A new modified technique of dynamic CT myelography to detect dural tears in spontaneous intracranial hypotension.

We propose a modified dynamic CT-myelography technique for patients with fast CSF leaks caused by ventral dural tears in order to reduce radiation exposure and complications. A fluoroscopy-guided lumbar puncture using an epidural anesthesia kit replaces a CT-guided lumbar puncture, and a smaller volume of less concentrated contrast media is used. This approach has advantages, including speeding up the procedure, reduced radiation exposure, and elimination of the risk of contrast injection into the epidural space.

Association of the presence and its types of lamina fractures with posterior dural tear and neurological deficits in traumatic thoracic and lumbar burst fractures.

INTRODUCTION: The appropriate and optimal treatment for thoracic and lumbar (TL) burst fractures remains a topic of debate. Characterization of vertical laminar fractures (coronal cross-sectional imaging) is presented in this study to determine the severity and treatment options in TL burst fractures. METHODS: A retrospective evaluation of 341 consecutive patients with TL burst fractures was divided into Group I (whole), Group II (partial), and Group III (intact) based on the vertical laminar fracture morphology from coronal images on computed tomography (CT) scans. The presence of preoperative neurological status was reviewed, and several radiological parameters were measured. In addition, the incidence of dural tears was calculated in patients that underwent a decompression with posterior approach. RESULTS: In total, 270 lumbar and 71 thoracic burst fractures were analyzed. Compared with the intact group, the two other groups had significantly shorter central canal distance, wider interpedicular distance, and smaller spinal canal area, in particular, Group III. The incidences of preoperative neurological deficits in Groups I to III were 63.0, 22.2, and 6.3%, respectively. The incidences of dural tears in Groups I to III were 25.6, 6.3, and 0%, respectively. CONCLUSION: The morphology of vertical laminar fractures observed across the coronal plane was important. Patients with "whole", "partial" and "intact" laminar fractures indicated different severity of TL burst fractures. Due to the high probability of dural tears, decompression is recommended as a primary intervention for patients with "whole" laminar fractures. However, for patients without vertical laminar fractures, minimally invasive technique might be a better choice to avoid approach-related complications.

Intradural extraarachnoid sutureless technique combined with laminoplasty for indirect repair of ventral dural defects in spontaneous intracranial hypotension: technical note and case series.

BACKGROUND: There is a significant variance in surgical treatment strategies of ventral cerebrospinal fluid (CSF) leaks causing spontaneous intracranial hypotension (SIH). Posterior approaches might represent a preferable alternative to the more invasive anterior and lateral routes, as long as the spinal cord is not exposed to harmful manipulation. The aim of this technical note is to report and illustrate a new surgical technique using an intradural extraarachnoid sutureless technique via laminoplasty for indirect repair of ventral CSF leaks causing intractable SIH symptoms. METHODS: The surgical technique is described in a step by step fashion. Between May 2018 and May 2020, five patients with ventral spinal CSF leaks were operated on, utilizing this technique. All dural defects were located at the level of the thoracic spine. A retrospective review on demographic and radiological findings, symptoms, outcome, and follow-up was performed. RESULTS: The intra- and postoperative course was uneventful in all patients with no surgery-related complications. Three patients recovered completely at discharge, while neurological symptoms significantly improved in two patients. A postoperative MRI of the spine was obtained for all patients, demonstrating regressive signs of CSF leak. CONCLUSION: Based on the presented case series, this intradural extraarachnoid sutureless technique combined with laminoplasty seems to be a safe and effective option for indirect repair of ventral dural defects in SIH. In our opinion, it represents a valid alternative to traditional more aggressive approaches.

"A decade with micro-tubular decompression": Peri-operative complications and surgical outcomes in single and multilevel lumbar canal stenosis.

