Category: Spine

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Can patients with symptomatic Tarlov cysts be differentiated from patients with specific low back pain based on comprehensive history taking?

Acta Neurochirurgica (2018) 160:839–844

Tarlov cysts (TCs) are expanded nerve root sheaths that occur near the dorsal root ganglion and result from increased intraspinal hydrostatic pressure. TCs most frequently affect the lumbosacral plexus and therefore may cause specific symptoms such as perineal pain and neurogenic bladder, bowel, and sphincter problems. It has been estimated that 1% of the population has symptomatic Tarlov cysts (STCs). However, STCs appear to be underdiagnosed, with the pain reported by patients commonly attributed to degenerative alterations seen on MRI. The aim of the present study is to investigate the utility of a comprehensive questionnaire for use by physicians in establishing the diagnosis of STCs.

Methods We compared questionnaire responses regarding patient history between 33 patients diagnosed with symptomatic TCs and 42 patients with chronic low back pain and sciatica due to disc problems or degenerative or inflammatory disorders. The diagnosis of STCs was confirmed using nerve conduction studies (NCS) and electromyography (EMG) of the sacral myotomes by an expert neurophysiologist.

Results The questionnaire responses revealed specific differences in perineal symptoms (perineal pain, dyspareunia, coccygodynia), bowel symptoms (constipation, diarrhea), bladder symptoms (hesitation, retention, frequency), and anal sphincter problems (anal pain, mild fecal incontinence). Additionally, sitting, walking, and straining aggravated pain more frequently in STC patients, and STC patients were more often forced to stop working and/or reduce their social activities.

Conclusions Including the above-listed items in the patient history might facilitate differentiation of low back pain and sciatica due to STCs from that due to disc problems or degenerative or inflammatory disorders.

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Is Eighty the New Sixty? Outcomes and Complications after Lumbar Decompression Surgery in Elderly Patients over 80 Years of Age

World Neurosurg. (2018) 112:e555-e560.

An increasing demographic aging of the general population results in a rising incidence of octogenarians and nonagenarians with spine disease. Patients older than 65 years represent the majority of patients with degenerative lumbar spine disease in our daily clinical routine. Surgical treatment is undertaken reluctantly because of an increased rate of comorbidities. We therefore assessed complication rates of lumbar decompression in regard to neurological outcome and medical conditions in patients age 80 years or older in a retrospective singlecenter series.

METHODS: Data for 244 patients (124 female, 120 male; mean age, 83.1  3 years; age range, 80e95 years) who underwent decompressive surgery for lumbar spinal stenosis or disc herniation between April 2007 and February 2016 were assessed retrospectively. Age at surgery, neurologic deficits (preoperative and postoperative), relevant medical comorbidities and previous lumbar decompression, intraoperative and postoperative complications (e.g., surgery-related, medical), duration of surgery, length of hospital stay, and rate of revision surgeries were recorded.

RESULTS: Surgery was performed for lumbar stenosis (184 patients; 75.4%), lumbar disc herniation (13 patients; 5.3%) or both (47 patients; 19.3%). Seventy-six patients (31.3%) patients experienced preoperative neurologic deficits; 48 (63.2%) of these patients improved, 28 (36.8%) of them were unchanged after surgery, and none deteriorated. New transient, postoperative, neurologic deficits occurred in 6 patients (2.5%). All 55 (22.5%) intraoperative complications were mild to moderate, and no severe surgical complications occurred. Two hundred fifteen patients (88%) had relevant medical disorders. Nineteen (7.7%) postoperative medical complications were reported in 17 patients (7%), of which 14 (73.7%) were severe and 5 (26.3%) were mild (4 pulmonary embolisms, 6 pneumonias, 3 myocardial infarctions, 1 postoperative renal failure, 5 urinary tract infections). Medical complications that necessitated intensive care unit treatment and resulted in lethal outcome were seen in 2 patients (0.8%).

CONCLUSION: Despite their age, the vast majority of octogenarians and nonagenarians benefited from lumbar decompression surgery. Mild to moderate intraoperative complications were relatively frequent, whereas severe intraoperative complications did not occur. The majority of medical complications was severe, but the incidence was acceptable, and the postoperative outcome was still favorable in most patients

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Incidence and clinical relevance of cage subsidence in anterior cervical discectomy and fusion

Acta Neurochirurgica (2018) 160:873–880

The placement of intervertebral cages in anterior cervical discectomy (ACDF) supposedly maintains foraminal height. The most commonly reported cage-related complication is subsidence, although it is unknown whether a correlation between subsidence and clinical outcome exists. Aim To assess the incidence and relevance of subsidence.

