies.

OBJECTIVE: Lumbar interbody cage subsidence has a multifactorial etiology. Cage material, although well studied after transforaminal lumbar interbody fusion, has not been investigated as a contributing factor to subsidence after lateral lumbar interbody fusion (LLIF). In this study the authors compared rates of subsidence and reoperation after LLIF between polyetheretherketone (PEEK) and 3D-printed porous titanium (pTi) in an institutional propensity score-matched and cost analysis. METHODS: This is a retrospective observational cohort analysis of adult patients who underwent LLIF with pTi versus PEEK between 2016 and 2020. Demographic, clinical, and radiographic characteristics were collected. Propensity scores were calculated and 1:1 matching without replacement of surgically treated levels was performed. The primary outcome of interest was subsidence. The Marchi subsidence grade was determined at the time of last follow-up. Chi-square or Fisher's exact tests were used to compare subsidence and reoperation rates between lumbar levels treated with PEEK versus pTi. Modeling and cost analysis were performed using TreeAge Pro Healthcare. RESULTS: The authors identified a total of 192 patients; 137 underwent LLIF with PEEK (212 levels) and 55 had LLIF with pTi (97 levels). After propensity score matching, a total of 97 lumbar levels remained in each treatment group. After matching, there were no statistically significant differences between groups in baseline characteristics. Levels treated with pTi were significantly less likely to exhibit subsidence (any grade) compared to those treated with PEEK (8% vs 27%, p = 0.001). Five (5.2%) levels treated with PEEK required reoperation for subsidence, but only 1 (1.0%) level treated with pTi required reoperation for subsidence (p = 0.12). Given subsidence and revision rates experienced in the cohorts in this study, the pTi interbody device is economically superior to PEEK in a single-level LLIF as long as its cost is at least $1185.94 lower than that of PEEK. CONCLUSIONS: The pTi interbody device was associated with less subsidence, but statistically similar revision rates after LLIF. pTi is potentially a superior economic choice at this study's reported revision rate.

Direct Iliac Screw vs Sacral-2-Alar-Iliac Screws Technique for Sacropelvic Fixation: Technical Nuances and a Review of the Literature.

Sacropelvic (SP) fixation is the immobilization of the sacroiliac joint to attain lumbosacral fusion and prevent distal spinal junctional failure. SP fixation is indicated in numerous spinal conditions (eg, scoliosis, multilevel spondylolisthesis, spinal/sacral trauma, tumors, or infections). Many SP fixation techniques have been described in the literature. Currently, the most used surgical techniques for SP fixation are direct iliac screws and sacral-2-alar-iliac screws. There is currently no consensus in the literature on which technique carries more favorable clinical outcomes. In this review, we aim to assess the available data on each technique and discuss their respective advantages and disadvantages. We will also present our experience with a modification of direct iliac screws using a subcrestal approach and outline the future prospects of SP fixation.

Relationship between pelvic incidence-adjusted relative spinopelvic parameters, global sagittal alignment and lower extremity compensations.

PURPOSE: In response to sagittal malalignment, compensatory spinal and lower extremity mechanisms are recruited. Thoracolumbar realignment surgery has been shown to yield reciprocal changes in these compensations. Thus, whole-body radiographic assessment has come to the fore. This study aimed to evaluate the relationship between spinopelvic parameters and lower extremity compensation angles and to examine their coupled change with deformity correction. METHODS: This was a multicenter retrospective analysis of patients who had ≥ 4 levels posterior fusion, whole-body radiographs, and ≥ 2 years follow-up. Relative Pelvic Version (RPV), Relative Lumbar Lordosis (RLL), Relative Spinopelvic Alignment (RSA), Femoral Obliquity Angle (FOA), Knee Flexion Angle (KFA) and Global Sagittal Axis (GSA) were measured preoperatively and 6 week postoperatively. Kruskal-Wallis tests were performed to assess the relation of relative spinopelvic parameters to global sagittal alignment and lower extremity compensation angles. Spearman's correlations were performed to assess correlations of pre-to-postoperative changes. RESULTS: 193 patients (156F, 37 M) were included. The mean age was 57.2 ± 16.6 years. The mean follow-up duration was 50.6 (24-90) months. On average, 10.3 ± 3.8 levels were fused. Among the cohort, 124 (64.2%) had a sacral or sacroiliac fixation, and 43 (22.3%) had 3-column osteotomies. Preoperative FOA, KFA and GSA significantly differed between RPV, RLL and RSA categories. Significant weak-to-strong correlations were observed between spinopelvic parameters, global sagittal alignment and lower extremity compensation angles (rho range: - 0.351 to 0.767). CONCLUSIONS: PI-adjusted relative spinopelvic parameters significantly correlated with measurements of the lower extremity compensation. Postoperative changes in RPV, RLL and RSA reflected changes in FOA, KFA and GSA. These measurements may serve as a valuable proxy for surgical planning when whole-body imaging is not available.

