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Background: Few have explored the safety and efficacy of posterior vertebral column subtraction osteotomy (PVCSO) to treat tethered cord syndrome (TCS)., Objective: To evaluate surgical outcomes after PVCSO in adults with TCS caused by lipomyelomeningocele, who had undergone a previous detethering procedure(s) that ultimately failed., Methods: This is a multicenter, retrospective analysis of a prospectively collected cohort. Patients were prospectively enrolled and treated with PVCSO at 2 institutions between January 1, 2011 and December 31, 2018. Inclusion criteria were age ≥18 yr, TCS caused by lipomyelomeningocele, previous detethering surgery, and recurrent symptom progression of less than 2-yr duration. All patients undergoing surgery with a 1-yr minimum follow-up were evaluated., Results: A total of 20 patients (mean age: 36 yr; sex: 15F/5M) met inclusion criteria and were evaluated. At follow-up (mean: 23.3 ± 7.4 mo), symptomatic improvement/resolution was seen in 93% of patients with leg pain, 84% in back pain, 80% in sensory abnormalities, 80% in motor deficits, 55% in bowel incontinence, and 50% in urinary incontinence. Oswestry Disability Index improved from a preoperative mean of 57.7 to 36.6 at last follow-up (P < .01). Mean spinal column height reduction was 23.4 ± 2.7 mm. Four complications occurred: intraoperative durotomy (no reoperation), wound infection, instrumentation failure requiring revision, and new sensory abnormality., Conclusion: This is the largest study to date assessing the safety and efficacy of PVCSO in adults with TCS caused by lipomyelomeningocele and prior failed detethering. We found PVCSO to be an excellent extradural approach that may afford definitive treatment in this particularly challenging population., (© Congress of Neurological Surgeons 2020.)

Objective: Enhanced Recovery After Surgery (ERAS) protocols have rapidly gained popularity in multiple surgical specialties and are recognized for their potential to improve patient outcomes and decrease hospitalization costs. However, they have only recently been applied to spinal surgery. The goal in the present work was to describe the development, implementation, and impact of an Enhanced Recovery After Spine Surgery (ERASS) protocol for patients undergoing elective spine procedures at an academic community hospital., Methods: A multidisciplinary team, drawing on prior publications and spine surgery best practices, collaborated to develop an ERASS protocol. Patients undergoing elective cervical or lumbar procedures were prospectively enrolled at a single tertiary care center; interventions were standardized across the cohort for pre-, intra-, and postoperative care using standardized order sets in the electronic medical record. Protocol efficacy was evaluated by comparing enrolled patients to a historic cohort of age- and procedure-matched controls. The primary study outcomes were quantity of opiate use in morphine milligram equivalents (MMEs) on postoperative day (POD) 1 and length of stay. Secondary outcomes included frequency and duration of indwelling urinary catheter use, discharge disposition, 30-day readmission and reoperation rates, and complication rates. Multivariable linear regression was used to determine whether ERASS protocol use was independently predictive of opiate use on POD 1., Results: In total, 97 patients were included in the study cohort and were compared with a historic cohort of 146 patients. The patients in the ERASS group had lower POD 1 opiate use than the control group (26 ± 33 vs 42 ± 40 MMEs, p < 0.001), driven largely by differences in opiate-naive patients (16 ± 21 vs 38 ± 36 MMEs, p < 0.001). Additionally, patients in the ERASS group had shorter hospitalizations than patients in the control group (51 ± 30 vs 62 ± 49 hours, p = 0.047). On multivariable regression, implementation of the ERASS protocol was independently predictive of lower POD 1 opiate consumption (β = -7.32, p < 0.001). There were no significant differences in any of the secondary outcomes., Conclusions: The authors found that the development and implementation of a comprehensive ERASS protocol led to a modest reduction in postoperative opiate consumption and hospital length of stay in patients undergoing elective cervical or lumbar procedures. As suggested by these results and those of other groups, the implementation of ERASS protocols may reduce care costs and improve patient outcomes after spine surgery.