Methods Literature searches were performed in PubMed, MEDLINE, Embase,Web of Science, COCHRANE, and CENTRAL. The inclusion criteria were as follows: ≥ 20 patients, ADCF with cage, subsidence assessed, and primary data. Risk of bias was assessed using adjusted Cochrane checklists.

Results Seventy-one studies, comprising 4784 patients, were included. Subsidence was generally defined as ≥ 3-mm loss of height comparing postoperative intervertebral heights with heights at last follow-up. Mean incidence of subsidence was 21% (range 0–83%). Of all patients, 46% of patients received polyether-ether-ketone (PEEK) cages, 31% received titanium cages, 18% received cage-screw-combinations, and 5% received polymethyl-methacrylate (PMMA) cages. Patients treated with cagescrew- combinations had significantly less subsidence than patients treated with PEEK, titanium, or PMMA cages (15.1% vs. 23.5% vs. 24.9% vs. 30.2%; p < 0.001). Thirteen studies assessed clinical outcome in relation to subsidence; the majority did not find a significant correlation. Only four studies correlated subsidence to cage size and/or height; no correlation was established.

Conclusions Subsidence in ACDF with cages occurs in 21% of patients. The risk for subsidence seems lower using PEEK or titanium cages or adding screws.Whether subsidence affects clinical outcome is not satisfactorily evaluated in the available literature. Future studies on this correlation are warranted in order to establish the additional value of the interposition of a cage in ACDF.

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Endplate changes after lumbar discectomy with and without implantation of an annular closure device

Acta Neurochirurgica (2018) 160:855–862

The implantation of a bone-anchored annular closure device (ACD) might be associated with the developed new endplate changes (EPC) after surgery.

Methods A post hoc analysis has been done in patients from a prospective randomized multicenter study. All patients underwent limited lumbar discectomy with intraoperative randomization into the groups limited lumbar discectomy alone or additional ACD implantation. Low-dose lumbar computed tomography (CT) and clinical investigations were performed preoperatively and 12 months after the operation.

Results A total of 554 patients were randomized. After exclusion of dropouts, the per-protocol population included 493 patients (251 in the control group and 242 in the ACD group); the follow-up rate was ≥ 90%. The number of patients showing EPC at baseline was similar in both groups. The number of patients showing EPC and the total EPC lesion area significantly increased in both groups over time, but significantly increased more in the EPC group for the superior and inferior endplate (all P < 0.0001). There was no association of pre-existing number and size of EPC with sex, age, or smoking habits. Correlation of clinical variables showed no relation with number, size, and increase of EPC area after surgery.

Conclusions Patients with primary lumbar disc herniation show EPC in the corresponding segments. There is a significant increase of lesion number and size within 12 months after discectomy. This increase is significantly more pronounced in the ACD group. Presence and growth of EPC is not correlated with low-back pain or ODI.

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Management of Odontoid Fractures in the Elderly

Neurosurgery 82:419–430, 2018

Odontoid fractures are the most common fracture of the axis and the most common cervical spine fracture in patients over 65. Despite their frequency, there is considerable ambiguity regarding optimal management strategies for these fractures in the elderly. Poor bone health and medical comorbidities contribute to increased surgical risk in this population; however, nonoperative management is associated with a risk of nonunion or fibrous union.

We provide a review of the existing literature and discuss the classi- fication and evaluation of odontoid fractures. The merits of operative vs nonoperative management, fibrous union, and the choice of operative approach in elderly patients are discussed. A treatment algorithm is presented based on the available literature.

We believe that type I and type III odontoid fractures can be managed in a collar in most cases. Type II fractures with any additonal risk factors for nonunion (displacement, comminution, etc) should be considered for surgical management. However, the risks of surgery in an elderly population must be carefully considered on a case-by-case basis. In a frail elderly patient, a fibrous nonunion with close follow-up is an acceptable outcome. If operative management is chosen, a posterior approach is should be chosen when fracture- or patient-related factors make an anterior approach challenging.

The high levels of morbidity and mortality associated with odontoid fractures should encourage all providers to pursue medical co- management and optimization of bone health following diagnosis.

