Robotic navigation in spine surgery: Where are we now and where are we going?

Robotic navigation is a new and rapidly emerging niche within minimally invasive spine surgery. The robotic arms-race began in 2004 and has resulted in no less than four major robotic surgical adjuncts. Current Food and Drug Administration (FDA)-approved applications of robotic navigation are limited to pedicle screw instrumentation, but new indications and experimental applications are rapidly emerging. As with any new technology, robotic navigation must be vetted for clinical efficacy, efficiency, safety, and cost-effectiveness. Given the rapid advancements made on a yearly basis, it is important to make frequent and objective assessments of the available technology. Thus, the authors seek to provide the most up-to-date review of the history, currently available technology, learning curve, novel applications, and cost effectiveness of today’s available robotic systems as it relates to spine surgery.     

Application of robotic assistance in surgical treatment of degenerative disease of lumbosacral spine

Robotic assistance has gained increasing popularity in spinal surgery recently. Robotic assistance provides higher effectiveness and safety especially in conditions of complicated anatomy. It also enables the novel, previously unavailable surgical techniques, such as GO-Lif for lumbar spine fusion. The aim of the study is to assess the applicability and effectiveness of the robotic assistance in surgical treatment of degenerative lesion of lumbar spine. 16 patients were operated with robotic assistance device (SpineAssist; MAZOR Surgical Technologies, Caesarea, Israel) between August 2009 and February 2010 in Spinal Department of Burdenko Neurosurgical Institute (Moscow, Russia) with degenerative disc disease. Preoperative assessment included MRI, X-rays and high-resolution CT (slice < 1 mm). The CT is essential for preoperative planning using computed work station SpineAssist. The robot was utilized for automated intraoperative positioning of the instruments according to preoperatively planned trajectories. Basic parameters of surgeries were thoroughly recorded: overall surgery time, radiation dose (all manipulations were performed under fluoroscopic control), accuracy of screw placement relative to preoperative planning, which was assessed using postoperative high-resolution CT with 3D reconstruction. Particular interest of the study was focused on the novel fusion technique for lumbar spine: Go-Lif (Guided Oblique Lumbar Interbody Fusion). This fusion modality enables segment fixation with two screws only, it is comparable with pedicular screws in terms of stability, being far less invasive. It may be used standalone or together with TLIF techniques. Robotic assistance enabled optimal screw placement even in complex anatomical cases (thin pedicles and rotational deformity). No implant-related complications were recorded. Surgery time was much longer in first 2 cases, though in further it decreased nearly to conventional (without robot) surgery time. For radiation dose same tendency was observed--in first 2 cases all surgical steps were fluoroscopically controlled, in further cases--only for primary anatomy registration. Based on control CT, accuracy of implant placement with robotic assistance is 1 mm.     

神经外科手术机器人置入椎弓根螺钉的精准性

目的 探讨神经外科手术机器人在人体腰椎模型进行椎弓根螺钉置入的精准性.方法 利用0型臂影像系统对模型进行正侧位扫描,并三维重建,获取3D-CT数据,传入手术机器人系统,规划椎弓根螺钉的最佳进钉点和进钉方向.手术机器人系统利用3D-CT数据自动注册后,置入椎弓根螺钉.应用置钉前后的3D融合图像,按照Gertzbein-R...     

Image-guided pedicle screws using intraoperative cone-beam CT and navigation. A cost-effectiveness study

