Long-term outcome after en bloc resection and reconstruction of the spinal column and posterior chest wall in the treatment of malignant tumors.

BACKGROUND: Malignant tumors occurring around both the spinal column and posterior chest wall are uncommon. Surgical resection of chest wall tumors adjacent to the spinal column is still challenging due to the surrounding anatomical structures. The purpose of the present study was to evaluate the long-term outcomes of surgical management in malignant tumors involving the spinal column and posterior chest wall. METHODS: Between 1999 and 2007, 10 consecutive patients underwent en bloc resection combined with the posterior chest wall in the treatment of malignant tumors around the spinal column. There were 6 males and 4 females with a mean age at the surgery of 40.9 years old (range, 14-62 years old). The mean postoperative follow-up period was 159.7 months (range, 84-245 months). The clinical history, physical examination, laboratory data, radiological findings, and operative findings for each patient were retrospectively reviewed. RESULTS: All surgeries were performed via a combined anterior and posterior approach. The mean numbers of partially resected vertebrae and ribs were 3.1 and 4.1, respectively. Lower or upper lobectomy was performed in four patients, and the diaphragm was partially resected in two patients. The surgical margin was wide in seven patients and marginal in two patients. Although five patients had postoperative respiratory problem, all patients improved immediately without life-threatening complications. There were no patients with respiratory insufficiency after surgery. One patient with osteosarcoma died of lung metastases 99 months after surgery. At the final follow-up, only one patient had local recurrence, five had been continuously disease-free, and three were alive with no evidence of disease. CONCLUSIONS: En bloc resection and reconstruction in selected patients with malignant tumors involving both the spinal column and posterior chest wall demonstrated good long-term results for local control and the respiratory function.

Clinical features of multiple spinal schwannomas without vestibular schwannomas.

BACKGROUND: Multiple spinal cord tumors in a single patient are very rare and most often seen in cases of neurofibromatosis and associated disorders. Schwannomatosis, which is characterized by the development of multiple schwannomas without vestibular schwannomas, has been newly defined as a distinct form of neurofibromatosis. The purpose of the present study was to describe and review the clinical and radiological features and the management of patients with multiple spinal schwannomas without vestibular schwannomas. METHODS: Between 1986 and 2016, 19 patients with multiple spinal schwannomas without vestibular schwannoma were diagnosed and treated. Of the 19 patients, 13 were males, and 6 were females. The mean age at the first surgery for spinal schwannoma was 45.2 years old. The mean follow-up period was 123.4 months. The clinical features and radiological findings of the patients with multiple spinal schwannomas were retrospectively reviewed. RESULTS: Among the 19 patients, there were more than 140 spinal schwannomas. The most common area of spinal schwannoma was the thoracolumbar-lumbar region. Initial symptoms and chief complaints caused by spinal schwannomas were primarily pain in the trunk or extremities in 17 (89.5%) of 19 patients. More than 60 spinal schwannomas were surgically resected. Multiple spinal surgeries were required in six patients. In all 19 patients, surgical treatment has provided successful relief of symptoms and neurological recovery. CONCLUSIONS: Surgical treatment was safe and effective in patients with multiple spinal schwannomas without vestibular schwannomas. After surgery, we recommend that all patients be followed with magnetic resonance imaging to monitor for asymptomatic tumors or detect new tumors early.

Clinical features and outcomes of spine surgery in patients with ankylosing spondylitis.

OBJECTIVES: The study aimed to comprehend the clinical features and outcomes of surgical treatments for spinal disorders in patients with ankylosing spondylitis. METHODS: This retrospective study enrolled patients with ankylosing spondylitis who underwent spine surgery between 2000 and 2019 in our facility. RESULTS: Thirteen patients with ankylosing spondylitis underwent spine surgeries. The mean age was 56.2 years, and the mean disease duration was 25.1 years at the time of surgery. Nine patients had vertebral fracture, two had kyphotic deformity, and two had myelopathy due to the spinal ligament ossification. Fracture cases included five patients with secondary pseudarthrosis/delayed palsy due to conservative treatment failure. Spinal fixation was performed in all patients. Pedicle subtraction osteotomy for kyphosis and laminectomy for myelopathy were also conducted. All patients improved after surgeries. One patient with kyphotic deformity underwent additional surgery of bilateral hip prosthesis, which resulted in better spine alignment. Four cases of perioperative complications were observed. CONCLUSION: Myelopathy was newly found as the aetiology requiring surgery in patients with ankylosing spondylitis. This summarized case series could help physicians to identify patients with surgically treatable spinal disorders among patients with ankylosing spondylitis.