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Prospective, randomized, multicenter study with 2-year follow-up to compare the performance of decompression with and without interlaminar stabilization

J Neurosurg Spine 28:406–415, 2018

Surgical decompression is extremely effective in relieving pain and symptoms due to lumbar spinal stenosis (LSS). Decompression with interlaminar stabilization (D+ILS) is as effective as decompression with posterolateral fusion for stenosis, as shown in a major US FDA pivotal trial. This study reports a multicenter, randomized controlled trial in which D+ILS was compared with decompression alone (DA) for treatment of moderate to severe LSS.

METHODS Under approved institutional ethics review, 230 patients (1:1 ratio) randomized to either DA or D+ILS (coflex, Paradigm Spine) were treated at 7 sites in Germany. Patients had moderate to severe LSS at 1 or 2 adjacent segments from L-3 to L-5. Outcomes were evaluated up to 2 years postoperatively, including Oswestry Disability Index (ODI) scores, the presence of secondary surgery or lumbar injections, neurological status, and the presence of device- or procedure-related severe adverse events. The composite clinical success (CCS) was defined as combining all 4 of these outcomes, a success definition validated in a US FDA pivotal trial. Additional secondary end points included visual analog scale (VAS) scores, Zürich Claudication Questionnaire (ZCQ) scores, narcotic usage, walking tolerance, and radiographs.

RESULTS The overall follow-up rate was 91% at 2 years. There were no significant differences in patient-reported outcomes at 24 months (p > 0.05). The CCS was superior for the D+ILS arm (p = 0.017). The risk of secondary intervention was 1.75 times higher among patients in the DA group than among those in the D+ILS group (p = 0.055). The DA arm had 228% more lumbar injections (4.5% for D+ILS vs 14.8% for DA; p = 0.0065) than the D+ILS one. Patients who underwent DA had a numerically higher rate of narcotic use at every time point postsurgically (16.7% for D+ILS vs 23% for DA at 24 months). Walking Distance Test results were statistically significantly different from baseline; the D+ILS group had > 2 times the improvement of the DA. The patients who underwent D+ILS had > 5 times the improvement from baseline compared with only 2 times the improvement from baseline for the DA group. Foraminal height and disc height were largely maintained in patients who underwent D+ILS, whereas patients treated with DA showed a significant decrease at 24 months postoperatively (p < 0.001).

CONCLUSIONS This study showed no significant difference in the individual patient-reported outcomes (e.g., ODI, VAS, ZCQ) between the treatments when viewed in isolation. The CCS (survivorship, ODI success, absence of neurological deterioration or device- or procedure-related severe adverse events) is statistically superior for ILS. Microsurgical D+ILS increases walking distance, decreases compensatory pain management, and maintains radiographic foraminal height, extending the durability and sustainability of a decompression procedure. Clinical trial registration no.: NCT01316211 (clinicaltrials.gov)

 

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Modified Laminoplasty Preserving the Posterior Deep Extensor Insertion into C2 Improves Clinical and Radiologic Results Compared with Conventional Laminoplasty: A Meta-Analysis

World Neurosurg. (2018) 111:157-165

Whether modified laminoplasty is better than conventional laminoplasty is unclear. Thus, a meta-analysis comparing the outcomes of preserving or repairing the posterior deep extensor insertion to C2 in laminoplasty was conducted for patients with multilevel cervical spondylotic myelopathy (MCSM).

METHODS: Several electronic databases were chosen to search for relevant studies. The primary indices included preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, JOA recovery rate, muscle atrophy rate, preoperative and postoperative range of motion (ROM), ROM decrease rate, and incidence of axial pain. Results are expressed as odds ratios with 95% confidence intervals for the dichotomous outcomes and mean differences for continuous outcomes.

RESULTS: Eight studies involving 763 patients were included in this study. The postoperative cervical ROM was significantly higher in the modified group (P [ 0.01, MD [ 3.0 [0.66, 5.35]), as was the cervical posterior muscle volume (P [ 0.02, MD [ 28.28 [4.42, 52.3]) and the operation time (MD [ L45.04, 95% CI L49.79, L40.29; P < 0.01). The incidence of axial symptoms in the modified group was lower than that in the conventional group (P < 0.01, OR 0.28 [0.17, 0.46]), as was the rate of decrease of cervical ROM (P [ 0.004, MD [ L6.72 [L11.25, 2.19]). There was no significant difference (P > 0.05) between the groups in blood loss, preoperative and postoperative JOA score, or JOA recovery rate.

CONCLUSIONS: Modified laminoplasty had shorter operation times, a lower incidence of axial pain, a higher cervical ROM, and a lower atrophy rate compared with conventional laminoplasty. The clinical and radiologic results of modified laminoplasty have been partly superior to those of conventional laminoplasty to date.

