Dural Tear Research Articles

Learning Curve and Clinical Outcomes of Ultrasonic Osteotome-based En Bloc Laminectomy for Thoracic Ossification of the Ligamentum Flavum.

Despite rapid advances in minimally invasive surgery, en bloc laminectomy remains the most common surgical approach for treating thoracic ossification of the ligamentum flavum (TOLF). However, the learning curve of this risky operation is rarely reported. Therefore, we aimed to describe and analyze the learning curve of ultrasonic osteotome-based en bloc laminectomy for TOLF. Among 151 consecutive patients with TOLF who underwent en bloc laminectomy performed by one surgeon between January 2012 and December 2017, we retrospectively analyzed their demographic data, surgical parameters, and neurological function. Neurological outcome was evaluated with the modified Japanese Orthopaedic Association (mJOA) scale, and the Hirabayashi method was used to calculate the neurological recovery rate. The learning curve was assessed with logarithmic curve-fitting regression analysis. Univariate analysis methods were used for statistical analysis, including t-test, rank sum test, and chi-square test. A total of 50% of learning milestones could be reached in approximately 14 cases, and the asymptote in 76 cases. Therefore, 76 of the 151 enrolled patients were defined as the "early group," and the remaining 75 were delimitated as the "late group" for comparison. There was a significant intergroup difference in the corrected operative time (94.80 ± 27.77 vs 65.93 ± 15.67 min, P < 0.001) and the estimated blood loss (median 240 vs 400 mL, P < 0.001). The overall follow-up was 83.1 ± 18.5 months. The mJOA significantly increased from a median of 5 (IQR: 4-5) before the surgery to 10 (IQR: 9-10) at the last follow-up (P < 0.001). The overall complication rate was 37.1%, and no significant intergroup difference was found, except for the incidence of dural tears (31.6% vs 17.3%, p = 0.042). Initially, mastering the en bloc laminectomy technique using ultrasonic osteotome for TOLF treatment can be challenging, but the surgeon's experience improves as the operative time and blood loss decrease. Improved surgical experience reduced the risk of dural tears but was not associated with the overall complication rate or long-term neurological function. Despite the relatively long learning curve, en bloc laminectomy is a secure and valid technique for TOLF treatment.

Vertebral Body Sliding Osteotomy as a Surgical Strategy for the Treatment of Cervical Myelopathy: Complications and Pitfalls.

This retrospective cohort study has been aimed at evaluating the incidence of complications after vertebral body sliding osteotomy (VBSO) and analyzing some cases. Furthermore, the complications of VBSO were compared with those of anterior cervical corpectomy and fusion (ACCF). This study included 154 patients who underwent VBSO (n = 109) or ACCF (n = 45) for cervical myelopathy and were followed up for > 2 years. Surgical complications, clinical and radiological outcomes were analyzed. The most common surgical complications after VBSO were dysphagia (n = 8, 7.3%) and significant subsidence (n = 6, 5.5%). There were 5 cases of C5 palsy (4.6%), followed by dysphonia (n = 4, 3.7%), implant failure (n = 3, 2.8%), pseudoarthrosis (n = 3, 2.8%), dural tears (n = 2, 1.8%), and reoperation (n = 2, 1.8%). C5 palsy and dysphagia did not require additional treatment and spontaneously resolved. The rates of reoperation (VBSO, 1.8%; ACCF, 11.1%; p = 0.02) and subsidence (VBSO, 5.5%; ACCF, 40%; p < 0.01) were significantly lower in VBSO than in ACCF. VBSO restored more C2-7 lordosis (VBSO, 13.9° ± 7.5°; ACCF, 10.1° ± 8.0°; p = 0.02) and segmental lordosis (VBSO, 15.7° ± 7.1°; ACCF, 6.6° ± 10.2°; p < 0.01) than ACCF. The clinical outcomes did not significantly differ between both groups. VBSO has advantages over ACCF in terms of low rate of surgical complications related to reoperation and significant subsidence. However, dural tears may still occur despite the lessened need for ossified posterior longitudinal ligament lesion manipulation in VBSO; hence, caution is warranted.

Complication Rates and Utilization Trends of 3-Level Posterior Column Osteotomy Compared to Single-Level Pedicle Subtraction Osteotomy.

