A novel MRI-based classification of spinal cord shape and CSF presence at the curve apex to assess risk of intraoperative neuromonitoring data loss with thoracic spinal deformity correction

Assessing Neurological Complications in Thoracic Three-Column Osteotomy: A Clinical Application of a Novel MRI-Based Classification Approach

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

To investigate the occurrence of neurological complications in patients undergoing thoracic three-column osteotomy (3CO) utilizing an magnetic resonance imaging (MRI)-based classification that assesses spinal cord shape and the presence of cerebrospinal fluid at the curve apex and evaluate its prognostic capacity for postoperative neurological deficits.

SUMMARY OF BACKGROUND DATA

Recent advancements in correction techniques have improved outcomes for severe spinal deformity patients undergoing 3CO. A novel MRI-based spinal cord classification system was introduced, but its validation and association with postoperative complications remain unexplored.

MATERIALS AND METHODS

Between September 2012 and September 2018, a retrospective analysis was conducted on 158 adult patients with spinal deformities undergoing 3CO. Radiographic parameters were measured. T2-weighted axial MRI was used to describe spinal cord morphology at the apex. Intraoperative neurophysiological monitoring alerts were recorded, and preoperative and postoperative neurological functions were assessed using the Frankel score. Categorical data were compared using the χ 2 or the Fisher exact test. The paired t test was utilized to assess the mean difference between preoperative and postoperative measurements, while the one-way analysis of variance and independent t test were used for comparative analyses among the different spinal cord types.

RESULTS

Patients were categorized into three groups: type 1, type 2, and type 3, consisting of 12, 85, and 61 patients. Patients with type 3 morphology exhibited larger Cobb angles of the main curve ( P <0.001). This disparity persisted both postoperatively and during follow-up ( P <0.05). Intraoperative neurophysiological monitoring alerts were triggered in 32 patients (20.3%), with a distribution of one case in type 1, six cases in type 2, and 22 cases in type 3 morphologies ( P <0.001). New neurological deficits were observed in 15 patients (9.5%), with 1, 3, and 11 cases in type 1, 2, and 3 morphologies, respectively.

CONCLUSIONS

Patients with type 3 morphology exhibited greater spinal deformity severity, a higher likelihood of preoperative neurological deficits, and an elevated risk of postoperative neurological complications. This underscores the utility of the classification as a tool for predicting postoperative neurological complications in patients undergoing thoracic 3CO.

LEVEL OF EVIDENCE

4.

The Role of Spinal Cord Compression in Predicting Intraoperative Neurophysiological Monitoring Events in Patients With Kyphotic Deformity: A Magnetic Resonance Imaging-Based Study

OBJECTIVE

To establish a novel classification system for predicting the risk of intraoperative neurophysiological monitoring (IONM) events in surgically-treated patients with kyphotic deformity.

METHODS

Patients with kyphotic deformity who underwent surgical correction of cervicothoracic, thoracic, or thoracolumbar kyphosis in our center from July 2005 to December 2020 were recruited. We proposed a classification system to describe the morphology of the spinal cord on T2-weighted sagittal magnetic resonance imaging: type A, circular/symmetric cord with visible cerebrospinal fluid (CSF) between the cord and vertebral body; type B, circular/oval/symmetric cord with no visible CSF between the cord and vertebral body; type C, spinal cord that is fattened/deformed by the vertebral body, with no visible CSF between the cord and vertebral body. Furthermore, based on type C, the spinal cord compression ratio (CR) < 50% was defined as the subtype C-, while the spinal cord CR ≥ 50% was defined as the subtype C+. IONM event was documented, and a comparative analysis was made to evaluate the prevalence of IONM events among patients with diverse spinal cord types.