The 'candy cane' technique for construct augmentation and correction of severe angular chin-on-chest kyphoscoliosis.

PURPOSE: To manage severe angular chin-on-chest deformity. METHODS: A single midline incision and periosteal dissection were utilized to expose from C2 to T6. Bilateral C2 pars screws, C3 to C7 lateral mass screws, and T1 to T6 pedicle screws were placed. Following the placement of screws, multiple two column posterior osteotomies and interlaminar decompressions from C6 to T3 were performed to amplify both the sagittal and coronal corrections. Titanium rods were utilized in light of the patient's known osteopenia and nickel allergy. As such, the construct was augmented via the use of a third accessory rod. This third titanium rod was placed into a supplementary translaminar screw with three connectors to the right-sided main rod. Once the lordotic configuration of the contralateral main rod was secured, an additional corrective maneuver of gentle distraction across this third rod was employed to assist with coronal correction. RESULTS: In this patient with osteopenia, a known nickel allergy, and significant cervical imbalance, the Candy Cane construct allowed for a durable correction of the severe sagittal and coronal plane deformity. The chin-brow angle was corrected by 44°. The coronal Cobb angle improved by 10°. On long-term follow-up, the patient reported continued satisfaction with the operation and was able to perform his activities of daily living. CONCLUSION: A one-stage, posterior approach along with construct augmentation, with a third rod hooked into a supplementary C2 translaminar screw, can be employed for the correction of chin-on-chest kyphoscoliosis.

Long-Term Durability of Stand-Alone Lateral Lumbar Interbody Fusion.

BACKGROUND: The long-term durability of stand-alone lateral lumbar interbody fusion (LLIF) remains unknown. OBJECTIVE: To evaluate whether early patient-reported outcome measures after stand-alone LLIF are sustained on long-term follow-up. METHODS: One hundred and twenty-six patients who underwent stand-alone LLIF between 2009 and 2017 were included in this study. Patient-reported outcome measures included the Oswestry Disability Index (ODI), EuroQOL-5D (EQ-5D), and visual analog score (VAS) scores. Durable outcomes were defined as scores showing a significant improvement between preoperative and 6-week scores without demonstrating any significant decline at future time points. A repeated measures analysis was conducted using generalized estimating equations (model) to assess the outcome across different postoperative time points, including 6 weeks, 1 year, 2 years, and 5 years. RESULTS: ODI scores showed durable improvement at 5-year follow-up, with scores improving from 46.9 to 38.5 ( P = .001). Improvements in EQ-5D showed similar durability up to 5 years, improving from 0.48 to 0.65 ( P = .03). VAS scores also demonstrated significant improvements postoperatively that were durable at 2-year follow-up, improving from 7.0 to 4.6 ( P < .0001). CONCLUSION: Patients undergoing stand-alone LLIF were found to have significant improvements in ODI and EQ-5D at 6-week follow-up that remained durable up to 5 years postoperatively. VAS scores were found to be significantly improved at 6 weeks and up to 2 years postoperatively but failed to reach significance at 5 years. These findings demonstrate that patients undergoing stand-alone LLIF show significant improvement in overall disability after surgery that remains durable at long-term follow-up.

Evolution of polyetheretherketone (PEEK) and titanium interbody devices for spinal procedures: a comprehensive review of the literature.