PURPOSE: We present ten years experience with micro-tubular decompression (MTD) performed for single and multilevel lumbar canal stenosis (LCS) assessing the peri-operative complications and mid-term surgical outcome. The aims of this study were to review the incidence of peri-operative complications and classification of complications and define risk factors to prevent it while negotiating the learning curve. METHODS: A retrospective review of prospectively collected data over a period of ten years involving 625 patients who underwent single/multilevel lumbar MTD. Peri-operative clinical-radiological parameters, post-operative complications, clinical outcome (VAS and ODI), and satisfactory outcomes in the form of Wang and Bohlmann's criteria were evaluated. The peri-operative complications were divided into five broad categories based on their time of occurrence, severity, and system affected. The comparison between the patients with and without complications was done to evaluate the causative risk factors. RESULTS: The overall incidence of the peri-operative complication was 12.96% over ten years with higher rate (29.8%) during the initial three years of practice and lower rate (8.78%) in the last seven years. The most common peri-operative complications were urinary tract infections (UTI). The risk factors for complications with MTD revealed in statistical analysis were presence of one or more comorbidities, L4-L5 single-level stenosis, bilateral stenosis with ipsilateral and bilateral decompression done through unilateral approach, and multilevel MTD done through single incision for multilevel LCS. More than 95% patients operated with MTD showed excellent to good outcome as per the Wang and Bohlmann's criteria at the final follow-up. CONCLUSION: This study represents 12.96% overall incidence of peri-operative complications with higher rate (29.8%) during the initial three years of practice and lower rate (8.78%) in the last seven years with MTD for single/multilevel LCS with. MTD is an effective procedure with substantial clinical benefits in the form of excellent to good clinico-radiological outcomes at two year follow-up. However, there is a learning curve associated with the adoption of the technique. The described classification for peri-operative complications is helpful to record, to evaluate, and to understand the aetiology and risk factors based on its duration of occurrence in the peri-operative period.

Communicating hydrocephalus, a long-term complication of dural tear during lumbar spine surgery.

PURPOSE: Iatrogenic dural tears during lumbar spine surgery are not uncommon and may have multiple long-term sequelae if not managed promptly and definitively. Sequelae include pseudomeningocoeles due to a persistent cerebrospinal fluid leak, which may result in a subarachnoid hemorrhage or subdural hematoma. These, in turn, can lead to adult communicating hydrocephalus. The purpose of this study is to describe a case of an intraoperative iatrogenic dural tear leading to the formation of a pseudomeningocoele and progressing to hydrocephalus. METHODS: We present a case of a 62-year-old female who had an iatrogenic dural tear during a lumbar decompression and instrumented fusion. Attempts at closure were unsuccessful, which led to the formation of a pseudomeningocoele and an ascending subdural hygroma, progressing into a communicating hydrocephalus which was treated with a ventriculoperitoneal shunt. RESULTS: Imaging studies and clinical follow up after the incidental durotomy demonstrate complications arising from the persistent cerebrospinal fluid leak, beginning with the formation of the pseudomeningocoele and progression to hydrocephalus. Based on these imaging studies, it was possible to illustrate the development of each of the complications. CONCLUSION: The need for prompt recognition and proper management of iatrogenic dural tears are emphasized in order to avoid future complications that may arise from inadequate or proper treatment.

Incidental Dural Tears During Lumbar Spine Surgery: Prevalence and Evaluation of Management Outcomes.

INTRODUCTION:  Incidental dural tears (IDTs) are sometimes observed as an intraoperative complication associated with lumbar spine surgery. Commonly, this complication is recognized and repaired during surgery, but if it is undiagnosed or inadequately treated, a variety of consequences may occur. Many techniques have been developed to treat cerebrospinal fluid (CSF) leakage, and each has its limitations.  Objectives: To assess the prevalence of incidental dural tears in lumbar spine surgeries and evaluate the outcomes of the sandwich technique in the management of this complication. METHODS: A total of 92 patients who underwent lumbar spine surgery at the Royal Rehabilitation Center in Amman from January 2018 to December 2021 were retrospectively reviewed. Patients were divided into two groups: group A (patients without IDT) and group B (patients with IDT), where group B was repaired using the sandwich technique. The follow-up period was six months. Further, the sandwich technique involves repairing the dural defect with interlocking sutures, painting medical glue around the dural incision, covering this with gelatin sponge, and finally covering the gelatin sponge with medical glue again. RESULTS: The overall prevalence of IDT in the study group was 14.1%. IDT was more common among elderly patients above the age of 60 (17.2%), females (16.7%), patients with multiple lumbar levels treated (66.7%), open approaches (21%), and those who had previous spinal surgery (72.7%). Most IDTs were diagnosed and managed intraoperatively (84.6%). Among those patients, only one complained of a surgical site infection. Patients in group B had a significantly higher postoperative length of hospital stay, amount of drainage, and operative time compared to group A (P<0.001). Regarding postoperative pain, patients in group B had significantly higher pain on the Numerical Pain Scale at day three post-operation compared to patients in group A (P<0.001). CONCLUSION: Based on our results, the sandwich technique was effective in the management and prevention of CSF leakage. Further prospective studies with long-term follow-up are needed to confirm our findings.