There are potential pitfalls associated with the pursuit of accurate surgical navigation, such as vulnerability of the reference array to accidental dislodgment and damage or soiling of tracking arrays on tools. Additionally, there are hazards encountered when attempting accurate robotic screw placement in spine surgery, including skiving of the tool on bone, displacement of the robotic arm, or patient movement. Proven techniques are needed to address and mitigate these issues to ensure that navigation integrity is maintained and screw placement is accurate when using navigated robotic surgical guidance systems. The following research describes some potential hazards commonly encountered in robotic navigated screw placement, suggests techniques for overcoming these hazards, and provides examples of how these techniques have been incorporated into existing surgical robotic guidance systems.

Robotic systems in surgery have developed rapidly. Installations of the da Vinci Surgical System® (Intuitive Surgical, Sunnyvale, CA, USA), widely used in urological and gynecological procedures, have nearly doubled in the United States from 2010 to 2017. Robotics systems in spine surgery have been adopted more slowly; however, users are enthusiastic about their applications in this subspecialty. Spinal surgery often requires fine manipulation of vital structures that must be accessed via limited surgical corridors and can require repetitive tasks over lengthy periods of time - issues for which robotic assistance is well-positioned to complement human ability. To date, the United States Food and Drug Administration (FDA) has approved 7 robotic systems across 4 companies for use in spinal surgery. The available clinical data evaluating their efficacy have generally demonstrated these systems to be accurate and safe. A critical next step in the broader adoption of surgical robotics in spine surgery is the design and implementation of rigorous comparative studies to interrogate the utility of robotic assistance. Here we discuss current applications of robotics in spine surgery, review robotic systems FDA-approved for use in spine surgery, summarize randomized controlled trials involving robotics in spine surgery, and comment on prospects of robotic-assisted spine surgery.

Purpose: Intraoperative imaging plays an increased role in support of surgical guidance and quality assurance for interventional approaches. However, image quality sufficient to detect complications and provide quantitative assessment of the surgical product is often confounded by image noise and artifacts. In this work, we translated a three-dimensional model-based image reconstruction (referred to as "Known-Component Reconstruction," KC-Recon) for the first time to clinical studies with the aim of resolving both limitations., Methods: KC-Recon builds upon a penalized weighted least-squares (PWLS) method by incorporating models of surgical instrumentation ("known components") within a joint image registration-reconstruction process to improve image quality. Under IRB approval, a clinical pilot study was conducted with 17 spine surgery patients imaged under informed consent using the O-arm cone-beam CT system (Medtronic, Littleton MA) before and after spinal instrumentation. Volumetric images were generated for each patient using KC-Recon in comparison to conventional filtered backprojection (FBP). Imaging performance prior to instrumentation ("preinstrumentation") was evaluated in terms of soft-tissue contrast-to-noise ratio (CNR) and spatial resolution. The quality of images obtained after the instrumentation ("postinstrumentation") was assessed by quantifying the magnitude of metal artifacts (blooming and streaks) arising from pedicle screws. The potential low-dose advantages of the algorithm were tested by simulating low-dose data (down to one-tenth of the dose of standard protocols) from images acquired at normal dose., Results: Preinstrumentation images (at normal clinical dose and matched resolution) exhibited an average 24.0% increase in soft-tissue CNR with KC-Recon compared to FBP (N = 16, P = 0.02), improving visualization of paraspinal muscles, major vessels, and other soft-tissues about the spine and abdomen. For a total of 72 screws in postinstrumentation images, KC-Recon yielded a significant reduction in metal artifacts: 66.3% reduction in overestimation of screw shaft width due to blooming (P < 0.0001) and reduction in streaks at the screw tip (65.8% increase in attenuation accuracy, P < 0.0001), enabling clearer depiction of the screw within the pedicle and vertebral body for an assessment of breach. Depending on the imaging task, dose reduction up to an order of magnitude appeared feasible while maintaining soft-tissue visibility and metal artifact reduction., Conclusions: KC-Recon offers a promising means to improve visualization in the presence of surgical instrumentation and reduce patient dose in image-guided procedures. The improved soft-tissue visibility could facilitate the use of cone-beam CT to soft-tissue surgeries, and the ability to precisely quantify and visualize instrument placement could provide a valuable check against complications in the operating room (cf., postoperative CT)., (© 2019 American Association of Physicists in Medicine.)

