Background:Standard titanium pedicle screw systems are widely used in spinal fusion but produce imaging artifacts and may have limitations in fatigue resistance. CarboClear carbon fiber-reinforced PEEK (CFR-PEEK) implants offer improved radiolucency and fatigue properties, and negligible artifacts in MRI and CT scans. The purpose of this study was to evaluate the safety and effectiveness of CarboClear CFR-PEEK pedicle screw system for patients with degenerative disc disease (DDD) undergoing 1 level lumbar spinal fusion. Methods:A prospective, multicenter, FDA-regulated Investigational Device Exemption (IDE) clinical trial, including 55 patients with DDD at 1 level (L2 to S1). Patients received the CarboClear System and a PEEK interbody fusion device. They were evaluated preoperatively and postoperatively at 6 weeks, 3, 6, 12, and 24 months, and then annually until the last patient completed 24-month follow-up. Primary outcome measures included self-reporting Visual Analog Scale (VAS) pain scores and Oswestry Disability Index (ODI), radiographic fusion rate, and safety assessments. Secondary measures included self-reporting SF-12 Health Survey (SF-12) scores and patient satisfaction (VAS), and operative parameters. Results were compared to predefined literature control group. Results:At 24 months, 90.0% of the patients had clinically meaningful pain improvement (VAS ≥ 20), and 78.0% had ODI improvement ≥15 points. Rigorously defined fusion was achieved in 85.71% of the patients at 24 months and in 94.59% at 36 months. The neurological success rate was 93.33%. No serious device-related adverse events occurred. The 24-month index-level reoperation rate was 7.14%, including 1 implant removal case (1.79%). Compared to the literature control, CarboClear device demonstrated superior imaging clarity and at least equivalent clinical outcomes. Conclusions:The CarboClear System is a safe and effective alternative to titanium pedicle screws for lumbar fusion, providing improved imaging compatibility and fatigue resistance.

OBJECTIVE:To evaluate whether functional, clinical, and self-reported tests reflect lumbar spinal stenosis patients' decisions to undergo or defer surgery. METHODS:Among 108 participants, 77 chose surgery (SG), and 31 opted to wait and see (WaSG) whether they got better spontaneously. Both groups were assessed at baseline (t 0 ) and 3 months (t 1 ), with additional self-reported measures at 6 (t 2 ) and 12 months (t 3 ). Key outcomes included corridor walk distance, chair sit-to-stand repetitions, grip strength, and various pain and disability indices. RESULTS:At baseline, SG reported higher leg pain (NPRS-leg: Δ = 1.66, P = 0.002) and poorer functional outcomes across multiple tests. By t 1 , both groups improved in disability, but SG showed greater reductions in the Oswestry Disability Index (Δ = 7.85, P = 0.001) and sustained improvements in leg pain at subsequent assessments. WaSG consistently engaged in more walking (mean Δ = 123.5 minutes, P < 0.001). Regression analyses indicated that surgery status, flexibility, and strength significantly predicted improvements in disability (adjusted R² = 0.296). Logistic regression identified predictors for surgery choice, including biological sex, leg pain intensity, walking performance, and weekly walking hours. CONCLUSION:Functional status, self-reported disability, and fear-avoidance beliefs in lumbar spinal stenosis patients reflect their subjective decision regarding surgery and highlight the importance of baseline leg pain, calf strength, walking-related parameters, and physical function in recovery. STUDY DESIGN:Observational prospective cohort.

Anterior cervical corpectomy and fusion (ACCF) is an effective technique to address multi-level degenerative cervical myelopathy. However, as the number of surgical levels increases, the outcomes worsen with respect to complication rates, range of motion and length of surgery. This study aimed to determine the clinical outcome of ACCF procedures performed using a new distally curved and shielded drilling device. A retrospective study was conducted on 43 ACCF procedures in which the device was used for osteophyte removal. Patient files were reviewed to assess the early clinical results and complications following ACCF. Clinical outcomes were evaluated using patient neck and arm pain scores and SF-36 questionnaires. Hospitalization characteristics were compared with historical controls. All procedures were uneventful and without major complications or neurological deterioration. Single-level ACCF procedures required an average of 71 min and followed by an average hospitalization of 3.3 days. Osteophyte removal, verified by intraoperative imaging, was satisfactory. Average neck pain score was improved by 0.9 points (p = 0.24). Average arm pain score was improved by 1.8 points (p = 0.06). SF-36 scores were improved in all domains. The new curved device enabled safe and efficient removal of osteophytes sparing adjacent vertebral removal in ACCF procedures, thus improving the clinical outcome.

