The safety of perioperative antiplatelet continuation without selection biases in microsurgical decompression surgery for single level lumbar spinal stenosis and lumbar disc herniotomy.

PURPOSE: Each institution or physician has to decide on an individual basis whether to continue or discontinue antiplatelet (AP) therapy before spinal surgery. The purpose of this study was to determine if perioperative AP continuation is safe during single-level microsurgical decompression (MSD) for treating lumbar spinal stenosis (LSS) and lumbar disc hernia (LDH) without selection bias. METHODS: Patients who underwent single-level MSD for LSS and LDH between April 2018 to December 2022 at our institute were included in this retrospective study. We collected data regarding baseline characteristics, medical history/comorbidities, epidural hematoma (EDH) volume, reoperation for EDH, differences between preoperative and one-day postoperative blood cell counts (ΔRBC), hemoglobin (ΔHGB), and hematocrits (ΔHCT), and perioperative thromboembolic complications. Patients were divided into two groups: the AP continuation group received AP treatment before surgery and the control group did not receive antiplatelet medication before surgery. Propensity scores for receiving AP agents were calculated, with one-to-one matching of estimated propensity scores to adjust for patient baseline characteristics and past histories. Reoperation for EDH, EDH volume, ΔRBC, ΔHGB, ΔHCT, and perioperative thromboembolic complications were compared between the groups. RESULTS: The 303 enrolled patients included 41 patients in the AP continuation group. After propensity score matching, the rate of reoperation for EDH, the EDH volume, ΔRBC, ΔHGB, ΔHCT, and perioperative thromboembolic complication rates were not significantly different between the groups. CONCLUSION: Perioperative AP continuation is safe for single-level lumbar MSD, even without biases.

Treatment strategies for patients with out-of-hospital cardiac arrest associated with traumatic brain injury: A case series.

INTRODUCTION: Collapse after out-of-hospital cardiac arrest (OHCA) can cause severe traumatic brain injury (TBI). We aimed to investigate the clinical characteristics and treatment strategies for patients with OHCA and TBI. METHODS: We analyzed a consecutive cohort of patients with intrinsic OHCA retrospectively treated between January 2011 and December 2021 at a single critical care center, and presented a case series of seven patients. Patients with collapse-related TBI were examined for the causes and situations of cardiac arrest, laboratory data, radiological images, targeted temperature management (TTM), coronary angiography (CAG), percutaneous coronary intervention (PCI), and extracorporeal cardiopulmonary resuscitation (ECPR). RESULTS: Of the 197 patients with intrinsic OHCA, 7 (3.6%) had TBI (age range: 49-70 years; 6 men). All seven patients presented with ventricular fibrillation in the initial electrocardiograms, with four refractory cases treated with ECPR. All patients underwent CAG under heparinization, and four underwent PCI with antiplatelet administration. Initial head computed tomography indicated an intracranial hemorrhage (ICH) in three patients. ICH appeared or was exacerbated in six patients after CAG with or without PCI, except in one who underwent delayed PCI. All patients displayed elevated plasma D-dimer levels, and four underwent neurosurgical procedures. Four patients survived (three with cerebral performance category [CPC] 2, one with CPC 3) and three died; two had hypoxic-ischemic brain injury and one had severe TBI. CONCLUSION: Delayed ICH occurred frequently. Individualized management is required based on the extent of brain and cardiac damage, including optimal TTM, PCI procedures, and antiplatelet medications. Early detection of ICH and emergency treatment are critical for multi-disciplinary collaboration.

Microvascular Decompression for Trigeminal Neuralgia with Complicated Offending Vessel Involving Trigeminocerebellar Artery: 2-Dimensional Operative Video.