Objective: To evaluate risk factors for the development of dysphagia after anterior cervical surgery., Methods: The records of 249 patients who underwent anterior cervical surgery were reviewed. The presence and severity of dysphagia were assessed with the Dysphagia Disability Index 6 weeks and 3, 6, and 12 months after surgery. Age; sex; ethnicity; cigarette smoking; previous cervical surgeries; reoperation for same pathology; type of procedure, incision, and instrumentation; number and levels involved; side of procedure, length of surgery; and use of postoperative bracing were analyzed., Results: During the first 6 months after surgery, 27 (10.8%) patients developed dysphagia. From these patients the presence of dysphagia at 6 weeks and at 3 and 6 months was 88.8%, 29.6%, and 7.4%, respectively. By 12 months, dysphagia had resolved in all cases. The mean age of patients with dysphagia was 55 years (SD 12.98) and 50 years (SD 12.07) in patients without dysphagia (P = 0.05). Dysphagic patients had an average of 2.2 (SD 1.15) levels operated compared with 1.84 (SD 0.950) in nondysphagic patients (P = 0.05). Patients who developed dysphagia were most often treated at C4-5 (67%) and C5-6 (81%: P < 0.001). Although mean operative time was slightly longer in patients with dysphagia (186 minutes) compared with those without (169 minutes), the difference was not significant., Conclusions: In our patients, the incidence of dysphagia was low, and it had completely resolved at 12 months in all cases. Risk factors for dysphagia were multilevel procedures, involvement of C4-5 and C5-6, and age., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Object: Coccidioides immitis is a dimorphous fungus endemic in the southwestern US and northern Mexico. While its primary presentation is pulmonary, it can have devastating neurological sequelae., Methods: The authors provide a retrospective review with long-term follow-up between 1986 and 2008 at a single institution., Results: The authors identified 27 patients between 13 and 81 years old (mean 41.4 years) with spinal coccidioides who were treated surgically at the Barrow Neurological Institute between 1986 and 2008. There were 24 males (89%) and 3 females (11%). Eleven patients (41%) had cervical spine involvement, 15 (56%) had thoracic involvement, 7 (26%) had lumbar involvement, and 2 (7%) had sacral involvement. All 27 patients presented with localized or radiating pain. Nine patients (33%) had myelopathic symptoms at presentation, 5 (19%) had radiculopathy, 4 (15%) had fever, and 12 (44%) had progressive kyphosis. The disease was most frequently seen among African American patients (14 patients [52%]), followed by Caucasians (5 patients [19%]), Asians (3 patients [11%]), and Hispanics (3 patients [11%]). Ten patients (37%) required multiple operations at the same level. Follow-up was available in 19 patients (70%) (mean 9.8 months, range 1-39 months). Sixteen (84%) of these 19 patients improved from their preoperative baseline states, 1 (5%) was stable on examination, 1 patient's condition (5%) deteriorated compared with the preoperative examination, and 1 patient (5%) died in the postoperative period., Conclusions: Although spinal involvement of coccidioidomycosis is relatively uncommon, a high index of suspicion and aggressive therapy are warranted to prevent devastating neurological injury, and lifelong antifungal therapy is often warranted.

Object: The object of this study was to investigate the effects of iatrogenic pedicle perforations from screw misplacement on the mean pullout strength of thoracic pedicle screws., Methods: Forty human thoracic vertebrae (T6-11) from human cadavers were studied. Before pedicle screws were inserted, the specimens were separated into 4 groups according to the type of screw used: 1) standard pedicle screw (no cortical perforation); 2) screw with medial cortical perforation; 3) screw with lateral cortical perforation; and 4) "airball" screw (a screw that completely missed the vertebral body). Consistency among the groups for bone mineral density, pedicle diameter, and screw insertion depth was evaluated. Finally, each screw was pulled out at a constant displacement rate of 10 mm/minute while ultimate strength was recorded., Results: Compared with well-placed pedicle screws, medially misplaced screws had 8% greater mean pullout strength (p = 0.482) and laterally misplaced screws had 21% less mean pullout strength (p = 0.059). The difference in mean pullout strength between screws with medial and lateral cortical perforations was significant (p = 0.013). Airball screws had only 66% of the mean pullout strength of well-placed screws (p = 0.009) and had 16% lower mean pullout strength than laterally misplaced screws (p = 0.395)., Conclusions: This in vitro study showed a significant difference in mean pullout strength between medial and lateral misplaced pedicle screws. Moreover, airball screws were associated with a significant loss of pullout strength.