RESULTS

A total of 294 patients were reviewed, including 73 in type A; 153 in type B; 53 in subtype C- and 15 in subtype C+. Lower extremity transcranial motor-evoked potentials and/or somatosensory evoked potentials were lost intraoperatively in 41 cases (13.9%), among which 4 patients with type C showed no return of spinal cord monitoring data. The 14 subtype C+ patients (93.3%) had IONM events. Univariate logistic regression analysis showed that patients with a type C spinal cord (subtype C-: odds ratio [OR], 10.390; 95% confidence interval [CI], 2.215-48.735; p = 0.003; subtype C+, OR, 497.000; 95% CI, 42.126- 5,863.611; p < 0.001) are at significantly higher risk of a positive IONM event during deformity correction compared to those with a type A. In further multiple logistic regression analysis, the spinal cord classification (OR, 5.371; 95% CI, 2.966-9.727; p < 0.001) was confirmed as an independent risk factor for IONM events.

CONCLUSION

We presented a new spinal cord classification system based on the relative position of the spinal cord and vertebrae to predict the risk of IONM events in patients with kyphotic deformity. In patients with type C spinal cord, especially those in C+ cases, it is essential to be aware of potential IONM events, and adopt standard operating procedures to facilitate neurological recovery.

Delayed postoperative neurological deficits from scoliosis correction: a case series and systematic review on clinical characteristics, treatment, prognosis, and recovery

OBJECTIVE

This study was designed to investigate the clinical features, treatment modalities, and risk factors influencing neurological recovery in patients who underwent scoliosis correction with delayed postoperative neurological deficit (DPND).

METHODS

Three patients with DPND were identified from 2 central databases for descriptive analysis. Furthermore, all DPND cases were retrieved from the PubMed and Embase databases. Neurological function recovery was categorized into complete and incomplete recovery groups based on the American Spinal Injury Association (ASIA) impairment scale.

RESULTS

Two patients were classified as type 3, and one was classified as type 2 based on the MRI spinal cord classification. Intraoperative neurophysiological monitoring (IONM) was consistently negative throughout the corrective procedure, and intraoperative wake-up tests were normal. The average time to DPND development was 11.8 h (range, 4-18 h), and all three patients achieved complete recovery of neurological function after undergoing revision surgery. A total of 14 articles involving 31 patients were included in the literature review. The mean time to onset of DPND was found to be 25.2 h, and 85.3% (29/34) of patients experienced DPND within the first 48 h postoperatively, with the most common initial symptoms being decreased muscle strength and sensation (26 patients, 83.9%). Regarding neurological function recovery, 14 patients were able to reach ASIA grade E, while 14 patients were not able to reach ASIA grade E. Univariate analysis revealed that preoperative diagnosis (p = 0.004), operative duration (p = 0.017), intraoperative osteotomy method (p = 0.033), level of neurological deficit (p = 0.037) and deficit source (p = 0.0358) were significantly associated with neurological outcomes. Furthermore, multivariate regression analysis indicated a strong correlation between preoperative diagnosis (p = 0.003, OR, 68.633; 95% CI 4.299-1095.657) and neurological prognosis.

CONCLUSION

Our findings indicate that spinal cord ischemic injury was a significant factor for patients experiencing DPND and distraction after corrective surgery may be a predisposing factor for spinal cord ischemia. Additionally, it is important to consider the possibility of DPND when limb numbness and decreased muscle strength occur within 48 h after corrective scoliosis surgery. Moreover, emergency surgical intervention is highly recommended for DPND caused by mechanical compression factors with a promising prognosis for neurological function, emphasizing the importance of taking into account preoperative orthopedic diagnoses when evaluating the potential for neurological recovery.

Prospective Validation of the Spinal Cord Shape Classification System in the Prediction of Intraoperative Neuromonitoring Data Loss: Assessing the Risk of Spinal Cord Data Loss During Spinal Deformity Correction

BACKGROUND

The Spinal Cord Shape Classification System (SCSCS) class has been associated with spinal cord monitoring data loss during spinal deformity surgery. The objective of the current study was to prospectively validate the SCSCS as a predictor of spinal cord monitoring data loss during spinal deformity surgery.