The objective of this study is to assess differences in complication profiles between 3-level posterior column osteotomy (PCO) and single-level pedicle subtraction osteotomy (PSO) as both are reported to provide similar degrees of sagittal correction. The PearlDiver database was queried retrospectively using International Classification of Disease, 9th and 10th edition and Current Procedural Terminology codes to identify patients who underwent PCO or PSO for degenerative spine disease. Patients under age 18 or with history of spinal malignancy, infection, or trauma were excluded. Patients were separated into 2 cohorts, 3-level PCO or single-level PSO, matched at a 1:1 ratio based on age, sex, Elixhauser comorbidity index, and number of fused posterior segments. Thirtyday systemic and procedure-related complications were compared. Matching resulted in 631 patients for each cohort. PCO patients had decreased odds of respiratory (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.43-0.82; p = 0.001) and renal complications (OR, 0.59; 95% CI, 0.40-0.88; p = 0.009) compared to PSO patients. There was no significant difference in cardiac complications, sepsis, pressure ulcer, dural tear, delirium, neurologic injuries, postoperative hematoma, postoperative anemia, or overall complications. Patients who undergo 3-level PCO have decreased respiratory and renal complications compared to single-level PSO. No differences were found in the other complications studied. Considering both procedures achieve similar sagittal correction, surgeons should be aware that 3-level PCO offers an improved safety profile compared to single-level PSO.

Efficacy of patch technique for dural tear repair using hydrogel sealant: a pilot study

BACKGROUND CONTEXTDural tear is one of the common complications of lumbar spine surgery. Suture repair is often difficult due to the requirement of meticulous suture technique in limited space. Dural tear repair is particularly challenging in minimally invasive spine surgery. The patch technique, applying patch material and glue without suture, is an alternative method for dural tear repair. PURPOSETo verify the efficacy of patch technique for dural tear repair using polyethylene glycol hydrogel sealant and to compare patch materials. STUDY DESIGN/SETTINGBasic research. METHODSThere were three study groups: Group 1 (control group, n=4) had hydrogel sealant alone, Group 2 (n=8) had collagen sheet patch and hydrogel sealant, Group 3 (n=8) had mesh sheet patch and hydrogel sealant. A 4-mm durotomy was made in a piece of bovine dura using an arterial punch. Patch material (collagen or mesh sheet) was placed over the dural tear with 2 mm margin and then sprayed with hydrogel sealant. The pressure in the system was increased by 10 mm Hg and monitored. When the leakage occurred, the pressure threshold was measured. RESULTSThe mean pressure threshold for leakage was 32.5 (Standard deviation=15.0), 66.3 (37.0), and 88.8 (27.5) mm Hg for Group 1, 2 and 3, respectively. The mean pressure threshold for leakage for Group 3 was significantly higher than that for Group 1 (p<.05). There was no significant difference in the mean pressure threshold for leakage between Groups 1 and 2, and Groups 2 and 3. CONCLUSIONSPatch technique using mesh sheet and hydrogel sealant demonstrated significantly higher mean pressure threshold for leakage compared with hydrogel sealant alone. CLINICAL SIGNIFICANCEPatch technique using mesh sheet and hydrogel sealant without suture is potentially a reasonable option for dural tear repair in lumbar spine surgery.

Modified interfacet technique using shaped autologous occipital bone mass for basilar invagination

PurposeIn economically undeveloped areas, surgery for basilar invagination (BI) is still a serious economic burden for people. This study introduces a modified interfacet technique for the treatment of BI using shaped autologous occipital bone mass to reduce BI and to save economical expenditure. MethodsThe data of 6 patients with BI who underwent modified interfacet technique using shaped autologous occipital bone mass in our hospital from April 2020 to February 2021 were retrospectively analyzed. During the operation, osteotomy at the external occipital protuberance was performed using ultrasonic osteotome, followed by interfacet release and implantation of shaped autologous occipital bone mass to complete vertical reduction. The atlantodental interval (ADI), Chamberlain's line violation (CLV), clivo-axial angle (CXA) and cervico-medullary angle (CMA) were compared before and after surgery. Additionally, we observed implant stability during the follow-up period to assess the long-term success of the modified interfacet technique. ResultsThe surgical procedure was successful in all six patients, with no reported incidents of vascular injury, spinal cord injury, or dural tear. Following the operation, improvements were observed in the ADI, CLV, CXA, and CMA. Throughout the follow-up period, the implants remained stable, demonstrating no complications such as bone resorption of the autologous occipital bone mass, implant fracture, or displacement. ConclusionThe utilization of shaped autologous occipital bone mass in atlantoaxial interfacet bone grafting has demonstrated effectiveness and feasibility. This technique offers simplicity, ease of preparation, and cost-effectiveness, making it a viable option for treating BI.