INTRODUCTION: Removal of pathologic tissue during degenerative spinal surgery cases near a bone-nerve interface presents a challenge during spinal decompression, especially in minimally invasive procedures. Robotic systems for spinal surgeries can potentially offer greater accuracy than manual operations. However, today’s robotic systems are designed only for placement of fusion hardware and lack the ability to work in-situ and in proximity to neural structures. METHODS: In the proposed approach, the surgeon utilizes a 6-degrees-of-freedom joystick to control an industrial grade robotic arm connected to curved-at-the-tip high-speed, shielded drilling end-effectors to perform various bone removal tasks. Live visual feedback is displayed from top-view and endoscopic camera views. Force readouts, correlated to the force exerted on the end-effector through tissue contact, provide real time visual feedback. Additional safety restrictions are designed into the system to prevent excessive force. System orientation training was conducted on vertebral models. Initially, three spine surgeons used the system to perform ipsilateral decompression and foraminotomy in four surgeries in a live pig model. Next, six surgeons used the system to perform ipsilateral decompression on two human cadavers. All surgeons completed questionnaires assessing procedure efficacy and system usability. RESULTS: Animal studies: Required decompression was achieved in all cases, with no complications and minimum-to-moderate bleeding. Intuitive usability and acceptable kinematic range of motion of the robotic system was confirmed. Cadaver study: Questionnaire results demonstrated high scores of confidence in the technique (4.7/5), overall satisfaction (4.4/5) and achievement of adequate decompression (3.9/5). All neural structures remained intact. CONCLUSIONS: This preliminary data indicates that the proposed robotic system can facilitate safe and precise decompression through removal of sufficient tissue removal at the bone/nerve interface. Further studies with a medical grade robotic arm are planned.

# Abstract 45. Determining clinically important improvement following surgery for degenerative conditions of the spine: analysis of the Canadian Spine Outcomes and Research Network (CSORN) Registry {#article-title-2} There is significant variability in clinically important improvement (CII)

Background Transforaminal lumbar interbody fusion (TLIF) represents a commonly performed spinal procedure that poses a significant financial burden on patients, hospitals and insurers. Reducing these costs, while maintaining efficacy, may be assisted by a new powered endplate preparation device, designed to shorten procedural time while offering positive impacts on other elements that contribute to the cost of care. Objective The aim of the study was to assess and compare the individual cost elements of TLIF procedures with and without the use of the device, to determine whether application of this technology translated into any material procedural savings. Methods The records of 208 single-level TLIF procedures in a single hospital were reviewed. Surgical time, length of hospital stay, blood loss, infection rate, and other parameters were compared for the cases where the device was used (device group; n = 143) and cases which used standard tools (control group; n = 65). The cost per unit of each element was derived from the literature, online resources, and the hospital's financial department. Results The analysis revealed a shorter surgery duration in the device group (23 min, after controlling for procedure year and patient characteristics; statistically significant at p < 0.001) and lower complication and readmission rates (p = 0.67 and p = 0.21, respectively) associated with the use of the device, leading to a statistically significant cost reduction of approximately 2060 US dollars (US$) (p < 0.01). Conclusion The study suggests that use of the device may lead to a cost reduction and shorter procedure without deteriorating the clinical outcome.