The factors related to the poor ADL in the patients with osteoporotic vertebral fracture after instrumentation surgery.

PURPOSE: Osteoporotic vertebral fracture (OVF) with nonunion or neurological deficit may be a candidate for surgical treatment. However, some patients do not show improvement as expected. Therefore, we conducted a nationwide multicenter study to determine the predictors for postoperative poor activity of daily living (ADL) in patients with OVF. METHODS: We retrospectively reviewed the case histories of 309 patients with OVF who underwent surgery. To determine the factors predicting postoperative poor ADL, uni- and multivariate statistical analyses were performed. RESULTS: The frequency of poor ADL at final follow-up period was 9.1%. In univariate analysis, preoperative neurological deficit (OR, 4.1; 95% CI, 1.8-10.3; P < 0.001), perioperative complication (OR, 3.4; P = 0.006), absence of preoperative bone-modifying agent (BMA) administration (OR, 2.7; P = 0.03), and absence of postoperative recombinant human parathyroid hormone (rPTH) administration (OR, 3.9; P = 0.006) were significantly associated. In multivariate analysis, preoperative neurological deficit (OR, 4.6; P < 0.001), perioperative complication (OR, 3.4; P = 0.01), and absence of postoperative rPTH administration (OR, 3.9; P = 0.02) showed statistical significance. CONCLUSIONS: Preoperative neurological deficit, perioperative complication, and absence of postoperative rPTH administration were considered as predictors for postoperative poor ADL in patients with OVF. Neurological deficits and complications are often inevitable factors; therefore, rPTH is an important option for postoperative treatment for OVF. These slides can be retrieved under Electronic Supplementary Material.

Short- versus long-segment posterior spinal fusion with vertebroplasty for osteoporotic vertebral collapse with neurological impairment in thoracolumbar spine: a multicenter study.

BACKGROUND: Vertebroplasty with posterior spinal fusion (VP + PSF) is one of the most widely accepted surgical techniques for treating osteoporotic vertebral collapse (OVC). Nevertheless, the effect of the extent of fusion on surgical outcomes remains to be established. This study aimed to evaluate the surgical outcomes of short- versus long-segment VP + PSF for OVC with neurological impairment in thoracolumbar spine. METHODS: We retrospectively collected data from 133 patients (median age, 77 years; 42 men and 91 women) from 27 university hospitals and their affiliated hospitals. We divided patients into two groups: a short-segment fusion group (S group) with 2- or 3-segment fusion (87 patients) and a long-segment fusion group (L group) with 4- through 6-segment fusion (46 patients). Surgical invasion, clinical outcomes, local kyphosis angle (LKA), and complications were evaluated. RESULTS: No significant differences between the two groups were observed in terms of neurological recovery, pain scale scores, and complications. Surgical time was shorter and blood loss was less in the S group, whereas LKA at the final follow-up and correction loss were superior in the L group. CONCLUSION: Although less invasiveness and validity of pain and neurological relief are secured by short-segment VP + PSF, surgeons should be cautious regarding correction loss.

Effect of bisphosphonates or teriparatide on mechanical complications after posterior instrumented fusion for osteoporotic vertebral fracture: a multi-center retrospective study.