Introduction: Segmental spinal dysgenesis, a rare developmental malformation, usually manifests during pregnancy or at birth. The resulting gross spinal instability necessitates spinal stabilization, which is inherently challenging in neonates., Methods: We report four cases of segmental dysgenesis: three in the thoracolumbar region and one at the cervicothoracic junction. The latter was maintained in a custom orthosis that restricted all craniospinal motion while allowing routine care. Two neonates underwent surgical stabilization. The fourth patient will remain in a brace until 12-14 months old when fusion is planned., Results: Fusion with rib autografts failed in the two neonates. One patient has been followed for 13 years and is paraplegic. The second patient was lost to follow up. The patient with the cervicothoracic dysgenesis maintained normal neurologic function until his death at 8 months of cardiac failure. The fourth patient is 12 months old and has been maintained in a thoracolumbar orthosis with stable neurologic function., Conclusion: Several factors contribute to the challenge of creating a stable fusion in neonates. Incomplete ossification of the vertebral bodies and poor results with allograft materials restrict fusion options. Neurologic deficits often prevent ambulation and decrease the axial-loading forces that enhance fusion. To allow children to grow and develop, we advocate rigid spinal immobilization for 12-18 months before spinal fusion (preferably, rib or fibular autograft). Given the already narrow spinal canal, the use of instrumentation is controversial. We advocate the use of instrumentation in infants only when a sound construct cannot be obtained with the graft alone.

Background: Incidental intradural tumors of the spine in the pediatric population are rare lesions whose management remains unclear. Surgeons must balance the risks of iatrogenic deficits and complications after surgical resection against the risks from progressive growth of the tumor. Moreover, the natural history of an incidental finding can be difficult to predict. Here, we review the literature on incidental intradural tumors of the spine and present considerations for their management. Summary: Growth of the tumor or changes in radiographic features are usually indications for resection. Asymptomatic lesions can be found in patients with genetic syndromes that predispose to tumor formation, such as neurofibromatosis type 1 and 2, schwannomatosis, and Von-Hippel-Lindau syndrome, and careful workup of a genetic cause is warranted in any patient presenting with multiple tumors and/or cutaneous features. Close follow-up is generally favored given the heavy tumor burden; however, some recommend pre-emptive resection to prevent permanent neurological deficits. Incidental intradural tumors can also occur in association with hydrocephalus, significant syringomyelia, and cord compression, and surgical treatment is usually warranted. Tumors may also be discovered as part of the workup for scoliosis, where they are not truly incidental to the scoliosis but rather are contributing to curve deformation. Key Messages: Thorough workup of patients for associated genetic syndromes or comorbidities should be undertaken in pediatric patients with incidental intradural tumors. Further research is needed into the natural history of these incidental lesions. Incidental tumors can often be managed conservatively with close follow-up, with surgical intervention warranted for expanding tumors or new-onset symptoms. [ABSTRACT FROM AUTHOR]

The letter responds to a recent publication in the Global Spine Journal by Fushimi et al. The authors express agreement with the importance of occupying as much of the interbody space with a cage as possible to minimize the risk of subsidence and increase the rate of arthrodesis. However, they raise concerns about the authors' claim that their study is the first to biomechanically evaluate TLIF using double banana-shaped cages, as they reported similar findings in their own study. The authors invite Fushimi and colleagues to review their resources on the technical nuances of the nested interbody technique. They commend Fushimi and colleagues for advancing the transforaminal interbody technique and emphasize the need to optimize patient outcomes and minimize complications. [Extracted from the article]