BACKGROUND CONTEXT Spinal procedures often require the removal of bony tissues to prevent nerve compression and reduce pain. In order to reach difficult-access spinal regions such as the foramen, the surgeon is often required to drill (or otherwise remove) through healthy supporting bone structures, therefore increasing the risk of spinal instability. PURPOSE This study describes the authors' experience with a recently developed, FDA-approved, curved-at-the-tip drill-like device, designed to provide efficient bone removal from difficult-access areas. The device is shielded on one side of the tip in order to improve safety and reduce the risk of complications. STUDY DESIGN/SETTING Multi-center retrospective study and surgeon questionnaire analysis. PATIENT SAMPLE Device-use patterns were extracted from 103 lumbar foraminotomies, 53 cervical osteophyte removals and 143 transforaminal lumbar interbody fusion (TLIF) procedures conducted using the device and 66 comparable control TLIF procedures conducted by the same surgeon group used as a control group. OUTCOME MEASURES Device-related dural tear rate, surgeon assessment of the procedure, duration of device use. For the TLIF procedures, OR time and length of stay were also compared with the control group. METHODS The rate of device-related dural tears was calculated from 1,116 safety records of procedures conducted using the device and compared with literature rates of traditional-tools device-related tears. Surgeon assessment was obtained using questionnaires at the end of each procedure. The duration of device-use, length of procedure and other operative and postoperative parameters were extracted from procedure records and reviewed where available. RESULTS The device-related dural tear rate was 0.3% (three tears in 1,116 procedures). This rate is significantly lower than the device-related tear rate of 2.9% associated with the Kerrison rongeur and high-speed drill published in a prior literature review. Surgeon satisfaction rate was 94% and sufficient bone volume reduction was reported in 95% of the procedures. Surgery time reduction was the most common comment in surgeon questionnaires. In some cases, of multi-level complicated fusions, the time reduction was estimated as several hours. Lumbar foraminotomy using the device required, on average, 2 minutes/foramen. In some of the cases, the device enabled the surgeon to avoid a spinal fusion as the improved access eliminated the need for excessive bone removal. Cervical osteophyte removal required, on average, three minutes, and in the majority of the cases enabled the surgeons to avoid additional level discectomy or corpectomy. TLIF procedures required on average 10 minutes less than control procedures with a 0.5 days reduction in length-of-stay. The device was successfully used in both open and minimal invasive settings without a significant difference between settings. CONCLUSIONS The device is safe and effective for performing spinal surgery in multiple indications. Procedure time reduction was noted as the most significant advantage by the surgeons. FDA DEVICE/DRUG STATUS Dreal (Carevature Medical Ltd.) (Approved for this indication)

Objective: This study examines and compares excitability characteristics of tibialis anterior (TA) and abductor hallucis (AH) transcranial motor evoked potentials (tcMEP) during anterior cervical decompression and fusion (ACDF) surgery. Methods: Electrophysiological and clinical data of 89 patients who underwent ACDF procedure were retrospectively reviewed. TcMEP data of TA and AH muscles from 178 limbs were analyzed for availability, robustness and stability during the procedure. Results: TA tcMEP was available at 83% whereas AH tcMEP was available at 99% of the monitored lower limbs at preposition baseline. Availability of both TA and AH tcMEP was demonstrated in 147/178 limbs. The baseline amplitude of AH tcMEP was significantly greater than that of TA tcMEP recorded from the same limb (744.6 +/- 54.0 and 326.9 +/- 33.3 mV, respectively). Simultaneous deterioration of TA and AH tcMEP data was demonstrated in 10/147 limbs. Deterioration of either TA or AH tcMEP data accompanied by unchanged tcMEP data from the other lower limb muscle was noted in 32/147 compared to 1/147 limbs, respectively. The deteriorated TA and AH tcMEP data returned to baseline before closing at incidence of 17% compared to 46%, respectively. No new lower extremity (LE) neurological deficit was presented postoperatively in any patient. Conclusions: AH tcMEP is a more reliable candidate than TA tcMEP for intraoperative LE monitoring in ACDF procedure. Significance: The excitability differentials in LE tcMEP in ACDF is a variable that need to be considered while interpreting intraoperative neurophysiological data. (C) 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V.

