Thoracic root-related intradural extramedullary cavernoma presenting with subarachnoid hemorrhage: illustrative case.

BACKGROUND: Just 5% of all cavernomas are located in the spine. Thoracic root-related subtypes are the rarest, with a total of 14 cases reported in the literature to date. Among them, only 4 presented with subarachnoid hemorrhage (SAH). OBSERVATIONS: A 65-year-old female presented after an ictus of headache with no neurological deficits. Computed tomography (CT) demonstrated sulcal SAH, with the remainder of the workup nondiagnostic for etiology. Three weeks later, she re-presented with acute thoracic back pain and thoracic myelopathy. CT and magnetic resonance imaging suggested dubiously a T9-10 disc herniation with spinal cord compression. Surgical decompression and resection were then planned. Intraoperative ultrasound (IUS) demonstrated an intradural extramedullary lesion, confirmed to be cavernoma. Complete resection was achieved, and the patient was discharged a few days postoperatively to inpatient rehabilitation. LESSONS: Although spine imaging is deemed to be low yield in the evaluation of cryptogenic SAH, algorithms can be revisited even in the absence of spine-related symptoms. Surgeons can be prepared to change the initial surgical plan, especially when preoperative imaging is unclear. IUS is a powerful tool to assess the thecal sac after its exposure and to help guide this decision, as in this rare entity.

Impact of obesity on adult spinal deformity (ASD) long-segment spinal fusion radiographic and clinical outcomes.

STUDY DESIGN: Retrospective chart review of patients receiving long-segment fusion during a five-year period. OBJECTIVE: To determine whether obese patients receive comparable benefits when receiving long-segment fusion compared to non-obese patients and to identify factors that may predict hardware failure and post-surgical complications among obese patients. METHODS: Demographic, spinopelvic radiographic, patient-reported outcome measures (PROMs), and complications data was retrospectively collected from 120 patients who underwent long-segment fusion during a five-year period at one tertiary care medical center. Radiographic measurements were pelvic incidence, pelvic tilt (PT), lumbar lordosis, L4-S1 lordosis, thoracic kyphosis, sagittal vertical axis, PI-LL mismatch, and proximal junction cobb angle at upper instrumented vertebrae + 2 (UIV+2). PROMs were Oswestry disability index, numeric rating scale (NRS) Back Pain, NRS Leg Pain, RAND SF-36 pain, and RAND SF-36 physical functioning. Included patients were adults and had at least 2-years of postoperative follow-up. Descriptive and multivariate statistical analysis was performed with α = 0.05. RESULTS: Patients with a BMI ≥ 30 (n=63) and patients with a BMI < 30 (n=57) demonstrated comparable improvements (P>0.05) for all spinopelvic radiographic measurements and PROMs. Each cohort demonstrated significant improvements from pre-assessment to post-assessment on nearly all spinopelvic radiographic measurements and PROMs (P<0.05), except PT and L4-S1 lordosis where neither group improved (p=0.95 and 0.58 for PT and P=0.23 and 0.11 for L4-S1 lordosis fornon-obese and obese cohorts respectively) and SF-36 physical functioning where the non-obese cohort not statistically improve (P=0.08). Patients with a BMI ≥ 30 demonstrated an increased incidence of cardiovascular complications (P=0.0293), acute kidney injury (P=0.0241), rod fractures (P=0.0293), and reoperations (P=0.0241) when compared to patients with a BMI < 30. CONCLUSION: This study adds to a growing body of evidence linking demographic factors with risks of hardware failure. Further, this data challenges the assumption that obese patients may not receive sufficient benefit to be long-segment surgical candidates. However, given their elevated risk for post-operative and delayed hardware complications, obese patients should be appropriately counseling before undergoing surgery.

Promotion of higher rates of early fusion using activated titanium versus polyetheretherketone cages in adults undergoing 1- and 2-level transforaminal lumbar interbody fusion procedures: a randomized controlled trial.