Preliminary Clinical and Radiological Outcomes of the "No-Punch" Decompression Techniques for Unilateral Biportal Endoscopic Spine Surgery.

OBJECTIVE: To avoid the most offending surgical instrument for dural tears, we develop a "no-punch" decompression technique for unilateral biportal endoscopic (UBE) spine surgery. METHODS: This retrospective study enrolled 68 consecutive patients with degenerative lumbar spinal stenosis segments. The treatment results were evaluated using the visual analogue scale (VAS) for low back and leg pain, the Japanese Orthopaedic Association (JOA) scores, and the Oswestry Disability Index (ODI). Radiological outcomes were evaluated using the preoperative and postoperative magnetic resonance imaging. RESULTS: This study included 36 male and 32 female patients who received 109 segments of decompression, with an average age of 68.7 (37-90 years). The average operation time was 52.2 minutes. The average hospital stay was 3.1 days. There were no dural tears but 3 minor surgical complications, all treated conservatively. The VAS for low back and leg pain improved from 4.6 and 7.0 to 0.8 and 1.2. The JOA score improved from 16.2 to 26.8, with an improvement rate of 82.0%. The ODI improved from 50.1 to 18.7. All these improvements were statistically significant. The cross-sectional dural area improved from 61.1 to 151.3 mm2, with an average increase of 90.2 mm2 and 205.3%. 87.1% of the ipsilateral facet joints and 84.7% of the contralateral facet joints were preserved. In 61% of the decompressed segments, the ipsilateral facet joints were preserved better than the contralateral facet joints. CONCLUSION: The UBE "no-punch" decompression technique effectively avoids the dural tears. It provides effective neural decompression, excellent facet joint preservation, and good treatment outcomes.

Perspective: Timely diagnosis and repair of intraoperative thoracic/lumbar cerebrospinal fluid (CSF) leaks.

Background: Our review of 12 articles for this perspective showed the frequency of intraoperative thoracic and/or lumbar CSF fistulas/dural tears (DT) ranged from 2.6% - 8% for primary surgical procedures. Delayed postoperative CSF leak/DT were also diagnosed in 0.83% (17/2052 patients) to 14.3% (2/14 patients) of patients undergoing thoracic and/or lumbar procedures. Further, the rate of recurrent postoperative CSF leaks/DT varied from 13.3% (2/15 patients) to 33.3% (4/12 patients). Methods: Intraoperative, postoperative delayed, and recurrent postoperative traumatic postsurgical thorac CSF leaks/DT can be limited by performing initially sufficient operative decompressions and/or decompressions/fusions (i.e., utilizing adequate open exposures vs. inadequate minimally invasive (MI) approaches). The incidence of CSF leaks/DT can be further reduced by spine surgeons' utilization of operating microscopes, and their avoiding routine attempts at total synovial cyst excision and/or complete resection of hypertrophied/ossified yellow ligament in the presence of significant dural adhesions. Results: Multiple CSF leak/CT repair techniques included; using interrupted, non-resorbable sutures for direct dural repairs (i.e. 7-0 Gore-Tex sutures where the suture is larger than the needle thus plugging needle holes), and adding where needed muscle patch grafts, microfibrillar collagen, the rotation of Multifidus muscle pedicle flaps, fibrin sealants (FS)/fibrin glues (FG), lumbar drains (LD), and/or lumbo-peritoneal (LP) shunts. Conclusion: Intraoperative, postopertive delayed, and/or recurrent postoperative thorac and/or lumbar traumatic surgical CSF leaks can be reduced by choosing to initially perform the appropriately extensive open operative decompressions and/or decompresssions/fusions. It is critical to use an operating microscope, non-resorbable interrupted sutures, and where necessary, muscle patch grafts, microfibrillar collagen, the rotation of Multifidus Muscle Pedicle Flaps, FS/FG, LD, and/or LP shunts.

Natural language processing for the automated detection of intra-operative elements in lumbar spine surgery.