INTRODUCTION: Interbody fusion is commonly utilized for arthrodesis and stability among patients undergoing spine surgery. Over the last few decades, interbody device materials, such as titanium and polyetheretherketone (PEEK), have been replacing traditional autografts and allografts for interbody fusion. As such, with the exponential growth of bioengineering, a large variety cage surface technologies exist. Different combinations of cage component materials and surface modifications have been created to optimize interbody constructs for surgical use. This review aims to provide a comprehensive overview of common surface technologies, their performance in the clinical setting, and recent modifications and material combinations. MATERIALS AND METHODS: We performed a comprehensive review of the literature on titanium and PEEK as medical devices between 1964 and 2021. We searched five major databases, resulting in 4974 records. Articles were screened for inclusion manually by two independent reviewers, resulting in 237 articles included for review. CONCLUSION: Interbody devices have rapidly evolved over the last few decades. Biomaterial and biomechanical modifications have allowed for continued design optimization. While titanium has a high osseointegrative capacity, it also has a high elastic modulus and is radio-opaque. PEEK, on the other hand, has a lower elastic modulus and is radiolucent, though PEEK has poor osseointegrative capacity. Surface modifications, material development advancements, and hybrid material devices have been utilized in search of an optimal spinal implant which maximizes the advantages and minimizes the disadvantages of each interbody material.

Combining locoregional CAR-T cells, autologous + allogeneic tumor lysate vaccination and levamisole in treatment of glioblastoma.

Glioblastoma multiforme (GBM) is an aggressive brain malignancy and harbors a microenvironment limiting immune cells activity. CAR-T cells are being tested in the treatment of cancers and there exist reports which demonstrate dramatic regression of multicentric GBMs following intrathecal treatment with CAR-T cells. In this article, a triple approach for immune treatment of GBM is proposed. First, GBM tumor specimens for each patient will be saved and cultured to obtain tumor lysates. Then, levamisole will be applied, which possesses immunostimulating, anti-glycolytic, and anti-angiogenic features. Following priming the immune system, GBM patients will be injected with lysates of their own tumor cells plus lysates from a GBM cell line, U251. After 3 months of this treatment, CAR-T cells (transduced with IL13Rα2-CAR) will be applied via intratumoral approach. As such, genetically-modified and native immunocytes may 'meet' in the vicinity of deeply-invading tumor cells and demonstrate greater efficacy via cell-cell interactions. By this, a self-propagating cyclic process - a cancer-immunity cycle - may be initiated to eradicate cancer cells.

MGMT in glial carcinogenesis. Roles from prevention to treatment.

Many investigations exist regarding the effect of the DNA repair enzyme MGMT (O 6 -methylguanine- DNA-methyltransferase)-encoding gene methylation on the antineoplasticity of temozolomide in glioblastoma patients. However, there exist surprisingly lesser studies regarding the associations between MGMT enzyme biochemistry with glial carcinogenesis. MGMT involves in risk of malignancies associated with ionizing radiation, smoking, exposure to polycyclic aromatic hydrocarbons, chlorinated solvents, vinylchloride and hairdyes. All these factors are also proposed to link with gliomagenesis, yet MGMT interactions with these carcinogens in gliomagenesis are not studied yet. In future, MGMT sequencing may be employed in vulnerable populations working in industries associated with exposure to these carcinogens to develop preventive strategies. Given that MGMT is involved in DNA repair, a polymorphism may simultaneously modify the risk of gliomas while enhancing temozolomide cytotoxicity in both marrow and tumor cells.

Operative Outcomes After Cervical Diffuse Idiopathic Skeletal Hyperostosis Fracture in the Elderly.

BACKGROUND: Cervical diffuse idiopathic skeletal hyperostosis (DISH) fractures are frequently unstable and carry significant risk of neurologic injury and death. Most patients with DISH fractures are elderly (>70 years) with significant comorbidities. We assessed factors that contribute to outcomes in elderly patients with cervical DISH fractures. METHODS: Elderly patients with cervical DISH fractures from 2008 to 2017 were included in this retrospective multi-institutional cohort study. Predictor variables included injury level, surgical approach, preinjury comorbidities, American Society of Anesthesiologists (ASA) score, American Spinal Injury Association (ASIA) impairment scale grade, preoperative anticoagulation status, and the subaxial cervical spine injury classification system (SLIC) score. Univariate and multivariate analyses were utilized to identify factors associated with 30-day mortality and ambulatory status at discharge. RESULTS: A total of 48 patients, mean age 74.7 years old (range 60-96), underwent cervical fixation for DISH fractures. Average SLIC score was 6.30 ± 1.2 (range 5-8), and most frequent fracture level was at C6 to -C7 (31.3%) followed by C7-T1 (25.0%). Forty (83.3%) patients underwent posterior fixation, 7 (14.6%) with anterior fixation, and 1 (2.1%) had combined approach. Ten (20.4%) patients died within 30 days of surgery. Multivariate analysis demonstrated that poorer preoperative ASIA grade (OR 2.35, P = 0.003, CI = 1.33-4.14) and ASA score >3 (P = 0.027) had increased risk of being nonambulatory at discharge. Higher SLIC score was associated with increased 30-day mortality (P = 0.021, CI = 1.20-9.60). CONCLUSIONS: Cervical DISH fractures can be highly unstable, for which instrumentation and fixation are indicated. Surgical decision-making should focus on preoperative ASIA grade, SLIC score, and ASA score. CLINICAL RELEVANCE: The study is relevant due to an aging poulation predisposed to cervical DISH fractures.