Image-guided surgery using intraoperative cone-beam CT and navigation improves screw placement accuracy rates. However, this technology is associated with high acquisition costs. The aim of this study is to evaluate the costs of revision surgery from symptomatic pedicle screw malposition to justify whether the costs of acquiring intraoperative navigation justify the expected benefits. This is a retrospective cost-effectiveness analysis of consecutive patients who had pedicle screw instrumentation using intraoperative cone-beam CT and navigation compared with patients who underwent freehand pedicle screw instrumentation at our institution over 4 years. The costs associated with revision surgery for symptomatic pedicle screw malposition (excess length of stay, intensive care, theatre time, implants and additional outpatient appointments) were calculated. A total of 19 patients had symptomatic screw malpositioning requiring revision surgery. None of these patients had screws inserted under navigation. Revision surgery accounted for an extra 304 bed days and an additional 97 h theatre time. The total extra spent over 4 years was £464,038. When compared to the costs of revision surgery for screw malpositioning, it was cost neutral to acquire and maintain this technology. Intraoperative image-guided surgery reduces reoperation rates for symptomatic screw malposition and is cost-effective in high volume centers with improved patients outcomes. High acquisition and maintenance cost of such technologies is economically justifiable.     

Posterior thoracic segmental pedicle screw instrumentation: evolving methods of safe and effective placement

The use of pedicle screw instrumentation in the spine has evolved over the last two decades. The initial use of pedicle screws began in the lumbar spine. As surgeons have become more comfortable with the complex anatomy required for accurate screw placement, the use of pedicle instrumentation has evolved to include their use in the thoracolumbar and thoracic spine. The impetus behind their increased use is a result of the many advantages that pedicle screw anchorage offers over traditional hook and rod constructs. Improved deformity correction and overall construct rigidity are two important advantages of pedicle screw instrumentation due its three-column control over the spinal elements. First, pedicle screw instrumentation obviates the need to place instrumentation within the spinal canal with its inherent risk of neurologic injury. Second, the placement of pedicle screws is independent of facet or laminar integrity and thus has been extremely useful in traumatic, neoplastic, and degenerative conditions. The benefits of pedicle screws in the thoracic spine has been tempered by the potential for catastrophic neurological or soft tissue injuries due to the close proximity of these structures. The narrow and inconsistent shape of the thoracic pedicles, especially in spinal deformity, makes their placement technically challenging. As a result, surgeons have employed a number of techniques to ensure the safe and efficacious placement of thoracic pedicle screws. Detailed anatomic landmarks used to determine pedicle location, intraoperative imaging including navigation, and neurophysiological monitoring are some of the techniques currently used by surgeons. The implementation of these techniques and a thorough understanding of the complex three-dimensional anatomy have allowed surgeons to successfully place thoracic and thoracolumbar pedicle screws.     

Fijación lumbar posterior empleando el sistema de imagen quirúrgica O-arm: experiencia inicial

ObjectThe use of transpedicular screw fixation has been widely accepted for the treatment of degenerative and traumatic pathology of the lumbar spine. Complications of spinal instrumentation can be serious. Screw misplacement can result in unintended durotomy, nerve root and/or cauda equina injury. In comparison to fluoroscopy-assisted screw placement, computer-assisted image guidance has been shown to achieve overall higher rates of accuracy. The O-arm is able to obtain computed tomography (CT)-type images with multiplanar reconstruction. In this study we evaluated a cohort of patients who underwent posterior lumbar fusion with pedicle screws utilizing the O-arm imaging system.MethodsA retrospective review of 40 consecutive patients who underwent posterior lumbar fusion surgery with O-arm utilization, was performed. The study population included 14 males and 26 females. Age range was 39-85 years with an average of 63.8 years. Twenty one patients had degenerative lumbar stenosis (52.5%) and 19 had spondylolisthesis (47.5%). Intraoperative CT-images were obtained. The mean time for surgery and screw placement was assessed.ResultsA total of 252 pedicle screws were sited using O-arm navigation system, with a mean of 6.3 screws per patient (range 4-10). On the basis of intraoperative CT, 3 screws were redirected, representing a 98.81% accuracy rate.The mean duration of surgery was 157.2 (90-240) minutes and the mean time for screw placement was 7.13 (3.08-15) minutes per screw.Three patients (7.5%) developed superficial wound infections which were treated conservatively. No patients required a return to the operating room because of screw malposition.ConclusionThe use of intraoperative O-arm imaging system with computer-assisted navigation significantly increases the surgical accuracy and safety of pedicle screw placement in lumbar fusion surgery.     