Robotics in spinal surgery has significant potential benefits for both surgeons and patients, including reduced surgeon fatigue, improved screw accuracy, decreased radiation exposure, greater options for minimally invasive surgery, and less time required to train residents on techniques that can have steep learning curves. However, previous robotic systems have several drawbacks, which are addressed by the innovative ExcelsiusGPSTM robotic system. The robot is secured to the operating room floor, not the patient. It has a rigid external arm that facilitates direct transpedicular drilling and screw placement, without requiring K-wires. In addition, the ExcelsisuGPSTM has integrated neuronavigation, not present in other systems. It also has surveillance marker that immediately alerts the surgeon in the event of loss of registration, and a lateral force meter to alert the surgeon in the event of skiving. Here, we present the first spinal surgery performed with the assistance of this newly approved robot. The surgery was performed with excellent screw placement, minimal radiation exposure to the patient and surgeon, and the patient had a favorable outcome. We report the first operative case with the ExcelsisuGPSTM, and the first spine surgery utilizing real-time image-guided robotic assistance. [ABSTRACT FROM AUTHOR]

The optimal decompression time for patients presenting with acute traumatic central cord syndrome (ATCCS) has been debated, and a high level of evidence is lacking. To compare early (<24 hours) versus late (≥24 hours) surgical decompression for ATCCS. Systematic review and meta-analysis. Medline, PubMed, Embase, and CENTRAL were searched from inception to March 15th, 2023. The primary outcome was American Spinal Injury Association (ASIA) motor score. Secondary outcomes were venous thromboembolism (VTE), total complications, overall mortality, hospital length of stay (LOS), and ICU LOS. The GRADE approach determined certainty in evidence. The nine studies included reported on 5,619 patients, of whom 2,099 (37.35%) underwent early decompression and 3520 (62.65%) underwent late decompression. The mean age (53.3 vs 56.2 years, p=.505) and admission ASIA motor score (mean difference [MD]=−0.31 [−3.61, 2.98], p=.85) were similar between the early and late decompression groups. At 6-month follow-up, the two groups were similar in ASIA motor score (MD= −3.30 [−8.24, 1.65], p=.19). However, at 1-year follow-up, the early decompression group had a higher ASIA motor score than the late decompression group in total (MD=4.89 [2.89, 6.88], p<.001, evidence: moderate), upper extremities (MD=2.59 [0.82, 4.36], p=.004) and lower extremities (MD=1.08 [0.34, 1.83], p=.004). Early decompression was also associated with lower VTE (odds ratio [OR]=0.41 [0.26, 0.65], p=.001, evidence: moderate), total complications (OR=0.53 [0.42, 0.67], p<.001, evidence: moderate), and hospital LOS (MD=−2.94 days [−3.83, −2.04], p<.001, evidence: moderate). Finally, ICU LOS (MD=−0.69 days [−1.65, 0.28], p=.16, evidence: very low) and overall mortality (OR=1.35 [0.93, 1.94], p=.11, evidence: moderate) were similar between the two groups. The meta-analysis of these studies demonstrated that early decompression was beneficial in terms of ASIA motor score, VTE, complications, and hospital LOS. Furthermore, early decompression did not increase mortality odds. Although treatment decision-making has been individualized, early decompression should be considered for patients presenting with ATCCS, provided that the surgeon deems it appropriate. [ABSTRACT FROM AUTHOR]

Metastatic glioblastoma to the vertebral spine is rarely encountered. The decision to intervene surgically must consider the poor prognosis in these patients. Here we report the case of a 46-year-old woman who presented with sudden weakness of the lower extremities 10 months after diagnosis of a left parietal glioblastoma. Imaging revealed osseous metastases to the thoracic and lumbosacral vertebral bodies. She initially underwent vertebroplasty with symptomatic improvement, but the progression of disease precluded further surgical interventions, and the patient was referred for chemotherapy and radiotherapy. The case illustrates that the choice of treatment modality varies throughout the time course of the disease—patients with spinal instability or few solitary metastases may benefit from intervention, but as the disease burden increases, palliative radiotherapy and chemotherapy may offer greater benefit. [ABSTRACT FROM AUTHOR]