Subsidence after lateral lumbar interbody fusion using a 3D-printed porous titanium interbody cage: single-institution case series.

OBJECTIVE: Cage subsidence is a well-known phenomenon after lateral lumbar interbody fusion (LLIF), occurring in 10%-20% of cases. A 3D-printed porous titanium (pTi) cage has a stiffness that mimics the modulus of elasticity of native vertebrae, which reduces stress at the bone-hardware interface, lowering the risk of subsidence. In this study, the authors evaluated their institutional rate of subsidence and resultant reoperation in patients who underwent LLIF using a 3D-printed pTi interbody cage. METHODS: This is a retrospective case series of consecutive adult patients who underwent LLIF using pTi cages from 2018 to 2020. Demographic and clinical characteristics including age, sex, bone mineral density, smoking status, diabetes, steroid use, number of fusion levels, posterior instrumentation, and graft size were collected. The Marchi subsidence grade was determined at the time of last follow-up. Outcome measures of interest were subsidence and resultant reoperation. Univariable logistic regression analysis was performed to assess the extent to which clinical and operative characteristics were associated with Marchi grade I-III subsidence. Significance was assessed at p < 0.05. RESULTS: Fifty-five patients (38 with degenerative disc disease and 17 with adult spinal deformity) were treated with 97 pTi interbody cages with a mean follow-up of 18 months. The mean age was 63.6 ± 10.1 years, 60% of patients were female, and 36% of patients had osteopenia or osteoporosis. Patients most commonly underwent single-level LLIF (58.2%). Sixteen patients (29.1%) had posterior instrumentation. The subsidence grade distribution was as follows: 89 (92%) grade 0, 5 (5%) grade I, 2 (2%) grade II, and 1 (1%) grade III. No patients who were active or prior smokers and no patients with posterior instrumentation experienced graft subsidence. No clinical or operative characteristics were significantly associated with graft subsidence. One patient (1.8%) required reoperation because of subsidence. CONCLUSIONS: In this institutional case series, subsidence of pTi intervertebral cages after LLIF occurred in 8% of operated levels, 3% of which were grade II or III. Only 1 patient required reoperation. These reported rates are lower than those reported for polyetheretherketone implants. Further studies are necessary to compare the impact of these cage materials on subsidence after LLIF.

3D printing applications in spine surgery: an evidence-based assessment toward personalized patient care.

PURPOSE: Spine surgery entails a wide spectrum of complicated pathologies. Over the years, numerous assistive tools have been introduced to the modern neurosurgeon's armamentarium including neuronavigation and visualization technologies. In this review, we aimed to summarize the available data on 3D printing applications in spine surgery as well as an assessment of the future implications of 3D printing. METHODS: We performed a comprehensive review of the literature on 3D printing applications in spine surgery. RESULTS: Over the past decade, 3D printing and additive manufacturing applications, which allow for increased precision and customizability, have gained significant traction, particularly spine surgery. 3D printing applications in spine surgery were initially limited to preoperative visualization, as 3D printing had been primarily used to produce preoperative models of patient-specific deformities or spinal tumors. More recently, 3D printing has been used intraoperatively in the form of 3D customizable implants and personalized screw guides. CONCLUSIONS: Despite promising preliminary results, the applications of 3D printing are so recent that the available data regarding these new technologies in spine surgery remains scarce, especially data related to long-term outcomes.