BACKGROUND: The optimal treatment of osteoporosis after reconstruction surgery for osteoporotic vertebral fractures (OVF) remains unclear. In this multicentre retrospective study, we investigated the effects of typically used agents for osteoporosis, namely, bisphosphonates (BP) and teriparatide (TP), on surgical results in patients with osteoporotic vertebral fractures. METHODS: Retrospectively registered data were collected from 27 universities and affiliated hospitals in Japan. We compared the effects of BP vs TP on postoperative mechanical complication rates, implant-related reoperation rates, and clinical outcomes in patients who underwent posterior instrumented fusion for OVF. Data were analysed according to whether the osteoporosis was primary or glucocorticoid-induced. RESULTS: A total of 159 patients who underwent posterior instrumented fusion for OVF were included. The overall mechanical complication rate was significantly lower in the TP group than in the BP group (BP vs TP: 73.1% vs 58.2%, p = 0.045). The screw backout rate was significantly lower and the rates of new vertebral fractures and pseudoarthrosis tended to be lower in the TP group than in the BP group. However, there were no significant differences in lumbar functional scores and visual analogue scale pain scores or in implant-related reoperation rates between the two groups. The incidence of pseudoarthrosis was significantly higher in patients with glucocorticoid-induced osteoporosis (GIOP) than in those with primary osteoporosis; however, the pseudoarthrosis rate was reduced by using TP. The use of TP also tended to reduce the overall mechanical complication rate in both primary osteoporosis and GIOP. CONCLUSIONS: The overall mechanical complication rate was lower in patients who received TP than in those who received a BP postoperatively, regardless of type of osteoporosis. The incidence of pseudoarthrosis was significantly higher in patients with GIOP, but the use of TP reduced the rate of pseudoarthrosis in GIOP patients. The use of TP was effective to reduce postoperative complications for OVF patients treated with posterior fusion.

A functional variant in MIR4300HG, the host gene of microRNA MIR4300 is associated with progression of adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity affecting millions of children. Since treatment and prognosis of AIS depend on curve progression, identifying factors related to AIS curve progression is important in its management. Although several genetic loci for AIS occurrence are reported, no locus for curve progression has been identified. To identify genes associated with AIS progression, we conducted a genome-wide association study followed by a replication study using a total of 2,543 AIS subjects who were evaluated for the curve progression. We identified a significantly associated locus on chromosome 11q14.1 (P = 1.98 × 10-9, odds ratio = 1.56). In silico and in vitro analyses identified a functional variant, rs35333564 in MIR4300HG, the host gene of a microRNA, MIR4300. The genomic region containing rs35333564 had enhancer activity, which was decreased in its risk allele. Our data suggest that decrease of MIR4300 is related to AIS progression.

Lumbar lordosis does not correlate with pelvic incidence in the cases with the lordosis apex located at L3 or above.

PURPOSE: To test the hypothesis that the relationship between PI and L1-S1 lumbar lordosis (LL) is always positive, even in cases with different lumbar sagittal profiles. METHODS: Standing whole-spine sagittal alignment was measured with EOS system in 100 healthy adults (46 men, 54 women, mean age 40.9 years). The apex of lumbar lordosis was defined as the most anterior lumbar vertebra or intervertebral disk from the gravity line determined by a force plate measurement. Subjects were stratified into three groups: the upper group with an apex between L1 and L3 (UppA, n = 19), the middle group with an apex from L3/4 to L4/5 (MidA, n = 67), and the lower group with an apex at L5 or below (LowA, n = 14). PI, PT, SS, thoracic kyphosis (TK), LL, SVA, T1 pelvic angle, and knee flexion angle were compared between the groups. The correlation between LL and PI in each group was also compared. RESULTS: PI and SS differed significantly between the three groups, and LL was significantly different between LowA and MidA and UppA. TK and KF did not differ significantly between groups. LL and PI were significantly positively correlated in the MidA and LowA groups, but not in the UppA group. CONCLUSION: Contrary to the hypothesis, the correlation coefficient between PI and LL was not significant in the cases with apex above L3, suggesting that the relationship between PI and LL is not always constant, and whole sagittal alignment should be taken into account. These slides can be retrieved under Electronic Supplementary Material.

Surgical outcomes of spinal fusion for osteoporotic thoracolumbar vertebral fractures in patients with Parkinson's disease: what is the impact of Parkinson's disease on surgical outcome?

