Spine Surgery and Related Research
Online ISSN : 2432-261X
ISSN-L : 2432-261X
Advance online publication
Showing 1-48 articles out of 48 articles from Advance online publication
  • Shunsuke Kanbara, Kei Ando, Kazuyoshi Kobayashi, Hiroaki Nakashima, Ma ...
    Article ID: 2021-0010
    Published: 2021
    [Advance publication] Released: April 28, 2021
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  • George Fagundes Firmino, Milena Luisa Schulze, Marco Antônio Machado S ...
    Article ID: 2021-0014
    Published: 2021
    [Advance publication] Released: April 28, 2021
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    The present academic work aims to contribute to an early diagnosis of neuralgic amyotrophy (NA) because of its high prevalence in the population. This disease is a neuromuscular syndrome with unclear etiology; it affects mostly the brachial plexus, causing acute pain in the affected shoulder, paralysis, and disabilities. Considering the importance of an early treatment that can modify the prognosis of the patient, knowing the last updates about the syndrome as its clinical presentation is important. Data analysis was conducted through an online non-systematic review that indicated the epidemiology, pathophysiology, and differential diagnosis and prognosis of NA. Knowledge of the clinical features of NA is not common; however, it is important in orthopedic practice because it requires differentiation from spine pathologies.

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  • Lukas Urbanschitz, Susanne Bensler, Sascha Merat, Christopher G. Lenz, ...
    Article ID: 2021-0048
    Published: 2021
    [Advance publication] Released: April 28, 2021
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    INTRODUCTION

    Despite being originally developed for the evaluation of lumbar disk degeneration, the Pfirrmann classification has emerged as the most popular classification system for cervical disk degeneration. However, with the Suzuki classification, a new classification system that is specifically tailored for the evaluation of cervical disk disease was introduced. In this study, we aim to evaluate differences in inter- and intraobserver reliability of both classifications in a head-to-head comparison.

    METHODS

    In total, we have evaluated 120 cervical disks within 40 patients via magnetic resonance imaging according to the Pfirrmann and Suzuki classification. The degree of disk degeneration was evaluated by two independent musculoskeletal radiologists. After 6 months, the classification was reassessed to evaluate the intraobserver reliability. The inter- and intraobserver reliabilities were then calculated using Cohen's kappa.

    RESULTS

    The inter- and intraobserver reliability provided a significant agreement between all ratings in Pfirrmann as well as the Suzuki classification (p > 0,001). The interobserver reliability was determined to be fair in both the Suzuki classification (κ = 0,290) and the Pfirrmann classification (κ = 0,265). The intraobserver reliability was substantial in the Suzuki classification (κ = 0,798), while it was almost perfect in the Pfirrmann classification (κ = 0,858).

    CONCLUSION

    Although not designed for the evaluation of cervical disk degeneration, the Pfirrmann classification yielded equal inter- and higher intraobserver reliability. Both classification systems are viable options for the grading of cervical disk degeneration. While the Pfirrmann classification has the advantage of being better established, the Suzuki classification may be clinically superior due to a better representation of cervical disk degeneration and the consideration of disk bulging for the classification of cervical disk degeneration.

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  • Shuhei Ohyama, Yasuchika Aoki, Masahiro Inoue, Takayuki Nakajima, Yusu ...
    Article ID: 2020-0195
    Published: 2021
    [Advance publication] Released: February 22, 2021
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    Introduction

    Preoperative factors that predict postoperative restoration of lumbar lordosis (LL) are not well understood. To investigate whether preoperative postural correction of LL, sagittal malalignment, or lumbar flexibility are associated with the postoperative restoration of LL in patients treated with a single-level transforaminal lumbar interbody fusion (TLIF), a retrospective cohort study was conducted.

    Methods

    We enrolled 104 patients (mean age: 67.5 ± 10.7 years old; 47 men and 57 women) with lumbar degenerative diseases treated with a single-level TLIF. The pre- and postoperative LL were examined using lateral radiographs in the standing position and computed tomography (CT) images in the supine position. The correlation between postoperative LL restoration and preoperative postural correction of LL (difference in LL between the standing and supine positions: D-LL), sagittal imbalance (pelvic incidence minus LL: PI-LL), and lumbar flexibility (difference in LL between the flexion and extension postures) were analyzed. Patients were divided into two groups according to the D-LL (D-LL ≥ 0° and D-LL < 0°). The rates of postoperative LL restoration (postoperative LL–preoperative LL in standing) were compared between the two groups.