Application of different thresholds for instrumentation device testing in minimally invasive lumbosacral spine fixation

The main aim of this study was evaluating the reliability of stimulus-evoked electromyography (using different thresholds for stimulation of the instrumentation devices) for minimally invasive pedicle screw placement in the lumbosacral spine. A threshold of 5 mA was applied for the pedicle access needle. 7 mA was applied for the tapscrew and pedicle screw stimulation. The existence of threshold differences between vertebral levels was also assessed. All patients underwent postoperative computed tomography (CT) to determine the accuracy of pedicle screw placement. A total of 172 percutaneous pedicle screws were placed in 52 patients. 94.1% of screws were placed at L4, L5 and S1 vertebral levels. No statistically significant differences existed in thresholds of the pedicle access needles, tapscrews and pedicle screws between vertebral levels. In four instances, the pedicle access needle stimulation had a threshold of 5 mA (no breaches were associated). In the rest of occasions, the pedicle access needles had stimulation thresholds above 5 mA. In all instances, tapscrew and pedicle screw thresholds were above 7 mA; the tapscrews and pedicle screws had significantly greater thresholds than the pedicle access needles. No statistically significant differences existed in thresholds between tapscrews and pedicle screws. Postoperative CT imaging revealed one lateral pedicle violation. Both breach rate and false negative rate were 0.5%. No false positive cases were observed. No patients experienced postoperative pedicle screw–related neurologic deficits. A threshold of 5 mA for the pedicle access needle stimulation seems to be safe. Greater than 7 mA should be used for the tapscrew and pedicle screw stimulation.     

Current trends in pedicle screw stimulation techniques: lumbosacral, thoracic, and cervical levels

Unequivocally, pedicle screw instrumentation has evolved as a primary construct for the treatment of both common and complex spinal disorders. However an inevitable and potentially major complication associated with this type of surgery is misplacement of a pedicle screw(s) which may result in neural and vascular complications, as well as impair the biomechanical stability of the spinal instrumentation resulting in loss of fixation. In light of these potential surgical complications, critical reviews of outcome data for treatment of chronic, low-back pain using pedicle screw instrumentation concluded that "pedicle screw fixation improves radiographically demonstrated fusion rates;" however the expense and complication rates for such constructs are considerable in light of the clinical benefit (Resnick et al. 2005a). Currently, neuromonitoring using free-run and evoked (triggered) electromyography (EMG) is widely used and advocated for safer and more accurate placement of pedicle screws during open instrumentation procedures, and more recently, guiding percutaneous placement (minimally invasive) where the pedicle cannot be easily inspected visually. The latter technique, evoked or triggered EMG when applied to pedicle screw instrumentation surgeries, has been referred to as the pedicle screw stimulation technique. As concluded in the Position Statement by the American Society of Neurophysiological Monitoring (ASNM), multimodality neuromonitoring using free-run EMG and the pedicle screw stimulation technique was considered a practice option and not yet a standard of care (Leppanen 2005). Subsequently, the American Association of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS) Joint Section on Disorders of the Spine and Peripheral Nerves published their "Guidelines for the Performance of Fusion Procedures for Degenerative Disease of the Lumbar Spine" (Heary 2005, Resnick et al. 2005a, Resnick et al. 2005b). It was concluded that the "primary justification" of intraoperative neuromonitoring"... is the perception that the safety and efficacy of pedicle screw fixation are enhanced..." (Resnick et al. 2005b). However in summarizing a massive (over 1000 papers taken from the National Library of Medicine), contemporary, literature review spanning nearly a decade (1996 to 2003), this invited panel (Resnick et al. 2005b) recognized that the evidence-based documents contributing to the parts related to pedicle screw fixation and neuromonitoring were "... full of potential sources of error ..." and lacked appropriate, randomized, prospective studies for formulating rigid standards and guidelines. Nevertheless, current trends support the routine use and clinical utility of these neuromonitoring techniques. In particular free-run and triggered EMG have been well recognized in numerous publications for improving both the accuracy and safety of pedicle screw implantation. Currently, treatment with pedicle screw instrumentation routinely involves all levels of the spine - lumbosacral, thoracic, and cervical. Significant historical events, various neuromonitoring modalities, intraoperative alarm criteria, clinical efficacy, current trends, and caveats related to pedicle screw stimulation along the entire vertebral column will be reviewed.     

