Proximal Junctional Failure in Adult Spinal Deformity Surgery: An In-depth Review

Mitsuru Yagi,Kento Yamanouchi,Naruhito Fujita,Haruki Funao,Shigeto Ebata 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Adult spinal deformity (ASD) surgery aims to correct abnormal spinal curvature in adults, leading to improved functionality and reduced pain. However, this surgery is associated with various complications, one of which is proximal junctional failure (PJF). PJF can have a significant impact on a patient’s quality of life, necessitating a comprehensive understanding of its causes and the development of effective management strategies. This review aims to provide an in-depth understanding of PJF in ASD surgery. PJF is a complex complication resulting from a multitude of factors including patient characteristics, surgical techniques, and postoperative management. Age, osteoporosis, overcorrection of sagittal alignment, and poor bone quality are identified as significant risk factors. The clinical implications of PJF are substantial, often requiring revision surgery and causing a considerable decrease in patients’ quality of life. Prevention strategies include careful preoperative planning, appropriate patient selection, and optimization of surgical techniques. Treatment often necessitates a multifaceted approach, including surgical intervention and the management of underlying risk factors. Predictive modeling is an emerging field that may offer a promising avenue for the risk stratification of patients and individualized preventive strategies. A thorough understanding of PJF’s pathogenesis, risk factors, and clinical implications is essential for surgeons involved in ASD surgery. Current preventive measures and treatment strategies aim to mitigate the risk and manage the complications of PJF, but the complication cannot be entirely prevented. Future research should focus on the development of more effective preventive and treatment strategies, and predictive models could be valuable in this pursuit.

Coronal Plane Gap Increases Postoperative Pseudoarthrosis after Lateral Interbody Fusion for Adult Spinal Deformity

Okada Eijiro,Yagi Mitsuru,Yamamoto Yusuke,Suzuki Satoshi,Nori Satoshi,Tsuji Osahiko,Nagoshi Narihito,Fujita Nobuyuki,Nakamura Masaya,Matsumoto Morio,Watanabe Kota 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.3

Study Design: This is a retrospective study.Purpose: This study aims to evaluate the risk factor associated with pseudoarthrosis after placement of lateral interbody fusion (LIF) cages for adult spinal deformity (ASD) treatment. Overview of Literature: LIF technique is widely used for ASD correction. Furthermore, pseudoarthrosis is a major complication of fusion surgery required for revision surgery.Methods: This study included 42 patients with ASD (two men and 40 women; 112 segments; mean, 68.5±8.4 years; and mean follow-up, 31.6±17.0 months) who underwent LIF and posterior correction surgery. The concave slot of the LIF cage was filled with an autologous iliac crest bone graft (IBG), and the convex slot with a porous hydroxyapatite/collagen (HAp/Col) composite was soaked with bone marrow aspirate. Endplate injury, the gap between vertebral endplate and cage in the coronal or sagittal plane, and fusion status were evaluated using computed tomography multiplanar reconstruction at 12 months after surgery. Moreover, the associated risk factors for pseudoarthrosis were analyzed.Results: Fusion at LIF segments were observed in 71.4% segments at 12 months after surgery. Fusion on the concave slot (autologous IBG side), convex slot (porous HAp/Col composite side), and both concave and convex slots were observed in 66.1%, 37.5%, and 36.6% of patients, respectively. Moreover, pseudoarthrosis was observed in 28.6% at 12 months after surgery. Consequently, logistic regression analysis of the fusion at the LIF segment revealed that the gap between the LIF cage and endplate in the coronal plane (p=0.030; odds ratio, 0.183; 95% confidence interval, 0.030–0.183) was significantly associated with pseudoarthrosis at the LIF segments.Conclusions: ASD surgery fusion rate using LIF cages was 71.4% at 12 months after surgery. The fusion rate was higher on the concave slot filled with autologous IBG than on the convex slot filled with a porous HAp/Col composite. The gap in the coronal plane was a risk factor for pseudoarthrosis at the LIF segment.