Direct Pars Repair with Cannulated Screws in Adults: A Case Series and Systematic Literature Review.

OBJECTIVE: Lumbar spondylolysis occurs in 5%-8% of adults. This study aimed to report clinical and radiographic outcomes of direct pars repair in adults with lumbar spondylolysis. METHODS: We conducted a retrospective review of all patients treated for lumbar spondylolysis via open fracture reduction and direct pars repair with cannulated screws using a lag technique. Demographics, clinical presentation, perioperative and intraoperative imaging, and postoperative data were collected. We subsequently performed a systematic review to describe radiographic and clinical outcomes following direct pars repair. RESULTS: Three patients were identified (mean age 40.3 years; range, 21-72 years; 2 male). All patients had bilateral L5 pars fractures treated via open, direct repair with cannulated screws. There were no intraoperative complications. Length of stay was <24 hours for each patient. All patients reported back/radicular symptom relief and returned to full-time manual labor by latest follow-up. Noncontrast lumbar computed tomography performed 14-20 months postoperatively confirmed that all patients had good bilateral screw placement without fracture. Two patients (21 and 28 years old at surgery) had evidence of fusion across fracture sites, while 1 patient exhibited radiolucency around the screws and no progression of spondylolisthesis. Additionally, we reviewed 8210 articles and included 15 in a systematic review of direct pars repair. Fusion rates were 67%-100%, with improved average Oswestry Disability Index and visual analog scale back pain scores by latest follow-up. CONCLUSIONS: Lumbar spondylolysis treatment with open fracture reduction and direct pars repair with cannulated screws in adults is safe and may result in mechanical back/radicular pain relief, even in the absence of radiographic fusion.

A Novel 5-Aminolevulinic Acid-Enabled Surgical Loupe System-A Consecutive Brain Tumor Series of 11 Cases.

BACKGROUND: The concept of maximally safe resection (MSR) has been shown to improve clinical outcomes in the treatment of high-grade gliomas (HGGs). To achieve MSR, surgical adjuncts such as functional imaging, neuronavigation, intraoperative mapping, ultrasound, and fluorescence-guided surgery are routinely used. 5-Aminolevulinic acid (5-ALA) is an oral agent that has been increasingly adopted in fluorescence-guided resection of HGG. In randomized clinical trials of 5-ALA, it has been shown to increase the extent of resection and progression-free survival in HGG. Current commercially available 5-ALA detection systems are all microscope-based and can sometimes be cumbersome to use. OBJECTIVE: To present our experience using a novel 5-ALA-enabled surgical loupe system. METHODS: 5-ALA-enabled loupes were used in 11 consecutive patients with either suspected HGG on magnetic resonance imaging or recurrence of known lesions. Lesion appearance was examined under white light, 5-ALA loupes, and a 5-ALA microscope. Tumor specimens were checked for fluorescence and sent for pathologic examination. RESULTS: In our experience, a 5-ALA-enabled surgical loupe system offers excellent visualization of 5-ALA in patients with HGG. In 10 of 11 patients, fluorescent tissue was confirmed to be high-grade glioma by pathology. In 1 patient, tissue was not fluorescent, and final pathology was World Health Organization grade I meningioma. CONCLUSION: A 5-ALA-enabled surgical loupe system offers excellent intraoperative visualization of 5-ALA fluorescence in HGG and can be a viable surgical adjunct for achieving MSR of HGG.

A hypothetical proposal to employ meperidine and tamoxifen in treatment of glioblastoma. Role of P-glycoprotein, ceramide and metabolic pathways.