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Risk Factors for Recollapse of the Augmented Vertebrae After Percutaneous Vertebral Augmentation: A Systematic Review and Meta-Analysis

World Neurosurg. (2018) 111:119-129

Recollapse of the augmented vertebrae after percutaneous vertebral augmentation treatment for osteoporotic vertebral compression fractures has obtained much attention. Although many potential risk factors have been proposed, they are still disputed. The aim of our study was to identify the characteristics of the augmented vertebrae that had undergone a recollapse according to a systematic review from the earliest available records up to August 2017 and then conduct a meta-analysis based on eligible studies to assess significant potential risk factors for recollapse of the augmented vertebrae.

METHODS: Fourteen studies were identified for investigating recollapse of the augmented vertebrae. Of those studies, 9 studies were eligible for metaanalysis.

RESULTS: Pooled results showed that 5 primary factors were associated with recollapse of the augmented vertebrae, including preoperative intravertebral cleft, the affected vertebrae in the thoracolumbar region, preoperative severe kyphotic deformity, solid lump cement distribution pattern, and higher vertebral height restoration. It was possibly another risk factor that the distance between PMMA and superior end plate was relatively large.

CONCLUSIONS: Careful observation of patients with these risk factors and reasonable intervention could be useful to prevent deterioration of their clinical course

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Minimally Invasive Microsurgical Resection of Primary, Intradural Spinal Tumors is Feasible and Safe: A Consecutive Series of 83 Patients

Neurosurgery 82:365–371, 2018

To date, the traditional approach to intraspinal tumors has been open laminectomy or laminoplasty followed by microsurgical tumor resection. Recently, however, minimally invasive approaches have been attempted by some.

OBJECTIVE: To investigate the feasibility and safety of minimally invasive surgery (MIS) for primary intradural spinal tumors.

METHODS:Medical charts of 83 consecutive patients treated with MIS for intradural spinal tumors were reviewed. Patients were followed up during the study year, 2015, by either routine history/physical examination or by telephone consultation, with a focus on tumor status and surgery-related complications. RESULTS: Mean age at surgery was 53.7 yr and 52% were female. There were 49 schwannomas, 18 meningeomas, 10 ependymomas, 2 hemangioblastomas, 1 neurofibroma, 1 paraganglioma, 1 epidermoid cyst, and 1 hemangiopericytoma. The surgical mortality was 0%. In 87% of cases, gross total resection was achieved. The complication rate was 11%, including 2 cerebrospinal fluid leakages, 1 asymptomatic pseudomeningocele, 2 superficial surgical site infections, 1 sinus vein thrombosis, and 4 cases of neurological deterioration. There were no postoperative hematomas, and no cases of deep vein thrombosis or pulmonary embolism. Ninety-three percent of patients were ambulatory and able to work at the time of follow-up.

CONCLUSION: This study both demonstrates that it is feasible and safe to remove select, primary intradural spinal tumors using MIS, and augments the previous literature in favor of MIS for these tumors.

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Intramedullary ependymoma: long-term outcome after surgery

Acta Neurochirurgica (2018) 160:439–447

Overall (OS) and progression-free survival (PFS) of patients undergoing spinal ependymoma resection has been frequently reported. Contrarily, OS and PFS of purely intramedullary ependymomas have not been clearly determined yet.

Methods The data of 37 patients undergoing resection of an intramedullary ependymoma (IE) from January 2000 to December 2016 were analysed retrospectively.

Results The mean age was 46 years. The male:female ratio was 24:13. The median duration of symptoms was 12 months. Sixtytwo per cent of ependymomas were in the cervical, 24% in the thoracic, and 14% in the conus region in our series. The median volume was 1.3 ml. A syrinx was found in 49%and a cyst in 32%. GTR was achieved in 89%, STR in three (8%), and PR in one patient (3%). Median follow-up was 114 months. PFS was 87%, 82%, and 82%at 5, 10, and 15 years, respectively. OS was 97%, 88%, and 63% at 5, 10, and 15 years, respectively. There was a significant difference in PFS depending on the extent of resection and in OS depending on the pre-operative clinical status. There was no significant difference in OS and PFS regarding the other examined influencing factors.

Conclusion GTR resection was the most important factor influencing PFS. According to our results OS of IEs is much worse than that of spinal ependymomas. Our analysis confirms that patients with good pre-operative (McCormick grade 1 and 2) clinical status have significantly better OS than patients with McCormick grade 3 and higher.