Advances in surgical strategies for ossification of posterior longitudinal ligament involving the C 2 segment

To evaluate the application of surgical strategies for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) involving the C 2 segment. The literature about the surgery for cervical OPLL involving C 2 segment was reviewed, and the indications, advantages, and disadvantages of surgery were summarized. For cervical OPLL involving the C 2 segments, laminectomy is suitable for patients with OPLL involving multiple segments, often combined with screw fixation, and has the advantages of adequate decompression and restoration of cervical curvature, with the disadvantages of loss of cervical fixed segmental mobility. Canal-expansive laminoplasty is suitable for patients with positive K-line and has the advantages of simple operation and preservation of cervical segmental mobility, and the disadvantages include progression of ossification, axial symptoms, and fracture of the portal axis. Dome-like laminoplasty is suitable for patients without kyphosis/cervical instability and with negative R-line, and can reduce the occurrence of axial symptoms, with the disadvantage of limited decompression. The Shelter technique is suitable for patients with single/double segments and canal encroachment >50% and allows for direct decompression, but is technically demanding and involves risk of dural tear and nerve injury. Double-dome laminoplasty is suitable for patients without kyphosis/cervical instability. Its advantages are the reduction of damage to the cervical semispinal muscles and attachment points and maintenance of cervical curvature, but there is progress in postoperative ossification. OPLL involving the C 2 segment is a complex subtype of cervical OPLL, which is mainly treated through posterior surgery. However, the degree of spinal cord floatation is limited, and with the progress of ossification, the long-term effectiveness is poor. More research is needed to address the etiology of OPLL and to establish a systematic treatment strategy for cervical OPLL involving the C 2 segment.

Early-effectiveness of unilateral biportal endoscopic laminectomy in treatment of two-level lumbar spinal stenosis

To analyze the early effectiveness of unilateral biportal endoscopy (UBE) laminectomy in the treatment of two-level lumbar spinal stenosis (LSS). The clinical data of 98 patients with two-level LSS treated with UBE between September 2020 and December 2021 were retrospectively analyzed. There were 53 males and 45 females with an average age of 59.9 years (range, 32-79 years). Among them, there were 56 cases of mixed spinal stenosis, 23 cases of central spinal canal stenosis, and 19 cases of nerve root canal stenosis. The duration of symptoms was 1.5- 10 years, with an average of 5.4 years. The operative segments were L 2, 3 and L 3, 4 in 2 cases, L 3, 4 and L 4, 5 in 29 cases, L 4, 5 and L 5, S 1 in 67 cases. All patients had different degrees of low back pain, among of which 76 cases were with unilateral lower extremity symptoms and 22 cases were with bilateral lower extremity symptoms. There were 29 cases of bilateral decompression in both segments, 63 cases of unilateral decompression in both segments, and 6 cases of unilateral decompression and bilateral decompression of each segment. The operation time, intraoperative blood loss, total incision length, hospitalization stay, ambulation time, and related complications were recorded. Visual analogue scale (VAS) score was used to assess the low back and leg pain before operation and at 3 days, 3 months after operation, and at last follow-up. The Oswestry disability index (ODI) was used to evaluate the functional recovery of lumbar spine before operation and at 3 months and last follow-up after operation. Modified MacNab criteria was used to evaluate clinical outcomes at last follow-up. Imaging examinations were performed before and after operation to measure the preservation rate of articular process, modified Pfirrmann scale, disc height (DH), lumbar lordosis angle (LLA), and cross-sectional area of the canal (CAC), and the CAC improvement rate was calculated. All patients underwent surgery successfully. The operation time was (106.7±25.1) minutes, the intraoperative blood loss was (67.7±14.2) mL, and the total incision length was (3.2±0.4) cm. The hospitalization stay was 8 (7, 9) days, and the ambulation time was 3 (3, 4) days. All the wounds healed by first intention. Dural tear occurred in 1 case during operation, and mild headache occurred in 1 case after operation. All patients were followed up 13-28 months with an average of 19.3 months, and there was no recurrence or reoperation during the follow-up. At last follow-up, the preservation rate of articular process was 84.7%±7.3%. The modified Pfirrmann scale and DH were significantly different from those before operation ( P<0.05), while the LLA was not significantly different from that before operation ( P=0.050). The CAC significantly improved ( P<0.05), and the CAC improvement rate was 108.1%±17.8%. The VAS scores of low back pain and leg pain and ODI at each time point after operation significantly improved when compared with those before operation, and the differences between each time points were significant ( P<0.05). According to the modified MacNab criteria, 63 cases were excellent, 25 cases were good, and 10 cases were fair, with an excellent and good rate of 89.8%. UBE laminectomy is a safe and effective technique with little trauma and fast recovery for two-level LSS and the early effectiveness is satisfactory.