METHODS

A prospective cohort study of consecutive patients who were undergoing primary deformity surgery at a single institution from 2018 to 2023 and whose major curve was in the spinal cord region was undertaken. Spinal cord morphology at the apex of the major curve on preoperative axial T2-weighted magnetic resonance imaging was used to categorize patients into 3 spinal cord shape types based on the SCSCS. The primary outcome was intraoperative neuromonitoring (IONM) data loss related to spinal cord dysfunction. Demographics and surgical and radiographic variables were compared between patients with IONM data loss and those without loss. Predictors of IONM loss were determined using bivariate and multivariable logistic regression analyses.

RESULTS

A total of 256 patients (168 adult, 88 pediatric) were included and were separated into 3 SCSCS types: 110 (43.0%) with Type I, 105 (41.0%) with Type II, and 41 (16.0%) with Type III. IONM loss was observed in 30 (11.7%) of the 256 patients, including 7 (6.4%) of 110 with SCSCS Type I, 7 (6.7%) of 105 with Type II, and 16 (39.0%) of 41 with Type III. IONM loss was associated with SCSCS Type III, the preoperative deformity angular ratio, performance of 3-column osteotomies, greater operative time, greater transfusion volume, and greater postoperative sagittal corrections. SCSCS type was the strongest independent predictor of IONM data loss. SCSCS Type III had the greatest odds of IONM loss (odds ratio [OR] = 6.68, 95% confidence interval [CI] = 2.45 to 18.23 compared with Types I and II combined). The overall predictive performance with respect to IONM loss (area under the receiver operating characteristic curve = 0.827) was considered excellent.

CONCLUSIONS

This prospective cohort study of patients undergoing spinal deformity correction confirmed that patients with a Type-III spinal cord shape had greater odds of IONM loss. Inclusion of the SCSCS in preoperative risk stratification and intraoperative management of spinal deformity corrective surgery is recommended.

LEVEL OF EVIDENCE

Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Delayed paraparesis after posterior spinal fusion for congenital scoliosis: a case report

INTRODUCTION

Although multimodal intraoperative neuromonitoring (IONM), which has high sensitivity and specificity, is typically performed during spinal deformity surgery, neurological status may deteriorate with delay after surgical maneuvers. Here, we report a rare case of delayed postoperative neurological deficit (DPND) that was not detected by IONM during posterior spinal fusion (PSF) for congenital scoliosis.

CASE PRESENTATION

A 14-year-old male presented with congenital scoliosis associated with T3 and T10 hemivertebrae. Preoperative Cobb angle of proximal thoracic (PT) and main thoracic (MT) curves were 50° and 41°, respectively. PSF (T1-L1) without hemivertebrectomy was performed, and the curves were corrected to 31° and 21° in the PT and MT curves, respectively, without any abnormal findings in IONM, blood pressure, or hemoglobin level. However, postoperative neurological examination revealed complete loss of motor function. A revision surgery, release of the curve correction by removing the rods, was immediately performed and muscle strength completely recovered on the first postoperative day. Five days postoperatively, PSF was achieved with less curve correction (36° in the PT curve and 26° in the MT curve), without postoperative neurological deficits.

DISCUSSION

Possible mechanisms of DPND in our patient are spinal cord ischemia due to spinal cord traction caused by scoliosis correction and spinal cord kinking by the pedicle at the concave side. Understanding the possible mechanisms of intra- and postoperative neural injury is essential for appropriate intervention in each situation. Additionally, IONM should be continued to at least skin closure to detect DPND observed in our patient.

Potential impairment of spinal cord around the apical vertebral level in hyperkyphotic patients: findings from diffusion tensor imaging

PURPOSE

To evaluate the neuronal metrics/microstructure of the spinal cord around apical region in patients with hyperkyphosis using diffusion tensor imaging (DTI).

