Category: Spine

Posted on

Spinal Anterior Dural Dissection: Moving From Differential to Unifying Diagnosis

Neurosurgery 95:207–214, 2024

Cerebrospinal fluid (CSF) collections extending longitudinally at the anterior aspect of the spinal dura have been reported in association with various conditions and under multiple names. The aim of this study was to report cases associated with brachial amyotrophy (BA) and examine its relationship with other clinical variants.

METHODS: We conducted a retrospective cohort study including patients who presented with a motor deficit of the upper limbs and an anterior interdural CSF collection on spinal MRI. We performed a systematic review of the literature to include cases revealed by BA.

RESULTS: Seven patients presenting with BA and a confirmed dural dissection on spinal MRI were included. All patients were male with a slowly progressing history of asymmetrical and proximal motor deficit of the upper limbs. Chronic denervation affecting mostly C5 and C6 roots was found on electroneuromyography. Spinal MRI demonstrated an anterior CSF collection dissecting the interdural space and exerting a traction on cervical motor roots. Dynamic computed tomography myelogram localized the dural defect every time it was performed (4/7 cases), and surgical closure was possible for 3 patients, leading to resolution of the collection. Literature review yielded 18 other published cases of spinal dural dissections revealed by BA, including 4 in association with spontaneous intracranial hypotension and 4 others in association with superficial siderosis.

CONCLUSION: We propose a unifying diagnosis termed “spinal anterior dural dissection” (SADD) to encompass spinal dural CSF collections revealed by BA (SADD-BA), spontaneous intracranial hypotension (SADD-SIH), or superficial siderosis (SADD-SS).

Posted on

Impact of bilateral facet joint violation on radiographic degeneration of superior adjacent segments and clinical outcomes

J Neurosurg Spine 41:1–8, 2024

Facet joint violation (FJV) is associated with postoperative low-back pain and is a confirmed risk factor for adjacent-segment degeneration, a long-term complication of lumbar fusion surgery. The authors’ knowledge of its mechanisms comes from in vitro biomechanical research only; there is a lack of radiographic evidence of the effects of violation on the superior adjacent-segment facet joint, intervertebral disc, and other local radiographic parameters. Furthermore, any differences between unilateral and bilateral violation remain relatively unclear. The authors therefore aimed to explore the effects of nonviolation and unilateral and bilateral violation on radiographic degeneration of the facet joint and intervertebral disc at the fusion and superior adjacent segment. Patient-reported clinical outcomes were compared at the 2-year follow-up.

METHODS The authors retrospectively analyzed data from 148 patients with lumbar degenerative diseases who underwent single-segment minimally invasive transforaminal lumbar interbody fusion between 2016 and 2020. FJV and facet joint degeneration were evaluated and graded using Shah’s method and Pathria’s standard, respectively. Radiographic parameters, including disc height and intervertebral Cobb angle at the fusion and superior adjacent segment, were measured. Clinical outcomes were evaluated using visual analog scale (VAS) and Japanese Orthopaedic Association scores.

RESULTS Preoperative data were comparable among the 3 groups (nonviolation, unilateral violation, and bilateral violation) (p > 0.05). Patient-reported clinical outcomes were followed up for at least 2 years (average duration 28.17 ± 6.17 months). At the last follow-up, facet joint degeneration grades were sequentially increased in the nonviolation, unilateral violation, and bilateral violation groups (p = 0.006). The unilateral (2.45 ± 2.17 mm) and bilateral (2.70 ± 1.94 mm) violation groups had more severe losses of disc height in the superior adjacent segment than did the nonviolation group (1.31 ± 2.01 mm). The VAS low-back pain and Japanese Orthopaedic Association scores in the bilateral (2.57 ± 1.44 and 19.83 ± 2.84, respectively) and unilateral (2.26 ± 0.79 and 20.43 ± 3.85, respectively) violation groups were significantly worse than in the nonviolation group (1.69 ± 1.12 and 21.80 ± 3.36, respectively) (p < 0.05). By contrast, there were no significant between-group differences in disc height, intervertebral Cobb angle in the fusion segment, or VAS leg pain scores (p > 0.05).

CONCLUSIONS FJV was associated with postoperative low-back pain and worse functional outcomes. It also aggravated facet joint and intervertebral disc changes in the superior adjacent segment, especially when bilateral violation occurred; this may be part of the mechanisms of adjacent-segment degeneration.

Posted on

Novel Use of Bilateral Prone Transpsoas Approach for the Treatment of Transforaminal Interbody Fusion Pseudarthrosis and Interbody Cage Subsidence

Operative Neurosurgery 27:86–93, 2024

Pseudarthrosis is a complication after transforaminal lumbar interbody fusion (TLIF) that leads to recurrent symptoms and potential revision surgery. Subsidence of the interbody adds to the complexity of surgical revision. In addition, we report a novel technique for the treatment of TLIF pseudarthrosis with subsidence and propose an approach algorithm for TLIF cage removal.