Background: The aim of this study was to develop natural language processing (NLP) algorithms to conduct automated identification of incidental durotomy, wound drains, and the use of sutures or skin clips for wound closure, in free text operative notes of patients following lumbar surgery. Methods: A single-centre retrospective case series analysis was conducted between January 2015 and June 2022, analysing operative notes of patients aged >18 years who underwent a primary lumbar discectomy and/or decompression at any lumbar level. Extreme gradient-boosting NLP algorithms were developed and assessed on five performance metrics: accuracy, area under receiver-operating curve (AUC), positive predictive value (PPV), specificity, and Brier score. Results: A total of 942 patients were used in the training set and 235 patients, in the testing set. The average age of the cohort was 53.900 ± 16.153 years, with a female predominance of 616 patients (52.3%). The models achieved an aggregate accuracy of >91%, a specificity of >91%, a PPV of >84%, an AUC of >0.933, and a Brier score loss of ≤0.082. The decision curve analysis also revealed that these NLP algorithms possessed great clinical net benefit at all possible threshold probabilities. Global and local model interpretation analyses further highlighted relevant clinically useful features (words) important in classifying the presence of each entity appropriately. Conclusions: These NLP algorithms can help monitor surgical performance and complications in an automated fashion by identifying and classifying the presence of various intra-operative elements in lumbar spine surgery.

Late presentation of dural tears: Two case reports and review of literature.

BACKGROUND: The late presentation of dural tears (LPDT) has a low incidence rate and hidden symptoms and is easily ignored in clinical practice. If the disease is not treated in time, a series of complications may occur, including low intracranial pressure headache, infection, pseudodural cyst formation, and sinus formation. Here, we describe two cases of LPDT. CASE SUMMARY: Two patients had sudden fever 1 wk after lumbar surgery. Physical examination showed obvious tenderness in the operation area. The patients were confirmed as having LPDT by lumbar magnetic resonance imaging and surgical exploration. One case was caused by continuous negative pressure suction and malnutrition, and the other was caused by decreased dural ductility and low postoperative nutritional status. The first symptom of both patients was fever, with occasional headache. Both patients underwent secondary surgery to treat the LPDT. Dural defects were observed and dural sealants were used to seal the dural defects, then drainage tubes were retained for drainage. After the operation, the patients were treated with antibiotics and the patients' surgical incisions healed well, without fever or incision tenderness. Both recovered and were discharged 1 wk after the operation. CONCLUSION: LPDT is a rare complication of spinal surgery or neurosurgery that has hidden symptoms and can easily be overlooked. Since it may cause a series of complications, LPDT needs to be actively addressed in clinical practice.

Preoperative Lumbar Epidural Steroid Injection Increases the Risk of a Dural Tear During Minimally Invasive Lumbar Discectomy.

BACKGROUND: Preoperative lumbar epidural steroid injections (LESI) are known to be a risk factor for intraoperative dural tears in traditional spine surgery. However, whether the same holds true after minimally invasive surgery is debatable. The authors decided to investigate the incidence of complications in patients undergoing minimally invasive lumbar discectomy after a preoperative LESI. METHODS: A retrospective analysis was carried out on patients ages 21 to 65 years who underwent minimally invasive lumbar discectomy over 3 years between November 2017 and October 2020. These were classified into 2 groups based on the administration of an LESI within a year of surgery. Those receiving LESI were further subdivided on the basis of the proximity of the injection to the surgery. The complications encountered during and up to 6 months after the surgery were recorded. Various demographic variables were also noted. RESULTS: A total of 315 patients were included in the study, of which 129 were in the LESI group and 186 were in the non-LESI group. The overall complication rate was 13.65%, with 17.83% in the LESI group and 10.75% in the non-LESI group (P = 0.07). Patients receiving an LESI were 2.49 times more likely to suffer from intraoperative dural tears compared to the other group (95% CI: 1.00-6.20, P = 0.049). This was more prevalent in those who were administered an LESI within 3 months of the surgery (OR: 3.24, 95% CI: 1.12-9.40, P = 0.03). However, the rates of other complications including infections were comparable. CONCLUSIONS: A history of LESI within 3 months of the surgery is a risk factor of intraoperative dural tears. However, other complications, including infections, are not affected by a preoperative LESI. CLINICAL RELEVANCE: A history of an LESI within 3 months of a proposed minimally invasive discectomy should make the surgeon extra-cautious of the risk of a dural tear.

Nerve root entrapment with pseudomeningocele after percutaneous endoscopic lumbar discectomy: A case report.