Localization of the trunk muscles using musculoskeletal ultrasound guidance for pedicle screw stimulation during spine surgery

The precise placement of recording electrodes at the relevant myotome is mandatory while performing pedicle screw stimulation (PSS) during spine surgery; however, their placement at trunk muscles is challenging. This study aimed to determine whether ultrasound guidance is useful for trunk muscle localization for PSS during spine surgery. A retrospective clinical study was conducted from a prospective database. Eighty-four patients eligible for spine surgery were recruited. Ultrasound was used to localize the intercostal, rectus abdominis, and internal oblique and psoas muscles if pedicle screw placement was performed at T3 to L1. After the operation, patients were examined for any new neurological deficits related to this procedure, and computed tomography was performed to check screw position if indicated. Four to 22 pedicle screws were used for spinal fixation. The threshold of stimulus to obtain a compound muscle action potential ranged from 1.29 to >20 mA during PSS. Six of our patients sustained new postoperative deficits, and only one case was related directly to pedicel screw misplacement. Loss of motor evoked potential (MEP) over both the lower limbs was noted during pedicle screw placement, and the stimulus threshold during PSS were 1.29 mA at the left T9 and 3.8 mA at the right T5 level. MEP remained absent at the end of surgery despite removal of those two screws. The patient woke with significant weakness in both lower limbs (muscle power 0/0) and voiding difficulty. Fortunately, he regained walking ability 4.5 months later after intensive rehabilitation therapy.     

3D-Slicer联合sina软件辅助椎弓根置钉在椎管内肿瘤手术中的应用

目的 探讨3D-Slicer联合sina软件辅助椎弓根置钉技术在椎管内肿瘤手术中的应用效果。方法 回顾性分析2018年1月至2021年1月手术治疗的46例椎管内肿瘤的临床资料。术中应用3D-Slicer联合sina软件辅助定位置钉26例（观察组）,徒手定位置钉20例（对照组）。术后行C臂、CT扫描,按照Gertzbein-Robbins方法评估置钉的准确性。结果 观察组术中射线量、单钉置入时间、术中出血量、术后术区引流量、术后住院时间均明显低于对照组（P<0.05）。观察组置钉穿破皮质骨发生率（16.38%）、不良置钉率（5.17%）、术中调整置钉率（18.10%）明显低于对照组（分别31.11%、13.33%、37.78%;P<0.05）。两组血管神经损伤及术后1年内钉棒相关并发症发生率均无统计学差异（P>0.05）。结论 与徒手定位置钉相比,3D-Slicer联合sina软件辅助椎弓根置钉,明显提高置钉的准确性,并具减少手术相关的副损伤,缩短住院时间。     

New generation intraoperative three-dimensional imaging (O-arm) in 100 spine surgeries: Does it change the surgical procedure?