Soft Modes in SrTi18O3 Studied by Light Scattering and Dielectric Measurements

Yohei Nakata,Mika Kobayashi,Mitsuru Itoh,Ruiping Wang,Toshirou Yagi,Yuhji Tsujimi 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.1

Light-scattering and dielectric easurements have been carried out, mainly in SrTi18O3, to clarify the physical origin of the two modes (Eu1 and Eu2) which were supposed to originate from a doubly degenerated ferroelectric Eu soft mode. The combined results of both measurements strongly suggest that the Eu1 and Eu2 modes correspond to the polarization uctuation parallel to the spontaneous polarization Ps (the mode of A1 symmetry) and to that perpendicular to Ps (the mode of B2 symmetry), respectively.

Growth of Ferroelectric Micro Region in SrTiO3 and SrTi(18O0.23 16O0.77)3 Studied by Raman Scattering

Hiroki Taniguchi,Masaki Takesada,Mitsuru Itoh,Toshirou Yagi 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.1

The oxygen-isotope exchange eect on the ferroelectric micro-regions (FMR) in SrTiO3 is investigated by Raman scattering in the low-temperature region near 1 K by using a 3He cryostat. With decreasing temperature, the intensity of the FMR spectra decreases and a sharp peak newly appears with increasing intensity. The sharp peak is assigned to be the polar Eu mode activated by local symmetry breaking induced by the growth of FMR.

Hyper-Raman scattering of SrTi18O3

Yusuke Minaki,Yuhji Tsujimi,Makoto Nakanishi,Mika Kobayashi,Mitsuru Itoh,Ruiping Wang,Toshirou Yagi 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.IV

Hyper-Raman scattering experiment has been performed in the SrTi(18Ox 16O1..x)3 single crystal plate with x = 0:87. Raman inactive ferroelectric Eu Slater mode is directly detected in the tetragonal phase. The mode clearly shows a softening behavior and seems to cause the ferroelectric transition at Tc = 26 1 K.

Surgical and Functional Outcomes of Expansive Open-Door Laminoplasty for Patients With Mild Kyphotic Cervical Alignment

Narihito Nagoshi,Satoshi Nori,Osahiko Tsuji,Satoshi Suzuki,Eijiro Okada,Mitsuru Yagi,Masaya Nakamura,Morio Matsumoto,Kota Watanabe 대한척추신경외과학회 2021 Neurospine Vol.18 No.4

Objective: To evaluate the cervical dynamics, neurological function, pain, and quality of life in patients with mild cervical kyphotic alignment who underwent expansive unilateral open-door laminoplasty (ELAP). Methods: In this retrospective single-center study, we reviewed the surgical outcomes of 80 patients with cervical spondylotic myelopathy who were followed for at least 2 years. The patients were categorized into the preoperative kyphotic group (C2–7 angle <0°) and nonkyphotic group (angle ≥0°). We compared clinical information, radiographic parameters, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) scores, and cervical Japanese Orthopaedic Association (JOA) scores between the groups. Results: The kyphotic and nonkyphotic groups comprised 17 and 63 patients, respectively. The preoperative C2–7 angles were -3.7° in the kyphotic group and 15.4° in the nonkyphotic group (p<0.01). In the kyphotic group, kyphotic alignment improved to lordosis at the final follow-up (2.6°, p=0.01). The preoperative (16.4° vs. 24.1°, p<0.01) and final-follow-up (17.8° vs. 24.5°, p<0.01) C7 slopes were significantly smaller in the kyphotic group. ELAP reduced pain in the arms or hands (p=0.02) and improved the JOA scores (p<0.01) in the kyphotic group. Patient-reported outcomes assessed using the JOACMEQ showed comparable effective rates in both groups. Conclusion: Patients with mild cervical kyphosis showed smaller C7 slopes as a compensatory mechanism. Kyphotic angles significantly improved to lordosis after ELAP, resulting in favorable clinical outcomes. ELAP is a useful surgical option for patients even if they present mild kyphotic cervical angles.