METHODS

Thirty-seven patients with hyperkyphosis aged 45.5 ± 19.6 years old who underwent 3.0 T magnetic resonance imaging (MRI) examination with DTI sequence were prospectively enrolled from July 2022 to July 2023. Patients were divided into three groups according to spinal cord/ cerebrospinal fluid (CSF) architecture on sagittal-T2 MRI of the thoracic apex (the axial spinal cord classification): Group A-circular cord with visible CSF, Group B-circular cord without visible CSF at apical dorsal, and Group C-spinal cord deformed without intervening CSF. The fractional anisotropy (FA) values acquired from DTI were compared among different groups. Correlations between DTI parameters and global kyphosis (GK)/sagittal deformity angular ratio (sagittal DAR) were evaluated using Pearson correlation coefficients.

RESULTS

In all patients, FA values were significantly lower at apical level as compared with those at one level above or below the apex (0.548 ± 0.070 vs. 0.627 ± 0.056 versus 0.624 ± 0.039, P < 0.001). At the apical level, FA values were significantly lower in Group C than those in Group B (0.501 ± 0.052 vs. 0.598 ± 0.061, P < 0.001) and Group A (0.501 ± 0.052 vs. 0.597 ± 0.019, P < 0.001). Moreover, FA values were significantly lower in symptomatic group than those in non-symptomatic group (0.498 ± 0.049 v. 0.578 ± 0.065, P < 0.001). Pearson correlation analysis showed that GK (r2 = 0.3945, P < 0.001) and sagittal DAR (r2 = 0.3079, P < 0.001) were significantly correlation with FA values at apical level.

CONCLUSION

In patients with hyperkyphosis, the FA of spinal cord at apical level was associated with the neuronal metrics/microstructure of the spinal cord. Furthermore, the DTI parameter of FA at apical level was associated with GK and sagittal DAR.

LEVEL OF EVIDENCE: 4

Utilization of pre-operative MRI to identify AIS patients at highest risk of intra-operative neuromonitoring alert

PURPOSE

Utility of pre-operative MRI for patients undergoing scoliosis correction has expanded to include an MRI classification for identifying patients at increased risk of experiencing intra-operative neuromonitoring (IONM) alerts based on the shape of the spinal cord and circumferential presence of CSF at the apex of the thoracic curve. In the present study, the authors explore the utility of this new MRI classification and multiple X-ray radiographic parameters in identifying the AIS sub-population at high risk of IONM alerts.

METHODS

AIS patients < 18 years old who underwent posterior spinal fusion between 2018 and 2022 at a single institution. Imaging reviewed to determine main thoracic (MT) and thoraco-lumbar (TL) Cobb angles, major thoracic Apical Vertebral Translation (AVT) and lumbar/thoraco-lumbar AVT (TL AVT), thoracic kyphosis (TK), coronal main thoracic Deformity Angular Ratio (cDAR), sagittal DAR (sDAR), and MRI to determine the spinal cord type (1, 2, or 3).

RESULTS

A total of 155 AIS patients who met the inclusion criteria between 2018 and 2022 were included. There was a trend to have an increased incidence of Type 3 spinal cord shape both with increase in the MT Cobb angle and MT AVT. There was also a shift toward more IONM alerts in patients with Type 3 (19.5%) spinal cords, AVT ≥ 5 cm (18.9%), and Cobb angle ≥ 650 (28.2%).

CONCLUSION

Higher magnitude of thoracic Cobb angle and AVT are associated with higher likelihood of type 3 spinal cord at the apex in MRI. Patients with Type 3 spinal cord, Cobb angle ≥ 650, AVT > 5 cm, and cDAR > 10 have higher likelihood to have IONM alerts. Patient with a Type 3 spinal cord and a Cobb angle ≥ 650 (50.0%), cDAR > 10 (43.7%), and AVT > 5 cm (35.2%) have the highest risk of having IONM alerts.

Myelopathic Patients Undergoing Severe Pediatric Spinal Deformity Surgery Can Improve Neurologic Function to That of Non-Myelopathic Patients by 1-Year Postoperative

STUDY DESIGN

Multi-center, prospective, observational cohort.

OBJECTIVE

To compare myelopathic vs. non-myelopathic ambulatory patients in short- and long-term neurologic function, operative treatment, and patient-reported outcomes.