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Percutaneous transforaminal endoscopic discectomy compared with microendoscopic discectomy for lumbar disc herniation

J Neurosurg Spine 28:300–310, 2018

A prospective randomized controlled study was conducted to clarify whether percutaneous transforaminal endoscopic discectomy (PTED) results in better clinical outcomes and less surgical trauma than microendoscopic discectomy (MED).

METHODS In this single-center, open-label, randomized controlled trial, patients were included if they had persistent signs and symptoms of radiculopathy with corresponding imaging-confirmed lumbar disc herniation. Patients were randomly allocated to the PTED or the MED group by computer-generated randomization codes. The primary outcome was the Oswestry Disability Index (ODI) score 1 year after surgery. Secondary outcomes included scores of the Medical Outcomes Study 36-Item Short-Form Health Survey bodily pain and physical function scales, EuroQol Group’s EQ-5D , and the visual analog scales for back pain and leg pain. Data including duration of operation, in-bed time, length of hospital stay, surgical cost and total hospital cost, complications, and reoperations were recorded.

RESULTS A total of 153 participants were randomly assigned to 2 treatment groups (PTED vs MED), and 89.5% (137 patients) completed 1 year of follow-up. Primary and secondary outcomes did not differ significantly between the treatment groups at each prespecified follow-up point (p > 0.05). For PTED, there was less postoperative improvement in ODI score in the median herniation subgroup at 1 week (p = 0.027), 3 months (p = 0.013), 6 months (p = 0.027), and 1 year (p = 0.028) compared with the paramedian subgroup. For MED, there was significantly less improvement in ODI score at 3 months (p = 0.008), 6 months (p = 0.028), and 1 year (p = 0.028) in the far-lateral herniation subgroup compared with the paramedian subgroup. The total complication rate over the course of 1 year was 13.75% in the PTED group and 16.44% in the MED group (p = 0.642). Five patients (6.25%) in the PTED group and 3 patients (4.11%) in the MED group suffered from residue/recurrence of herniation, for which reoperation was required.

CONCLUSIONS Over the 1-year follow-up period, PTED did not show superior clinical outcomes and did not seem to be a safer procedure for patients with lumbar disc herniation compared with MED. PTED had inferior results for median disc herniation, whereas MED did not seem to be the best treatment option for far-lateral disc herniation. Clinical trial registration no.: NCT01997086 (clinicaltrials.gov).

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Management of spinal infection: a review of the literature

Acta Neurochirurgica (2018) 160:487–496

Spinal infection (SI) is defined as an infectious disease affecting the vertebral body, the intervertebral disc, and/or adjacent paraspinal tissue and represents 2–7% of all musculoskeletal infections. There are numerous factors, which may facilitate the development of SI including not only advanced patient age and comorbidities but also spinal surgery. Due to the low specificity of signs, the delay in diagnosis of SI remains an important issue and poor outcome is frequently seen. Diagnosis should always be supported by clinical, laboratory, and imaging findings, magnetic resonance imaging (MRI) remaining the most reliable method. Management of SI depends on the location of the infection (i.e., intraspinal, intervertebral, paraspinal), on the disease progression, and of course on the patient’s general condition, considering age and comorbidities. Conservative treatment mostly is reasonable in early stages with no or minor neurologic deficits and in case of severe comorbidities, which limit surgical options. Nevertheless, solely medical treatment often fails. Therefore, in case of doubt, surgical treatment should be considered. The final result in conservative as well as in surgical treatment always is bony fusion. Furthermore, both options require a concomitant antimicrobial therapy, initially applied intravenously and administered orally thereafter. The optimal duration of antibiotic therapy remains controversial, but should never undercut 6 weeks. Due to a heterogeneous and often comorbid patient population and the wide variety of treatment options, no generally applicable guidelines for SI exist and management remains a challenge. Thus, future prospective randomized trials are necessary to substantiate treatment strategies.

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Minimally Invasive Transforaminal Lumbar Interbody Fusion Using Banana-Shaped and Straight Cages: Radiological and Clinical Results from a Prospective Randomized Clinical Trial

Neurosurgery 82:289–298, 2018

In minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), cage type and position play important roles in fusion achievement and sagittal alignment correction. However, no prospective randomized comparison of the results using different types of cage has been reported to date.

OBJECTIVE: To compare the radiological and clinical outcomes of unilateral MIS-TLIF using 2 types of cage.