BACKGROUND: To date, there have been little published data on surgical outcomes for patients with PD with thoracolumbar OVF. We conducted a retrospective multicenter study of registry data to investigate the outcomes of fusion surgery for patients with Parkinson's disease (PD) with osteoporotic vertebral fracture (OVF) in the thoracolumbar junction. METHODS: Retrospectively registered data were collected from 27 universities and their affiliated hospitals in Japan. In total, 26 patients with PD (mean age, 76 years; 3 men and 23 women) with thoracolumbar OVF who underwent spinal fusion with a minimum of 2 years of follow-up were included (PD group). Surgical invasion, perioperative complications, radiographic sagittal alignment, mechanical failure (MF) related to instrumentation, and clinical outcomes were evaluated. A control group of 296 non-PD patients (non-PD group) matched for age, sex, distribution of surgical procedures, number of fused segments, and follow-up period were used for comparison. RESULTS: The PD group showed higher rates of perioperative complications (p < 0.01) and frequency of delirium than the non-PD group (p < 0.01). There were no significant differences in the degree of kyphosis correction, frequency of MF, visual analog scale of the symptoms, and improvement according to the Japanese Orthopaedic Association scoring system between the two groups. However, the PD group showed a higher proportion of non-ambulators and dependent ambulators with walkers at the final follow-up (p < 0.01). CONCLUSIONS: A similar surgical strategy can be applicable to patients with PD with OVF in the thoracolumbar junction. However, physicians should pay extra attention to intensive perioperative care to prevent various adverse events and implement a rehabilitation regimen to regain walking ability.

Surgical outcomes of spinal fusion for osteoporotic vertebral fracture in the thoracolumbar spine: Comprehensive evaluations of 5 typical surgical fusion techniques.

BACKGROUND: A consensus on the optimal surgical procedure for thoracolumbar OVF has yet to be reached due to the previous relatively small number of case series. The study was conducted to investigate surgical outcomes for osteoporotic vertebral fracture (OVF) in the thoracolumbar spine. METHODS: In total, 315 OVF patients (mean age, 74 years; 68 men and 247 women) with neurological symptoms who underwent spinal fusion with a minimum 2-year follow-up were included. The patients were divided into 5 groups by procedure: anterior spinal fusion alone (ASF group, n = 19), anterior/posterior combined fusion (APSF group, n = 27), posterior spinal fusion alone (PSF group, n = 40), PSF with 3-column osteotomy (3CO group, n = 92), and PSF with vertebroplasty (VP + PSF group, n = 137). RESULTS: Mean operation time was longer in the APSF group (p < 0.05), and intraoperative blood loss was lower in the VP + PSF group (p < 0.05). The amount of local kyphosis correction was greater in the APSF and 3CO groups (p < 0.05). Clinical outcomes were approximately equivalent among all groups. CONCLUSION: All 5 procedures resulted in acceptable neurological outcomes and functional improvement in walking ability. Moreover, they were similar with regard to complication rates, prevalence of mechanical failure related to the instrumentation, and subsequent vertebral fracture. Individual surgical techniques can be adapted to suit patient condition or severity of OVF.

Complications after spinal fixation surgery for osteoporotic vertebral collapse with neurological deficits: Japan Association of Spine Surgeons with ambition multicenter study.

BACKGROUND: There have been few reports on the incidence and risk factors of the complications after spinal fixation surgery for osteoporotic vertebral collapse (OVC) with neurological deficits. This study aimed to identify the incidence and risk factors of the complications after OVC surgery. METHODS: In this retrospective multicenter study, a total of 403 patients (314 women and 89 men; mean age 73.8 years) who underwent spinal fixation surgery for OVC with neurological deficits between 2005 and 2014 were enrolled. Data on patient demographics were collected, including age, sex, body mass index, smoking, steroid use, medical comorbidities, and surgical procedures. All postoperative complications that occurred within 6 weeks were recorded. Patients were classified into two groups, namely, complication group and no complication group, and risk factors for postoperative complications were investigated by univariate and multivariate analyses. RESULTS: Postoperative complications occurred in 57 patients (14.1%), and the most common complication was delirium (5.7%). In the univariate analysis, the complication group was found to be older (p = 0.039) and predominantly male (p = 0.049), with higher occurrence rate of liver disease (p = 0.001) and Parkinson's disease (p = 0.039) compared with the no-complication group. In the multivariate analysis, the significant independent risk factors were age (p = 0.021; odds ratio [OR] 1.051, 95% confidence interval [CI] 1.007-1.097), liver disease (p < 0.001; OR 8.993, 95% CI 2.882-28.065), and Parkinson's disease (p = 0.009; OR 3.636, 95% CI 1.378-9.599). CONCLUSIONS: Complications after spinal fixation surgery for OVC with neurological deficits occurred in 14.1%. Age, liver disease, and Parkinson's disease were demonstrated to be independent risk factors for postoperative complications.