METHODS

Pediatric deformity patients from 16 centers were enrolled with the following inclusion criteria: aged 10-21 years-old, a Cobb angle ≥100° in either the coronal or sagittal plane or any sized deformity with a planned 3-column osteotomy, and community ambulators. Patients were dichotomized into 2 groups: myelopathic (abnormal preoperative neurologic exam with signs/symptoms of myelopathy) and non-myelopathic (no clinical signs/symptoms of myelopathy).

RESULTS

Of 311 patients with an average age of 14.7 ± 2.8 years, 29 (9.3%) were myelopathic and 282 (90.7%) were non-myelopathic. There was no difference in age (P = 0.18), gender (P = 0.09), and Risser Stage (P = 0.06), while more patients in the non-myelopathic group had previous surgery (16.1% vs. 3.9%; P = 0.03). Mean lower extremity motor score (LEMS) in myelopathic patients increased significantly compared to baseline at every postoperative visit: Baseline: 40.7 ± 9.9; Immediate postop: 46.0 ± 7.1, P = 0.02; 1-year: 48.2 ± 3.7, P < 0.001; 2-year: 48.2 ± 7.7, P < 0.001). The non-myelopathic group had significantly higher LEMS immediately postoperative (P = 0.0007), but by 1-year postoperative, there was no difference in LEMS between groups (non-myelopathic: 49.3 ± 3.6, myelopathic: 48.2 ± 3.7, P = 0.10) and was maintained at 2-years postoperative (non-myelopathic: 49.2 ± 3.3, myelopathic: 48.2 ± 5.7, P = 0.09). Both groups improved significantly in all SRS domains compared to preoperative, with no difference in scores in the domains for pain (P = 0.12), self-image (P = 0.08), and satisfaction (P = 0.83) at latest follow-up.

CONCLUSION

In severe spinal deformity pediatric patients presenting with preoperative myelopathy undergoing spinal reconstructive surgery, myelopathic patients can expect significant improvement in neurologic function postoperatively. At 1-year and 2-year postoperative, neurologic function was no different between groups. While non-myelopathic patients had significantly higher postoperative outcomes in SRS mental-health, function, and total-score, both groups had significantly improved outcomes in every SRS domain compared to preoperative.

The deformity angular ratio: can three-dimensional computed tomography improve prediction of intraoperative neuromonitoring events?

PURPOSE

Assess whether a novel deformity angular ratio (DAR) calculated using preoperative three-dimensional computed tomography (3D CT) is more accurate than total DAR (T-DAR) radiographic measurements at predicting intraoperative neuromonitoring (IONM) events during vertebral column resection (VCR).

METHODS

Consecutive, unique patients undergoing thoracic VCR by a single surgeon from 2015 to 2021 were identified. The T-DAR was calculated by dividing the total radiographic Cobb angle by the number of vertebral segments the angle subtends. 3D CT DAR was calculated for each patient from a preoperative CT scan by finding the maximum angle subtended by three contiguous vertebral segments. All patients were assessed for IONM events. A binary threshold of 25 was used for T-DAR and 3D CT DAR measurements for predictive analysis. p < 0.05 indicated significance.

RESULTS

In total, 68 patients were identified. Mean age was 28 years. Mean levels fused was 15. Twenty-one patients (31%) had IONM events. In patients, with and without an IONM event, mean T-DAR was 26.6 ± 9.8 and 21.5 ± 8.8 (p = 0.04), respectively. 3D CT DAR mean values were 26.4 ± 10.8 and 18.4 ± 5.6, respectively (p < 0.001). 3D CT DAR accurately classified 81% of patients with a positive predictive value (PPV) of 75%. In comparison, T-DAR accurately classified 60% of patients with a PPV of 39%.

CONCLUSION

3D CT substantially improves preoperative IONM event prediction when compared to traditional radiographic measurements. A 3D CT DAR of 25 or greater was correlated with an increased rate of IONM events. 3D CT reconstructions are a useful adjunct for planning prior to a VCR.