The O-arm (Medtronic Sofamor Danek, Inc., Memphis, TN, USA), an intraoperative CT scan imaging system, may provide high-quality imaging information to the surgeon. To our knowledge, its impact on spine surgery has not been studied. We reviewed 100 consecutive spine surgical procedures which utilized the new generation mobile intraoperative CT imaging system (O-arm). The most common diagnoses were degenerative conditions (disk disease, spondylolisthesis, stenosis and acquired kyphosis), seen in 49 patients. The most common indication for imaging was spinal instrumentation in 81 patients (74 utilized pedicle screws). In 52 (70%) of these, the O-arm was used to assess screw position after placement; in 22 (30%), it was coupled with Stealth navigation (Medtronic Sofamor Danek, Inc.) to guide screw placement. Another indication was to assess adequacy of spinal decompression in 38 patients; in 19 (50%) of these, intrathecal contrast material was used to obtain an intraoperative CT myelogram. In 20 patients O-arm findings led to direct surgeon intervention in the form of screw removal/repositioning (n = 13), further decompression (n = 6), interbody spacer repositioning (n = 1), and removal of kyphoplasty trocar (n = 1). In 20% of spine surgeries, the procedure was changed based on O-arm imaging findings. We found the O-arm to be useful for assessment of instrumentation position, adequacy of spinal decompression, and confirmation of balloon containment and cement filling in kyphoplasty. When used with navigation for image-guided surgery, it obviated the need for registration.     

True accuracy of percutaneous pedicle screw placement in thoracic and lumbar spinal fixation with a CT-based navigation system: Intraoperative and postoperative assessment of 763 percutaneous pedicle screws

PurposeTo investigate intraoperative reinsertion of percutaneous pedicle screw (PPS) with intraoperative CT-based navigation and to evaluate the rate of deviation of PPS at postoperative radiographic examination.MethodsSeven hundred sixty-three screws were inserted in 138 patients. We investigated the rate of occurrence of intraoperative PPS reinsertion after the diagnosis of screw deviation by fluoroscopy and the causes of each screw deviation. The subsequent distribution of PPS deviation was evaluated by postoperative CT. We also assess the difference in variance between the group judged to be PPS misplaced intra-/postoperatively (IOD group/POD group) and appropriate PPS placement (ND group).ResultsAmong all the screws inserted, 10 (1.3%) were diagnosed as being deviated by fluoroscopy during surgery, and 74 (9.7%) screws were found to be deviated at postoperative CT evaluation. We found more pedicle screw mismatch in the POD group than in the ND group (52.7 vs 11.0%, P < 0.001). The distance between the screw and the reference was greater in the IOD group than that in the ND group (1.4 ± 1.2 vs 2.4 ± 1.1 vertebral levels, P = 0.016). In one patient in the IOD group, a motor function deficit was observed postoperatively.ConclusionPPS fixation under intraoperative CT-based navigation did not prevent screw deviation completely. It is necessary to consider errors that occur during surgery and to confirm placement with real-time assistance such as fluoroscopy even in a surgery performed under CT navigation assistance.     

Design and application of a novel patient-specific 3D printed drill navigational guiding template in percutaneous thoracolumbar pedicle screw fixation: A cadaveric study

The conventional surgical method of percutaneous pedicle screw fixation (PPSF) mainly uses X-ray fluoroscopy guidance to target the vertebral pedicle for screw placement. This study aimed to explore the feasibility of establishing a personalized drill guide template for PPSF based on a three-dimensional (3D) printing technique and to evaluate the accuracy and safety of the method for assisting screw insertion in cadaveric specimens. The T3-L3 trunk cadaveric specimens from six adults were subject to a computed tomography (CT) scan in the prone position. A three-dimensional model containing the back skin contour was reconstructed. A bilateral ideal pedicle screw in the T6-L1 segment was designed. Then, the reverse templates were designed. The two templates were fused and printed into an individualized guide template. PPSF was performed under the assistance of the guide template, and the CT scan was taken postoperatively to access the screw position. Ninety-six pedicle screws were successfully placed on the bilateral vertebral body of the T6-L1 segment with the assistance of a guide template. The guide plate was not loosened or displaced when operated by a single hand, and the operation time was 24.6 ± 7.9 s. The axial CT images after puncture indicated that in 96 puncture needles, 90 needles were grade I and 6 were grade II, with a puncture accuracy rate of 98.6%. In conclusion, an individualized PPSF navigation template was developed using Mimics software and 3D printing prototyping, which improved the accuracy of PPSF in cadaveric specimens.     