OBJECTIVE: There is ongoing debate on the relative benefits and drawbacks of polyetheretherketone (PEEK) versus titanium (Ti) in generating a bone-to-implant surface microenvironment conducive to osseointegration. Micro- and nanoscale internal and topographic cage modifications have recently been posited to facilitate osseointegration and fusion, but human in vivo confirmation remains lacking. The authors of this study sought to directly compare early radiological outcomes in adults undergoing 1- and 2-level transforaminal lumbar interbody fusion (TLIF) procedures using either PEEK or nano-etched Ti interbody cages with an incorporated microlattice structure. METHODS: Patients were enrolled in a single academic center using a single-blind randomized controlled superiority design. Screening was undertaken from a pool of consecutive patients eligible for TLIF to undergo placement in a 1:1 ratio of either lordotic PEEK or activated Ti cages at each level of 1- or 2-level procedures. An a priori power analysis was performed and a preplanned interim analysis was undertaken once 50 of 70 patients were enrolled. Patient study data were collected perioperatively and uploaded to a Research Electronic Data Capture (REDCap) registry. Interbody fusion was assessed based on 6-month postoperative lumbar dual-energy CT (DECT) studies using the method of Brantigan and Steffee, as modified to describe the Fraser definition of locked pseudarthrosis (Brantigan-Steffee-Fraser [BSF] scale). RESULTS: In the final cohort of 50 patients, 40 interbody levels implanted with PEEK cages were compared with 34 interbody levels with activated Ti cages. The trial was stopped early given the results of an interim analysis with respect to the primary outcome. Surgical parameters including number of levels treated, average cage height, and position were not different between groups. For the PEEK and activated Ti groups, 20.6% versus 84.0% demonstrated BSF grade 3 fusion on 6-month postoperative DECT imaging (p < 0.001). Subsidence at 6 months on DECT was identified in 12 (41.4%) of PEEK levels versus 5 (20.8%) of activated Ti levels (p < 0.001). BSF-3 grading was predictive of segmental stability and numeric rating scale (NRS) leg pain improvement at 1 year postoperatively. Oswestry Disability Index and NRS back and leg pain scores all improved similarly in both cohorts at 1 year postoperatively. CONCLUSIONS: Activated Ti interbody cages mediate early fusion at significantly higher rates with lower rates of subsidence as compared with PEEK cages. These findings support the idea that interbody cage microscale properties, including surface topography, may play a primary role in facilitating osseointegration and fusion.

Delayed stenosis associated with sublaminar band placement in the thoracic spine for proximal junctional kyphosis.

Background: Proximal junctional thoracic kyphosis (PJK) is common following adult spinal deformity (ASD) surgery and may require revision operations. In this case series, we present delayed complications associated with the use of sublaminar banding (SLBs) for PJK prophylaxis. Case Description: Three patients underwent long-segment thoracolumbar decompression and fusions for ASD. All had undergone SLB placement for PJK prophylaxis. All three subsequently developed neurologic complications secondary to cephalad spinal cord compression/stenosis requiring urgent revision surgery. Conclusion: The placement of SLBs placed to prevent PJK may lead to sublaminar inflammation contributing to severe cephalad spinal canal stenosis and myelopathy following ASD surgery. Surgeons should be aware of this potential complication and may consider alternatives to SLB placement to avoid this complication.

Electronic versus paper patient-reported outcome measure compliance rates: A retrospective analysis.

OBJECTIVE: Patient-reported outcome measures (PROMs) are key tools used to inform clinical research and patient-centered care. Application of data collected from PROMs, however, may be limited by incomplete responses, and little is known regarding the efficacy of varied PROM delivery methods. The objective of this study was to compare PROMs compliance when delivered via paper and electronic formats. METHODS: Elective adult spinal deformity patients were screened for inclusion. Data collected included demographics, type of surgery, PROMs compliance, and discharge care. Descriptive statistics and multivariate analysis (MVA) were performed to compare pre- and postoperative compliance rates. RESULTS: Of the 474 included patients, 177 were administered paper PROMs, while 297 were electronic. Preoperatively, 101 patients (57.1%) had any portion of their paper PROMs available; 179 (60.3%) had any of their electronic PROMs available (p = 0.492). Among all patients, 76 (42.9%) and 170 (57.2%) had all of their completed preop PROMs available (p = 0.003). Among patients with any of their preop PROMs completed, 75.2% with paper and 95.0% with electronic were completed in their entirety (p < 0.001). Similar trends were observed among postoperative PROMs. MVA demonstrated electronic delivery as the only significant correlate with pre- and post-operative PROMs compliance (p < 0.001 and p = 0.003, respectively). CONCLUSIONS: No differences were observed across modalities when considering any available PROMs, yet electronic PROM delivery was associated with higher completion of PROMs. In order to improve the quality of patient-reported data, electronic delivery with alternative methods of quality improvement may be considered to increase PROMs retention rates.