Background: The appropriate approach for surgical removal of thoracic disc herniations is controversial. The posterior approach historically acquired a bad reputation due to high rates of neurologic deterioration subsequent to spinal cord manipulation. The anterior approach has consequently gained popularity but entails a larger magnitude of surgery if open and is technically demanding if approached thoracoscopically. Approaching the thoracic disc posteriorly following unilateral facetectomy and pediculectomy was suggested in 1978. This study presents a technique for posterior unilateral thoracic discectomy through a hemilaminectomy, unilateral facetectomy, and hemipediculectomy, facilitated by a novel curved dorsally shielded high-speed device. Introducing the device ventral to the dural sac allows removal of calcified and soft disc fragments without relying on forceful manual maneuvers and avoiding manipulation of the spinal cord. Methods: The maximal disc protrusion side is approached through a hemilaminectomy, unilateral facetectomy, and hemipediculectomy removing the superior half of the pedicle and exposing the disc transforaminally, allowing its removal using the device. Pedicle fixation and fusion concluded all procedures (TTIF). Between June 2014 and November 2018, 12 patients (6 men and 6 women) ages 23 to 74 years underwent posterior thoracic discectomy applying the above approach. The affected levels were D3 to D4 (1), D5 to D6 (1), D7 to D8 (1), D9 to D10 (1), D10 to D11 (3), D11 to D12 (4), and D12 to L1 (1). Results: All patients presented with neurologic deterioration and all but 2 with pyramidal signs. All procedures were uneventful, without dural tears. None of the patients deteriorated neurologically. Average back pain visual analog scale scores decreased by 1.2, from 6.6 to 5.4. Average leg pain visual analog scale scores decreased by 2.2, from 6.6 to 4.4. Improvement was noted in Oswestry Disability Index scores and 6 SF-36 metrics. Conclusions: The new curved device and approach allow for a faster, safer thoracic disc herniation removal.

INTRODUCTION:The purpose of the present study was to examine the effect of various extra- and intraoperative factors on the ability of neuromonitoring to predict neurological complications.METHODS:We reviewed the data from 592 patients who had undergone cervical spine surgery with neuromonitoring at Assuta Medical Center from 2006 to 2013. We compared the somatosensory evoked potentials, transcranial electric motor evoked potentials, and electromyographic signals collected throughout surgery with the patient surgical outcome measures, demographic data, pre-existing pathological features found on neurological examination, and radiographic findings. Descriptive and inferential analyses were used to estimate the relative explanatory power contributed by these factors.RESULTS:We included 468 patients in the present study. Neuromonitoring changes occurred in 100 patients, and the appropriate clinical intervention was undertaken in all 100, with recovery of the signals in 69. A transient neuromonitoring change was not associated with a poor outcome (only 8 of 69 patients). However, a permanent neuromonitoring change was associated with a new neurological deficit (13 of 31 patients) Changes occurring during positioning or decompression were associated with better clinical outcomes than were changes occurring during the rest of the procedure. Extraoperative factors were not associated with an increased risk of neuromonitoring changes during surgery or poorer surgical outcomes.CONCLUSIONS:Permanent neuromonitoring changes predicted for new neurological deficits. However, transient changes were not associated with a new deficit. Neuromonitoring changes occurring during positioning and decompression had better clinical outcomes compared with those occurring during the rest of the procedure.

Background: Durotomy is a major complication of spinal surgery, potentially leading to additional clinical complications, longer hospitalization, and increased costs. A reference durotomy incidence rate is useful for the evaluation of the safety of different surgical aspects. However, the literature offers a wide range of incidence rates, complicating this comparison. Theoretically, a reference incidence value can be extracted from administrative databases, containing a large number of procedures. However, it is suspected that these databases suffer from underreporting of complications. This study aims to evaluate durotomy incidence using several large-scale databases and to assess the ability to use it as a reference by comparison to durotomy incidences directly associated with 4 bone removal devices, including the commonly used high-speed drill. Methods: Durotomy overall incidence was estimated from several administrative databases using different methods in order to achieve minimal and maximal estimations. Durotomy incidences for 3 bone removal devices were derived using literature meta-analysis, and the incidence for the fourth device was calculated using clinical data. Results: The incidence range of durotomy according to the databases was 2.8–3.5%. The calculated incidence of durotomy for the studied devices was 0.4–2.91%. The highest rate, 2.91%, is associated with the commonly used highspeed drill combined with Kerrison Rongeur and bone punches. Since bone-removal devices are just one of the possible causes of dural tears, the general incidence is expected to be higher than the incidence associated with the devices, yet even the maximal estimation, 3.5%, was only slightly higher, suggesting that the speculation of underreporting of dural tears to these databases is probably true, as also supported by the mostly higher incidences reported in the literature. Conclusions: Hospital administrative databases seem to show a lower-than-reasonable incidence of durotomy, suggesting possible underreporting. Researchers should therefore use this tool with caution. Reduction of the absolute durotomy incidence by approximately 2.5% can be achieved by improving the safety of bone-removal devices.