Unilateral Laminotomy vs. Conventional Laminectomy: Which is Better for Degenerative Lumbar Spinal Stenosis?

Objectives: To compare the outcomes of conventional laminectomy and unilateral laminotomy for lumbar spinal stenosis. Materials and Methods: The results of our research were compared between unilateral laminotomy (Group A) and conventional laminectomy (Group B) for lumbar spinal stenosis using a sample of 60 cases (30 in each group) selected through non-probability convenient sampling. We calculated the sample size using OPENEPI and analyzed the data with SPSS 26.0. For qualitative and quantitative data. Results: Mean age of participants was 49.7 years in both groups, The sample consisted of 37 male and 23 female participants made up the patient population. Dural tears (5%), progressive neurological deficit (0%), and surgical site infections (1%), among other postoperative complications, were all treated with antibiotics based on culture and sensitivity. Conclusion: Bilateral decompression via unilateral laminotomy is a less invasive alternative to conventional laminectomy for lumbar spinal stenosis, with significantly improved pain scores and minimized hospital stay. This technique offers appropriate decompression of neuronal components at the affected level with no increased risk of complications. Keywords: Degenerative, Spinal Stenosis, Unilateral Laminotomy, Conventional Laminectomy

Dural injury following elective spine surgery – A prospective analysis of risk factors, management and complications

Incidental dural tears being a familiar complication in spine surgery could result in dreaded postoperative outcomes. Though the literature pertaining to their incidence and management is vast, it is limited by the retrospective study designs and smaller case series. Hence, we performed a prospective study in our institute to determine the incidence, surgical risk factors, complications and surgical outcomes in patients with unintended durotomy during spine surgery over a period of one year. The overall incidence in our study was 2.3% (44/1912). Revision spine surgeries in particular had a higher incidence of 16.6%. The average age of the study population was 51.6 years. The most common intraoperative surgical step associated with dural tear was removal of the lamina, and 50% of the injuries were during usage of kerrison rongeur. The most common location of the tear was paramedian location (20 patients) and the most common size of the tear was about 1 mm-5mm (31 patients). We observed that the dural repair techniques, placement of drain and prolonged post-operative bed rest didnot significantly affect the post-operative outcomes. One patient in our study developed persistent CSF leak, which was treated by subarachnoid lumbar drain placement. No patients developed pseudomeningocele or post-operative neurological worsening or re-exploration for dural repair. Wound complications were noted in 4 patients and treated by debridement and antibiotics. Based on our study, we have proposed a treatment algorithm for the management of dural tears in spine surgery.