METHODS: Cases of reoperation for TLIF pseudarthrosis were reviewed. We report a novel technique using a bilateral prone transpsoas (PTP) approach to remove a subsided TLIF cage and place a new lateral cage. An approach algorithm was developed based on the experience of TLIF cage removal. The patient was placed in the prone position with somatosensory evoked potential and electromyography monitoring. A PTP retractor was placed using standard techniques on the ipsilateral side of the previous TLIF. After the discectomy, the subsided TLIF cage was visualized but unable to be removed. The initial dilator was closed, and a second PTP retractor was placed on the contralateral side. After annulotomy and discectomy to circumferentially isolate the subsided cage, a box cutter was used to push and mobilize the TLIF cage from this contralateral side, which could then be pulled out from the ipsilateral side. A standard lateral interbody cage was then placed.

RESULTS: Retractor time was less than 10 minutes on each side. The patient’s symptoms resolved postoperatively. We review illustrative cases of various approaches for TLIF cage removal spanning the lumbosacral spine and recommend an operative approach based on the lumbar level, degree of subsidence, and mobility of the interbody.

CONCLUSION: Bilateral PTP retractors for TLIF cage removal may be effectively used in cases of pseudarthrosis with severe cage subsidence. Careful consideration of various factors, including patient surgical history, body habitus, and intraoperative findings, is essential in determining the appropriate treatment for these complex cases.

Posted on

A Retrospective Cohort Study Evaluating the Comparative Effectiveness of Unilateral Hemilaminectomy and Bilateral Laminectomy in the Resection of Spinal Meningiomas

Operative Neurosurgery 26:685–694, 2024

The primary treatment modality for spinal meningiomas (SM) is surgical resection. In recent years, minimal invasive spine surgery has gained considerable popularity, attributing its growth to advancements in surgical technologies and improved training of surgeons. Nonetheless, the suitability and effectiveness of minimal invasive spine surgery for intradural spinal tumor resection remain a subject of debate. In this cohort study, we aimed to compare the extent of resection of the unilateral hemilaminectomy approach, a less invasive technique, with the more traditional and invasive bilateral laminectomy.

METHODS: We performed a retrospective cohort study including patients with SM who underwent surgery at our department between 1996 and 2020. Cohorts included patients who underwent tumor resection through bilateral laminectomy and patients who underwent a unilateral hemilaminectomy. The primary end point was extent of resection according to the Simpson classification.

RESULTS: Of 131 with SM, 36 had a bilateral laminectomy and 95 were operated through a unilateral hemilaminectomy. In both groups, gross total resection, Simpson grades 1 and 2, was achieved in 94.44% and 94.74%, respectively (P = .999). The neurological outcome was also comparable in both cohorts (P = .356). Both length of hospital stay and estimated blood loss were significantly lower in the unilateral cohort (P < .05).

CONCLUSION: The results of this study indicate that the unilateral hemilaminectomy yields comparable results in both oncological and neurological outcome when compared with the bilateral laminectomy. Thus, unilateral hemilaminectomy may serve as a viable and safe alternative for the surgical removal of SM.

Posted on

Are there differences in the reoperation rates for operative adjacent-segment disease between ALIF+PS, PLIF+PS, TLIF+PS, and LLIF+PS? An analysis of a cohort of 5291 patients

J Neurosurg Spine 40:733–740, 2024

Biomechanical factors in lumbar fusions accelerate the development of adjacent-segment disease (ASD). Stiffness in the fused segment increases motion in the adjacent levels, resulting in ASD. The objective of this study was to determine if there are differences in the reoperation rates for symptomatic ASD (operative ASD) between anterior lumbar interbody fusion plus pedicle screws (ALIF+PS), posterior lumbar interbody fusion plus pedicle screws (PLIF+PS), transforaminal lumbar interbody fusion plus pedicle screws (TLIF+PS), and lateral lumbar interbody fusion plus pedicle screws (LLIF+PS).

METHODS A retrospective study using data from the Kaiser Permanente Spine Registry identified an adult cohort (≥ 18 years old) with degenerative disc disease who underwent primary lumbar interbody fusions with pedicle screws between L3 to S1. Demographic and operative data were obtained from the registry, and chart review was used to document operative ASD. Patients were followed until operative ASD, membership termination, the end of study (March 31, 2022), or death. Operative ASD was analyzed using Cox proportional hazards models.

RESULTS The final study population included 5291 patients with a mean ± SD age of 60.1 ± 12.1 years and a followup of 6.3 ± 3.8 years. There was a total of 443 operative ASD cases, with an overall incidence rate of reoperation for ASD of 8.37% (95% CI 7.6–9.2). The crude incidence of operative ASD at 5 years was the lowest in the ALIF+PS cohort (7.7%, 95% CI 6.3–9.4). In the adjusted models, the authors failed to detect a statistical difference in operative ASD between ALIF+PS (reference) versus PLIF+PS (HR 1.06 [0.79–1.44], p = 0.69) versus TLIF+PS (HR 1.03 [0.81–1.31], p = 0.83) versus LLIF+PS (HR 1.38 [0.77–2.46], p = 0.28).