Macrophage Infiltration Is a Causative Factor for Ligamentum Flavum Hypertrophy through the Activation of Collagen Production in Fibroblasts.

Ligamentum flavum (LF) hypertrophy causes lumbar spinal canal stenosis, leading to leg pain and disability in activities of daily living in elderly individuals. Although previous studies have been performed on LF hypertrophy, its pathomechanisms have not been fully elucidated. In this study, we demonstrated that infiltrating macrophages were a causative factor for LF hypertrophy. Induction of macrophages into the mouse LF by applying a microinjury resulted in LF hypertrophy along with collagen accumulation and fibroblasts proliferation at the injured site, which were very similar to the characteristics observed in the severely hypertrophied LF of human. However, we found that macrophage depletion by injecting clodronate-containing liposomes counteracted LF hypertrophy even with microinjury. For identification of fibroblasts in the LF, we used collagen type I α2 linked to green fluorescent protein transgenic mice and selectively isolated green fluorescent protein-positive fibroblasts from the microinjured LF using laser microdissection. A quantitative RT-PCR on laser microdissection samples revealed that the gene expression of collagen markedly increased in the fibroblasts at the injured site with infiltrating macrophages compared with the uninjured location. These results suggested that macrophage infiltration was crucial for LF hypertrophy by stimulating collagen production in fibroblasts, providing better understanding of the pathophysiology of LF hypertrophy.

The neurological outcome of radiotherapy versus surgery in patients with metastatic spinal cord compression presenting with myelopathy.

PURPOSE: While radiotherapy is generally an acceptable treatment for metastatic spinal cord compression, surgical intervention is controversial due to the invasiveness and diversity of diseases in the patients being considered. The ideal treatment, therefore, depends on the situation, and the most acute treatment possible is necessary in patients presenting with myelopathy. We compared the neurological outcomes between radiotherapy and surgery in patients with metastatic spinal cord compression presenting with myelopathy. METHODS: A total 54 patients with metastatic spinal cord compression presenting with myelopathy treated in our institution between 2006 and 2016 were analyzed retrospectively. Twenty patients were selected by radiotherapy alone (radiation group), and 36 patients were selected by decompression and stabilization surgery with or without radiotherapy (surgery group). The neurological outcomes and complications were compared between the two treatment groups. RESULTS: Seven patients initially in the radiation group underwent surgery because of a substantial decline in their motor strength during radiotherapy. One of the remaining 13 patients (8%) in the radiation group and 30 of the 34 patients (88%) in the surgery group showed improvement in their neurological symptoms (P < 0.01). One patient (8%) in the radiation group and 21 patients (62%) in the surgery group were ambulatory after treatment (P < 0.01). There were no major complications related to radiotherapy, but surgery-related complications occurred in 9 of 34 (26%) patients, and 6 (18%) patients needed reoperation. CONCLUSIONS: Surgical decompression and stabilization may be required to improve the neurological function in patients with metastatic spinal cord compression presenting with myelopathy. However, the high rate of complications associated with surgery should be taken into consideration.

Elevated expression of HSP90 and the antitumor effect of an HSP90 inhibitor via inactivation of the Akt/mTOR pathway in undifferentiated pleomorphic sarcoma.