Sacral Dural Tears as a Cause of Spontaneous Intracranial Hypotension

PurposeDural tears at the level of the cervical, thoracic, and lumbar spine cause spontaneous intracranial hypotension (SIH) in patients with a spinal longitudinal extradural CSF collection (SLEC); however, sacral dural tears have rarely been reported so far. This study focuses on sacral dural tears as a cause of SIH.MethodsRetrospective data from SIH patients with confirmed sacral dural tears studied between October 2020 and November 2022 were analyzed with respect to demographic, clinical and imaging features. Digital subtraction myelography (DSM) and lumbar epidural blood patch (EBP) were modified by placing the patient in reversed Trendelenburg position.ResultsOf the SIH patients, 9 (all women; mean age, 38.5 years; mean body mass index, BMI, 22.9) out of 149 had a sacral dural leak (6%) that occurred spontaneously in 7/9, while 2/9 were likely associated with minor trauma. None had a sacral fracture. The mean SIH score was 6.8. All patients showed SLEC on heavily T2-weighted MR myelography (T2-MRM), 4/9 exclusively sacral and 5/9 with partial or complete involvement of the remaining spine. 4/9 had none, but 5/9 had meningeal sacral cysts, 2/5 had large cysts/ectasia. Confirmation of the sacral origin of the leak was provided in 4/9 by T2-MRM, in 2/9 by DSM and 3/9 by CT myelography (CTM) whereas 0/9 revealed the exact site of leak within the sacrum.ConclusionSacral dural tears should be considered as a possible cause for SIH. It is concluded to implement T2-MRM covering the entire sacrum in the standard MRI protocol and propose EBP in the reverse Trendelenburg position as a therapeutic approach.

Are modular pedicle screws associated with a high complication rate following posterior spinal fixation?

Modular pedicle screws have a separate head that can be intraoperatively assembled to the inserted shank. The aim of this study was to report associated intra- and post-operative complications and reoperation rates of posterior spinal fixations with modular pedicle screws at a single center. A retrospective, institutional chart review was performed on 285 patients who underwent posterior thoracolumbar spinal fusion with modular pedicle screw fixation between January 1, 2017, and December 31, 2019. The primary outcome was failure of the modular screw component. Other measures recorded were length of follow-up, other complications, and need for additional procedures. There were 1,872 modular pedicle screws (average 6.6 per case). There were no (0.0%) screw head dissociations at the rod screw junction. There was 20.8% overall complication rate (59/285) with 25 reoperations: 6 due to non-union and rod breakage, 5 for screw loosening, 7 for adjacent segment disease, 1 for acute postoperative radiculopathy, 1 for epidural hematoma, 2 for deep surgical-site infections, and 3 for superficial surgical-site infections. Other complications included superficial wound dehiscence [8], dural tears [6], non-unions not requiring reoperation [2], lumbar radiculopathies [3], and perioperative medical complications [5]. This study demonstrates that modular pedicle screw fixation has reoperation rates similar to those previously reported for standard pedicle screws. There was no failure at the screw-head junction, and no increases in other complications. Modular pedicle screws present an excellent option to allow surgeons to place pedicle screws without the risk of extra complications.

Surgical complications and incomplete canal widening of the vertebral body sliding osteotomy to treat cervical myelopathy.

Vertebral body sliding osteotomy (VBSO) is a surgical technique that anteriorly translates the vertebral body with compressive lesions and achieves cord decompression through canal widening. However, data on the surgical complications of VBSO are lacking. Furthermore, it has not been known whether VBSO could be a viable alternative in the treatment of cervical myelopathy even when the preoperative canal-occupying ratio (COR) is large, which seems to frequently result in incomplete canal widening. This study aimed to describe the incidence of VBSO-associated surgical complications and to evaluate the incidence and risk factors of incomplete canal widening. A total of 109 patients who underwent VBSO to treat cervical myelopathy were retrospectively reviewed. Neck pain visual analog scale, Neck Disability Index, Japanese Orthopaedic Association (JOA) scores, and surgical complications were evaluated. For radiological evaluation, C2-7 lordosis, C2-7 sagittal vertical axis, and COR were measured. Patients with a preoperative COR < 50% (n = 60) and those with a COR ≥ 50% (n = 49) were compared and logistic regression analysis was performed to identify factors associated with incomplete canal widening. The most frequent complication in the patients was mild dysphagia (7.3%). Dural tears were observed during posterior longitudinal ligament resection (n = 1) and foraminotomy (n = 1). Two patients underwent reoperation due to radiculopathy from adjacent-segment disease. Incomplete canal widening occurred in 49 patients. According to logistic regression analysis, high preoperative COR was the only factor associated with incomplete canal widening. The amount of canal widening and JOA recovery rate in the COR ≥ 50% group were significantly higher than in the COR < 50% group. Mild dysphagia was the most common complication following VBSO. Although VBSO aims to decrease the complication rate of corpectomy, it was not free of dural tears. Special care would be required during the posterior longitudinal ligament resection. Incomplete canal widening occurred in 45.0% of patients, and high preoperative COR was the only risk factor for incomplete canal widening. However, high preoperative COR would not be a contraindication for VBSO, given that favorable clinical outcomes were presented in the COR ≥ 50% group.