Context: Pseudomeningocele is a relatively uncommon postoperative complication of spine surgery. Although the condition tends to be asymptomatic and self-limiting, it may cause radicular pain and neurological defect due to herniation of the nerve root or the spinal cord. Its pathophysiology remains unclear. Only few cases with intraoperative photos have been reported. Finding: We present a case of pseudomeningocele with nerve root entrapment after percutaneous endoscopic lumbar discectomy (PELD). A 52-year-old man had undergone PELD for sciatic pain and showed good postoperative recovery. Unfortunately, he was readmitted for progressive right leg pain at six weeks after the surgery. After the failure of conservative therapy, he received PELD again to explore the surgical site. Intraoperatively, a pseudomeningocele-containing nerve root, herniating through a small defect in the dural sac, was identified. During the dissection process, the pseudomeningocele was broken, which led to entrapment of the nerve root. Thereafter, the microsurgical technique was adopted to relocate the nerve root into the thecae sac and to repair the dural tear by non-resorbable suture. Conclusion: To our knowledge, this case report is the first documented instance of identification of a pseudomeningocele under an endoscope, and provides insights into the transformation of a pseudomeningocele into a cerebrospinal fluid fistula with nerve root entrapment. For neurological deficit caused by pseudomeningocele following PELD, operative revision by the microsurgery technique is the appropriate strategy.

Conservative Management for Late Presenting Dural Tears After Spine Surgery: An Institutional Experience and Literature Review.

BACKGROUND: Symptoms and evidence of cerebrospinal fluid (CSF) leak after an uneventful intraoperative and immediate postoperative course are a rare entity in spine surgery. The literature is sparse on the description of such late presenting dural tears (LPDTs). They may need further admissions, wound management, and additional surgical procedures that add to the morbidity of the patient. METHODS: A retrospective review of spine surgeries done at our institute for degenerative spinal conditions between January 2017 and January 2018 was conducted. A mini meta-analysis was performed on studies comparing conservative and surgical management of LPDTs. RESULTS: Among 1929 patients, 6 cases (5 lumbar and 1 cervical) had an LPDT. Five of them had a CSF fistula and 1 patient had a pseudomeningocele. Two patients with CSF fistula were complicated by superficial surgical site infection (SSI). There was additional evidence of pneumocephalus and pneumorachis in 1 case. The SSI was managed by bedside debridement, regular dressing, and culture-sensitive antibiotics. CSF fistulas were managed by deep suturing, and pseudomeningocele was managed by excision of the sac and plication of the neck. All the patients had a good to an excellent outcome at the end of a 1-year follow-up. CONCLUSIONS: One should be aware of the possibility of LPDTs. A combination of history, clinical examination, and imaging may aid in the diagnosis. It can be associated with complications like CSF fistula, pseudomeningocele, SSI, pneumocephalus, or pneumorachis. Conservative trial can have good to excellent outcomes in the management of such cases though there is insufficient evidence to establish it.

Use of Zipper Ratcheting Straps as a Bailout for Postoperative Cerebrospinal Fluid Leaks: Our Experience.

STUDY DESIGN: Technical note. OBJECTIVES: Management of postoperative cerebrospinal fluid (CSF) leaks is a challenge. Reexploration increases the morbidity risks. The main objective was to evaluate the outcomes of noninvasive zipper-like system (Zip surgical skin closure system, ZipLine Medical, Inc, Campbell, CA, USA) as a bailout technique for postoperative CSF leaks. METHODS: Retrospective case series. Consecutive patients with postoperative CSF leaks that occurred secondary to spinal surgeries performed between January 2017 and September 2018 were part of the study. All these patients were managed conservatively by reinforcement with zipper ratcheting straps over the sutured surgical wound. Successful clinical outcomes included cessation of CSF leaks and adequate wound healing in the postoperative period and at follow-up. RESULTS: Ten patients underwent the application of zipper ratcheting straps. The mean follow-up was 6 months (range 6 months to 1 year). In 7 cases, the dural tears were recognized postoperatively and in 3 cases, the tears were noted intraoperatively and repaired and reinforced with fibrin sealants. None of the patients developed wound soakage or subsequent CSF leak from the wound after the application of zipper ratcheting straps. CONCLUSIONS: Zipper ratcheting straps as augmentation to sewing of the wound seem to be a good alternative and bailout in treating patients with postoperative CSF leaks. The ease of its application, the ability in minimizing the complications associated with CSF leaks, and negating the need of surgical reexploration makes it a worthy option.