Meperidine (pethidine) is a µ-opioid receptor (MOR) agonist widely used in the treatment of cancer pain. While MOR agonists in experimental models have demonstrated both pro- and antitumorigenic properties, meperidine has unique features which may be predominantly anticancer in nature. Meperidine both inhibits NMDA (N-methyl-D-Aspartate) receptors, which are involved in the progression of glioblastoma, and blocks NADH:Ubiquinone Oxidoreductase, which may hinder mitochondrial respiration. In the developing embryonic neural tissue, meperidine reduces cell proliferation around the neural tube and lowers the expression of the B RE (brain and reproductive organ-expressed). This is notable given that the B RE gene is implicated in cancer chemoresistance and gliomagenesis. Further, meperidine inhibits P-glycoprotein, which is involved in cancer multidrug resistance and the degradation of the sphingolipid backbone, ceramide. By enhancing the pro-autophagic and pro-apoptotic ceramide levels in cancer cells, meperidine stimulates cell death and reverses multidrug resistance. Tamoxifen, a safe medication employed in the treatment of breast cancer, directly blocks P-glycoprotein and boosts levels of ceramide both via inhibition of glycosylceramide synthase and ceramidase. Further, tamoxifen blocks NMDA-neurotoxicity and therefore it may act synergistically with meperidine in reducing glioblastoma progression associated with NMDA-activation. Finally, tamoxifen blocks glycolysis which may enhance the mitochondrial-blocking activity of meperidine to shut down energy metabolism of glioblastoma cells. Because of these properties, we believe that the combination of meperidine and tamoxifen merits study in cell culture and animal models to investigate a potential synergistic relationship in the treatment of glioblastoma.

Longitudinal Analysis of Peripheral Nerve Surgery Training: Comparison of Neurosurgery to Plastic and Orthopedic Surgery.

BACKGROUND: Residents in multiple surgical specialties are trained to perform peripheral nerve surgery (PNS), but the extent of exposure to this field varies among specialties. This study evaluates trends in volume of PNS performed during residency for neurologic surgery trainees compared to those in plastic and orthopedic surgery between 2009 and 2019. METHODS: We queried ACGME for neurologic, plastic, and orthopedic surgery resident case-logs and compared mean number of PNS between graduating residents of each specialty using a one-way analysis of variance test. Linear regression was utilized to determine trends within and across the specialties over the study period. RESULTS: Neurosurgery residents (24.76 ± 3.41) performed significantly fewer PNS than their counterparts in orthopedic (54.56 ± 6.85) and plastic surgery (71.96 ± 12.20), P < 0.001. Residents in neurologic surgery reported over 1.5-fold as many cases as their ACGME-required minimum, in contrast to plastic (2.5-fold) and orthopedic (5-fold). Plastics residents (3.46 cases/year) demonstrated the greatest longitudinal increase in PNS, followed by neurosurgery residents (0.81 cases/year). PNS accounted for a mean of 5.81% of neurosurgery resident cases, 4.20% of plastic surgery resident cases, and 2.98% of orthopedic surgery resident cases (P < 0.001). CONCLUSIONS: Neurosurgery residents exceeded the required minimum number of PNS and were increasingly more exposed to PNS. However, compared with their counterparts in orthopedic and plastic surgery, neurosurgery residents performed significantly fewer cases. Exposure for neurosurgery residents remains unchanged over the study period while plastic surgery residents experienced an increase in case volume. The deficiency in exposure for neurosurgical residents must be addressed to harness interest and proficiency in PNS.

Patient perception of scoliosis correction surgery on Instagram.

OBJECTIVE: Patient feedback surveys provide important insight into patient outcomes, satisfaction, and perioperative needs. Recent critiques have questioned provider-initiated surveys and their capacity to accurately gauge patient perspectives due to intrinsic biases created by question framing. In this study, the authors sought to evaluate provider-independent, patient-controlled social media Instagram posts in order to better understand the patient experience following scoliosis correction surgery. METHODS: Twitter and Instagram were queried for posts with two tagged indicators, #scoliosissurgery or @scoliosissurgery, resulting in no relevant Twitter posts and 25,000 Instagram posts. Of the initial search, 24,500 Instagram posts that did not directly involve the patient's own experience were eliminated. Posts were analyzed and coded for the following criteria: the gender of the patient, preoperative or postoperative timing discussed in the post, and classified themes related to the patient's experiences with scoliosis correction surgery. RESULTS: Females made 87.6% of the Instagram posts about their experience following scoliosis correction surgery. The initial postoperative stage of surgery was mentioned in 7.6% of Instagram posts. The most common theme on Instagram involved offering or seeking online support from other patients, which constituted 85.2% of all posts. Other common themes included concern about the surgical scar (31.8%), discussing the results of treatment (28.8%), and relief regarding results (21.2%). CONCLUSIONS: Social media provided a platform to analyze unprompted feedback from patients. Patients were most concerned with their scoliosis correction surgery in the period of time 2 weeks or more after surgery. Themes that were most commonly found on Instagram posts were offering or seeking online support from other patients and concern about the surgical scar. Patient-controlled social media platforms, like Instagram, may provide a useful mechanism for healthcare providers to understand the patient experience following scoliosis correction surgery. Such platforms may help in evaluating postoperative satisfaction and improving postoperative quality of care.