Subsidence Rates Associated With Porous 3D-Printed Versus Solid Titanium Cages in Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: To determine whether 3D-printed porous titanium (3DPT) interbody cages offer any clinical or radiographic advantage over standard solid titanium (ST) interbody cages in transforaminal lumbar interbody fusions (TLIF). METHODS: A consecutive series of adult patients undergoing one- or two-level TLIF with either 3DPT or ST "banana" cages were analyzed for patient reported outcome measures (PROMs), radiographic complications, and clinical complications. Exclusion criteria included clinical or radiographic follow-up less than 1 year. RESULTS: The final cohort included 90 ST interbody levels from 74 patients, and 73 3DPT interbody levels from 50 patients for a total of 124 patients. Baseline demographic variables and comorbidity rates were similar between groups (P > .05). Subsidence of any grade occurred more frequently in the ST group compared with the 3DPT group (24.4% vs 5.5%, respectively, P = .001). Further, the ST group was more likely to have higher grades of subsidence than the 3DPT group (P = .009). All PROMs improved similarly after surgery and revision rates did not differ between groups (both P > .05). On multivariate analysis, significant positive correlators with increasing subsidence grade included greater age (P = .015), greater body mass index (P = .043), osteoporosis/osteopenia (P < .027), and ST cage type (P = .019). CONCLUSIONS: When considering interbody material for TLIF, both ST and 3DPT cages performed well; however, 3DPT cages were associated with lower rates of subsidence. The clinical relevance of these findings deserves further randomized, prospective investigation.

Early Postural Stability Changes in Patients Undergoing Correction of Spinal Deformity: A Prospective, Controlled Pilot Study.

BACKGROUND CONTEXT: Adult spinal deformity (ASD) is a prevalent condition often requiring surgical intervention. Improved outcomes among ASD patients have been shown to correlate with postoperative spinopelvic parameters, yet little is currently known about the role of postural stability and balance assessment for ASD patients. PURPOSE: Explore early changes in postural stability following ASD correction. STUDY DESIGN: Prospective cohort study. PATIENT SAMPLE: Sixteen adult patients who underwent four-level or greater posterolateral fusion to address global spinal malalignment and 14 healthy controls with no known spinal deformity nor surgery. OUTCOME MEASURES: Postural stability parameters, spinopelvic parameters preoperatively and postoperatively. METHODS: Force plate balance assessment was completed where participants and healthy controls were instructed to stand with their hands at their sides, standing still, with eyes open. Center of pressure (COP), center of gravity (COG), and cone of economy (COE) parameters were analyzed with paired and unpaired t tests with an alpha of 0.05. RESULTS: Preoperatively, ASD patients demonstrated more COG (P=0.0244) and sagittal and coronal head (P<0.05) sway than healthy controls. Postoperatively, ASD patients exhibited less COP (P=0.0308), COG (P=0.0276) and head (P=0.0345) sway. Compared to healthy controls, ASD patients postoperatively exhibited similar postural stability, aside from COP and COG sway amplitudes (P<0.05), and coronal head sway (P=0.0309). Pelvic incidence-lumbar lordosis and sagittal vertical axis improved from 16.2° to 4.8° (P<0.01) and 82.2 to 22.5 mm (P<0.01), respectively. CONCLUSION: We report a novel early improvement in postural stability, comparable to healthy controls, following ASD correction that may be related to improved spinopelvic alignment. Force plate evaluation may be a useful tool for ASD patients postoperatively. Future clinical trials assessing the impact of postural stability on clinical and radiographic outcomes are warranted.

Influence of clinical and radiological parameters on the likelihood of neurological improvement after surgery for degenerative cervical myelopathy.