CONCLUSIONS In a large cohort of over 5000 patients with an average follow-up of > 6 years, the authors found no differences in the reoperation rates for symptomatic ASD (operative ASD) between ALIF+PS and PLIF+PS, TLIF+PS, or LLIF+PS.

Posted on

Posterolateral approaches to the thoracic spine for calcific disc herniation: is wider exposure always better?

Objective To compare the costotransversectomy (CTV) and transpedicular (TP) approaches versus the transfacet (TF) approach for the surgical treatment of calcific thoracic spine herniations (cTDH), in terms of surgical and clinical outcomes.

Background Surgical approaches for cTDH are debated. Anterior approaches are recommended, while posterolateral approaches are preferred for non-calcific, paramedian, and lateral hernias. Currently, there is limited evidence about the superiority of a more invasive surgical approach, such as CTV or TP, over TF, a relatively less invasive approach, in terms of neurological outcome, pain, and surgical complications, for the treatment of cTDH.

Methods A retrospective, observational, monocentric study was conducted on patients who underwent posterolateral thoracic approaches for symptomatic cTDH, between 2010 and 2023, at our institute. Three groups were drafted, based on the surgical approach used: TF, TP, and CTV. All procedures were assisted by intraoperative CT scan, spinal neuronavigation, and intraoperative neuromonitoring. Analyzed factors include duration of surgery, amount of bone removal, intraoperative blood loss, CSF leak, need of instrumentation for iatrogenic instability, degree of disc herniation removal, myelopathy recovery. Afterwards, a statistical analysis was performed to investigate the bony resection of the superior posterior edge of the vertebral soma. The primary outcome was the partial or total herniation removal.

Results This study consecutively enrolled 65 patients who underwent posterolateral thoracic surgery for cTDH. The TF approach taking the least, and the CTV the longest time (p < 0.01). No statistical difference was observed between the three mentioned approaches, in terms of intraoperative blood loss, dural leakage, post-resection instrumentation, total herniation removal, or myelopathy recovery. An additional somatic bony resection was successful in achieving total herniation removal (p < 0.01), and the extent of bony resection was directly proportional to the extent of hernia removal (p < 0.01).

Conclusions No statistically significant differences were highlighted between the TP, TF, and CTV regarding the extent of cTDH removal, the postoperative complications, and the neurological improvement. The described somatic bone resection achieved significant total herniation removal and was directly proportional to the preop against postop anteroposterior diameter difference.

Posted on

A novel approach to evaluation of lumbar bone density using Hounsfield units in volume of interest on computed tomography imaging

J Neurosurg Spine 40:708–716, 2024

The purpose of this retrospective study was to evaluate the relationship between bone mineral density (BMD), as assessed with dual-energy x-ray absorptiometry (DEXA), and Hounsfield units (HU) measured in volumes of interest (VOIs) and regions of interest (ROIs) on lumbar spine CT.

METHODS A retrospective analysis was performed on data of lumbar vertebrae obtained from patients who underwent both DEXA and lumbar spine CT scan within a 6-month period. Vertebrae with a history of compression fracture, infectious spondylitis, cement reinforcement, or lumbar surgery were excluded. HU measurements were performed in the VOI and ROI (midaxial, midcoronal, and midsagittal sections) with CT, whereas BMD was assessed with DEXA. Statistical analyses, including correlation assessments and receiver operating characteristic (ROC) curve analyses, were performed.

RESULTS This analysis included 712 lumbar vertebrae, with a median patient age of 72.0 years. BMD values and HU measurements in the VOI increased sequentially from L1 to L4, whereas HU values in the ROI did not show a consistent pattern. HU values in the VOI consistently showed a stronger correlation with BMD than those in the ROI. ROC analysis revealed patient-level cutoff values for the diagnosis of osteoporosis at different lumbar vertebral levels with high sensitivity and specificity, as well as an excellent area under the curve.

CONCLUSIONS This is the first study to introduce a novel approach using the HU value in the VOI to assess bone health at the lumbar spine. There is a strong correlation between the HU value in the VOI and BMD, and the HU value in the VOI can be used to predict osteoporosis.

Posted on

Postoperative Measurement of the Retropharyngeal Space Predicts the Risk of Dysphagia After Anterior Cervical Diskectomy and Fusion

Neurosurgery 94:1116–1121, 2024

Postoperative dysphagia is a common complication of anterior cervical diskectomy and fusion (ACDF), although its pathophysiology remains poorly understood. Patients with severe dysphagia may suffer from serious complications such as aspiration pneumonia, in addition to difficulty with oral intake or malnutrition; therefore, a prompt indicator for postoperative management would be helpful. We quantitatively evaluated the retropharyngeal space (RS) after ACDF and investigated its association with postoperative dysphagia.

METHODS: This multicenter retrospective study analyzed the clinical data of 82 consecutive patients who underwent ACDF. The anteroposterior distance (APD) of the RS was measured at the C2 level using a lateral radiographic view on postoperative day 1. Postoperative dysphagia was subjectively assessed using the Bazaz-Yoo Dysphagia Severity Scale. We statistically evaluated the association between the APD of the RS and postoperative dysphagia.