Intraparenchymal hematoma and intraventricular catheter placement using robotic stereotactic assistance (ROSA): A single center preliminary experience

BackgroundLarge supratentorial intraparenchymal hemorrhages are managed emergently with image-guided catheters that aim to minimize injury to surrounding parenchyma. Robotic assistance may offer advantages for stereotactic guidance and placement of such catheters. We describe our center’s experience with minimally invasive ROSA-assisted intraventricular and intraparenchymal hemorrhage catheter placement and delineate its safety and outcomes.MethodsA retrospective analysis was performed including all patients with intraparenchymal hematoma that underwent ROSA-assisted intraparenchymal and intraventricular catheter placement at the University of Pittsburgh Medical Center between 2017 and 2019. All patients received tissue plasminogen activator (tPA) through the intraparenchymal catheter. We performed a manual chart review of these patients. Pertinent clinical and radiological characteristics and patient outcomes were recorded and analyzed. Catheter trajectory was independently quantified and analyzed by two independent reviewers. Error between the planned trajectory and final position was calculated and analyzed.ResultsFour patients (2 males and 2 females, mean age of 64 years) with deep brain large volume intraparenchymal hemorrhages were treated with catheter evacuation with robotic assistance. For 2 of the 4 patients, thin-cut CT imaging allowed for the real trajectory of the catheter to be compared to the targeted trajectory to calculate error. The mean error of catheter placement was 3.48 mm. ROSA-assisted catheter placement achieved up to 95% reduction of intraparenchymal hematoma volume with a statistically significant decrease following catheter drainage (pre- 51.8 ± 19.1 cc vs. post- 13.0 ± 14.4; p < 0.01).ConclusionRobotic stereotactic assistance offers a safe and sufficiently accurate technique for intraparenchymal hematoma and intraventricular catheter placement.     

First case report using optical topographic-guided navigation in revision spinal fusion for calcified thoracic disk

Computer assisted navigation systems are frequently used in spine surgery to improve the accuracy of pedicle screw placement. The 7D Surgical System utilizes optical topographic imaging (OTI) with a camera positioned directly above the surgical field to perform rapid registration from a pre-operative CT scan onto anatomical landmarks with zero intra-operative radiation exposure. This current technology requires an open approach with well-exposed bony anatomy, raising concerns about using the 7D Surgical System in revision surgery, where typical anatomical landmarks may be altered, missing, or obscured by prior hardware. To overcome this, the 7D Surgical System is capable of registering off prior hardware. Here, we present the first published report of 7D Surgical System’s registration off prior hardware in a revision spinal fusion. The registration was accurate, and the workflow was easy and efficient with one registration required for 3 levels of instrumentation and discectomy/corpectomy. This demonstrates that the 7D Surgical System can be used in revision cases with altered, missing, or obscured anatomy.     

Unilateral versus bilateral pedicle screw instrumentation for single-level minimally invasive transforaminal lumbar interbody fusion

Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) has become an increasingly popular method of lumbar arthrodesis. However, there are few published studies comparing the clinical outcomes between unilateral and bilateral instrumented MIS TLIF. Sixty-five patients with degenerative lumbar spine disease were enrolled in this study. Thirty-one patients were randomized to the unilateral group and 34 to the bilateral group. Recorded demographic data included sex, age, preoperative diagnosis, and degenerated segment. Operative time, blood loss, hospital stay length, complication rates, and fusion rates were also evaluated. The Oswestry Disability Index (ODI) score and Visual Analog Scale (VAS) pain score data were obtained. All patients were asked to follow-up at 3 and 6 months after surgery, and once every 6 months thereafter. The mean follow-up was 26.6 months (range 18–36 months). The two groups were similar in sex, age, preoperative diagnosis, and operated level. The unilateral group had significantly shorter operative time, lower blood loss, and shorter hospital time than the bilateral group. The average postoperative ODI and VAS scores improved significantly in each group. No significant differences were found between the two groups in relation to ODI and VAS. All patients showed evidence of fusion at 12 months postoperatively. The total fusion rate, screw failure, and general complication rate were not significantly different. Results showed that single-level MIS TLIF with unilateral pedicle screw fixation would be sufficient in the management of preoperatively stable patients with lumbar degenerative disease. It seems that MIS TLIF with unilateral pedicle screw instrumentation is a better choice for single-level degenerative lumbar spine disease.     