OBJECTIVE: Degenerative cervical myelopathy (DCM) is routinely treated with surgical decompression, but disparate postoperative outcomes are frequently observed, ranging from complete neurological recovery to persistent decline. Although numerous clinical and radiological factors have been independently associated with failure to improve, the relative impact of these proposed risk factors remains obscure. In this study, the authors assess the combined role of clinical and radiographic parameters in contributing to failure to attain neurological improvement after surgery. METHODS: A consecutive series of patients who underwent surgery for DCM between July 2013 and August 2018 at a single institution was identified from a prospectively maintained database. Retrospective chart review was undertaken to record perioperative clinical and radiographic parameters. Failure to improve on the last follow-up evaluation after surgery, defined as a change in modified Japanese Orthopaedic Association (mJOA) score less than 2, was the primary outcome in univariate and multivariate analyses. RESULTS: The authors included 183 patients in the final cohort. In total, 109 (59.6%) patients improved (i.e., responders with ΔmJOA score ≥ 2) after surgery and 74 (40.4%) were nonresponders with ΔmJOA score < 2. Baseline demographic variables and comorbidity rates were similar, whereas baseline Nurick score was the only clinical variable that differed between responders and nonresponders (2.7 vs 3.0, p = 0.02). In contrast, several preoperative radiographic variables differed between the groups, including presence and degree of cervical kyphosis, number of levels with bidirectional cord compression, presence and number of levels with T2-weighted signal change, intramedullary lesion (IML) length, Torg ratio, and both narrowest spinal canal and cord diameter. On multivariate analysis, preoperative degree of kyphosis at C2-7 (OR 1.19, p = 0.004), number of levels with bidirectional compression (OR 1.83, p = 0.003), and IML length (OR 1.14, p < 0.001) demonstrated the highest predictive power for nonresponse (area under the receiver operating characteristic curve 0.818). A risk factor point system that predicted failure of improvement was derived by incorporating these 3 variables. CONCLUSIONS: When a large spectrum of both clinical and radiographic variables is considered, the degree of cervical kyphosis, number of levels with bidirectional compression, and IML length are the most predictive of nonresponse after surgery for DCM. Assessment of these radiographic factors can help guide surgical decision-making and more appropriately stratify patients in clinical trials.

Association between synthetic sealants and increased complication rates in posterior fossa decompression with duraplasty for Chiari malformations regardless of graft type.

OBJECTIVE: Dural sealants are commonly used in posterior fossa decompression with duraplasty (PFDD) for Chiari malformation type I (CMI). Prior evidence suggests that combining certain sealants with some graft material is associated with an increased rate of complications. In 2018, the authors noted an increased rate of symptomatic pseudomeningocele and aseptic meningitis after PFDD in CMI patients. The authors utilized retrospective and prospective analyses to test the hypothesis that complication rates increase with the use or combination of certain sealants and grafts. METHODS: The analysis was split into 2 periods. The authors retrospectively reviewed patients who underwent PFDD for CMI at their center between August 12, 2011, and December 31, 2018. The authors then eliminated use of DuraSeal on the basis of the retrospective analysis and prospectively examined complication rates from January 1, 2019, to August 4, 2021. The authors defined a complication as symptomatic pseudomeningocele, bacterial or aseptic meningitis, cerebrospinal fluid leak, subdural hygroma, hydrocephalus, surgical site infection, or wound dehiscence. RESULTS: From 2011 to 2018, complications occurred in 24.5% of 110 patients. Sealant choice was correlated with complication rates: no sealant (0%), Tisseel (6%), and DuraSeal (15.3%) (p < 0.001). No difference in complication rate was noted on the basis of choice of graft material (p = 0.844). After eliminating DuraSeal, the authors followed 40 patients who underwent PFDD after 2018. The complication rate decreased to 12.5%. All complications after 2018 were associated with Tisseel. CONCLUSIONS: At the authors' single center, use of sealants in PFDD surgery for CMI, especially DuraSeal, was correlated with a higher complication rate. Eliminating DuraSeal led to a significant decrease in the rate of symptomatic pseudomeningocele and aseptic meningitis.

Spinal deformity correction in ankylosing spondylitis.

Background: Ankylosing spondylitis (AS) is a complex, debilitating disease with few available medical therapies in its later stages. Methods: We reviewed current clinical approaches for caring for AS patients with an emphasis on the risks and outcomes associated with surgical intervention. Results: It is critical to understand the natural history and surgical outcomes of patient with AS. Surgery is not without risks, as a vertebral body osteotomy is often required to re-establish spinopelvic equilibrium. However, surgery can lead to clinical improvements in pain, disability, cardiac function, respiration, digestion, and sexual activity. Conclusion: Deformity correction for AS should be carefully considered in symptomatic patients.

Radiographic and clinical outcomes in one- and two-level transforaminal lumbar interbody fusions: a comparison of bullet versus banana cages.