RESULTS: The mean APD of the RS in all 82 patients was 3.6 mm preoperatively and significantly increased to 8.2 mm postoperatively (P < .0001). Twenty-two patients (26.8%) had postoperative dysphagia. Multivariable analysis revealed that the postoperative APD was associated with postoperative dysphagia (odds ratio 1.27, 95% CI 1.10-1.50, P = .0007). The receiver operating characteristic curve (area under the curve 0.70, 95% CI 0.58-0.83) demonstrated that the postoperative APD of the RS cutoff value was 6.1 mm, with a sensitivity of 100% and a specificity of 35%. With this cutoff value, the positive and negative predictive values for postoperative dysphagia were 36% and 100%, respectively.

CONCLUSION: Our data demonstrate that a value of 6.1 mm for the APD of the RS is an effective indicator for dysphagia after ACDF, which contributes to optimizing the patient management in the acute postoperative period.

Posted on

Stable Regional and Global Alignment in Patients Treated With Minimally Invasive Lateral Retropleural Thoracic Diskectomy Without Fixation

Operative Neurosurgery 26:511–518, 2024

Thoracic disk herniations are challenging to treat, and open transthoracic or minimally invasive thoracoscopic approaches are associated with significant morbidity, substantial costs, and steep learning curves. The minimally invasive lateral retropleural thoracic diskectomy (MIS-LRP-TD) approach is straightforward and is associated with lower perioperative morbidity. With MIS-LRP-TD, the overlying rib, ipsilateral pedicle, ligamentum flavum, posterior longitudinal ligament, and posterior third of the adjacent vertebral bodies are resected. Adjunct fixation is typically not performed, eliminating hardware-related complications and costs. This radiographic study investigates long-term global and thoracic spine alignment after MIS-LRP-TD without fixation.

METHODS: This study was a single-institution, retrospective evaluation of all patients who underwent MIS-LRP-TD without fixation between November 7, 2017 and July 19, 2022. Preoperative and the most recent postoperative radiographs were used to determine the C7 plumb line to central sacral vertical line, thoracic Cobb angle (TCA), segmental Cobb angle, C7 to sagittal vertical axis, thoracic kyphosis, and segmental kyphosis.

RESULTS: In total, 22 patients with 24 disk herniations underwent MIS-LRP-TD without fixation. The mean (SD) radiographic follow-up was 12.9 (11.2) months. Overall, no significant differences were seen in C7 plumb line to central sacral vertical line (P = .65), C7 to sagittal vertical axis (P = .99), thoracic kyphosis (P = .30), TCA (P = .28), segmental kyphosis (P = .27), or segmental Cobb angle (P = .56) at follow-up. One patient demonstrated a >5°change in TCA but remained asymptomatic.

CONCLUSION: Despite requiring extensive resection of the middle column and ipsilateral costovertebral joint at the index level, MIS-LRP-TD without adjunct fixation does not lead to significant global, regional, or segmental deformity. Thus, MIS-LRP-TD appears to be a safe, effective treatment approach for challenging thoracic disk herniations.

Posted on

Radiographic and Clinical Outcomes After Stand-Alone Anterior Lumbar Interbody Fusion for Symptomatic L5-S1 Retrolisthesis

Operative Neurosurgery 26:559–567, 2024

Degenerative lumbar spondylolisthesis is associated with significant pain and disability. The literature on the treatment options and clinical outcomes for lumbar anterolisthesis is robust, but very few reports specifically evaluate lumbar retrolisthesis. This study investigated surgical outcomes for symptomatic L5–S1 retrolisthesis treated with stand-alone L5–S1 anterior lumbar interbody fusion (ALIF).

METHODS: All patients with symptomatic L5–S1 retrolisthesis treated with stand-alone L5–S1 ALIF at a single institution over a 7-year period were identified. Exhaustive nonoperative management had failed for all patients. Patients with previous lumbar fusion were excluded. Preoperative and postoperative radiographic images and patient-reported outcome measures for 20 patients (14 males and 6 females; mean [SD] age, 50.3 [13.7] years) were analyzed.

RESULTS: The mean (SD) follow-up was 43.0 (23.7) months (range, 12.1-102.5 months). Patients experienced postoperative improvements in L5–S1 retrolisthesis (P = .048), L5–S1 disk height and angle (P < .001), L5 foraminal height (P < .001), L5–S1 lordosis (P < .001), and lumbar lordosis (P = .01). There were no significant changes in spinopelvic parameters. At the most recent follow-up, minimal clinically important differences in Oswestry Disability Index score, 36-Item Short-Form Survey (SF-36), and numerical rating scale score for leg pain were achieved in 11 of 20 (55%), 7 of 14 (50%), and 7 of 13 (54%) patients, respectively. All patients demonstrated fusion with no graft subsidence at up to 32 months. No patient experienced intraoperative complications, was readmitted, or required a subsequent posterior decompression or fusion because of refractory symptoms.