Remnant Tumor Margin as Predictive Factor for Its Growth After Incomplete Resection of Cervical Dumbbell-Shaped Schwannomas

Kazuya Kitamura,Narihito Nagoshi,Osahiko Tsuji,Satoshi Suzuki,Satoshi Nori,Eijiro Okada,Mitsuru Yagi,Morio Matsumoto,Masaya Nakamura,Kota Watanabe 대한척추신경외과학회 2022 Neurospine Vol.19 No.1

Objective: The purpose of our study was to investigate the risk factors of remnant tumor growth after incomplete resection (IR) of cervical dumbbell-shaped schwannomas (DS). Methods: Twenty-one patients with IR of cervical DS with at least 2 years of follow-up were included and were divided into 2 groups: the remnant tumor growth (G) (n = 10) and no growth (NG) (n = 11) groups. The tumor location in the axial plane according to Toyama classification, the location of the remnant tumor margin, and the tumor growth rate (MIB1 index) index were compared. Results: No significant differences in Toyama classification and MIB-1 index were found. Age was significantly higher in the G group (61.4 years vs. 47.6 years; p = 0.030), but univariate logistic regression analysis revealed little correlation to the growth (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.001–1.166; p = 0.047). Seventeen patients (9 in the G and 8 in the NG group) underwent the posterior one-way approach, and significant differences in the location of the remnant tumor margin were confirmed: within the spinal canal in 1 and 0 case, at the entrance of the intervertebral foramen in 7 and 1 cases, and in the foramen distal from the entrance in 1 and 7 cases, in the G and NG groups, respectively (p = 0.007). The proximal margin was identified as a significant predictor of the growth (OR, 56.0; 95% CI, 2.93–1,072; p = 0.008). Conclusion: Remnant tumors with margins distally away from the entrance of the foramen were less likely to grow after IR of cervical DS.

Effectiveness of Duloxetine for Postsurgical Chronic Neuropathic Disorders after Spine and Spinal Cord Surgery

Tsuji Osahiio,Kosugi Shizuko,Suzuki Satoshi,Nori Satoshi,Nagoshi Narihito,Okada Eijiro,Fujita Nobuyuki,Yagi Mitsuru,Nakamura Masaya,Matsumoto Morio,Watanabe Kota 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.5

Study Design: This is a retrospective observational study with an outpatient setting. Purpose: This study aimed to describe the effects of duloxetine (DLX) administration for postsurgical chronic neuropathic disorders (both pain and numbness) following spinal surgery in patients without depression. Overview of Literature: Although several reports indicated the potential of DLX to effectively treat postoperative symptoms as a perioperative intervention, there have been no reports of its positive effect on postsurgical chronic neuropathic disorders. Methods: A total of 24 patients with postsurgical chronic pain and/or numbness Numeric Rating Scale (NRS) scores of ≥4 were enrolled. All patients underwent spine or spinal cord surgery at Keio University Hospital and received daily administration of DLX for more than 3 months. The mean postoperative period before the first administration of DLX was 35.5±57.0 months. DLX was administered for more than 3 months at a dose of 20, 40, or 60 mg/day, and the degree of pain and numbness was evaluated using the NRS before administration and 3 months after administration. Effectiveness was defined as more than a 2-point decrease in the NRS score following administration. Results: In terms of the type of symptoms, 15 patients experienced only numbness, eight experienced both pain and numbness, and one experienced only pain. Of the 24 patients, 19 achieved effective relief with DLX. DLX was effective for all patients with postsurgical chronic pain (n=9), and it reduced postsurgical chronic numbness in 18 of 23 patients. No significant difference was observed in background spinal disorders. DLX was not effective for five patients who complained only of postsurgical chronic numbness. Conclusions: This study reports the effectiveness of DLX for postsurgical chronic neuropathic disorders. Although DLX reduced postsurgical chronic pain (efficacy rate=100%) and numbness (78.3%) in certain patients, further investigation is needed to determine its optimal use.

Metabolic Syndrome is a Predisposing Factor for Diffuse Idiopathic Skeletal Hyperostosis

Eijiro Okada,Shinichi Ishihara,Koichiro Azuma,Takehiro Michikawa,Satoshi Suzuki,Osahiko Tsuji,Satoshi Nori,Narihito Nagoshi,Mitsuru Yagi,Michiyo Takayama,Takashi Tsuji,Nobuyuki Fujita,Masaya Nakamura 대한척추신경외과학회 2021 Neurospine Vol.18 No.1