OBJECTIVE: The aim of this study was to determine whether cage morphology influences clinical and radiographic outcomes following short-segment transforaminal lumbar interbody fusion (TLIF) procedures. METHODS: The authors retrospectively reviewed one- and two-level TLIFs at a single tertiary care center between August 2012 and November 2019 with a minimum 1-year radiographic and clinical follow-up. Two cohorts were compared based on interbody cage morphology: steerable "banana" cage or straight "bullet" cage. Patient-reported outcome measures (PROMs), radiographs, and complications were analyzed. RESULTS: A total of 135 patients with 177 interbody levels were identified; 45 patients had 52 straight cages and 90 patients had 125 steerable cages. Segmental lordosis increased with steerable cages, while it decreased with straight cages (+3.8 ± 4.6 vs -1.9 ± 4.3, p < 0.001). Conversely, the mean segmental lordosis of adjacent lumbar levels decreased in the former group, while it increased in the latter group (-0.52 ± 1.9 vs +0.52 ± 2.1, p = 0.004). This reciprocal relationship results in global sagittal parameters, including pelvic incidence minus lumbar lordosis and lumbar distribution index, which did not change after surgery with either cage morphology. Multivariate analysis confirmed that steerable cage morphology, anterior cage positioning, and less preoperative index-level segmental lordosis were associated with greater improvement in index-level segmental lordosis. PROMs were improved after surgery with both cage types, and the degree of improvement did not differ between cohorts (p > 0.05). Perioperative and radiographic complications were similar between cohorts (p > 0.05). Overall reoperation rates, as well as reoperation rates for adjacent-segment disease within 2 years of surgery, were not significantly different between cohorts. CONCLUSIONS: Steerable cages are more likely to lie within the anterior disc space, thus increasing index-level segmental lordosis, which is accompanied by a reciprocal change in segmental alignment at the adjacent lumbar levels. The converse relationship occurs for straight cages, with a kyphotic change at the index levels and reciprocal lordosis occurring at adjacent levels.

Static Cage Morphology in Short-Segment Transforaminal Lumbar Interbody Fusions Is Associated With Alterations in Foraminal Height But Not Clinical Outcomes.

INTRODUCTION: Steerable "banana" cages have been posited to increase segmental lordosis in short-segment transforaminal lumbar interbody fusions (TLIF). The same is not necessarily true for straight "bullet" cages. Although increased lordosis is generally thought to be advantageous, a potential complication is decreased foraminal height. Here we evaluate for any association between cage type and change in foraminal height and clinical outcomes following short-segment TLIFs. METHODS: We retrospectively reviewed consecutive 1- and 2-level TLIFs with bilateral facetectomies with minimum 1-year clinical and radiographic follow-up. Two cohorts were based on cage morphology: steerable "banana" cage or straight "bullet" cage. Patient reported outcome measures (PROMs), radiographic measurements, and revision rates were compared. RESULTS: A total of 46 patients with 53 straight and 95 patients with 131 steerable cage levels were included. Steerable cages showed increased segmental lordosis (9.1° vs. 13.5°, P < 0.001) and decreased foraminal height (20.3 vs. 18.5 mm, P < 0.001) after surgery. Straight cages demonstrated similar segmental lordosis (8.7° vs 8.1°, P = 0.30) and foraminal height (19.4 vs 20.0 mm, P < 0.065). Both cohorts showed improved PROMs at last follow-up (P ≤ 0.005). Subanalysis comparing patients who had increased or decreased foraminal height revealed similarly improved PROMs between cohorts. Revision rates at 1 year were similar between cohorts (4.3% for straight and 3.2% for steerable group, P = 0.72). CONCLUSIONS: Although the increased segmental lordosis afforded by placement of steerable cages may decrease foraminal height after short segment TLIF, clinical outcomes are not negatively affected by this association.

Can activated titanium interbody cages accelerate or enhance spinal fusion? a review of the literature and a design for clinical trials.

While spinal interbody cage options have proliferated in the past decade, relatively little work has been done to explore the comparative potential of biomaterial technologies in promoting stable fusion. Innovations such as micro-etching and nano-architectural designs have shown purported benefits in in vitro studies, but lack clinical data describing their optimal implementation. Here, we critically assess the pre-clinical data supportive of various commercially available interbody cage biomaterial, topographical, and structural designs. We describe in detail the osteointegrative and osteoconductive benefits conferred by these modifications with a focus on polyetheretherketone (PEEK) and titanium (Ti) interbody implants. Further, we describe the rationale and design for two randomized controlled trials, which aim to address the paucity of clinical data available by comparing interbody fusion outcomes between either PEEK or activated Ti lumbar interbody cages. Utilizing dual-energy computed tomography (DECT), these studies will evaluate the relative implant-bone integration and fusion rates achieved by either micro-etched Ti or standard PEEK interbody devices. Taken together, greater understanding of the relative osseointegration profile at the implant-bone interface of cages with distinct topographies will be crucial in guiding the rational design of further studies and innovations.