CONCLUSION: In our cohort, stand-alone L5–S1 ALIF was associated with radiographic and clinical improvement in patients with symptomatic L5–S1 retrolisthesis.

Posted on

Novel classification of foramen magnum meningiomas predicted by topographic position relative to neurovascular bundle

Acta Neurochirurgica (2024) 166:199

Proximity to critical neurovascular structures can create significant obstacles during surgical resection of foramen magnum meningiomas (FMMs) to the detriment of treatment outcomes. We propose a new classification that defines the tumor’s relationship to neurovascular structures and assess correlation with postoperative outcomes.

Methods In this retrospective review, 41 consecutive patients underwent primary resection of FMMs through a far lateral approach. Groups defined based on tumor-neurovascular bundle configuration included Type 1, bundle ventral to tumor; Type 2a-c, bundle superior, inferior, or splayed, respectively; Type 3, bundle dorsal; and Type 4, nerves and/or vertebral artery encased by tumor.

Results The 41 patients (range 29–81 years old) had maximal tumor diameter averaging 30.1 mm (range 12.7–56 mm). Preoperatively, 17 (41%) patients had cranial nerve (CN) dysfunction, 12 (29%) had motor weakness and/or myelopathy, and 9 (22%) had sensory deficits. Tumor type was relevant to surgical outcomes: specifically, Type 4 demonstrated lower rates of gross total resection (65%) and worse immediate postoperative CN outcomes. Long-term findings showed Types 2, 3, and 4 demonstrated higher rates of permanent cranial neuropathy. Although patients with Type 4 tumors had overall higher ICU and hospital length of stay, there was no difference in tumor configuration and rates of postoperative complications or 30-day readmission.

Conclusion The four main types of FMMs in this proposed classification reflected a gradual increase in surgical difficulty and worse outcomes. Further studies are warranted in larger cohorts to confirm its reliability in predicting postoperative outcomes and possibly directing management decisions.

Posted on

Risk factors of adjacent-segment disease after short-segment fusion in patients with de novo degenerative lumbar scoliosis

J Neurosurg Spine 40:570–579, 2024

Short-segment fusion (SSF) is an effective surgical option for appropriately selected patients with de novo degenerative lumbar scoliosis (DNDLS). Considering that DNDLS is frequently accompanied by multisegment degeneration and potential instability across the entire lumbar segments, it is inevitable that unhealthy segments remain after SSF, thereby increasing the potential risk of adjacent-segment disease (ASD) occurrence. Therefore, the authors aimed to identify the risk factors for ASD in patients with DNDLS who underwent SSF.

METHODS This retrospective study included 80 patients with DNDLS (Cobb angle > 10°) who underwent SSF (1 or 2 levels) between December 2010 and July 2018 with a minimum follow-up duration of 5 years. The participants were divided into two groups: ASD and non-ASD. ASD was defined as clinical ASD rather than radiographic ASD. Various patient and operative variables were compared between the groups. Global and regional radiographic parameters (preoperatively and postoperatively) were also compared between the two groups using plain radiography and MRI. Consequently, univariate and multivariate analyses were conducted to identify the risk factors for ASD occurrence. The receiver operating characteristic (ROC) curve was used to calculate the cutoff values.

RESULTS The mean ± SD age was 67.7 ± 7.2 years at the time of SSF, and there were 62 women (77.5%) enrolled in the study. Thirty patients (37.5%) were in the ASD group and 50 patients (62.5%) were in the non-ASD group. The mean time from the surgery to ASD diagnosis was 34.9 ± 28.2 months in ASD group. Thirteen patients required revision surgery at a mean time of 8.8 ± 7.0 months after ASD occurrence. Multivariate logistic regression analysis demonstrated that preoperative disc wedging angle (OR 1.806, 95% CI 1.255–2.598, p = 0.001), presence of facet tropism (defined as ≥ 10° difference between the facet joint angles of the right and left sides) (OR 5.534, 95% CI 1.528–20.040, p = 0.009), and foraminal stenosis ≥ grade 2 (OR 5.935, 95% CI 1.253–28.117, p = 0.025) were significant risk factors for ASD development. The cutoff value of the preoperative disc wedging angle was calculated to be 2.5° using the ROC curve.

CONCLUSIONS Preoperative disc wedging angle ≥ 2.5°, presence of facet tropism, and foraminal stenosis ≥ grade 2 were identified as significant risk factors for ASD development after SSF in patients with DNDLS.

Posted on

Health Care Costs Following Anterior Cervical Discectomy and Fusion or Cervical Disc Arthroplasty

Spine 2024;49:530–535

Study Design. Observational cohort study.

Objective. To describe the postoperative costs associated with both anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) in the two-year period following surgery.

Summary of Background Data. CDA has become an increasingly common alternative to ACDF for the treatment of cervical disc disorders. Although a number of studies have compared clinical outcomes between both procedures, much less is known about the postoperative economic burden of each procedure.