Microvascular decompression (MVD) is a well-established and definitive treatment option for trigeminal neuralgia (TN).1 However, complex vascular geometry and numerous offending vessels make it difficult to perform nerve decompression in certain cases.2 The trigeminocerebellar artery (TCA) is a unique branch of the basilar artery. The vessel is named the TCA because it supplies both the trigeminal nerve root and the cerebellar hemisphere.3 This anatomical variant may increase the risk of neurovascular compression in the trigeminal nerve. We present the case of a 74-year-old man with left TN in whom a TCA was one of the responsible compression vessels. Preoperative images revealed the ipsilateral anterior inferior cerebellar artery, well-developed TCA, and superior cerebellar artery, wherein these branches were all suspected to be involved in trigeminal nerve compression. In MVD, 3 arteries were suspected to compress the trigeminal nerve in 5 sites, and all of them needed to be meticulously dissected from the nerve root and decompressed. Moreover, 2 of them branched many short perforators to the brainstem. Three decompression procedures (transposition to the dura, transposition to the brain, and interposition) were performed to decompress the trigeminal nerve. Postoperatively, TN was completely resolved immediately. MVD for TN could be difficult to perform in cases with TCA, as in the present case, and rigorous procedures were required intraoperatively.

Plasma D-Dimer Levels Can Provide Useful Diagnostic Information on Acute Vertebral Compression Fractures in Patients with Low Back Pain in the Emergency Room.

BACKGROUND: Patients with acute vertebral compression fractures (aVCFs) are frequently transferred to an emergency department by ambulance. The most useful imaging modality is magnetic resonance imaging (MRI); however, which patients should be prioritized for MRI evaluation may be unclear. The aim of this study was to evaluate plasma D-dimer levels as a biomarker for aVCFs. METHODS: This retrospective cohort study included patients with low back pain in the emergency department between November 2017 and October 2020. Patients with infections, patients with coagulation disorders, and patients without D-dimer level measurements were excluded. The presence of an aVCF was detected with MRI. Blood samples were collected for routine blood tests. The predictive factors for aVCFs were evaluated with univariate and multivariable logistic regression analyses. RESULTS: Overall, 191 consecutive MRI evaluations were ordered. After exclusions, 101 patients were reviewed. Based on MRI, 65 (64.4%) patients were diagnosed with aVCF. The presence of aVCF was significantly correlated with age (odds ratio [OR] = 1.052, 95% confidence interval [CI] 1.018-1.191), an old vertebral compression fracture (OR = 3.290, 95% CI 1.342-8.075), hemoglobin (OR = 0.699, 95% CI 0.535-0.912), and D-dimer levels (OR = 1.829, 95% CI 1.260-2.656). Results from a multivariable logistic regression analysis showed that D-dimer levels (OR = 1.642, 95% CI 1.188-2.228) remained a significant risk factor for the presence of aVCFs after adjustment for potential confounders. CONCLUSIONS: Plasma D-dimer levels can provide useful diagnostic information about whether an aVCF is present.

A Case of Symptomatic Multiple Tarlov Cysts Treated with Microsurgical Wrapping Technique -Efficacy and Limitation of Surgical Procedure.

Tarlov cysts (TCs) rarely cause clinical symptoms, such as leg pain, buttock pain, and bladder/bowel dysfunction. Surgery is considered when these symptoms persist despite medical treatments. Among several surgical procedures, microsurgical wrapping (MSW) is a relatively novel, simple technique with few complications, including cerebrospinal fluid leakage. Herein, we report a case of multiple TCs treated with MSW and present the mechanism of symptoms generated by TC and the procedure's limitations. A 58-year-old man complained of severe right leg and buttock pain for 3 months and was admitted to our hospital. His symptoms aggravated with sitting and standing and improved with the prone position. Spinal magnetic resonance imaging (MRI) demonstrated multiple sacral cysts containing intense cerebrospinal fluid. The cysts connect to the right S3 and S4 nerve roots. He was treated conservatively with medications; however, his symptoms were not improved. Therefore, MSW was performed for TCs connected to the S3 and S4 roots. The postoperative course was uneventful, and cerebrospinal fluid leakage did not occur. MRI performed 1 year after the operation demonstrated no recurrence of the TCs, and his leg pain was completely relieved; however, the buttock pain remained. MSW for TCs is effective for symptoms of adjacent nerve root compression; however, repairing the damaged nerve root in TCs is sometimes difficult. This may be a limitation of present surgical interventions because these symptoms may be difficult to treat even with other interventions.

Factors influencing slippage after microsurgical single level lumbar spinal decompression surgery - Are the psoas and multifidus muscles involved?