BACKGROUND: Undifferentiated pleomorphic sarcoma (UPS) is a heterogeneous tumor group, and little is known about molecular target therapy for UPS. Heat shock protein 90 (HSP90) is an expressed chaperone that refolds certain denatured proteins under stress conditions. One of these proteins is Akt. The disruption of Akt signaling plays an important role in tumor progression. The present study's purpose was to analyze the HSP90 expression, Akt/mTOR pathway activation and the correlation between HSP90 expression and its pathway activation in UPS. METHODS: The status of HSP90 and the profiles of the Akt/ mTOR pathway were assessed by immunohistochemistry in 79 samples of UPS, and these data were compared with clinicopathological and histopathological findings. The expressions of indicated proteins were assessed by Western blotting in five frozen samples. After treating UPS cells with the HSP90 inhibitor, we assessed the antitumor effect of the inhibitor. RESULTS: Immunohistochemically, phosphorylated Akt (p-Akt), p-mTOR, p-S6RP and p-4EBP were positive in 57.3, 51.9, 54.5 and 57.1% of the UPS samples, respectively. The expressions of those phosphorylated proteins were correlated with each other. HSP90 expression was elevated in 56.4% of the samples and was correlated with p-Akt, p-mTOR and p-S6RP. The immunohistochemical results were confirmed by Western blotting. The HSP90 inhibitor led to decreased viability and invasiveness of the cells and inactivated the AKT/mTOR pathway in vitro. CONCLUSION: Elevated expression of HSP90 is a poor-prognosis factor and is involved in the activation of the Akt/mTOR pathway in UPS. HSP90 inhibition is a potential treatment option for UPS.

Scoliosis in patients with multiple hereditary exostoses.

PURPOSE: To investigate the prevalence of and to identify independent predictors associated with scoliosis in patients with multiple hereditary exostoses (MHE). METHODS: Fifty patients with MHE were clinically examined, and the diagnosis of scoliosis was made based on radiographs. To classify disease severity, three classes based on the presence of deformities and functional limitations were defined. Significant independent predictors of scoliosis in MHE were statistically analyzed. RESULTS: Scoliosis was present in 36 patients (MHE-scoliosis) (72 %). In the MHE-scoliosis group, the mean primary curve was 15.3° ± 5.7° (range 10°-34°) and the mean minor curve was 10.6° ± 7° (range 6°-32°). Left curve was predominant (72 %), and the apex was located in the thoracolumbar or lumbar spine in 64 % of patients. Univariable and multivariable analyses confirmed that MHE severity was a significant predictor of moderate scoliosis (≥20°). CONCLUSIONS: Our study confirmed that scoliosis is a common feature of MHE and disease severity is a predictor of moderate scoliosis (≥20°).

Malignant peripheral nerve sheath tumors presenting as spinal dumbbell tumors: clinical outcomes and characteristic imaging features.

PURPOSE: To investigate the clinical outcomes and imaging features of malignant peripheral nerve sheath tumors (MPNSTs) presenting as spinal dumbbell tumors. METHODS: We retrospectively reviewed the clinical outcomes and imaging features of consecutive cases of spinal dumbbell MPNSTs (n=8) and schwannomas (n=15). RESULTS: A maximal diameter>5 cm was more frequently seen in MPNSTs (88%) than in schwannomas (14%). Irregularly lobulated margins occurred frequently in MPNSTs (75%), but not in schwannomas (21%). Indistinguishable boundaries were observed in 63% of MPNSTs, but only 7% of schwannomas. Osteolytic bone destruction was found exclusively in MPNSTs (50% of MPNSTs vs. 0% of schwannomas). CONCLUSIONS: There is little clinical information relating to spinal dumbbell MPNSTs. We propose that the following imaging features are suggestive of spinal dumbbell MPNSTs: maximal diameter>5 cm, irregularly lobulated shape, boundary indistinguishable from surrounding tissues, and osteolytic bone destruction.

Intraosseous hemangioma arising in the clavicle.