Objective: Diffuse idiopathic skeletal hyperostosis (DISH) causes spinal ankylosis, which can result in patients suffering specific spinal fractures that lead to a reduction in the activities of daily life in older patients. Currently, DISH is associated with diabetes mellitus and cardiovascular disease; however, the association between DISH and metabolic syndrome has not been established. The purpose of this study was to investigate a potential association between DISH and metabolic syndrome. Methods: We retrospectively reviewed clinical data from consecutive subjects undergoing the musculoskeletal health medical checkups, and enrolled 327 subjects (174 men and 153 women; mean, 63.4±13.7-years). Subjects who had spinal ankylosis at least 4 contiguous vertebral bodies were classified as the DISH group (n=39) while the others were part of the non-DISH group (n=288). The definition of the metabolic syndrome comes from diagnostic criteria used by the Japanese Society for Internal Medicine. Age, sex, body max index (BMI), hematological evaluation, blood pressure, presence of metabolic syndrome, the visceral fat area on abdominal computed tomography, and spinal epidural lipomatosis (SEL) on magnetic resonance imaging were evaluated. Results: Compared to the non-DISH group, in the DISH group, mean age (DISH group, 74.3 years; non-DISH group, 1.9 years; p<0.001), male prevalence were higher (DISH group, 82.1%; non-DISH group, 49.3%; p<0.001), and BMI was greater (DISH group, 24.8; non-DISH group, 23.0; p=0.006). the metabolic syndrome was more frequently observed in DISH group (28.9%) than in the non-DISH group (16.0%) (p=0.045). The visceral fat area was significantly larger in the DISH group than in the non-DISH group (DISH group, 130.7±58.2 cm2; Non-DISH group, 89.0±48.1 cm2; p<0.001). The prevalence of SEL was similar between the 2 groups (10.3% in the DISH group vs. 8.7% in the non-DISH group; p=0.464). Poisson regression analysis revealed that the metabolic syndrome was significantly associated with DISH with odds ratio of 2.0 (95% confidence interval, 1.0–3.7; p=0.004). Conclusion: Metabolic syndrome was significantly associated with DISH. Our data showed metabolic syndrome is potentially related to DISH.

Poor Prognostic Factors for Surgical Treatment of Spinal Intramedullary Ependymoma (World Health Organization Grade II)

Tsuji Osahiko,Nagoshi Narihito,Ishii Ryota,Nori Satoshi,Suzuki Satoshi,Okada Eijiro,Fujita Nobuyuki,Yagi Mitsuru,Matsumoto Morio,Nakamura Masaya,Watanabe Kota 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.6

Study Design: Single-center retrospective study.Purpose: We aimed to explore the postoperative prognostic factors for spinal intramedullary ependymoma.Overview of Literature: Ependymoma (World Health Organization grade II) is the most frequent intramedullary spinal tumor and is treated by total resection. However, postoperative deterioration of motor function occasionally occurs.Methods: Eighty patients who underwent surgical resection at Keio University and Fujita Health University in Tokyo, Japan between 2003 and 2015 with more than 2 years of follow-up were enrolled. A good surgical result was defined as an improvement in the modified McCormick Scale score by one grade or more or having the same clinical grade as was observed preoperatively. Meanwhile, a poor result was defined as a reduction in the McCormick Scale score of one grade or more or remaining in grade IV or V at final follow-up. Univariate and multivariate logistic regression analyses of the following factors were performed in the two groups: sex, age, preoperative Visual Analog Scale (VAS), tumor location, the extent of tumor resection, hemosiderin caps, cavity length, and tumor length on magnetic resonance imaging.Results: At final follow-up, 15 patients were included in the poor results group and 65 in the good results group. In the univariate analysis, the factors related to poor results were as follows: higher age, preoperative McCormick Scale score severity, higher preoperative VAS, thoracic location, hemosiderin capped, and non-gross total resection (GTR). A multiple logistic regression analysis was conducted and showed that age, worse preoperative McCormick Scale score, and non-GTR were significant factors for poor prognosis.Conclusions: The independent risk factors for motor deterioration after ependymoma resection were age, worse preoperative McCormick Scale score, and non-GTR. Early surgery for patients with even mild neurological disorders could facilitate functional outcomes. These results may contribute to determining the optimal timing of surgery for spinal intramedullary ependymoma.