PURPOSE: Patients with lumbar spinal stenosis (LSS) require microsurgical decompression (MSD) surgery; however, MSD is often associated with postoperative instability at the operated level. Paraspinal muscles support the spinal column; lately, paraspinal volume has been used as a good indicator of sarcopenia. This study aimed to determine preoperative radiological factors, including paraspinal muscle volume, associated with postoperative slippage progression after MSD in LSS patients. METHODS: Patients undergoing single-level (L3/4 or L4/5) MSD for symptomatic LSS and followed-up for ≥ 5 years in our institute were reviewed retrospectively to measure preoperative imaging parameters focused on the operated level. Paraspinal muscle volumes (psoas muscle index [PMI] and multifidus muscle index [MFMI]) defined using the total cross-sectional area of each muscle/L3 vertebral body area in the preoperative lumbar axial CT) were calculated. Postoperative slippage in the form of static translation (ST) ≥ 2 mm was assessed on the last follow-up X-ray. RESULTS: We included 95 patients with average age and follow-up periods of 69 ± 8.2 years and 7.51 ± 2.58 years, respectively. PMI and MFMI were significantly correlated with age and significantly larger in male patients. Female sex, preoperative ST, dynamic translation, sagittal rotation angle, facet angle, pelvic incidence, lumbar lordosis, and PMI were correlated with long-term postoperative worsening of ST. However, as per multivariate analysis, no independent factor was associated with postoperative slippage progression. CONCLUSION: Lower preoperative psoas muscle volume in LSS patients is an important predictive factor of postoperative slippage progression at the operated level after MSD. The predictors for postoperative slippage progression are multifactorial; however, a well-structured postoperative exercise regimen involving psoas muscle strengthening may be beneficial in LSS patients after MSD.

Changes in spinal sagittal balance after a new osteoporotic vertebral compression fracture.

We conduct a longitudinal study to examine how new VCF alter spinal sagittal balance. New VCF increased SVA by an average of 2.8 cm. Sagittal balance deteriorates as a VCF develops in the lower lumbar spine. A new fracture below L1 increased the relative risk of a deterioration of sagittal balance 2.9-fold compared to one above Th12. PURPOSE: Studies on the relationship between osteoporotic vertebral fractures and spinal sagittal balance have all been limited to cross-sectional studies. The aim of this study is to conduct a longitudinal study to examine how new vertebral compression fracture (VCF) alter spinal sagittal balance. METHODS: Subjects were patients undergoing periodic examinations after treatment of a vertebral fracture or lumbar spinal canal stenosis. Forty patients who developed a new VCF were included in this study. Full-spine standing radiographs were compared before and after the fracture to examine changes in spinopelvic parameters and factors determining the changes in sagittal balance. RESULTS: The mean age of the patients was 79.0 years. The mean interval between pre- and post-fracture radiographs was 22.7 months, and the mean time between development of a fracture and post-fracture radiographs was 4.6 months. After a fracture, sagittal vertical axis (SVA) increased an average of 2.78 cm and spino-sacral angle (SSA) decreased an average of 5.3°. Both ⊿SVA and ⊿SSA were not related to pre-fracture parameters. The wedge angle of the fractured vertebra was not related to changes in sagittal balance. ⊿SVA increased markedly in patients with a fracture of the lower lumbar vertebrae. receiver operating characteristic analysis revealed that the relative risk of a deterioration of sagittal balance was 2.9 times higher for a new fracture below L1 than for a fracture above Th12. CONCLUSION: New VCF increased SVA by an average of 2.8 cm. Sagittal balance deteriorates as a new fracture develops in the lower lumbar spine. Early intervention in osteoporosis is vital for the elderly.

Hematomyelia Presenting with Neurogenic Stunned Myocardium.

Various neurological disorders and emotional stress may cause left ventricular dysfunction, known as a neurogenic stunned myocardium. A previously healthy 71-year-old woman collapsed immediately after experiencing left arm numbness and pain. Thereafter, the patient complained of anterior chest pain and became comatose. An electrocardiogram showed ST-segment elevation of I, aVL, and V2-3 and depression of II, III, and aVF. Echocardiography revealed anteroseptal hypokinesis of the left ventricle. Emergency coronary angiography revealed no significant stenosis in the coronary arteries; however, left ventriculography revealed obvious anteroseptal hypokinesis. When the patient regained consciousness the following day, tetraplegia was observed. Spinal computed tomography and magnetic resonance imaging revealed an intramedullary spinal cord hemorrhage from the medulla to the conus. The cardiac function recovered, but the patient remained tetraplegic with poor spontaneous respiration. Although its incidence is extremely rare, hematomyelia should be recognized as a potential cause of neurogenic stunned myocardium.

