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.

Postoperative Airway Management after Anterior Cervical Spine Surgery: Retrospective Neurosurgical Multicenter Study.

Airway complications that occur after anterior cervical spine surgery pose a life-threatening risk, which encompasses complications including prolonged intubation, unplanned reintubation, and/or necessity of tracheostomy. The present study aimed to identify the surgical risks associated with postoperative airway complications in neurosurgical training institutes. A retrospective, multicenter, observational review of data from 365 patients, who underwent anterior cervical spine surgery between 2018 and 2022, at three such institutes was carried out. Postoperative airway complication was defined as either the need for prolonged intubation on the day of surgery or the need for unplanned reintubation. The perioperative medical information was obtained from their medical records. The average age of the cohort was over 60 years, with males comprising approximately 70%. Almost all surgeries predominantly involved anterior cervical discectomy and fusion or anterior cervical corpectomy and fusion, with most surgeries occurring at the level of C5/6. In total, 363 of 365 patients (99.5%) were extubated immediately after surgery, and the remaining two patients were kept under intubation because of the risk of airway complications. Of the 363 patients who underwent extubation immediately after surgery, two (0.55%) required reintubation because of postoperative airway complications. Patients who experienced airway complications were notably older and exhibited a significantly lower body mass index. The results of this study suggested that older and frailer individuals are at an elevated risk for postoperative airway complications, with immediate postoperative extubation generally being safe but requiring careful judgment in specific cases.

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.

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.

The Safety of Spine Surgery in the Late-Stage Elderly of 75 Years of Age or Older: A Retrospective Multicenter Study.

OBJECTIVE: The objective of this study was to verify that spine surgery for late-stage elderly (LSE) (age 65-74 years) is as safe as that for early-stage elderly (ESE) (age 65-74 years). METHODS: This retrospective multicenter study included elderly patients aged ≥65 years who underwent spine surgery between 2018 and 2021. The medical information for individual patients was obtained from medical records. Activities of daily living (ADL) were estimated using a 5-grade scale based on the Eastern Cooperative Oncology Group performance status. Good outcome was defined as ADL grade 0 or 1 at discharge; poor outcome was defined as ADL grade 2 to 4 at discharge. The postoperative complications were listed with reference to the Common Terminology Criteria for Adverse Events v5.0. RESULTS: There were 311 patients in the ESE group and 395 patients in the LSE group. Reoperation during hospitalization was significantly higher in the LSE group (4.6%) than in the ESE group (1.6%). The total number of days of hospitalization was significantly longer in the LSE group than in the ESE group. However, there was no significant difference in the postoperative complications or ADL at discharge between the 2 groups. In the statistical analysis, preoperative American Society of Anesthesiologists physical status class 3-6, underlying heart or renal disease, and cervical or thoracic spine level of surgical procedures were significantly associated with poor ADL outcomes at discharge. CONCLUSIONS: Spine surgery even for LSE can be safely done, if perioperative risk factors are appropriately managed.

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.

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.

Vertebral Fracture in an Elderly Golfer.

Golf is one of the most popular sports among seniors. Here, we report the case of a 76-year-old woman who developed a vertebral fracture while playing golf. The patient had been suffering from leg pain for several years but developed sudden back pain after her golf swing. Because magnetic resonance imaging demonstrated a new vertebral fracture of the L1 vertebral body and canal stenosis at the L4/5 level, she successfully underwent L1 vertebroplasty and L4/5 decompression. For older golfers, a classical swing that twists the pelvis and shoulders at the same time may be recommended.

The Characteristic of Light Sources and Fluorescence in the 3-Dimensional Digital Exoscope "ORBEYE" for 5-Aminolevulinic Acid-Induced Fluorescence-Guided Surgery Compared with a Conventional Microscope.

BACKGROUND: The ORBEYE (ORB), an innovative 3-dimensional digital exoscope, is an equipped system for fluorescence-guided surgery with 5-aminolevulinic acid. Therefore, this study aimed to verify the characteristics of fluorescence-guided surgery with 5-aminolevulinic acid and excitation light source with ORB. METHODS: The same operative field of glioblastoma was recorded under blue light (BL) excitation using a conventional microscope (MS) and ORB. For in vitro studies, the energy of 405-nm wavelength light in white light and BL modes of each scope was examined in various focal lengths. To examine the degree of photobleaching with BL for each scope, protoporphyrin IX-soaked filter papers were continuously exposed with BL of an MS and ORB, and the video-recorded red fluorescence intensity was analyzed. RESULTS: The color tone of tumor-induced red fluorescence was remarkably different under each scope. Furthermore, nonfluorescent normal structures without red fluorescence were well recognized under ORB. The energy of 405-nm wavelength light in BL was significantly higher in ORB than that in an MS, especially in the short focal length. With continuous BL excitation to filter papers, the relative red fluorescence intensity of filter papers was significantly decreased over time in ORB than in an MS. In low protoporphyrin IX concentration, the difference was more significant. CONCLUSIONS: With ORB, the good visibility due to BL energy as compared with an MS might improve the surgical manipulation even in BL mode. However, the weak fluorescent tissue and short focal length should be carefully considered because photobleaching might be critical for FGS.

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.