Intraosseous hemangioma (IH) is commonly seen in the vertebral column and skull: however, IH occurring in the appendicular skeleton, including the clavicle, is uncommon. We herein report the case of a 69-year-old female presenting with IH of the left clavicle. The findings of preoperative imaging studies, including radiographs, computed tomography (CT), magnetic resonance imaging, fluorine-18-fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)/CT and ultrasonography, are described. In particular, (18)F-FDG PET/CT showed an ill-defined osteolytic lesion with abnormally high FDG uptake. Surgical en bloc resection with preoperative embolization was carried out and a histopathological examination confirmed the presence of an intraosseous cavernous hemangioma in the clavicle.

Dedifferentiated chondrosarcoma of the cervical spine: a case report.

Dedifferentiated chondrosarcoma (DDCS) is a rare and aggressive bone tumor with poor prognosis. Primary DDCS of the mobile spine is extremely rare, particularly in the cervical spine. We herein describe a first case of cervical DDCS in an 81-year-old male presenting with a slowly growing mass. Radiographs showed an expansion of the cortical contour of the C2 lamina and a soft tissue mass with punctate calcification. Magnetic resonance imaging demonstrated a lobulated lesion expanding over the entire lamina and pedicles of C2 with the tumor protuberant to the adjacent soft tissue. A complete tumor resection was performed. Histologically, the majority of the tumor was a low-grade chondrosarcoma component. However, atypical spindle cells that had proliferated in a fascicular pattern with a collagenous stroma, mimicking fibrosarcoma, were focally observed without a transitional zone, and these features confirmed that the tumor was DDCS.

Safety and Clinical Results of Continuous Low-Dose Aspirin in Microendoscopic Laminectomy.

Introduction: It remains controversial whether it is better to continue oral low-dose aspirin (LDA) during the perioperative period in spinal surgery. This study aims to evaluate the safety of continued LDA administration in the perioperative periods of microendoscopic laminectomy (MEL) by assessing perioperative complications and clinical outcomes. Methods: We ultimately included 88 patients (35 males, 53 females) who underwent one level of MEL for lumbar spinal canal stenosis from April 2016 to March 2022. Patients who did not undergo anticoagulation therapy were classified into Group A (65 patients), those who stopped anticoagulation therapy at the perioperative periods were classified into Group B (9 patients), and those who continued oral administration of LDA throughout the perioperative periods were classified into Group C (14 patients). Surgery time, intraoperative estimate blood loss (EBL), differences between hemoglobin (Hb) and platelet (Plt) before and after surgery, perioperative complications, and cross-sectional area of hematoma and dural sac on MRI taken within 1 week and at 6 months or more after surgery were assessed between three groups. The EuroQol-5 dimensions (EQ-5D), Oswestry Disability Index (ODI), and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were also evaluated as the clinical outcomes. Results: There was no statistically significant difference between the three groups in operation time, intraoperative EBL, differences between Hb and Plt before and after surgery, and cross-sectional area of hematoma and dural sac on MRI. A case of hematoma removal was confirmed in Group A. There was also no statistically significant difference between the three groups in EQ-5D, ODI, and each domain of JOABPEQ. Conclusions: The continuation of LDA throughout the perioperative periods did not affect perioperative complications and clinical outcomes of one-level MEL. In MEL, it might be possible to continue oral administration of LDA throughout the perioperative periods.

A Presenile Patient with Filar Lipoma Who Developed Tethered Spinal Cord Syndrome Triggered by Lumbar Canal Stenosis.

Lumbar canal stenosis (LCS) has been reported as a precipitating factor by which a tethered spinal cord, which is asymptomatic during childhood, develops into tethered cord syndrome (TCS) in adulthood. However, only a few reports on surgical strategies for such cases are available. A 64-year-old woman presented with unbearable pain in the left buttock and dorsal aspect of the thigh approximately 1 year ago. Magnetic resonance imaging showed cord tethering with a filar-type spinal lipoma and LCS due to the thickening of the ligamentum flavum at the L4-5 vertebral level. Five months after the decompressive laminectomy for the treatment of LCS, an untethering surgery was performed at the dural cul-de-sac at the S4 level. The severed end of the filum was elevated rostrally by 7 mm, and the pain subsided postoperatively. This case study shows that surgeries for both lesions should be indicated for adult-onset TCS triggered by LCS.