    Results

    Multiple regression analysis performed after adjustment for age, gender, body mass index, and cage angle revealed that postoperative LL restoration was significantly correlated with D-LL (p < 0.001), but not with PI-LL, and lumbar flexibility. Patients with a preoperative D-LL ≥ 0° showed a significantly greater increase of LL after TLIF (7.1° ± 11.2°) than those with D-LL < 0° (1.4° ± 6.6°) (p = 0.003).

    Conclusions

    A preoperative evaluation of a lateral radiograph or CT taken in the supine position is useful in predicting postoperative improvement of sagittal alignment. Postoperative improvement of sagittal spinopelvic alignment would be expected when LL is corrected in the supine position preoperatively. Surgeons should pay attention to the postural correction of LL when performing short-segment fusion surgery for lumbar degenerative disease with sagittal malalignment.

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  • Kazuhiro Inomata, Yoichi Iizuka, Hiromi Koshi, Eiji Takasawa, Tokue Mi ...
    Article ID: 2020-0219
    Published: 2021
    [Advance publication] Released: April 14, 2021
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  • Katsuhisa Yamada, Ken Nagahama, Yuichiro Abe, Eihiro Murota, Shigeto H ...
    Article ID: 2020-0232
    Published: 2021
    [Advance publication] Released: April 14, 2021
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    Introduction: A percutaneous endoscopic transforaminal lumbar interbody fusion (PETLIF) procedure has been previously developed. During postoperative follow-up, in some patients, bone fusion occurred between opened facet joints, despite not having bone grafting in the facet joints. Here, we investigated facet fusion's frequency and tendencies following PETLIF.

    Methods: A retrospective analysis was conducted on a prospectively collected, nonrandomized series of patients. Forty-two patients (6 males and 36 females, average age: 69.9 years) who underwent single-level PETLIF at our hospital from February 2016 to March 2019 were included in this study. Patients were assessed with lumbar X-ray images and computed tomography (CT) prior to, immediately after, and 1 year after surgery.

    Results: Pseudarthrosis was not observed in any patients, and facet fusion was observed in 26 of 42 post-PETLIF patients (61.9%) by CT 1 year postoperatively. The average interfacet distance increased from 1.3 mm preoperatively to 4.5 mm postoperatively, and facet fusion was observed under the opened conditions of 3.8 mm at 1 year. Segmental lordotic angle of the fusion segment in the lumbar X-ray images was significantly larger in the facet fusion subgroup prior to surgery, immediately following surgery, and 1 year after surgery compared to the facet non-fusion group (p = 0.02, p < 0.01, p = 0.01, respectively). There were no significant differences in patient background, correction loss of segmental lordosis, interfacet distance, or clinical score between the facet fusion and facet non-fusion subgroups.

    Conclusions: Facet fusion was achieved over time within the facet joints that were opened through indirect decompression after PETLIF. We hypothesized that the preserved facet joints potentially became the base bed for spontaneous bone fusion due to the preserved facet joint capsule and surrounding soft tissue, which maintained cranio-caudal facet traffic and blood circulation in the facet joints. The complete preservation of the facet joints was a key advantage of minimally invasive lumbar interbody fusion procedures.

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  • Ken Ishii, Norihiro Isogai, Kenshi Daimon, Tomoharu Tanaka, Yoshifumi ...
    Article ID: 2021-0015
    Published: 2021
    [Advance publication] Released: April 14, 2021
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    Introduction: In 2018, the first Mobi-C® total disk replacement (TDR) case was performed in Japan. In this study, we examined the preliminary clinical outcome of Mobi-C® for degenerative cervical spine disease.

    Methods: We examined 24 consecutive patients who underwent 1-level TDR after 2018 and followed up for more than 6 months after surgery. The evaluation criteria included age, gender, diagnosis, follow-up period, surgical level, implant size, surgery time, intraoperative bleeding volume, complications, revision surgery, imaging findings, JOA score, and various questionnaires.