Technical Notes and Clinical Outcomes of Full-Endoscopic Interbody Fusion Via Transforaminal Approach for Hard Disc Herniations in Thoracolumbar Junction.

Obtaining sufficient decompression and solid fusion and avoiding approach-related injuries simultaneously are still challenging for the treatment of hard disc herniation in thoracolumbar junction. A combined full-endoscopic decompression and interbody fusion via a transforaminal approach was used to achieve this goal. The purpose of this study was to introduce the technical notes and clinical outcomes of this novel technique. Twenty segments of hard disc herniations in the thoracolumbar junction of 14 patients treated with full-endoscopic interbody fusion via the transforaminal approach between January 2018 and September 2021 were analyzed. The patients were an average age of 43.3 years. Full-endoscopic interbody fusion and discectomy via the transforaminal approach were performed under local anesthesia, followed by percutaneous pedicle screw system fixation under general anesthesia. Imaging, including magnetic resonance imaging (MRI), computed tomography (CT), and X-ray, was carried out. MRI was performed on the second day and 3 months postoperatively. CT was performed on the second day, 6 months, and 1 year (as needed) postoperatively. Back and radicular pain, neurological function, and thoracic spine function were scored using a visual analog scale, the Nurick scale, and modified Japanese Orthopaedic Association (mJOA) scale, and the Oswestry disability index at 1 week, 3 months, 6 months, and 1 year postoperatively. All the operations were successfully completed, and no intraoperative conversion of the surgical methods occurred. Postoperative thoracolumbar junction MRI and CT examinations of all the patients revealed a sufficiently decompressed spinal cord or cauda equina, without any residual compression. At the 1-year follow-up, all the surgical segments were fused. Back and radicular pain was relieved in all the patients, and neurological function was restored. The average recovery rate of the mJOA was 72.5%, including seven excellent, five good, and two fair cases. Although dural tears occurred in two cases during the operation, no cerebrospinal fluid leakage or pseudomeningocele occurred during follow-up. No other surgical complications were noted. A combined full-endoscopic decompression and interbody fusion via a transforaminal approach can achieve complete spinal canal decompression and solid interbody fusion with fewer approach-related injuries. It is a safe and effective minimally invasive spine surgery for treating hard disc herniation in the thoracolumbar junction.

Incidence and management of dural tears in full-endoscopic unilateral laminotomies for bilateral lumbar decompression.

To report incidence of dural lacerations in lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) and to describe patient outcomes following a novel full-endoscopic bimanual durotomy repair. Retrospective review of prospectively collected database including 5.5years of single surgeon experience with LE-ULBD. Patients with no durotomy were compared with patients who experienced intraoperative durotomy, including demographics, ASA score, prior surgery, number of levels treated, procedure time, hospital length of stay (LOS), visual analogue scale, perioperative complications, revision surgeries, use of analgesics, and Oswestry Disability Index (ODI). In total, 13/174 patients (7.5%) undergoing LE-ULBD experienced intraoperative durotomy. No significant differences in demographic, clinical or operative variables were identified between the 2 groups. Sustaining a durotomy increased LOS (p = 0.0019); no differences in perioperative complications or rate of revision surgery were identified. There was no difference in minimally clinically important difference for ODI between groups (65.6% for no durotomy versus 55.6% for durotomy, p = 0.54). In this cohort, sustaining a durotomy increased LOS but, with accompanying intraoperative repair, did not significantly affect rate of complications, revision surgery or functional outcomes. Our method of bimanual endoscopic dural repair provides an effective approach for repair of dural lacerations in interlaminar ULBD cases.