Materials and Methods. By analyzing a commercial insurance claims database (Marketscan, Merative), patients who underwent one-level or two-level ACDF and CDA procedures between January 1, 2017 and December 31, 2017 were identified and included in the study. The primary outcome was the cost of payments for postoperative management in the two-year period following ACDF or CDA. Identified postoperative interventions included in the study were: (i) physical therapy, (ii) pain medication, (iii) injections, (iv) psychological treatment, and (iv) subsequent spine surgeries.

Results. Totally, 2304 patients (age: 49.0 ± 9.4 yr; male, 50.1%) were included in the study. In all, 1723 (74.8%) patients underwent ACDF, while 581 (25.2%) underwent CDA. The cost of surgery was similar between both groups (ACDF: $26,819 ± 23,449; CDA: $25,954 ± 20,620; P = 0.429). Thirty-day, 90-day, and two-year global costs were all lower for patients who underwent CDA compared with ACDF ($31,024 vs. $34,411, $33,064 vs. $37,517, and $55,723 vs. $68,113, respectively).

Conclusion. Lower two-year health care costs were found for patients undergoing CDA compared with ACDF. Further work is necessary to determine the drivers of these findings and the associated longer-term outcomes.

Posted on

Biportal endoscopic cervical open‑door laminoplasty to treat cervical spondylotic myelopathy

Acta Neurochirurgica (2024) 166:182

Although cervical laminoplasty is a frequently utilized surgical intervention for cervical spondylotic myelopathy, it is primarily performed using conventional open surgical techniques. We attempted the minimally invasive cervical laminoplasty using biportal endoscopic approach.

Methods Contralateral lamina access is facilitated by creating space through spinous process drilling, followed by lamina hinge formation. Subsequently, the incised lamina is elevated from ipsilateral aspect, and secure metal plate fixation is performed.

Conclusion We successfully performed the cervical open door laminoplasty using biportal endoscopic approach. Biportal endoscopic cervical open-door laminoplasty may be a minimally invasive technique that can prevent complications related with open surgery.

Posted on

Postoperative complications after surgery for lumbar spinal stenosis, assessment using two different data sources

Acta Neurochirurgica (2024) 166:189

Lumbar spinal stenosis (LSS) is a prevalent disorder, and surgery for LSS is a common procedure. Postoperative complications occur after any surgery and impose costs for society and costs and additional morbidity for patients. Since complications are relatively rare, medical registries of large populations may provide valuable knowledge. However, recording of complications in registries can be incomplete. To better estimate the true prevalence of complications after LSS surgery, we reviewed two different sources of data and recorded complications for a sample of Norwegian LSS patients.

Methods 474 patients treated surgically for LSS during 2015 and 2016 at four hospitals reported to a national spine registry (NORspine). Postoperative complications were recorded by patients in NORspine, and we cross-referenced complications documented in NORspine with the patients´ electronic patient records (EPR) to re-test the complication rates. We performed descriptive statistics of complication rates using the two different data sources above, and analyzed the association between postoperative complications and clinical outcome with logistic regression.

Results The mean (95%CI) patient age was 66.3 (65.3–67.2) years, and 254 (53.6%) were females. All patients were treated with decompression, and 51 (10.7%) received an additional fusion during the index surgery. Combining the two data sources, we found a total rate for postoperative complications of 22.4%, the NORspine registry reported a complication rate of 15.6%, and the EPR review resulted in a complication rate of 16.0%. However, the types of complications were inconsistent across the two data sources. According to NORspine, the frequency of reoperation within 90 days was 0.9% and according to EPR 3.4%. The rates of wound infection were for NORspine 3.1% and EPR review 2.1%. There was no association between postoperative complication and patient reported outcome.

Conclusion Postoperative complications occurred in 22% of LSS patients. The frequency of different postoperative complications differed between the two data sources.

Posted on

Predictors of pelvic tilt normalization: a multicenter study on the impact of regional and lower-extremity compensation on pelvic alignment after complex adult spinal deformity surgery

J Neurosurg Spine 40:505–512, 2024

OBJECTIVE The objective was to determine the degree of regional decompensation to pelvic tilt (PT) normalization after complex adult spinal deformity (ASD) surgery.

METHODS Operative ASD patients with 1 year of PT measurements were included. Patients with normalized PT at baseline were excluded. Predicted PT was compared to actual PT, tested for change from baseline, and then compared against age-adjusted, Scoliosis Research Society–Schwab, and global alignment and proportion (GAP) scores. Lowerextremity (LE) parameters included the cranial-hip-sacrum angle, cranial-knee-sacrum angle, and cranial-ankle-sacrum angle. LE compensation was set as the 1-year upper tertile compared with intraoperative baseline. Univariate analyses were used to compare normalized and nonnormalized data against alignment outcomes. Multivariable logistic regression analyses were used to develop a model consisting of significant predictors for normalization related to regional compensation.