Establishing consensus: determinants of high-risk and preventative strategies for neurological events in complex spinal deformity surgery

PURPOSE

To establish expert consensus on various parameters that constitute elevated risk during spinal deformity surgery and potential preventative strategies that may minimize the risk of intraoperative neuromonitoring (IONM) events and postoperative neurological deficits.

METHODS

Through a series of surveys and a final virtual consensus meeting, the Delphi method was utilized to establish consensus among a group of expert spinal deformity surgeons. During iterative rounds of voting, participants were asked to express their agreement (strongly agree, agree, disagree, strongly disagree) to include items in a final set of guidelines. Consensus was defined as ≥ 80% agreement among participants. Near-consensus was ≥ 60% but < 80% agreement, equipoise was ≥ 20% but < 60%, and consensus to exclude was < 20%.

RESULTS

Fifteen of the 15 (100%) invited expert spinal deformity surgeons agreed to participate. There was consensus to include 22 determinants of high-risk (8 patient factors, 8 curve and spinal cord factors, and 6 surgical factors) and 21 preventative strategies (4 preoperative, 14 intraoperative, and 3 postoperative) in the final set of best practice guidelines.

CONCLUSION

A resource highlighting several salient clinical factors found in high-risk spinal deformity patients as well as strategies to prevent neurological events was successfully created through expert consensus. This is intended to serve as a reference for surgeons and other clinicians involved in the care of spinal deformity patients.

LEVEL OF EVIDENCE

Level V.

Development of consensus-based best practice guidelines for response to intraoperative neuromonitoring events in high-risk spinal deformity surgery

PURPOSE

To expand on previously described intraoperative aids by developing consensus-based best practice guidelines to optimize the approach to intraoperative neuromonitoring (IONM) events associated with "high-risk" spinal deformity surgery.

METHODS

Consensus was established among a group of experienced spinal deformity surgeons by way of the Delphi method. Through a series of iterative surveys and a final virtual consensus meeting, participants expressed their agreement (strongly agree, agree, disagree, and strongly disagree) with various items. Consensus was defined as ≥ 80% agreement ("strongly agree" or "agree"). Near-consensus was defined as ≥ 60% but < 80%. Equipoise was ≥ 20% but < 60%, and consensus to exclude was < 20%.

RESULTS

15 out of 15 (100%) invited surgeons agreed to participate. Final consensus supported inclusion of 105 items (53 in Response Algorithm, 13 in Ongoing Consideration of Etiology, 31 in Real-Time Data Scenarios, 8 in Patterns of IONM Loss), which were organized into a final set of best practice guidelines.

CONCLUSION

Detailed consensus-based best practice guidelines and aids were successfully created with the intention to help organize and direct the surgical team in exploring and responding to neurological complications during high-risk spinal deformity surgery.

LEVEL OF EVIDENCE

Level V.

Be Prepared: Preoperative Coronal Malalignment Often Leads to More Extensive Surgery Than Sagittal Malalignment During Adult Spinal Deformity Surgery

Objective

To evaluate the effect of coronal alignment on: (1) surgical invasiveness and operative complexity and (2) postoperative complications.

Methods

A retrospective, cohort study of adult spinal deformity patients was conducted. Alignment groups were: (1) neutral alignment (NA): coronal vertical axis (CVA) ≤ 3 cm and sagittal vertical axis (SVA) ≤ 5 cm; (2) coronal malalignment (CM) only: CVA > 3 cm; (3) Sagittal malalignment (SM) only: SVA > 5 cm; and (4) coronal and sagittal malalignment (CCSM): CVA > 3 cm and SVA > 5 cm.