Gliosarcoma with PNET features mimicking a metastatic neuroendocrine carcinoma: A diagnostic dilemma.

OBJECTIVE: Gliosarcomas (GS) comprise ~ 2 - 8% of glioblastomas and are associated with a similar poor prognosis. GS have rarely been found with a primitive neuroectodermal component (PNET). We present a case of gliosarcoma with PNET features (GS-PNET) that mimicked a neuroendocrine carcinoma on initial biopsy. MATERIALS AND METHODS: A 68-year-old male presented with 2 weeks of increasing headaches and difficulties with reading, writing, and word-finding. He was found to have a left-sided parieto-occipital heterogeneously enhancing mass. RESULTS: Pathologic analysis after surgical resection initially diagnosed a poorly differentiated carcinoma with neuroendocrine features, and adjuvant therapy was guided by this diagnosis as well as systemic imaging, which was suggestive of gastrointestinal primary malignancy with central nervous system (CNS) metastasis. Subsequent progression and re-resection established a diagnosis of GS with PNET component. Genomic profiling showed shared PTEN, TERT promotor, and TP53 mutations in the original and recurrent tumors. CONCLUSION: There have only been 5 previously reported cases of GS-PNET, to our knowledge, with this case representing the first with comprehensive molecular profiling. The case also highlights the importance of further work-up of presumed metastatic carcinoma with indeterminate immunostaining and/or suspected non-epithelioid component.

Negative pressure wound therapy in spinal fusion patients.

Post-operative wound complications are some of the most common acute complications following spine surgery. These surgical site infections (SSI) contribute to increased healthcare related costs. Negative pressure wound therapy (NPWT) has long been used for treatment of soft tissue injury or defects. NPWT may reduce the incident of SSI following spinal fusion procedures; however, its potential applications need further clarification. Thus, we conducted a retrospective analysis of two cohorts to compare NPWT to traditional sterile dressings following spinal fusions in regards to post-operative outcomes. Following institutional review board approval, 42 patients who had a NPWT were matched by type of surgery to 42 patients who had traditional dressings. A retrospective chart-review was completed. Outcome measures, particularly SSI and need for reoperation, were analyzed using one-way ANOVA for both univariate and multivariate analysis. When controlled for sex and body-mass index, the use of a NPWT was independently correlated with decreased SSI (P = .035). Superficial dehiscence, seroma, need for additional outpatient care, and need for operative revision were all found to occur at higher rates in the traditional dressing cohort. Closed incisional negative pressure wound therapy provides a cost-effective method of decreasing surgical site infection for posterior elective spine surgeries.

Damned if you monitor, damned if you don't: medical malpractice and intraoperative neuromonitoring for spinal surgery.

OBJECTIVE: The aim of this study was to identify trends in medical malpractice litigation related to intraoperative neuromonitoring. METHODS: The Westlaw Edge legal research service was queried for malpractice litigation related to neuromonitoring in spine surgery. Cases were reviewed to determine if the plaintiff's assertion of negligence was due to either failure to use neuromonitoring or negligent monitoring. Comparative statistics and a detailed qualitative analysis of the resulting cases were performed. RESULTS: Twenty-six cases related to neuromonitoring were identified. Spinal fusion was the procedure in question in all cases, and defendants were nearly evenly divided between orthopedic surgeons and neurosurgeons. Defense verdicts were most common (54%), followed by settlements (27%) and plaintiff verdicts (19%). Settlements resulted in a mean $7,575,000 damage award, while plaintiff verdicts resulted in a mean $4,180,213 damage award. The basis for litigation was failure to monitor in 54% of the cases and negligent monitoring in 46%. There were no significant differences in case outcomes between the two allegations of negligence. CONCLUSIONS: The use and interpretation of intraoperative neuromonitoring findings can be the basis for a medical malpractice litigation. Spine surgeons can face malpractice risks by not monitoring when required by the standard of care and by interpreting or reacting to neuromonitoring findings inappropriately.