    Results: The mean age was 52.7 years, 13 males and 11 females. There were 15 cases of cervical disk herniation and 9 cases of cervical spondylosis. The mean follow-up period was 17.4 months. Surgical levels were C3/4 in 4 cases, C4/5 in 2 cases, C5/6 in 16 cases, and C6/7 in 2 cases. The mean operation time was 138.5 minutes, the amount of intraoperative bleeding was 32.1 ml, and there were no serious intraoperative complications. The range of motion of the affected level increased significantly, from 6.6 degrees preoperatively to 12.2 degrees at final follow-up. No patients required revision surgery at final follow-up, and there were no cases of heterotopic ossification or adjacent segment disease. One patient exhibited radiculopathy due to mild subsidence 1 year after surgery, and 1 had asymptomatic contact of device plates. Preoperative and final JOA scores improved from 11.7 to 15.8 points, and NRS improved from 4.3 to 1.3 points for neck pain and 4.3 to 1.7 points for arm pain. Preoperative and final NDI improved from 39.7% to 14.0%, and EQ-5D improved from 0.602 to 0.801.

    Conclusions: The short-term treatment outcomes of Mobi-C® TDR were generally favorable. Spine surgeons should comply with guidelines when introducing this procedure and strive to adopt this new technology in Japan.

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  • Tetsuya Tamaki, Muneharu Ando, Yukihiro Nakagawa, Hiroshi Iwasaki, Shu ...
    Article ID: 2020-0194
    Published: 2021
    [Advance publication] Released: March 10, 2021
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    An intraoperative functional spinal cord monitoring system is a technology used by spine and spinal cord surgeons to perform a safe surgery and to gain further surgical proficiency. However, no existing clinical neurophysiological method used in the operating room can monitor all complex spinal cord functions. Therefore, by observing the activities of certain neural action potentials transferred via limited neural tissues, surgeons need to deductively estimate the function of the whole spinal cord. Thus, as the number of spinal cord functions that need to be observed increases, spinal cord monitoring can be more reliable. However, in some situations, critical decision-making is affected by the limited capability of these methods. Nevertheless, good teamwork enables sharing of seamless information within the team composed of a surgeon, anesthesiologist, monitoring technician and nurses greatly contributes to making quick and accurate decisions. The surgeon, who is the person in charge of the team, should communicate with multidisciplinary team members using common technical terms. For this reason, spine and spinal cord surgeons must have appropriate knowledge of the methods currently used, especially of their utility and limitations. To date, at least six electrophysiological methods are available for clinical utilization: three are used to monitor sensory-related tracts, and three are used to monitor motor-related spinal cord functions. If surgeons perform electrode setting, utilizing their expertise, then the range of available methods is broadened, and more meticulous intraoperative functional spinal cord monitoring can be carried out. Furthermore, if the team members share information effectively by utilizing a clinically feasible judicious checklist or tools, then spinal cord monitoring will be more reliable.

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  • Shiro Sugiura, Yasuchika Aoki, Takeshi Toyooka, Tetsuo Shiga, Takato O ...
    Article ID: 2020-0199
    Published: 2021
    [Advance publication] Released: March 10, 2021
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    Introduction

    This study aimed to elucidate low-back pain (LBP) characteristics, i.e., its qualities, extent, and location, in patients with early-stage spondylolysis (ESS).

    Methods

    We recruited patients (≤18 years old) who presented with acute LBP lasting up to 1 month. Patients were divided into ESS and nonspecific LBP (NS-LBP) groups based on their magnetic resonance imaging findings; patients showing no pathological findings that might explain the cause of LBP were classified as NS-LBP. All patients were evaluated using the following tests: hyperextension and hyperflexion (pain provocation tests in a standing position), pain quality (sharp/dull), pain extent (fingertip-sized area/palm-sized area), and pain location (left and/or right pain in side [side]/central pain [center]). We have also compared outcomes between the ESS and NS-LBP groups in terms of gender and physical symptoms.

    Results

    Of 101 patients, 53 were determined to have ESS (ESS group: mean age: 14.3 years old; 43 males/10 females), whereas 48 had no pathological findings explaining the LBP origin [NS-LBP group (mean age, 14.4 years old; 31 males/17 females) ]. Chi-squared test has identified gender (male), a negative result on hyperflexion test, pain extent (fingertip-sized area), and pain location (side) to be significantly associated with ESS. Among these, regression analysis revealed that male gender and LBP located on the side were significantly associated with ESS (p < 0.05).