BACKGROUND CONTEXT Intraoperative neurophysiological monitoring (IONM) has gained rather wide-spread acceptance as a method to mitigate risk to the lumbar plexus during Lateral Lumbar Interbody Fusion (LLIF) surgery. The most common approach to IONM involves using only electromyography (EMG) monitoring, and the rate of postoperative deficit remains unacceptably high. Other test modalities, such as transcranial electric motor-evoked potentials (tcMEPs) and somatosensory-evoked potentials (SSEPs), may be more suitable for monitoring neural integrity but they have not been widely adopted during LLIF. Recent studies have begun to examine their utility in monitoring LLIF surgery with favorable results. PURPOSE To evaluate the efficacy of different IONM paradigms in the prevention of iatrogenic neurologic sequelae during LLIFand to specifically evaluate the utility of including tcMEPs in an IONM strategy for LLIF surgery. STUDY DESIGN/SETTING Nonrandomized, retrospective analysis of 479 LLIF procedures at a single institution over a 4-year period. During the study epoch, three different IONM strategies were employed for LLIF procedures: (1) Surgeon-directed T-EMG monitoring ("SD-EMG"), (2) neurophysiologist-controlled T-EMG monitoring ("NC-EMG"), and (3) neurophysiologist-controlled T-EMG monitoring supplemented with MEP monitoring ("NC-MEP"). PATIENT SAMPLE The patient population was comprised of 254 males (53.5%) and 221 females (46.5%). Patient age ranged from a minimum of 21 years to a maximum of 89 years, with a mean of 56.6 years. OUTCOME MEASURES Physician-documented physiologic measures included manual muscle test (MMT) grading of hip-flexion, hip-adduction, or knee-extension, as well as hypo- or hyperesthesia of the groin and/or anterolateral thigh on the surgical side. Self-reported measures included numbness or tingling in the groin and/or anterolateral thigh on the surgical side. METHODS Patient progress notes were reviewed from the postoperative period up to 12 months after surgery. The rates of postoperative sensory and/or motor deficit consistent with lumbar plexopathy or peripheral nerve palsy on the surgical side were compared between the three cohorts. RESULTS Using the dependent measure of neurologic deficit, whether motor and/or sensory, patients with NC-MEP monitoring had the lowest rate of immediate postoperative deficit (22.3%), compared to NC-EMG monitoring (37.1%) and SD-EMG monitoring (40.4%). This result extended to sensory deficits consistent with lumbar plexopathy (pure motor deficits being excluded); patients with NC-MEP monitoring had the lowest rate (20.5%) compared to NC-EMG monitoring (34.3%) and SD-EMG monitoring (36.9%). Additionally, evaluation of postoperative motor deficits consistent with peripheral nerve palsy (pure sensory deficits being excluded), the NC-MEP group had the lowest rate (5.7%) of motor deficit compared to the SD-EMG (17.0%) and NC-EMG (17.1%) cohorts. Finally, when assessing only those patients whose last follow-up was greater than or equal to 12 months (n=251), the rate of unresolved motor deficits was significantly lower in the NC-MEP group (0.9%), as compared to NC-EMG (6.9%) and SD-EMG (11.0%). Comparison of the NC-MEP versus NC-EMG and SD-EMG groups, both independently and combined, was statistically significant (>95% confidence level) for all analyses. CONCLUSIONS The results of the present study indicate that preservation of tcMEPs from the adductor longus, quadriceps, and tibialis anterior muscles are of paramount importance for limiting iatrogenic sensory and motor injuries during LLIF surgery. In this regard, the inclusion of tcMEPs serves to compliment EMG and allows for the periodic, functional assessment of at-risk nerves during these procedures. Thus, tcMEPs appear to be the most effective modality for the prevention of both transient and permanent neurologic injury during LLIF surgery. We propose that the standard paradigm for protecting the nervous system during LLIF be adapted to include tcMEPs. Intraoperative neurophysiological monitoring (IONM) has gained rather wide-spread acceptance as a method to mitigate risk to the lumbar plexus during Lateral Lumbar Interbody Fusion (LLIF) surgery. The most common approach to IONM involves using only electromyography (EMG) monitoring, and the rate of postoperative deficit remains unacceptably high. Other test modalities, such as transcranial electric motor-evoked potentials (tcMEPs) and somatosensory-evoked potentials (SSEPs), may be more suitable for monitoring neural integrity but they have not been widely adopted during LLIF. Recent studies have begun to examine their utility in monitoring LLIF surgery with favorable results. To evaluate the efficacy of different IONM paradigms in the prevention of iatrogenic neurologic sequelae during LLIFand to specifically evaluate the utility of including tcMEPs in an IONM strategy for LLIF surgery. Nonrandomized, retrospective analysis of 479 LLIF procedures at a single institution over a 4-year period. During the study epoch, three different IONM strategies were employed for LLIF procedures: (1) Surgeon-directed T-EMG monitoring ("SD-EMG"), (2) neurophysiologist-controlled T-EMG monitoring ("NC-EMG"), and (3) neurophysiologist-controlled T-EMG monitoring supplemented with MEP monitoring ("NC-MEP"). The patient population was comprised of 254 males (53.5%) and 221 females (46.5%). Patient age ranged from a minimum of 21 years to a maximum of 89 years, with a mean of 56.6 years. Physician-documented physiologic measures included manual muscle test (MMT) grading of hip-flexion, hip-adduction, or knee-extension, as well as hypo- or hyperesthesia of the groin and/or anterolateral thigh on the surgical side. Self-reported measures included numbness or tingling in the groin and/or anterolateral thigh on the surgical side. Patient progress notes were reviewed from the postoperative period up to 12 months after surgery. The rates of postoperative sensory and/or motor deficit consistent with lumbar plexopathy or peripheral nerve palsy on the surgical side were compared between the three cohorts. Using the dependent measure of neurologic deficit, whether motor and/or sensory, patients with NC-MEP monitoring had the lowest rate of immediate postoperative deficit (22.3%), compared to NC-EMG monitoring (37.1%) and SD-EMG monitoring (40.4%). This result extended to sensory deficits consistent with lumbar plexopathy (pure motor deficits being excluded); patients with NC-MEP monitoring had the lowest rate (20.5%) compared to NC-EMG monitoring (34.3%) and SD-EMG monitoring (36.9%). Additionally, evaluation of postoperative motor deficits consistent with peripheral nerve palsy (pure sensory deficits being excluded), the NC-MEP group had the lowest rate (5.7%) of motor deficit compared to the SD-EMG (17.0%) and NC-EMG (17.1%) cohorts. Finally, when assessing only those patients whose last follow-up was greater than or equal to 12 months (n=251), the rate of unresolved motor deficits was significantly lower in the NC-MEP group (0.9%), as compared to NC-EMG (6.9%) and SD-EMG (11.0%). Comparison of the NC-MEP versus NC-EMG and SD-EMG groups, both independently and combined, was statistically significant (>95% confidence level) for all analyses. The results of the present study indicate that preservation of tcMEPs from the adductor longus, quadriceps, and tibialis anterior muscles are of paramount importance for limiting iatrogenic sensory and motor injuries during LLIF surgery. In this regard, the inclusion of tcMEPs serves to compliment EMG and allows for the periodic, functional assessment of at-risk nerves during these procedures. Thus, tcMEPs appear to be the most effective modality for the prevention of both transient and permanent neurologic injury during LLIF surgery. We propose that the standard paradigm for protecting the nervous system during LLIF be adapted to include tcMEPs.