DuraSeal Exact Is a Safe Adjunctive Treatment for Durotomy in Spine: Postapproval Study.

STUDY DESIGN: A nonrandomized, two-armed prospective study. OBJECTIVE: Water-tight dural closure is paramount to the prevention of cerebrospinal fluid (CSF) leakage and associated complications. Synthetic polyethylene glycol (PEG) hydrogel has been used as an adjunct to sutured dural repair; however, its expansion postoperatively is a concern for neurological complications. A low-swell formulation of PEG sealant was introduced as DuraSeal Exact Spine Sealant System (DESS). A Post-Approval Study was performed primarily to evaluate the safety and efficacy of DESS for spinal dural repair compared to current alternatives, in a large patient population, reflecting a real-world practice. METHODS: A total of 36 sites in the United States enrolled 429 patients treated with DESS as an adjunct to dural repair in the spinal sealant group and 406 patients treated with all other modalities in the control arm, from October 2011 to June 2016. The primary endpoint was the incidence of CSF leak within 90 days of operation. The secondary endpoints evaluated were deep surgical site infection and neurological serious adverse events. RESULTS: The CSF leakage in the DESS group (6.6%) was not significantly different from the control group (6.5%) (p = .83), and there was no significant difference in the time to first leak. The two groups had no significant differences in deep surgical site infection (1.6% versus control 2.1%, p = .61) or proportion of subjects with neurological serious adverse events (2.9% versus control 1.6%, p = .516). CONCLUSIONS: DuraSeal Exact Spinal Sealant is safe when compared to current alternatives for spinal dural repair.

Posterior Approach and Spinal Cord Release for 360° Repair of Dural Defects in Spontaneous Intracranial Hypotension.

BACKGROUND: Spinal cerebrospinal fluid (CSF) leaks are the cause of spontaneous intracranial hypotension (SIH). OBJECTIVE: To propose a surgical strategy, stratified according to anatomic location of the leak, for sealing all CSF leaks around the 360° circumference of the dura through a single tailored posterior approach. METHODS: All consecutive SIH patients undergoing spinal surgery were included. The anatomic site of the leak was exactly localized. We used a tailored hemilaminotomy and intraoperative neurophysiological monitoring (IOM) for all cases. Neurological status was assessed before and up to 90 d after surgery. RESULTS: Forty-seven SIH patients had an identified CSF leak between the levels C6 and L1. Leaks, anterior to the spinal cord, were approached by a transdural trajectory (n = 28). Leaks lateral to the spinal cord by a direct extradural trajectory (n = 17) and foraminal leaks by a foraminal microsurgical trajectory (n = 2). The transdural trajectory necessitated cutting the dentate ligament accompanied by elevation and rotation of the spinal cord under continuous neuromonitoring (spinal cord release maneuver, SCRM). Four patients had transient defiticts, none had permanent neurological deficits. We propose an anatomic classification of CSF leaks into I ventral (77%, anterior dural sac), II lateral (19%, including nerve root exit, lateral, and dorsal dural sac), and III foraminal (4%). CONCLUSION: Safe sealing (with IOM) of all CSF leaks around the 360° surface of the dura is feasible through a single posterior approach. The exact surgical trajectory is selected according to the anatomic category of the leak.

Dural Tears in Adult Deformity Surgery: Incidence, Risk Factors, and Outcomes.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Describe the rate of dural tears (DTs) in adult spinal deformity (ASD) surgery. Describe the risk factors for DT and the impact of this complication on clinical outcomes. METHODS: Patients with ASD undergoing surgery between 2008 and 2014 were separated into DT and non-DT cohorts; demographics, operative details, radiographic, and clinical outcomes were compared. Statistical analysis included t tests or χ2 tests as appropriate and a multivariate analysis. RESULTS: A total of 564 patients were identified. The rate of DT was 10.8% (n = 61). Patients with DT were older (61.1 vs 56.5 years, P = .005) and were more likely to have had prior spine surgery (odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.2-3.3, P = .007). DT patients had higher pelvic tilt, lower lumbar lordosis, and greater pelvic-incidence lumbar lordosis mismatch than non-DT patients (P < .05). DT patients had longer operative times (424 vs 375 minutes, P = .008), were more likely to undergo interbody fusions (OR = 2.0, 95% CI = 1.1-3.6, P = .021), osteotomies (OR = 2.2, 95% CI = 1.1-4.0, P = .012), and decompressions (OR = 2.3, 95% CI = 1.3-4.3, P = .003). In our multivariate analysis, only decompressions were associated with an increased risk of DT (OR = 3.2, 95% CI = 1.4-7.6, P = .006). There were no significant differences in patient outcomes at 2 years. CONCLUSIONS: The rate of DT was 10.8% in an ASD cohort. This is similar to rates of DT reported following surgery for degenerative pathology. A history of prior spine surgery, decompression, interbody fusion, and osteotomies are all associated with an increased risk of DT, but decompression is the only independent risk factor for DT.