Single-Level Endoscopic TLIF Has Decreased Surgery Duration, Blood Loss, and Length of Hospital Stay While Achieving Similar 1-Year Clinical and Radiological Outcomes Compared With Conventional Minimally Invasive TLIF.

This study presents a single surgeon's experience comparing 1-year outcomes of endoscopic transforaminal lumbar interbody fusion (E-TLIF) vs minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in an Asian population. Retrospective review of consecutive patients who underwent single-level E-TLIF or MIS-TLIF by a single surgeon in a tertiary spine institution from 2018 to 2021 with 1-year follow-up. Inclusion criteria for both procedures were degenerative disc disease with grade I or II spondylolisthesis and mild to moderate central canal stenosis. Clinical outcomes assessed included surgery duration, blood loss, and length of stay. Patient-reported outcomes assessed included the visual analog score for back pain and lower limb pain, Oswestry Disability Index, and North American Spine Society Neurogenic Symptom Score. Radiographic parameters assessed included segmental lordosis, posterior disc height, listhesis, and the presence of cage migration or subsidence. Twelve E-TLIF and 34 MIS-TLIF patients were identified. E-TLIF had shorter surgery duration (165 ± 15 vs 259 ± 43 min for E-TLIF and MIS-TLIF groups, respectively; P < 0.001), reduced blood loss (83 ± 75 vs 181 ± 225 mL; P = 0.033), and decreased length of stay (1.8 ± 0.9 vs 4.7 ± 2.9 days; P < 0.001) compared with MIS-TLIF. E-TLIF and MIS-TLIF patients had significant improvements (P < 0.05) at 1 year in all patient-reported outcomes scores and radiographic parameters assessed. Both E-TLIF and MIS-TLIF patient groups also had similar postoperative patient-reported outcomes scores and radiographic parameters. No complications were recorded for E-TLIF, while MIS-TLIF had a case of dura tear and another case of meralgia paresthetica. There were no instances of cage subsidence, cage migration, or implant loosening in either group at 1 year. Although the study size was limited because E-TLIF is a relatively new technique in our institution, 1-year results demonstrate that E-TLIF can be a safe and efficacious option that achieves clinical and radiological results similar to MIS-TLIF with the additional benefits of decreased surgical duration, blood loss, and length of hospital stay. The results of this study support the effectiveness and potential advantages of endoscopic TLIF compared with MIS-TLIF.

Superficial Cerebellar Siderosis and Spontaneous Intracranial Hypotension Secondary to Dural Tear.

Spinal dural tears are being increasingly recongnized to cause superficial siderosis and intracranial hypotension. We report a patient with chronic headache who was detected to have cerebellar superficial siderosis and subtle signs of intracranial hypotension on imaging. Spinal imaging showed an upper thoracic dural tear secondary to a paradiscal osteophyte. She improved significantly with surgical repair of the tear. We highlight the importance of recognizing superficial sideorsis in patients with chronic headache as it serves as a marker for dural tear and intracranial hypotension.

Conebeam CT as an Additional Tool in Digital Subtraction Myelography for the Detection of Spinal Lateral Dural Tears.

Lateral dural tears as a cause spontaneous intracranial hypotension occur in ∼20% of patients. Common imaging modalities for their detection are lateral decubitus digital subtraction myelography or dynamic CT myelography. Reports on the use of conebeam CT are scarce. We show 3 patients in whom the targeted use of conebeam CT during digital subtraction myelography was helpful in confirming the site of the leak.

Overview of Spontaneous Intracranial Hypotension and Differential Diagnosis with Chiari I Malformation.