METHODS: All candidates for single-level MIS-TLIF were randomized into banana-shaped cage and straight-cage groups. Plain radiographs and computed tomography scans were used for assessment of cage positions, fusion status, disc height, segmental lordotic angle, cage subsidence, and pelvic parameters. Clinical outcome was assessed using visual analog scale and Oswestry Disability Index scores.

RESULTS: Forty-four and 40 consecutive patients were operated on using banana-shaped and straight cages, respectively. Cage position was more anterior and lateral in the straightcage group and more medial and posterior in the banana-shaped cage group. Solid fusion was achieved in 95.2% and 96.6% of the 2 groups, respectively, at 12 mo. The change in disc height and segmental lordotic angle postoperatively was significantly greater in the banana-shaped cage group. The incidence of subsidence during follow-up was significantly higher in the banana-shaped cage group (P<.04). Clinically, the visual analog scale and Oswestry Disability Index scores decreased significantly after surgery in both groups, with no significant difference between the groups.

CONCLUSION: Our preliminary outcomes suggest that the subsidence rate may be higher using banana-shaped cages in MIS-TLIF, possibly due to their more medial final position.

 

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Design and Testing of 2 Novel Scores That Predict Global Sagittal Alignment Utilizing Cervical or Lumbar Plain Radiographs

Neurosurgery 82:163–171, 2018

Global sagittal deformity is an established cause of disability. However, measurements of sagittal alignment are often ignored when patients present with symptoms localizing to the cervical or lumbar spine.

OBJECTIVE: To develop scoring scales to predict the risk of sagittal malalignment in patients with only cervical or lumbar spine radiographs.

METHODS: A retrospective review of a prospectively maintained multicenter adult spinal deformity database was performed. Primary outcome (sagittal malalignment) was defined as a C7 plumbline ≥ 50 mm. Two multivariate logistic regressions were performed using patient characteristics and measurements derived from cervical or lumbar radiographs as covariates. Point scores were assigned to age, body mass index (BMI), and lumbar lordosis or T1 slope by rounding their ß coefficients to the nearest integer.

RESULTS: Nine hundred seventy-nine patients were included, with 652 randomly assigned to the derivation cohort (used to build the score) and 327 comprising the validation set. Final cervical score for the primary outcome included BMI ≥ 25 (1 point), age ≥ 55 yr (2 points), and T1 slope ≥ 27º (2 points). Final lumbar score for the primary outcome included BMI≥25 (1 point), age≥55 yr (1 point), and lumbar lordosis ≥45º (–1 points). High scores for both the cervical and lumbar spine presented with high specificity and positive likelihood ratios of sagittal malalignment.

CONCLUSION: We developed scoring scales to predict global sagittal malalignment utilizing clinical covariates and cervical or lumbar radiographs. Patients with high scores may prompt imaging with long-cassette plain films to evaluate for global sagittal imbalance.

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Endoscopic Transseptal Approach with Posterior Nasal Spine Removal: A Wide Surgical Corridor to the Craniovertebral Junction and Odontoid

World Neurosurg. (2018) 110:373-385

The transnasal approach to lesions involving the craniovertebral junction represents a technical challenge because of limited inferior exposure. The endoscopic transseptal approach (EtsA) with posterior nasal spine (PNS) removal is described. This technique can create a wide exposure of the craniovertebral junction, thereby increasing the caudal exposure.

METHODS: On patients undergoing anterior craniovertebral junction decompression, we calculated the degree of exposure on the sagittal plan through a paraseptal route, an EtsA without and with PNS removal. The horizontal exposure and working area with the latter approach were also evaluated.

RESULTS: Five patients underwent the transnasal procedure. The age of patients ranged from 34-71 years. All patients harbored basilar impression. The mean postoperative Nurick grade was improved versus the average preoperative grade. The average follow-up duration was 16 months. All patients underwent occipitocervical fixation. The mean vertical distances, from the clinoid recess to the inferior most limit with the paraseptal approach, EtsA without and with PNS removal were 38.52, 44.12, and 51.16 mm, respectively. The difference between our approach and a standard paraseptal route was statistically significant (P [ 0.041; P< 0.05). The mean horizontal distances were 31.68 mm (mononostril entry) and 35.37 mm (binostril entry). The mean working area was 1795.53 mm2.

CONCLUSIONS: Endoscopic endonasal approaches to the craniovertebral junction are increasing, but the downward extension on the anterior cervical spine represents a limit. Therefore, many surgeons prefer transoral or transcervical approaches. The EtsA with PNS removal allows for a more caudal exposure than the standard paraseptal approach, with reduced nasal trauma.