Purpose: To evaluate the frequency of loss of neurophysiological potentials during head positioning, the usefulness of head repositioning to restore the potentials, and the effect on neurological outcome. Methods: We retrospectively reviewed consecutive cervical spine surgeries performed at the Israel Spine Center, Assuta Medical Center, during 2006 to 2013. Surgeries performed with neuromonitoring (transcranial-electric motor evoked potentials, somatosensory evoked potentials, electromyographic recordings) were included. Demographic data, medical history, findings at neurological examination and imaging, electrophysiological data recorded during surgery, and neurological outcomes were collected and analyzed. Results: Three hundred eighty-one patients met inclusion criteria. Loss of potentials detected in nine patients during patient positioning and repositioning was undertaken with the aim of restoring electrophysiological signals. In 5/9 patients, repositioning resulted in immediate reappearance of potentials; in 1/5, potentials were affected again during decompression. In 4/9, repositioning did not immediately restore electrophysiological signals; in ¼, potentials reappeared later during the decompression and in ¾, potentials had not recovered till the conclusion of surgery. There were new neurological deficits in 2/9, including one patient with loss of potential that was not restored with repositioning and the one in whom potential was restored but lost again during decompression. Conclusions: Intraoperative neuro monitoring is an efficient tool to alert the surgical team to potential neurological damage. Head reposition often restores the electrophysiological signals with possible prevention of impending sequelae.