Results

Of 243 patients, alignment groups were: NA 115 (47.3%), CM 48 (19.8%), SM 38 (15.6%), and CCSM 42 (17.3%). Total instrumented levels (TILs) were highest in CM (14.5±3.7) and CCSM groups (14±4.0) (p<0.001). More 3-column osteotomies (3COs) were performed in SM (21.1%) and CCSM (28.9%) groups than CM (10.4%) (p=0.003). CM patients had more levels instrumented (p=0.029), posterior column osteotomies (PCOs) (p<0.001), and TLIFs (p=0.002) than SM patients. CCSM patients had more TLIFs (p=0.012) and higher estimated blood loss (EBL) (p=0.003) than SM patients. CVA displayed a stronger relationship with TIL (p=0.002), EBL (p<0.001), and operative time (p<0.001) than SVA, which had only one significant association with EBL (p=0.010). Both SM/CCSM patients had higher readmissions (p=0.003) and reoperations (p<0.001) than CM patients.

Conclusion

Amount of preoperative CM was a better predictor of surgical invasiveness than the amount of SM, despite 3COs more commonly performed in SM patients. CM patients had more instrumented levels, PCOs, and TLIFs than SM patients.

L5 Vertebral Column Resection for Correction of Severe Lumbar Hyperlordosis and Pelvic Anteversion in an Adolescent With Prior Myelomeningocele Repair and Lumbar Fusion: Case Report

BACKGROUND AND IMPORTANCE

Lumbar hyperlordosis in ambulatory children is an uncommon but potentially problematic spinal deformity, and the operative management has not been comprehensively described.

CLINICAL PRESENTATION

We report the case of a 14-yr-old girl presenting with severe progressive lumbar hyperlordosis (-122°) and sagittal imbalance (-6 cm). She had multiple prior surgeries, including myelomeningocele repair at 10 d old, midlumbar meningioma resection at 8 mo old, and posterior lumbar instrumented spinal fusion at 5 yr old. She presented with progressive lumbosacral back pain and intermittent numbness in her left lower extremity, and severe skin contractures over her prior posterior incisions. From an all posterior approach, prior implants and dural scar were removed and then an L5 vertebral column resection (VCR) was performed to disarticulate her lumbar spine from her anteverted pelvis, allowing for slow distraction forces to correct her lumbar hyperlordosis. This was followed by a T7-sacrum fusion using pedicle screws and iliac screws, with autologous bone graft and plastic surgery wound closure. Postoperatively, lumbar lordosis was corrected to -55° and sagittal balance reduced to -0.5 cm. At 10-wk and 14-mo follow-ups, the patient reported resolution of her back pain with no limitations in physical activities. Dramatic improvement was seen in both her preoperative to 14-mo postoperative Oswestry Disability Index (ODI) (54 to 12) and Scoliosis Research Society Scoliosis Research Society (SRS)-22r (54 to 93) scores.

CONCLUSION

This case highlights a rare presentation of severe progressive lumbar hyperlordosis in an ambulatory adolescent after myelomeningocele repair, meningioma resection, and posterior lumbar instrumented spinal fusion with subsequent surgical treatment incorporating important components of both spinal and plastic surgery involvement.

Complete paraplegia 36 h after attempted posterior spinal fusion for severe adolescent idiopathic scoliosis: a case report

INTRODUCTION

The incidence of neurologic complications with spinal surgery for adolescent idiopathic scoliosis (AIS) has been reported to be 0.69%. This rare complication typically occurs during surgery or immediately postoperatively. We report the occurrence of a delayed neurologic deficit that presented 36 h after the initial surgery of a staged posterior spinal fusion for severe AIS.

CASE PRESENTATION

A 12-year-old girl with severe thoracolumbar AIS of 125° underwent attempted posterior spinal fusion from T2-L4. The case was complicated by a transient loss of transcutaneous motor evoked potentials (TcMEP) that resolved with an increase in the mean arterial pressure (MAP) and relaxation of curve correction with rod removal. The patient awoke with normal neurologic function. She had a transient decrease in MAP 36 h post-op and awoke on postoperative day #2 with nearly complete lower extremity paraplegia (American Spinal Injury Association [ASIA] Impairment Scale B). Emergent exploration and removal of the concave apical pedicles resulted in improvement of TcMEPs and return of function.