 

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Reduced Field-of-View Diffusion Tensor Imaging of the Spinal Cord Shows Motor Dysfunction of the Lower Extremities in Patients With Cervical Compression Myelopathy

Spine 2018;43:89–96

Study Design. A cross-sectional study.

Objective. The aim of this study was to quantify spinal cord dysfunction at the tract level in patients with cervical compressive myelopathy (CCM) using reduced field-of-view (rFOV) diffusion tensor imaging (DTI).

Summary of Background Data. Although magnetic resonance imaging (MRI) is the standard used for radiological evaluation of CCM, information acquired by MRI does not necessarily reflect the severity of spinal cord disorder. There is a growing interest in developing imaging methods to quantify spinal cord dysfunction. To acquire high-resolution DTI, a new scheme using rFOV has been proposed.

Methods. We enrolled 10 healthy volunteers and 20 patients with CCM in this study. The participants were studied using a 3.0-T MRI system. For DTI acquisitions, diffusion-weighted spinecho rFOV single-shot echo-planar imaging was used. Regions of interest (ROI) for the lateral column (LC) and posterior column (PC) tracts were determined on the basis of a map of fractional anisotropy (FA) of the spinal cord and FA values were measured. The FA of patients with CCM was compared with that of healthy controls and correlated with Japanese Orthopaedic Association (JOA) score.

Results. In LC and PC tracts, FA values in patients with CCM were significantly lower than in healthy volunteers. Total JOA scores correlated moderately with FA in LC and PC tracts. JOA subscores for motor dysfunction of the lower extremities correlated strongly with FA in LC and PC tracts.

Conclusion. It is feasible to evaluate the cervical spinal cord at the tract level using rFOV DTI. Although FA values at the maximum compression level were not well correlated with total JOA scores, they were strongly correlated with JOA subscores for motor dysfunction of the lower extremities. Our findings suggest that FA reflects white matter dysfunction below the maximum compression level and FA can be used as an imaging biomarker of spinal cord dysfunction.

Key words: . Level of Evidence: 4

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Clinical and Radiological Mid-Term Outcomes of Lumbar Single-Level Total Disc Replacement

Spine 2018;43:105–113

Study Design. Prospective single-center case cohort study. Objective. Evaluation of clinical and radiographic outcomes of a consecutive 122-patient cohort with discogenic back pain, at 2- to 10-year follow-up periods, treated by a single surgeon, with CHARITE Artificial Disc (DePuy Spine, Raynham, MA).

Summary of Background Data. Minimum 2-year clinical and radiographic level 1 data for the first lumbar artificial disc, the CHARITE Artificial Disc (DePuy Spine), have recently been published, demonstrating sustained clinical benefit of the device for the treatment of degenerative disc disease.

Methods. Patients were assessed preoperatively using clinical outcome measures, including visual analog scale (VAS) score back and leg, Oswestry Disability Index (ODI), 36-Item Short Form Health Survey (SF-36), and Roland-Morris Questionnaires (RMDQ), and further assessed postoperatively, 3-, 6-, 12-months, and yearly thereafter.

Results. Average follow-up was 44.9±3.3 months (n=122). The median age at surgery was 43.0±9.0 years. Preoperative diagnosis included degenerative disc disease in 118 (96.7%) and internal disc disruption in 4 (3.3%). Surgery was performed at L5–S1 in 96 (77.9%) patients and at L4–L5 in 27 (22.1%). Statistically significant clinical improvements from baseline were observed on VAS (back and leg), ODI, SF-36 PCS, SF-36 MCS, and RMDQ 3 months onward. Back VAS scores decreased from 78.221.3 preoperatively to 21.927.8 by final follow-up. ODI scores decreased from 51.117.3 to 16.217.9 at last follow-up. The RMDQ scores also decreased from 16.7±4.7 to 4.2±5.8. SF-36 PCS and MCS increased from 25.7±11.0 to 46.4±10.3 for PCS and from 35.5±17.4 to 51.6±10.8 for MCS. Patient satisfaction surveys indicated that 90.56% patients rated their satisfaction with the surgery as ‘‘excellent’’ or ‘‘good’’ at 2 years. Range of motion averaged 8.6±3.5 (median=8.08) at the last follow-up time point.

Conclusion. Outcomes verify the clinical efficacy of total disc replacement for treatment of discogenic back pain with or without radiculopathy. The outcomes instruments demonstrated statistically significant improvements 3 months onward.