Spinal anesthesia and lumbar puncture may lead to intracerebral, subdural or subarachnoid bleeding and there have been previous reports on patients who developed subdural hematoma a few days after surgery on the spine. This is a case report of a patient who developed acute subdural hematoma during surgery performed to remove an intradural spine tumor. This report suggests that the possibility of an intracranial hematoma should be considered in cases of neurological deterioration following spinal surgery.

STUDY DESIGN:Case reports and retrospective review of accidental durotomies in lumbar surgeries during 5 years.OBJECTIVES:To draw attention to a potentially serious complication of incidental durotomy-remote cerebellar hemorrhage.SUMMARY AND BACKGROUND DATA:Accidental durotomy is a frequent complication of spinal surgery. In most cases the outcome of incidental durotomy is favorable. A delayed potentially serious complication of CSF loss during and after lumbar surgery is remote cerebellar hemorrhage (RCH).METHODS:During 2008-2012, 1169 lumbar spine procedures were performed at our spine center. In 210 surgeries incidental or intentional durotomies occurred. All patients with durotomies were managed with suturing of the dural wound followed by deep wound drainage left for 5 days and tight wound closure.RESULTS:Of the 210 patients with CSF loss three patients were identified to suffer from RCH-an incidence of 0.26%. The three patients ages 56, 67 and 75 years developed RCH between 36-192 hours after surgery. All three were managed with supportive treatment and close clinical supervision. A gradual clinical and radiological improvement was noted in all three patients.CONCLUSIONS:Severe headache after spinal surgery and or declining mental status should not be attributed only to low CSF pressure secondary to dural tearing. It can also be the result of remote cerebral or cerebellar hemorrhage. Once the diagnosis of RCH is made, close clinical supervision is mandatory. In most cases non-operative supportive treatment may lead to eventual full clinical recovery.

Background Context Although in situ posterolateral fusion is considered the gold standard for surgical treatment of low-grade adult spondylolisthesis, correction of the sagittal translation by instrumented slip reduction is more controversial in adults; nevertheless it may delay adjacent level disc degeneration. Purpose The present study was undertaken to evaluate the safety and clinical outcome of operative instrumented slip reduction in 12 adults with isthmic spondylolisthesis accompanied by advanced disc degeneration at that level. Study Design This study was a retrospective review of 12 consecutive lumbar or lumbosacral isthmic slip, which underwent operative slip reduction in our institute. Patient Sample All adult patients having operative instrumented slip reduction of isthmic spondylolisthesis from January 2000 to December 2005 were assessed. Outcome Measures Outcome measures included the Oswestry Disability Index (ODI) for low back pain and the visual analog scale (VAS) of back and leg pain. Patient outcome was assessed by work status, participation in sports activities and intake of pain medications. Methods Between January 2000 and December 2005, we performed slip reduction on 12 adults aged 28 to 62 years (average 47) with symptomatic lumbar or lumbosacral isthmic spondylolisthesis. The indications for surgery were long-standing low back and leg pain that had not responded to nonoperative management. Results The vertebral slip ranged between 15% and 90% (average 34%). Radiologic evidence of adult slip progression was available in 5 patients, one had a de novo slip formation and the others had increased sagittal translation on flexion-extension lateral x-rays. All 12 patients underwent posterior decompression, pedicle screw fixation, slip reduction, and posterior lumbar interbody fusion. The slip was anatomically reduced by 100% in 5 patients and between 90% and 95% in 7 (average 95% for the group). X-rays revealed no evidence of instrumentation failure at a mean follow-up of 38 months (range: 18 to 72). Minimal loss of correction (5%) was observed in 2 cases. No neurologic complications were encountered. The mean preoperative ODI of 49 dropped to 12 postoperatively (range: 0 to 20). The mean preoperative VAS for back pain of 7.3 dropped to 1.6 after surgery (range: 0 to 3). The mean preoperative VAS for leg pain of 8 dropped to 1 after surgery (range: 0 to 4). Five patients were followed for more than 3 years: none had evidence of adjacent level disc disease. Conclusions Our results may support performing slip reduction in selected adults with isthmic spondylolisthesis.