Long-Term Changes in Sagittal Balance After Microsurgical Decompression of Lumbar Spinal Canal Stenosis in Elderly Patients: A Follow-Up Study for 5-Years After Surgery.

OBJECTIVE: The purpose of this study is to investigate long-term changes in spinal sagittal balance after microsurgical decompression in lumbar canal stenosis (LCS). METHODS: Fifty-two patients who underwent microsurgical decompression for symptomatic single level L4/5 spinal canal stenosis at our hospital were included in the study. All patients had standing full spine radiographs taken preoperatively, 1 year postoperatively, and 5 years postoperatively. Spinal parameters including sagittal balance were measured from the obtained images. First, preoperative parameters were compared with 50 age-matched asymptomatic volunteers. Next, the parameters before and after surgery were compared to examine long-term changes. RESULTS: Sagittal vertical axis (SVA) was significantly increased in the LCS cases compared to the volunteers (P = 0.03). Postoperative lumbar lordosis (LL) was significantly increased (P = 0.03). Postoperative mean SVA decreased but the difference was not significant (P = 0.12). Although there was no correlation between preoperative parameters and the Japanese Orthopedic Association score, postoperative pelvic incidence (PI)-LL and pelvic tilt changes correlated with changes in Japanese Orthopedic Association score (PI-LL; P = 0.0001, pelvic tilt; P = 0.04). However, after 5 years of surgery, LL decreased and PI-LL increased (LL; P = 0.08, PI-LL; P = 0.03). Sagittal balance began to deteriorate but was not significant (P = 0.31). At 5 years postoperatively, 18 of 52 patients (34.6%) were found to have L3/4 adjacent segment disease. Cases with adjacent segment disease showed significantly worse SVA and PI-LL (SVA; P = 0.01, PI-LL; P < 0.01). CONCLUSIONS: In LCS, lumbar kyphosis improves and sagittal balance tends to improve after microsurgical decompression. However, after 5 years, adjacent intervertebral degeneration occurs more frequently and sagittal balance begins to deteriorate in about one third of cases.

Treatment for Osteoporotic Vertebral Fracture - A Short Review of Orthosis and Percutaneous Vertebroplasty and Balloon Kyphoplasty.

The management of osteoporotic vertebral fractures (OVFs) in the elderly includes nonoperative treatment and vertebroplasty, but has not been established due to the diversity of patient backgrounds. The purpose of this study was to compare the impact of 3 treatment modalities for the management of OVF: orthotic treatment, percutaneous vertebroplasty (PVP), and balloon kyphoplasty (BKP). The method was based on an analysis of the latest RCTs, meta-analyses, and systematic reviews on these topics. No study showed a benefit of bracing with high level of evidence. Trials were found that showed comparable outcomes without orthotic treatment. Only 1 randomized controlled trial (RCT) showed an improvement in pain relief up to 6 months compared with no orthosis. Rigid and nonrigid orthoses were equally effective. Four of 5 RCTs comparing vertebroplasty and sham surgery were equally effective, and one RCT showed superior pain relief with vertebroplasty within 3 weeks of onset. In open trials comparing vertebroplasty with nonoperative management, vertebroplasty was superior. PVP and BKP were comparable in terms of pain relief, improvement in quality of life, and adjacent vertebral fractures. BKP does not affect global sagittal alignment, although BKP may restore vertebral body height. An RCT was published showing that PVP was effective in chronic cases without pain relief. Vertebroplasty improved life expectancy by 22% at 10 years. The superiority of orthotic therapy for OVF was seen only in short-term pain relief. Soft orthoses proved to be a viable alternative to rigid orthoses. Vertebroplasty within 3 weeks may be useful. There is no significant difference in clinical efficacy between PVP and BKP. Vertebroplasty improves life expectancy.

The Effectiveness of Vertebral Height Restoration Based on the Vertebroplasty Procedure Used to Treat Osteoporotic Vertebral Fractures.