Does Variceal Drainage Affect Arteriovenous Malformation Obliteration and Hemorrhage Rates After Stereotactic Radiosurgery? A Case-Matched Analysis.

BACKGROUND: Stereotactic radiosurgery (SRS) is widely accepted as a minimally invasive alternative to surgery in the management of arteriovenous malformations (AVMs). Dilated AVM outflow veins or varices may be caused by high-flow or partial outflow obstruction, which may increase the risk of a hemorrhage before or after SRS. OBJECTIVE: To compare the obliteration and hemorrhage risks in patients with and without AVM varices (AVMv). METHODS: From our prospective database of 1012 AVM patients who underwent Gamma Knife® (Elekta) SRS, we identified 103 patients with AVMv, and 847 patients without varices. The median follow-up was 52 mo. Balancing variable score matching was performed to compare obliteration and hemorrhage rates between the 2 groups. RESULTS: Obliteration rates in the AVMv group were 38% at 3 yr, 65% at 4 yr, and 70% at 5 yr. Patients with an AVMv had no difference in the final obliteration rate compared to patients who did not have variceal drainage (P = .35). Actuarial hemorrhage after SRS in the matched patients with AVMv was 4.9%, 13%, and 13.7%, at 1, 3, and 5 yr, respectively. The rate of hemorrhage in the group with no varix was 2.9%, 5.4%, and 9.1% at 1, 3, and 5 yr, respectively (P = .14). CONCLUSION: The presence of AVM variceal venous drainage did not affect the obliteration rate and did not confer a higher risk of a subsequent hemorrhage both before and after SRS.

Incidence of adjacent-segment surgery following stand-alone lateral lumbar interbody fusion.

OBJECTIVE: Adjacent-segment disease (ASD) requiring operative intervention is a relatively common long-term consequence of lumbar fusion surgery. Although the incidence of ASD requiring reoperation is well described for traditional posterior lumbar approaches (2.5%-3.9% per year), it remains poorly characterized for stand-alone lateral lumbar interbody fusion (LLIF). In this study, the authors report their institutional experience with ASD requiring reoperation after LLIF over an extended follow-up period of 4 years. METHODS: Medical records were reviewed for 276 consecutive patients who underwent stand-alone LLIF by a single surgeon for degenerative spinal disorders. Inclusion criteria (single-stage, stand-alone LLIF without posterior supplementation, with no prior lumbar instrumentation, and a minimum of 4 years of follow-up) were met by 182 patients, who were analyzed for operative ASD incidence (per-year rate), demographics, and Oswestry Disability Index (ODI) score. Operative ASD was strictly defined as new-onset pathology following index surgery at directly adjacent levels to the prior construct. Operative, rather than symptomatic or radiographic, ASD was analyzed to provide a consistent and impactful endpoint while avoiding retrospective diagnosis. RESULTS: The study cohort of 182 patients had an operative ASD rate of 3.3% (n = 6 procedures) over 4 years of follow-up, for an incidence on Kaplan-Meier survival analysis of 0.88% (95% CI 0.67%-1.09%) per year. In comparing patients with operative ASD with those without, there were no significant differences in mean age (53.7 vs 56.2 years), male sex (33.3% vs 44.9%), smoking status (16.7% vs 25.0%), or number of levels fused (mean 1.33 vs 1.46). The operative ASD cohort had a greater mean BMI (37.3 vs 30.2, p < 0.01). Operative ASD patients had lower baseline ODI scores (33.8 vs 48.3, p = 0.02); however, no difference was observed in ODI at 6 weeks (34.0 vs 39.0) or 3 months (16.0 vs 32.8) postoperatively. CONCLUSIONS: The incidence of ASD in LLIF for degenerative lumbar etiologies in this cohort was 0.88% (95% CI 0.67%-1.09%) per year. Meanwhile, the reported reoperation rates for ASD in posterior spinal approaches was 2.5% to 3.9% per year, which implies that LLIF may be preferable for well-selected patients.