术中CT辅助下椎弓根螺钉置入的精确性和安全性评估

目的 评估术中CT辅助下椎弓根固定技术的安全性和准确性。方法 回顾性分析2014年5月至2015年5月术中CT辅助下椎弓根固定手术治疗的39例脊柱脊髓疾病患者的临床资料,其中脊柱脊髓损伤6例,颅颈交界区畸形6例,脊柱退行性变14例,脊柱脊髓肿瘤13例;术后应用Gertzbein-Robbins分级评价螺钉植入的精确性。结果 椎弓根螺钉固定总数为112枚,术中根据CT影像进行位置修正的螺钉共38枚;其中脊柱脊髓损伤23枚,颅颈交界区畸形8枚,脊柱退行性变40枚,脊柱脊髓肿瘤41枚;颈椎 23枚,胸椎48枚,腰椎41枚。根据Gertzbein-Robbins分级0级105枚,1级5枚,2级2枚。术后发生切口感染4例、脑脊液漏2例、神经损伤1例,未发生与螺钉植入直接相关的并发症,也无二次翻修病例。结论 术中CT能够帮助术者在术中发现位置不良的椎弓根螺钉并对其进行修正,提高椎弓根螺钉植入固定术的精确性和安全性。     

Thoracic vertebra interbody fusion surgery with robotic assisted system in a swine model

Minimally invasive procedures have been increasing in spine surgery, and interest in robotic systems has inclined. In this study, we aimed to evaluate feasibility of a robotic-assisted thoracic spine interbody fusion in a swine model. Neurosurgeons performed the surgical procedures with robotic surgery certificates on the Da Vinci Xi Surgical System. Surgical approaches were applied using four ports while the swine was in the left lateral position. The surgical procedure was accomplished in 70 min including positioning and preparation of robotic system (20 min), placement of ports and thoracic dissection and confirmation of level with the C-arm system (10 min), discectomy and cage insertion (15 min), control of cage position via the C-arm system and closure (10 min). This study showed the anterior thoracic approach with robotic surgery is safe and feasible with providing a wide working area and high image quality.     

Early complications after instrumentation of the lumbar spine using cortical bone trajectory technique

This retrospective chart review aimed to identify and report on a series of early complications that resulted from instrumentation of the lumbar spine using the cortical bone trajectory (CBT) technique. CBT technique is a novel method for fixation of the lumbar spine. Since it was first described in 2009 this technique has gained significant popularity. Here we report a series of early complications that have developed in patients who had lumbar spine fusion using the CBT technique. A retrospective chart review was performed in which all cases utilizing the CBT technique for instrumentation of the lumbar spine by two fellowship trained spine surgeons at our institution between July 2012 and May 2014 were reviewed. Medical records were reviewed to determine the number of patients who went on to develop an early complication after instrumentation with this technique. An early complication was defined as any of the following occurring within 3 months of surgery: (1) early screw loosening confirmed by post-operative CT scan, (2) evidence of fracture development confirmed by post-operative CT scan, (3) intra-operatively identified durotomy, (4) superficial or deep post-operative infection and (5) neurological injury. A total of 22 cases using the CBT technique were performed in our department. Of these cases two patients went onto develop early screw loosening, one developed an intra-operative pars fracture, one developed a dural tear and lastly, one patient developed both a pedicle fracture and early screw loosening. At our institution a total of five patients thus far have developed early complications after undergoing instrumentation of the lumbar spine using the CBT technique between 2012–2014.