OBJECTIVE: Whether the use of a balloon or stent in vertebroplasty for vertebral fractures, such as balloon kyphoplasty (BKP) or vertebral body stenting (VBS), actually contributes to the restoration of postoperative vertebral height is unclear. The aim of the current study was to compare the effectiveness of percutaneous vertebroplasty (PVP), BKP, and VBS in the correction of collapsed vertebrae in patients with painful vertebral fractures. METHODS: The cases studied involved 34 vertebrae in 28 patients treated with PVP, 43 vertebrae in 38 patients treated with BKP, and 20 vertebrae in 20 patients treated with VBS at Izinkai Takeda General Hospital. Changes in the vertebral height and local kyphosis angle were measured based on standing lumbar radiographs before and after surgery and were compared among the treatment groups. RESULTS: There were no differences in changes in the height of the anterior wall, middle body, or posterior wall of the treated vertebrae among the 3 treatment groups. The same was true for changes in the local kyphosis angle. The effectiveness of vertebral height restoration depended heavily upon preoperative vertebral instability in all the treatment groups. Correction loss due to balloon deflation effect or balloon sinking was noted with VBS or BKP. CONCLUSION: BKP and VBS have the advantage of reducing the risk of extravertebral leakage of injected bone cement, but they have a disadvantage in that they are no more effective than PVP in restoring collapsed vertebrae despite the use of a balloon or metal stent.

Targeted Temperature Management for Severe Subarachnoid Hemorrhage Using Endovascular and Surface Cooling Systems: A Nonrandomized Interventional Study Using Historical Control.

BACKGROUND: Although targeted temperature management (TTM) may mitigate brain injury for severe subarachnoid hemorrhage (SAH), rebound fever correlates with poor outcomes. OBJECTIVE: To study the effect of endovascular TTM after rewarming from initial surface cooling during a high-risk period for delayed cerebral ischemia. METHODS: We studied patients with World Federation of Neurological Surgeons grade V SAH before and after the introduction of endovascular TTM. Both groups (36 patients each) were treated with TTM at 34 °C with conventional surface cooling immediately after SAH diagnosis, together with emergency aneurysm repair. When rewarmed to 36 °C, around 7 days later, the study group underwent TTM at 36 to 38 °C for 7 days with an endovascular cooling system. The control group was treated with antipyretics. RESULTS: Sex, age, Glasgow Coma Scale score, modified Fisher computed tomography classification, aneurysm location, and treatment methods were not different between the study and control groups. Differences were detected in the incidence of fever >38 °C (13 vs 26 patients, P = .0021), duration of fever >38 °C (4.1 vs 18.8 hours, P = .0021), incidence of vasospasm-related cerebral infarction (17% vs 42%, P = .037), and the likelihood of excellent outcomes (0 and 1 on a modified Rankin Scale) at 6 months (42% vs 17%, P = .037). In endovascular TTM, shivering occurred more frequently in patients with better outcomes, requiring aggressive treatment to avoid fever. CONCLUSION: Endovascular TTM at 36 to 38 °C after surface cooling was feasible and safely performed in patients with severe SAH. Combined TTM for 2 weeks was associated with a lower incidence of vasospasm-related infarction and may improve outcomes.

Regression of retro-odontoid pseudotumor following botulinum injection into cervical muscles.

Background: Posterior fixation of C1/2 has become more commonly performed to treat retro-odontoid pseudotumor (ROP). Here, we report a 60-year-old female with cervical dystonia (CD), whose ROP regressed and whose quadriparesis improved after a series of cervical intramuscular botulinum injections. Case Description: A 60-year-old female with 30 years of CD newly presented with a progressive quadriparesis. When the MRI showed ROP compression the cervical spinal cord, she refused surgery and underwent multiple cervical muscular botulinum injections over the next 2 years. Following these injections, the patient's quadriparesis improved as the ROP regressed on subsequent MR studies. Conclusion: Over a 2-year period, multiple cervical botulinum injections caused regression of a retro-odontoid cervical pseudotumor improvement in the patient's quadriparesis.

A Case of Nonapoplectic Pituitary Adenoma Presenting with Isolated Oculomotor Nerve Palsy.