DISCUSSION

Delayed postoperative neurologic deficit is a very rare phenomenon, with only a few case reports in the literature to date. The delayed neurologic decline of our patient was likely secondary to a transient episode of postoperative hypotension combined with spinal cord compression by the apical concave pedicles. Close monitoring and support of spinal cord perfusion as well as emergent decompression are imperative in the setting of a delayed neurologic deficit. Further multicenter study on this rare occurrence is underway to identify potential causes and improve treatment.

Is the axial spinal cord classification predictive of intraoperative neurologic alert for pediatric scoliosis patients? An independent retrospective validation study

PURPOSE

We sought to determine whether the axial spinal cord classification by Sielatycki et al. would be associated with increased intraoperative neuromonitoring (IONM) alerts for pediatric scoliosis patients undergoing posterior spinal fusion (PSF) surgery.

METHODS

Children less than age 19 with scoliosis undergoing PSF were retrospectively reviewed. Axial-T2 MRI of the thoracic apex was reviewed for spinal cord/CSF architecture as described by Sielatycki et al.: Type 1-circular cord with visible CSF, Type 2-circular cord but no visible CSF at apical concavity, and Type 3-cord deformed with no intervening CSF. Intraoperative neuromonitoring reports, operative records and preoperative radiographs were reviewed.

RESULTS

90 patients met the inclusion criteria. Rate of neurologic events was Type 1: 2% (1/41 patients), Type 2: 14.3% (4/28), Type 3: 57.1% (12/21) (Type 1 vs 2 p = 0.06; Type 1 vs 3 p < 0.0001; Type 2 vs 3 p = 0.0017). Three patients with a Type 3 cord awoke with significant deficits. In comparison to Type 1 cords, Type 3 and Type 2 spinal cords were associated with increased coronal and total deformity angular ratios (Type 1 vs 3 p = 0.035 and 0.0054 respectively; Type 1 vs 2 p = 0.042 and 0.03 respectively). There was no difference in gender, diagnosis category, age at surgery, Cobb angle or kyphosis between the three groups.

CONCLUSION

The axial spinal cord classification correlated with IONM alerts and greater severity of spinal deformity in pediatric scoliosis patients.

LEVEL OF EVIDENCE

IV, retrospective cohort study.

Preoperative Halo-Gravity Traction for Patients with Severe Focal Kyphosis in the Upper Thoracic Spine: A Safe and Effective Alternative for Three-Column Osteotomy

STUDY DESIGN

Retrospective review.

OBJECTIVE

To evaluate the effect of preoperative Halo-gravity traction (HGT) in the treatment of severe focal kyphosis in the upper thoracic spine (UTS), and to propose the indications that HGT could serve as an alternative for three-column osteotomy (3CO) among these patients.

SUMMARY OF BACKGROUND DATA

The HGT has been proven to be effective for severe kyphoscoliosis secondary to multiple etiologies. However, the safety and efficacy of HGT in severe focal kyphosis in UTS was still unclear.

METHODS

Patients with focal kyphosis in UTS undergoing HGT and without 3CO operation were reviewed. The sagittal focal kyphosis was measured at pre-, posttraction, and postoperation. The neurologic function at pretraction, posttraction, and postoperation were assessed according to the American Spinal Injury Association (ASIA) grading. The complications during HGT, operation, and follow-up were recorded. The comparison between pretraction and posttraction was performed using paired samples t test.

RESULTS

A total of 19 patients were included in this study, with a mean age of 13.2 ± 5.8 years. The average duration of HGT was 62.6 ± 8.4 days, during which the average kyphosis decreased from 95.3 ± 16.4° to 64.1 ± 19.2° (P < 0.001). After HGT, the ASIA grade improved from C to D in three patients and from C to E in three patients, from D to E in seven patients, from B to D in one patient. No deterioration in neurologic function was observed during HGT. The neurological status in one patient improved from ASIA C at pretraction to ASIA E at postoperation, but deteriorated to C at 4 years follow-up.

CONCLUSION

Preoperative HGT could help to correct deformity and improve neurological deficit. 3CO procedure might be unnecessary in patients with severe focal kyphosis in UTS with the utilization of HGT.Level of Evidence: 4.