Pharmacogenomics may help personalize medicine and improve therapeutic selection. This is the first study investigating how pharmacogenomic testing may inform analgesic selection in patients with spine disease. We profile pharmacogenetic differences in pain medication–metabolizing enzymes across patients presenting at an outpatient spine clinic and provide preliminary evidence that genetic polymorphisms may help explain interpatient differences in preoperative pain refractory to conservative management. Adults presenting to our outpatient spine clinic with chief symptoms of neck and/or back pain were prospectively enrolled over 9 months. Patients completed the Wong-Baker FACES and numeric pain rating scales for their chief pain symptom and provided detailed medication histories and cheek swab samples for genomic analysis. Thirty adults were included (mean age, 60.6 ± 15.3 years). The chief concern was neck pain in 23%, back pain in 67%, and combined neck/back pain in 10%. At enrollment, patient analgesic regimens comprised 3 ± 1 unique medications, including 1 ± 1 opioids. After genomic analysis, 14/30 patients (47%) were identified as suboptimal metabolizers of ≥1 medications in their analgesic regimen. Of these patients, 93% were suboptimal metabolizers of their prescribed opioid analgesic. Nonetheless, pain scores were similar between optimal and suboptimal metabolizer groups. This pilot study shows that a large proportion of the spine outpatient population may use pain medications for which they are suboptimal metabolizers. Further studies should assess whether these pharmacogenomic differences indicate differences in odds of receiving therapeutic benefit from surgery or if they can be used to generate more effective postoperative analgesic regimens. [ABSTRACT FROM AUTHOR]

Background Physical data are lacking on nutrient transport in human intervertebral discs (IVDs), which support regeneration. Our objective was to study nutrient transport in porcine IVDs to determine the effects of biomechanical and physiological factors. Methods In vitro testing of whole porcine IVDs was performed under different loading conditions. Fifty cervical, thoracic, and lumbar discs with attached end plates were removed from 4 Yorkshire pigs (90–150 lbs). Discs were placed in Safranin O or Fast Green FCF histological stains in diffusion or diurnal compression-tested groups. The end plate was studied by the use of polyurethane to block it. Traction was studied with a mechanical testing frame. Discs were cut transversely and photographed. Images were analyzed for depth of annulus fibrosus (AF) stained. The nucleus pulposus (NP) was assigned a staining score. Results Results showed no difference in AF staining between the 2 stains ( P = 0.60). The depth of AF staining did not increase ( P = 0.60) due to convection or disc height change via diurnal loading. The NP in all open end plate samples was stained completely by day 3. NP staining was decreased in blocked end plate samples ( P = 0.07) and AF staining was significantly less in traction samples than in diffusion-only samples ( P = 0.04). Conclusions This method showed that most small molecule nutrient transport occurs via the end plate. Compressive load was a negligible benefit or hindrance to transport. Traction hindered transport in the short term. This method can be used to study strategies for increasing nutrient transport in IVDs. [ABSTRACT FROM AUTHOR]

Objective: To report five patients who underwent cervical decompressive surgeries and developed persistent postoperative neurologic deficits compatible with spinal cord infarctions and evaluate causes for these rare complications. Methods: The clinical courses and imaging studies of five patients were retrospectively analyzed. Imaging findings, types of surgeries, vascular compromise or risk factors, hypotensive episodes, intraoperative somatosensory evoked potentials, concomitant brain infarctions, and clinical degree and radiographic extent of spinal cord infarction were studied. The presence of spinal cord infarction was determined by clinical course and imaging evaluation. Results: All five patients had antecedent cervical cord region vascular compromise or generalized vascular risk factors. Four patients developed hypotensive episodes, two intraoperatively and two postoperatively. None of the four patients with hypotensive episodes had imaging or clinical evidence of concomitant brain infarctions. Conclusions: Neuroimaging evaluation of spinal cord infarction after decompressive surgery is done to exclude spinal cord compression, to ensure adequate surgical decompression, and to confirm infarction by imaging. Antecedent, unrecognized preoperative vascular compromise may be a significant contributor to spinal cord infarction by itself or in combination with hypotension. [Copyright &y& Elsevier]