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A New Volumetric Radiologic Method to Assess Indirect Decompression After Extreme Lateral Interbody Fusion Using High-Resolution Intraoperative Computed Tomography

World Neurosurg. (2018)109:59-67

Two-dimensional radiographic methods have been proposed to evaluate the radiographic outcome after indirect decompression through extreme lateral interbody fusion (XLIF). However, the assessment of neural decompression in a single plane may underestimate the effect of indirect decompression on central canal and foraminal volumes. The present study aimed to assess the reliability and consistency of a novel 3-dimensional radiographic method that assesses neural decompression by volumetric analysis using a new generation of intraoperative fan-beam computed tomography scanner in patients undergoing XLIF.

METHODS: Prospectively collected data from 7 patients (9 levels) undergoing XLIF was retrospectively analyzed. Three independent, blind raters using imaging analysis software performed volumetric measurements pre- and postoperatively to determine central canal and foraminal volumes. Intrarater and Interrater reliability tests were performed to assess the reliability of this novel volumetric method.

RESULTS: The interrater reliability between the three raters ranged from 0.800 to 0.952, P < 0.0001. The test-retest analysis on a randomly selected subset of three patients showed good to excellent internal reliability (range of 0.78e1.00) for all 3 raters. There was a significant increase in mean ±20% for right foramen, left foramen, and central canal volumes postoperatively (P = 0.0472; P = 0.0066; P = 0.0003, respectively).

CONCLUSIONS: Here we demonstrate a new volumetric analysis technique that is feasible, reliable, and reproducible amongst independent raters for central canal and foraminal volumes in the lumbar spine using an intraoperative computed tomography scanner

 

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Clinical Presentation, Diagnosis, and Surgical Treatment of Spontaneous Cervical Intradural Disc Herniations

World Neurosurg. (2018) 109:275-284

Spontaneous cervical intradural disc herniation (IDH) is a rare occurrence with limited and disparate information available regarding its presentation, diagnosis, and treatment. However, its accurate detection is vital for planning surgical treatment. In this review of the literature, we collected data from all cervical IDHs described to date. Particular attention was paid to diagnostic findings, surgical approach, and causation for cervical IDH, especially at the cervicothoracic junction.

METHODS: A review for cases of cervical IDH was performed via the following search criteria: (“neck”[MeSH Terms] OR “neck”[All Fields] OR “cervical”[All Fields]) AND intradural[All Fields] AND disc[All Fields]. Thirtyseven cases of cervical disc herniation were identified. Demographic variables identified included age, sex, cervical level of herniation, history of associated cervical trauma, presence of Brown-Séquard syndrome, Horner syndrome, and other neurologic findings, radiographic findings, direction of surgical approach, and postoperative outcomes.

RESULTS: A total of 37 cases of cervical IDH were identified. Most of the cases occurred at the lower levels of the cervical spine, with 35.1% at the C5e C6 level, followed by 24.3% at C6eC7, and lower still at other levels. Of the patients reviewed, 44.4% had a previous history of trauma before manifestation of symptom, with the majority being spontaneous IDH with no previous history of trauma or spine surgery. Brown-Séquard syndrome was present in 43.2% of the patients, whereas 10.8% of patients experienced Horner syndrome. The most common presentations of IDH included quadriplegia, finger/gait ataxia, radiculopathy, and nuchal pain. The degree of neurologic recovery was not associated with patient age. Most of the cervical IDHs in the literature were treated surgically via an anterior approach, but a larger portion of patients who underwent a posterior approach had improved recovery.

CONCLUSIONS: Cervical IDH is a rare event, with this review of the literature outlining the clinical and radiographic parameters of its presentation as well as comparing common surgical strategies for treatment. We outline theories underlying the development of cervical IDH and argue for a posterior surgical approach in which the disc herniation is sequestrated with migration

 

 

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Transdural Spinal Cord Herniation

World Neurosurg. (2018) 109:242-246.

Recognition of transdural spinal cord herniation has increased over the past decade. This condition remains little known, particularly outside the specialized fields of spinal surgery and neuroradiology, leading to a significant delay in clinical diagnosis and treatment. It should be considered among the differential diagnoses in patients with gradual-onset lower-limb weakness of presumed spinal origin. Reaching a diagnosis using magnetic resonance imaging is essential to refer patients for surgery before their myelopathy worsens.

We describe our surgical experience to untether the spinal cord by wrapping a dura graft around the spinal cord. Three case reports and a review of the literature are discussed.

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