Spontaneous intracranial hypotension (SIH) occurs due to a leakage of the cerebrospinal fluid (CSF) lowering the pressure of subarachnoid space, mostly caused by a dural breach or discogenic microspur. As a result of less support provided by CSF pressure, intracranial structures are stretched downward, leading to a constellation of more or less typical MRI findings, including venous congestion, subdural effusions, brainstem sagging and low-lying cerebellar tonsils. Clinic examination and an MRI are usually enough to allow for the diagnosis; however, finding the location of the dural tear is challenging. SIH shares some MRI features with Chiari malformation type I (CM1), especially low-lying cerebellar tonsils. Since SIH is likely underdiagnosed, these findings could be interpreted as signs of CM1, leading to a misdiagnosis and an incorrect treatment pathway. Medical treatment, including steroids, bed rest, hydration caffeine, and a blind epidural blood patch, have been used in this condition with variable success rates. For some years, CSF venous fistulas have been described as the cause of SIH, and a specific diagnostic and therapeutic pathway have been proposed. The current literature on SIH with a focus on diagnosis, treatment, and differential diagnosis with CM1, is reviewed and discussed.

Unilateral Biportal Endoscopic Decompression for Thoracic Spinal Stenosis

In conventional thoracic laminectomy, postoperative complications such as dural tears, cerebrospinal fluid leakage, postoperative infection, and iatrogenic spinal cord injury are relatively common. To address these issues, unilateral biportal endoscopy (UBE) techniques for thoracic laminectomy have been developed and published, demonstrating various advantages over conventional thoracic laminectomy with satisfactory clinical results. In comparison to conventional thoracic laminectomy, the UBE decompression technique with the unilateral approach and bilateral decompression (ULBD) appears to be safe and effective for treating thoracic ossified ligamentum flavum (OLF) or thoracic spinal stenosis. Thoracic ULBD by UBE preserves the paraspinal muscle and ligament that would otherwise be resected during the conventional posterior approach, and it has the added benefit of reducing back pain and muscle atrophy. This manuscript covers the technical aspects of UBE implementation using thoracic ULBD in patients with thoracic OLF or thoracic spinal stenosis, the indications and benefits of this procedure, and tips for preventing complications. With a review of previously published articles on thoracic laminectomy by UBE, we also summarize whether the procedure is safe and can prevent cord injuries.

Lumbar Pedicle Morphometry of Dry Vertebral Columns in Relation to Transpedicular Fixation: A Cross-Sectional Study From Central India.

The lumbar vertebrae are the largest vertebrae of the vertebral column, which support the maximum body weight. There has been an increased focus on transpedicular spinal fixation for addressing various lumbar spine pathology. However, its safety and efficacy require precise knowledge of the lumbar pedicle anatomy. Mismatched size of screw and pedicle may lead to failure of instrumentation. It may result in cortex perforation or pedicle fracture and loosening of the pedicle screw. The oversizing of the pedicle screw can result in dural tears, leakage of the cerebrospinal fluid, and injuries to the nerve root. As the racial variations in the anatomy of a pedicle are well known, this study was performed to assess the morphological parameters of the lumbar vertebrae pedicles in the Central Indian population so that the appropriate sizes of pedicular implants can be selected. The present study was conducted at a tertiary-level hospital and medical college on dry lumbar vertebrae specimens available in the department of anatomy. The measurement of morphometric parameters of the lumbar vertebrae pedicles was performed in 20 dry lumbar specimens using vernier calipers and a standard goniometer. The morphometric parameters included in the study are pedicle transverse external diameter (pedicle width), pedicle sagittal external diameter (pedicle height), transverse angle of the pedicle, and sagittal angle of the pedicle.Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) system version 25 (Chicago, IL: SPSS Inc.). The broadest external transverse diameter was at the L5 level, with a mean of (17.54±1.6 mm) in the lumbar vertebrae. The broadest external sagittal pedicle diameter was at the L1 level (13.7±0.88 mm). The maximum transverse angle of the pedicle was at L5 with a mean of 25.39±3.10°. The maximum sagittal angle was at L1 with a mean of 5.44±0.71°. The increased concern regarding the internal fixation of the spine with pedicle screw systems created the need to have almost accurate anatomical knowledge of lumbar pedicles. Due to the dynamic nature of the lumbar spine and the body's load, maximum degeneration occurs at this spine segment, making it the most commonly operated region of the vertebral column. In our study, pedicle dimensions are comparable to populations of other Asian countries. However, the pedicle dimension of our population is lower than the White American population. This morphological variation of pedicle anatomy will help surgeons choose appropriate size screws and optimum angulations to insert the implant, decreasing complications.