RESULTS In total, 156 patients met the inclusion criteria (mean ± SD age 64.6 ± 9.1 years, BMI 27.9 ± 5.6 kg/m 2 , Charlson Comorbidity Index 1.9 ± 1.6). Patients with normalized PT were more likely to have overcorrected pelvic incidence minus lumbar lordosis and sagittal vertical axis at 6 weeks (p < 0.05). GAP score at 6 weeks was greater for patients with nonnormalized PT (0.6 vs 1.3, p = 0.08). At baseline, 58.5% of patients had compensation in the thoracic and cervical regions. Postoperatively, compensation was maintained by 42% with no change after matching in age-adjusted or GAP score. The patients with nonnormalized PT had increased rates of thoracic and cervical compensation (p < 0.05). Compensation in thoracic kyphosis differed between patients with normalized PT at 6 weeks and those with normalized PT at 1 year (69% vs 35%, p < 0.05). Those who compensated had increased rates of implant complications by 1 year (OR [95% CI] 2.08 [1.32–6.56], p < 0.05). Cervical compensation was maintained at 6 weeks and 1 year (56% vs 43%, p = 0.12), with no difference in implant complications (OR 1.31 [95% CI −2.34 to 1.03], p = 0.09). For the lower extremities at baseline, 61% were compensating. Matching age-adjusted alignment did not eliminate compensation at any joint (all p > 0.05). Patients with nonnormalized PT had higher rates of LE compensation across joints (all p < 0.01). Overall, patients with normalized PT at 1 year had the greatest odds of resolving LE compensation (OR 9.6, p < 0.001). Patients with normalized PT at 1 year had lower rates of implant failure (8.9% vs 19.5%, p < 0.05), rod breakage (1.3% vs 13.8%, p < 0.05), and pseudarthrosis (0% vs 4.6%, p < 0.05) compared with patients with nonnormalized PT. The complication rate was significantly lower for patients with normalized PT at 1 year (56.7% vs 66.1%, p = 0.02), despite comparable health-related quality of life scores.

CONCLUSIONS Patients with PT normalization had greater rates of resolution in thoracic and LE compensation, leading to lower rates of complications by 1 year. Thus, consideration of both the lower extremities and thoracic regions in surgical planning is vital to preventing adverse outcomes and maintaining pelvic alignment.

Posted on

Pain alleviation and functional improvement: ultra-early patient-reported outcome measures after full endoscopic spine surgery

J Neurosurg Spine 40:465–474, 2024

Questions regarding anticipated pain improvement and functional recovery postsurgery are frequently posed in preoperative consultations. However, a lack of data characterizing outcomes for the first postoperative days only allows for anecdotal answers. Hence, the assessment of ultra-early patient-reported outcome measures (PROMs) is essential for patient-provider communication and patient satisfaction. The aim of this study was to elucidate this research gap by assessing and characterizing PROMs for the first days after full endoscopic spine surgery (FESS).

METHODS This multicenter study included patients undergoing lumbar FESS from March 2021 to July 2023. After informed consent was provided, data were collected prospectively through a smartphone application. Patients underwent either discectomy or decompression. Analyzed parameters included demographics, surgical details, visual analog scale scores for both back and leg pain, and the Oswestry Disability Index (ODI) score. Data were acquired daily for the 1st postoperative week, as well as after 2 weeks, 3 months, and 6 months.

RESULTS A total of 182 patients were included, of whom 102 underwent FESS discectomy and 80 underwent FESS decompression. Significant differences between the discectomy and decompression groups were found for age (mean 50.45 ± 15.28 years and 63.85 ± 13.25 years, p < 0.001; respectively), sex (p = 0.007), and surgery duration (73.45 ± 45.23 minutes vs 98.05 ± 46.47 minutes, p < 0.001; respectively). Patients in both groups reported a significant amelioration of leg pain on the 1st postoperative day (discectomy group VAS score: 6.2 ± 2.6 vs 2.4 ± 2.9, p < 0.001; decompression group: 5.3 ± 2.8 vs 1.9 ± 2.2, p < 0.001) and of back pain within the 1st postoperative week (discectomy group VAS score: 5.5 ± 2.8 vs 2.8 ± 2.2, p < 0.001; decompression group: 5.2 ± 2.7 vs 3.1 ± 2.4, p < 0.001). ODI score improvement was most pronounced at the 3-month time point (discectomy group: 21.7 ± 9.1 vs 9.3 ± 9.1, p < 0.001; decompression group: 19.3 ± 7.8 vs 9.9 ± 8.3, p < 0.001). For both groups, pain improvement within the 1st week after surgery was highly predictive of later benefits.

CONCLUSIONS Ultra-early PROMs reveal an immediate pain improvement after FESS. While the benefits in pain reduction plateaued within the 1st postoperative week for both groups, functional improvements developed over a more extended period. These results illustrate a biphasic rehabilitation process wherein initial pain alleviation transitions into functional improvement over time.

Posted on

Evaluating the safe zone for lumbar pedicle screws: are midline crossing screws indicative of pedicle breach?