OBJECTIVES:To evaluate long-term treatment outcome of patients with infected posterior lumbar interbody fusion (PLIF) managed with surgical debridement and or prolonged antiobiotic treatment without removal of the interbody cages. METHODS:Between 1996 and 1999, 8 out of 111 patients who underwent PLIF were diagnosed with deep wound infection (7.2%). All infected patients were clinically followed for at least 2 years after completion of the antibiotic treatment. Longer follow-up of at least 6 years duration was performed by a telephone interview. RESULTS:Six patients were managed with surgical debridement, wound irrigation, and primary closure of the wound. None of the patients required removal of the instrumentation. In 2 patients, the PLIF cages were repositioned in the face of infection. All 8 patients received 4 to 6 weeks of intravenous antibiotic therapy followed by another 6 to 9 weeks of oral antibiotic administration. At 2-year follow-up, no clinical or laboratory signs of recurrent infection were evident. Four of the 8 patients reported improved clinical status compared with their prefusion status. At 6-year follow-up, 3 patients had minimal disability according to the Oswestry Disability Index and 2 patients had moderate disability with residual leg pain. CONCLUSIONS:In cases of postoperative deep wound infection after PLIF with cages, removal of the interbody implants is not necessary. Treatment is composed of prolonged antibiotic therapy guided by antimicrobial susceptibility of the isolated bacteria and supplemented with extensive surgical debridement if needed.

BACKGROUND:Ipsilateral recurrent disc herniation after lumbar discectomy is a significant problem in the management of lumbar disc disease and may necessitate repeat surgical intervention. A population-based study in Finland found that about 14% of all primary lumbar discectomies required additional surgical interventions. Interspinous devices, which have been shown to unload the posterior anulus, may reduce the occurrence of recurrent herniations. We report our short-term experience with the use of the Wallis device in the management of patients with lumbar disc herniation undergoing primary disc excision. PATIENTS AND METHODS:Thirty-seven consecutive patients (23 males and 14 females, average age 36 y) underwent primary lumbar disc excision followed by fixation of the segment with the Wallis implant during a period of 1 year. Indications for implanting the Wallis device were a voluminous disc herniation and preservation of at least 50% of disc space height. Surgery was performed at level L4-5 in most patients. Average follow-up after surgery was 16 months (range 12 to 24). The last 14 patients were also evaluated by the preoperative and postoperative Oswestry Disability Index (ODI) questionnaire, the SF-36 survey, and by a visual analog scale (VAS) for back and leg pain. RESULTS:The average ODI dropped from 43 to 12.7. The average VAS for back pain dropped from 6.6 to1.4 and the average Vas for leg pain dropped from 8.2 to 1.5. Five patients (4 males and 1 female) with relapsing leg pain were diagnosed by contrast-enhanced magnetic resonance imaging as suffering from recurrent herniation (5/37, 13%). All reherniations occurred at level L4-5 level between 1 and 9 months after the index surgery. Two of the 5 patients subsequently underwent additional discectomy and fusion. SUMMARY:The current Wallis implant is probably incapable of reducing the incidence of recurrent herniations, but it still may be useful in patients with discogenic back pain due to early degenerative disc disease.

Lumbar or sacral nerve root compression is most commonly caused by intervertebral disc degeneration and/or herniation. Less frequently, other extradural causes may be implicated, such as infection, neoplasm, epidural hematoma, or ligamentum flavum pathology. We present the case of a patient with spontaneous ligamentum flavum hematoma compressing the L4 nerve root, without antecedent trauma. Although exceedingly rare, the diagnosis of ligamentum flavum pathology in general, and that of ligamentum flavum hematoma in particular, should be considered on those rare occasions when the etiology of lumbar or sacral nerve root compressions appears enigmatic on radiological studies. Usually surgical treatment produces excellent clinical outcome.