We report a rare case of nonapoplectic pituitary adenoma that did not invade the cavernous sinus and was associated with isolated oculomotor nerve palsy. A 61-year-old male was admitted to our hospital due to diplopia that had gradually worsened from 6 months to presentation. He was diagnosed with right oculomotor nerve palsy, and brain magnetic resonance imaging (MRI) showed a mass lesion within the sella. The tumor was homogeneously enhanced on contrast-enhanced MRI. However, no findings suggestive of pituitary apoplexy were found. Brain computed tomography revealed the tumor to have eroded the right side of the posterior clinoid process by gradual expansion. Endoscopic transsphenoidal surgery was used for complete resection of the tumor. Intraoperative findings showed that the tumor did not invade the cavernous sinus. The histological diagnosis was pituitary adenoma, and symptom improvement was observed from the early postoperative stage onward. Surgical treatment is essential because oculomotor nerve palsy caused by the enlargement of pituitary adenoma is not expected to resolve if treated conservatively, unlike that caused by pituitary apoplexy.

Intradural extramedullary hemangioblastoma of the thoracic cord: A case report.

BACKGROUND: Spinal hemangioblastomas account for 1-3% of all spinal cord tumors and are mostly intramedullary in location. Here, we report an intradural extramedullary hemangioblastoma of the thoracic spine, occurring in in a patient without von Hippel-Lindau disease. CASE DESCRIPTION: A 58-year-old female had a 5-year history of progressive left lower extremity weakness. When the MR demonstrated an intradural/extramedullary lesion with a syrinx at the T2-3 level, she successfully underwent gross total tumor excision following which she neurologically improved. CONCLUSION: Here, we report a rare case of an intradural/extramedullary thoracic hemangioblastoma successfully excised at the T 2-3 level in a patient without von Hippel-Lindau disease.

Resolution of retro-odontoid cyst in a patient with atlanto-occipital assimilation after occipitocervical fixation.

BACKGROUND: Fusion of the atlas with the lower part of the occiput is clinically known as atlanto-occipital assimilation (AOA) or atlas occipitalization. This can be either partial or complete depending on the extent of fusion. AOA is one of the most common congenital anomalies of the craniovertebral junction and is usually asymptomatic. CASE DESCRIPTION: An 80-year-old female presented with a retro-odontoid cyst in conjunction with AOA. Following posterior occipitocervical fixation without resection of the cyst, the patient improved, and the postoperative MR documented cyst resolution. CONCLUSION: Patients with AOA and a retro-odontoid cyst may be successfully managed with occipitocervical fixation without resection of the cyst. However, we would recommend preoperative computed tomography angiography to document whether the vertebral artery follows an anomalous course to avoid an intraoperative neurovascular injury.

Vascular occlusion in a previously unaffected territory after treatment with intravenous plasminogen activator: illustrative case.

BACKGROUND: Intravenous tissue plasminogen activator (IV t-PA) is effective for the treatment of distal artery occlusion. However, after the use of IV t-PA, vascular occlusion in unaffected territories may occur. Early recurrent ischemic stroke (ERIS) is defined as the occurrence of new neurological symptoms that suggest the involvement of initially unaffected vascular territories after intravenous thrombolysis (IVT). The authors reviewed the cases of ERIS that occurred within 24 hours after treatment with IVT. OBSERVATIONS: A 75-year-old woman with occlusion in the M2 segment of the left middle cerebral artery (MCA) was treated with IV t-PA. However, 360 minutes later, the patient presented with occlusion in the M1 distal segment of the contralateral side, the right MCA, which was recanalized by endovascular treatment. Her modified Rankin Scale score was 4; however, aphasia was not observed. She was transferred to a rehabilitation hospital after 3 months. LESSONS: ERIS is an extremely rare but catastrophic event. The underlying mechanism of ERIS most likely involves the disintegration and subsequent scattering of a preexisting intracardiac thrombus. Hence, caution must be used when managing not only hemorrhagic complications but also ischemic complications after IV t-PA. Endovascular management may be the only effective treatment for this type of large vessel occlusion.

Analgesic Posture and Pelvic Morphology in Patients with Lumbar Disc Herniation.