Abstract: Background context: In recent years, the number of complex spinal surgeries has increased significantly in the elderly population, where the prevalence of low bone density is highest. Consequently, spine surgeons often treat osteoporotic patients who are associated with higher rates of instrumentation failure. Therefore, establishing a successful fusion requires an appropriate substrate for bone formation and local bone remodeling. The fusion process can be supported by therapies that seek to shift the balance of bone homeostasis to increased formation and reduced resorption. Purpose: Thorough understanding of the physiology of bone formation and adjunctive therapies can help improve fusion rates. Therefore, we present a thorough review of the latest pharmacologic agents used to enhance bone strength and surgical spinal fusion. Methods: Systematic review of literature. Results: Current knowledge on bone physiology has led to the development of several pharmacologic agents that enhance bone formation and strengthen the human skeleton. At present, natural supplements of vitamin D and calcium or synthetic medications like bisphosphonates are widely used before and after spine surgeries to enhance bone fusion. Additional physiologic agents, including testosterone, parathyroid hormone, calcitonin, and growth hormone, have been shown to improve bone mass density or spinal fusion in both animal and human studies. As in other medical fields, gene therapy has shown viability and promise with the use of both viral and nonviral vectors. Conclusions: Through the understanding of bone physiology, numerous natural and synthetic pharmacologic agents have been developed to enhance the body's skeleton and to improve outcomes of spinal fusion surgery. [Copyright &y& Elsevier]

Abstract: Background context: Ewing''s sarcoma is the most common childhood malignancy of bone, but it rarely occurs as a primary extraosseous epidural tumor. Purpose: To heighten awareness and treatment options of this rare (epidural) presentation of Ewing''s sarcoma. Study design: Case report. Methods: Retrospective review. Results: We present a 13-year-old boy with progressive low back and bilateral lower extremity pain and normal neurologic examination. Magnetic resonance imaging showed an extradural tumor in the dorsal epidural space from T11 to L1. He underwent a posterior laminoplasty and gross total resection of tumor; histopathological diagnosis was consistent with Ewing''s sarcoma. After surgery, the patient underwent adjuvant chemotherapy and irradiation. At 10 months follow-up, the patient is neurologically intact without evidence of residual disease. Conclusions: Ewing''s sarcoma of the epidural space should be considered in the differential diagnosis of epidural mass lesions. Because wide surgical margins cannot be obtained, close follow-up with a low threshold for reoperation is mandatory. [Copyright &y& Elsevier]

Pedicle screws (PSs) are routinely used for stabilization to enhance fusion in a variety of spinal diseases. Although the accuracy of different PS placement methods has been previously reported, most of these studies have been limited to 1 or 2 techniques. The purpose was to determine the current accuracy of PS placement among 4 modalities of PS insertion (freehand [FH], fluoroscopy-assisted [FA], computed tomography navigation–guided [CTNav], and robot-assisted [RA]) and analyze variables associated with screw misplacement. A systematic review was performed of peer-reviewed articles reporting PS accuracy of 1 technique from January 1990 to June 2018. Accuracy of PS placement, PS insertion technique, and pedicle breach (PB) data were collected. A meta-analysis was performed to estimate the overall pooled (OP) rates of PS accuracy as a primary outcome, stratified by screw insertion techniques. Potential determinants were analyzed via meta-regression analyses. Seventy-eight studies with 7858 patients, 51,161 PSs, and 3614 cortical PBs were included. CTNav showed the highest PS placement accuracy compared with other techniques: OP accuracy rates were 95.5%, 93.1%, 91.5%, and 90.5%, via CTNav, FH, FA, and RA techniques, respectively. RA and CTNav were associated with the highest PS accuracy in the thoracic spine, compared with FH. The OP data show that CTNav has the highest PS accuracy rates. Thoracic PSs were associated with lower accuracy rates; however, RA showed fewer breaches in the thoracic spine compared with FH and FA. Given the heterogeneity among studies, further standardized and comparative investigations are required to confirm our findings. [ABSTRACT FROM AUTHOR]