The Spine Journal 24 (2024) 617−624

Pedicle screw breach (PSB) is not uncommon following lumbar instrumentation, and in some instances, it may lead to vascular and/or neurologic complications. Previous literature suggested that screws crossing the vertebral midline on an anterior-posterior (AP) radiograph (or midsagittal on CT) are concerning for medial pedicle breach.

OBJECTIVE: Our primary aim was to map out the safe zones (SZ) of bilateral pedicle instrumentation and their relationship at each lumbar vertebral level. Our secondary aim was to evaluate the presence of SZs’ intersection at each lumbar level, denoting safe midline pedicle screw crossing not otherwise associated with medial pedicle breach.

STUDY DESIGN/SETTING: Retrospective Anatomical Study.

PATIENT SAMPLE: Adult patients in the from “The Cancer Imaging Archive” (TCIA) database who have not had thoraco-lumbo-sacral fusion.

OUTCOME MEASURES: Physiologic measures obtained through 3D analysis of CT images and virtual pedicle screws.

METHOD: CT scans of 51 patients were randomly selected from “The Cancer Imaging Archive” (TCIA) online database for analysis. The Sectra 3D Spine software was used to create 3D renderings, place virtual screws, and make measurements. At each lumbar vertebra, the right and left pedicle corridors were mapped. At each pedicle, two screw positions were templated, the “medial limit screw” (MLS) and the “lateral limit screw” (LLS). Each limit screw was the most extreme position that the screw could exist in without causing a medial or lateral breach. The safe zone was defined as the zone between MLS and LLS. Measurements were taken for each level (between L1 and L5) and side (Left, Right).

RESULTS: A total of 253 lumbar vertebrae from 51 patients (mean age 53.1, 56.9% male) were included. Two vertebrae from two patients were removed for poor image quality. Out of the 506 screw positions analyzed in our study, 97.4% had overlapping SZ and crossed the midplane without medial pedicle breach. The significant factors (p<.01) for safe midplane-crossing screws included: the screw length (L1−L5); the laterality of the screw entry point (L1−L4); and the pedicle diameter (L2 and L5). CONCLUSIONS: A midline crossing pedicle screw on a lumbar AP radiograph is not necessarily indicative of a medial pedicle screw breach. Anatomical (ie, larger pedicle diameter) and technical (ie, longer screws, and lateral entry points) factors allow for safety zone intersections and indicate safe midline crossing by pedicle screws.

Posted on

Current concepts in adult cervical spine deformity surgery

J Neurosurg Spine 40:439–452, 2024

Cervical spine deformity surgery has significantly evolved over recent decades. There has been substantial work performed, which has furthered the true understanding of alignment and advancements in surgical technique and instrumentation.

Concomitantly, understanding of cervical spine pathology and the contributing drivers have also improved, which have influenced the development of classification systems for cervical spine deformity and the development of treatment-guiding algorithms.

This article aims to provide a synopsis of the current knowledge surrounding cervical spine deformity to date, with particular focus on preoperative expected alignment targets, perioperative optimization, and the whole operative strategy.

Posted on

Normative Measurements of L1–S1 Segmental Angulation, Disk Space Height, and Neuroforaminal Dimensions Using Computed Tomography

Neurosurgery 94:813–827, 2024

BACKGROUND AND OBJECTIVES: To establish normative anatomic measurements of lumbar segmental angulation (SA) and disk space height (DSH) in relation to neuroforaminal dimensions (NFDs), and to uncover the influence of patient demographic and anthropometric characteristics on SA, DSH, and NFDs.

METHODS: NFDs, SA, and anterior, middle, and posterior DSH were measured using computed tomography of 969 patients. NFDs were defined as sagittal anterior-to-posterior width, foraminal height, and area. Statistical analyses were performed to assess associations among SA, DSH, NFDs, and patient height, weight, body mass index, sex, and ethnicity.

RESULTS: SA and DSH measurements increased moving caudally from L1 to S1. Foraminal width decreased moving caudally from L1 to S1. Foraminal height and area demonstrated unimodal distribution patterns with the largest values clustered at L2–L3 on the right side and L3–L4 on the left. Significant differences in SA, DSH, and NFD measurements were observed based on the disk level. Inconsistent, marginal NFD differences were observed based on laterality. Across all disk levels, only weak-to-moderate correlations were observed between SA and DSH in relation to NFDs. Patient height, weight, and body mass index were only weakly associated with SA, DSH, and NFDs. Based on patient sex, significant differences were observed for SA, DSH, and NFD measurements from L1 to S1, with males demonstrating consistently larger values compared with females. Based on patient race and ethnicity, significant differences in SA and NFD measurements were observed from L1 to S1.

CONCLUSION: This study describes 48 450 normative measurements of L1–S1 SA, DSH, and NFDs. These measurements serve as representative models of normal anatomic dimensions necessary for several applications including surgical planning and diagnosis of foraminal stenosis. Normative values of SA and DSH are not moderately or strongly associated with NFDs. SA, DSH, and NFDs are influenced by sex and ethnicity, but are not strongly or moderately influenced by patient anthropometric factors.

Proudly powered by WordPress