Suitability of Administrative Databases for Durotomy Incidence Assessment: Comparison to the Incidence Associated With Bone-Removal Devices, Calculated Using a Systemic Literature Review and Clinical Data.

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

A Multicenter Study of the Presentation, Treatment, and Outcomes of Cervical Dural Tears.

STUDY DESIGN: Retrospective multicenter case series study. OBJECTIVE: Because cervical dural tears are rare, most surgeons have limited experience with this complication. A multicenter study was performed to better understand the presentation, treatment, and outcomes following cervical dural tears. METHODS: Multiple surgeons from 23 institutions retrospectively identified 21 rare complications that occurred between 2005 and 2011, including unintentional cervical dural tears. Demographic data and surgical history were obtained. Clinical outcomes following surgery were assessed, and any reoperations were recorded. Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA), Nurick classification (NuC), and Short-Form 36 (SF36) scores were recorded at baseline and final follow-up at certain centers. All data were collected, collated, and analyzed by a private research organization. RESULTS: There were 109 cases of cervical dural tears among 18 463 surgeries performed. In 101 cases (93%) there was no clinical sequelae following successful dural tear repair. There were statistical improvements (P < .05) in mJOA and NuC scores, but not NDI or SF36 scores. No specific baseline or operative factors were found to be associated with the occurrence of dural tears. In most cases, no further postoperative treatments of the dural tear were required, while there were 13 patients (12%) that required subsequent treatment of cerebrospinal fluid drainage. Analysis of those requiring further treatments did not identify an optimum treatment strategy for cervical dural tears. CONCLUSIONS: In this multicenter study, we report our findings on the largest reported series (n = 109) of cervical dural tears. In a vast majority of cases, no subsequent interventions were required and no clinical sequelae were observed.

The morphology and clinical significance of the intraforaminal ligaments at the L5-S1 levels.

BACKGROUND CONTEXT: The extraforaminal ligaments between the L5 and S1 lumbar spinal nerves and the tissues surrounding the intervertebral foramina have been well studied. However, little research has been undertaken to describe the local anatomy of the intraforaminal portion of the L5-S1 spine and detailed anatomical studies of the intraforaminal ligaments (IFLs) of the L5-S1 have not been performed. PURPOSE: The objective of this study was to identify and describe the IFLs in relation to the L5-S1 intervertebral foramen (IVF) and to determine their clinical significance. STUDY DESIGN: A dissection-based study of five embalmed and five fresh-frozen human cadavers was carried out. METHODS: Twenty L5-S1 intervertebral foramina from five embalmed cadavers and five fresh cadavers were studied, and the IFLs were identified. The quantity, morphology, origin, insertion, and spatial orientation of the IFLs in the L5-S1 region were observed. The length, width, diameter, and thickness of the ligaments were measured with a vernier caliper. This study has been supported by grants from the National Natural Science Foundation of China (Grant No. 31271286) without potential conflict of interest-associated biases in the text of the paper. RESULTS: The IFLs could be found from the entrance zone (inside) to the exit zone (outside) of the L5-S1 IVF. These ligaments were found to be of two types: a radiating ligament, which connected the nerve root sleeves that radiated to the transverse processes and wall of the IVF, and a transforaminal ligament, which connected the structures around the IVF. In our study, the radiating ligaments were found more often than the transforaminal ligaments. CONCLUSIONS: The results demonstrate that IFLs are common structures in the IVF and that there are two types of IFLs: the transforaminal ligaments and the radiating ligaments. Transforaminal ligaments may be the potential cause of back pain. The radiating ligaments may contribute to dura laceration and epidural hemorrhage during endoscopic spinal adhesiolysis through the sacral hiatus, and an appreciation of this relationship might help reduce the risk of such complications.