OBJECTIVE: Pelvic morphology is an important element in determination of spinal alignment. We retrospectively examined the correlation between spinal alignment, severity, and pelvic morphology in lumbar disc herniation (LDH) surgery. METHODS: The study included 62 cases of paramedian LDH surgeries (L4-5: 19 cases; L5-S1: 43 cases). For all cases, we performed x-ray imaging of the whole spine in the standing position preoperatively and 1 week postoperatively and measured spinopelvic parameters. Comparing preoperative parameters of patients with 82 healthy subjects, we examined changes before and after surgery. We also examined the relationship between preoperative severity and parameters. RESULTS: Compared with healthy subjects, patients with LDH exhibited significantly decreased lumbar lordosis and sacral slope and increased pelvic tilt and sagittal vertical axis (P < 0.01). Japanese Orthopaedic Association score improved from 16.1 ± 4.6 preoperatively to 23.5 ± 3.2 1 week postoperatively (P < 0.01). Spinopelvic parameters observed preoperatively improved significantly 1 week postoperatively (P < 0.01). Correlation analysis did not confirm any correlation of severity with preoperative pelvic tilt, sagittal vertical axis, or pelvic incidence. However, cases with high pelvic tilt/pelvic incidence were significantly more likely to be severe cases (R2 = 0.08, P = 0.027). A significant decrease in pelvic tilt was observed in cases with a large improvement in postoperative Japanese Orthopaedic Association score (P = 0.031). CONCLUSIONS: For LDH cases, pelvic retroversion is important to avoid pain. The range of mobility for pelvic retroversion varies depending on pelvic morphology of individuals. In cases of LDH, ratio of pelvic tilt to pelvic incidence correlates strongly with severity.

A Case of Dural Herniation of the Cauda Equina Caused by Enlarged Spinal Subdural Extra-arachnoid Hygroma Following Lumbar Microsurgical Decompression: Case Report.

We experienced a rare case of transdural herniation of cauda equina caused by increased pressure with spinal subdural extra-arachnoid hygroma (SSEH) following lumbar microsurgical decompression. A 68-year-old woman presented with complaints of right leg pain and intermittent claudication. By the diagnosis of L2/3 lumbar spinal stenosis, microsurgical decompression was performed. The surgery was successful with no issues arising such as damage to the dura mater. Lumbar magnetic resonance imaging (MRI) performed 8 days after the surgery confirmed asymptomatic SSEH on the ventral side of the cauda equina. However, posterior cervical pain and lower back pain developed 32 days after the surgery. Lumbar MRI demonstrated that SSEH had markedly increased and advanced from the lumbar spine to the cranium, compressing the spinal cord posteriorly. In addition, herniation of the cauda equina was confirmed in the dura. An emergency surgery was performed. The herniated cauda equina was fully positioned in the dural sac, and the arachnoid membrane with accumulation of spinal fluid on the ventral side was fenestrated. Immediately after the surgery, the patient's symptoms disappeared. Sufficient caution is required regarding the possibility of SSEH associated with spinal failed back surgery syndrome as it can become excessively enlarged, leading to a poor prognosis.

Factors of Adjacent Segment Disease Onset After Microsurgical Decompression for Lumbar Spinal Canal Stenosis.

OBJECTIVE: Few studies have examined the underlying cause of adjacent segment disease (ASD) after decompression surgery for lumbar spinal stenosis. The goal of this study is to investigate factors related to the onset of ASD after decompression surgery based on the imaging results. METHODS: We examined 95 patients who underwent single-level decompression for lumbar spinal stenosis (L3/4, L4/5) and follow-up for 5 or more years. Radiographic images were performed preoperatively and at each year of follow-up. We then examined image parameters by focusing on the level operated on and adjacent segments in relation to the postoperative onset of symptomatic ASD. RESULTS: During the mean observation period of 7.5 years, 39 of 95 patients developed symptomatic ASD. Patients with a high preoperative sagittal rotation angle in adjacent segments possibly developed postoperative ASD (P = 0.0006). Furthermore, postoperative ASD tended to be unlikely in patients who exhibited postoperative slip progression at the operated level (P = 0.025). Based on receiver operating characteristic analysis, ASD developed with a probability of 91.3% in patients with a preoperative sagittal rotation angle of ≥7.5° in adjacent segments when there was no postoperative slip progression at the operated level. However, ASD developed in only 16.7% of patients with a preoperative adjacent segment sagittal rotation angle of 7.5° or less when there was postoperative slip progression at the operated level. CONCLUSIONS: Biomechanical changes at the operated level and adjacent segments contribute to the onset of ASD after lumbar decompression. Preoperative high sagittal rotation angle of adjacent segments and negative postoperative slip progression at the operated level are risk factors of ASD.