    Conclusions

    Although the hyperextension test is generally considered useful for ESS, we demonstrated that its association is not deemed significant. Our results indicate that male gender, a negative result of the hyperflexion test, fingertip-sized pain area, and LBP on the side may be specific characteristics of ESS. Of these physical signs, male gender and LBP located on the side are characteristic factors suggesting ESS presence.

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  • Keitaro Matsukawa, Yuichiro Abe, Ralph Jasper Mobbs
    Article ID: 2020-0221
    Published: 2021
    [Advance publication] Released: March 10, 2021
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    Introduction:

    The sacral-alar-iliac (SAI) screw technique is becoming popular for sacropelvic fixation. However, appropriately placing SAI screws is technically demanding because of a narrow safe corridor and the risk of neurovascular/visceral injuries. Recently, a three-dimensional patient-specific template guiding technique for pedicle screw placement has been considered a promising method to improve accuracy and safety. The objective of the present study was to investigate the accuracy of SAI screw placement with a patient-specific template guide using cadaveric and prospective clinical pilot studies.

    Methods:

    Three-dimensional planning of SAI screw placement, including entry point, screw trajectory, length, and diameter, was performed using a computer simulation software. Then, three-dimensional printed patient-specific template guides were created based on the plan. Firstly, a total of 12 SAI screws were placed for 6 cadaveric specimens using the guides. Next, in a prospective clinical trial, a total of 20 SAI screws were placed for 10 consecutively enrolled patients. The safety and accuracy of screw placement were analyzed using postoperative computed tomography by the evaluation of any cortical breach and measurement of screw deviations between the planned and actual screw positions.

    Results:

    All the screws showed no perforation. In the cadaveric study, the mean horizontal and vertical deviations from the planned screw position at the entry point were 1.40 ± 1.21 mm and 1.34 ± 1.09 mm, respectively. The mean angular deviations in the sagittal and transverse planes were 1.68° ± 1.24° and 1.53° ± 1.06°, respectively. The results of the clinical study showed comparable accuracy with those of the cadaveric study, except for the vertical deviation at the entry point (p = 0.048).

    Conclusions:

    This is the first study to evaluate the feasibility and accuracy of using a patient-specific template guide for SAI screw placement. This technique could become an effective solution to achieve accurate screw placement.

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  • Shinji Takahashi, Etsuji Sohgawa, Akinobu Suzuki, Akira Yamamoto, Ryo ...
    Article ID: 2021-0011
    Published: 2021
    [Advance publication] Released: March 10, 2021
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  • Noriyuki Iesato, Kousuke Iba, Mitsunori Yoshimoto, Hidenori Otsubo, To ...
    Article ID: 2020-0165
    Published: 2021
    [Advance publication] Released: February 22, 2021
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    Introduction: Lumbar spondylolysis is usually single level, and only a few multiple-level cases have been reported. We investigated the frequency of multiple-level spondylolysis and the bone union rates among growth-stage children with lower back pain (LBP).

    Methods: The subjects were growth-stage children examined for LBP between April 2013 and December 2018. All patients with LBP persisting for at least 2 weeks and severe enough to make playing sports difficult underwent lumbar plain radiogram, computed tomography, and magnetic resonance imaging. The cases diagnosed as multiple-level spondylolysis and classified as early or progressive stage received conservative treatment to achieve bone union.

    Results: A total of 782 growth-stage children were examined for LBP. Of them, 243 children (31.1%) were diagnosed with lumbar spondylolysis. Of these 243 children, 23 (9.5%) children had multiple-level spondylolysis. Of the children diagnosed with multiple-level spondylolysis, most children (87.0%) had pars defects in the early or progressive stage in which bone union could be expected. Most children (78.3%) had pars defects in the terminal stage and combined with these defects, had pars defects in the early or progressive stage at a different spinal level.

    Twenty children diagnosed with multiple-level spondylolysis who also had pars defects in the early or progressive stage received conservative treatment for bone union, which was achieved in 31 of 39 sites (79.5%). The bone union rate by stage was 92.9% (26 of 28 sites) in the early stage and 45.5% (5 of 11 sites) in the progressive stage.

    Conclusions: In cases of multiple-level spondylolysis, bone union is likely to be achieved with conservative treatment when the pars defects are in the early or progressive stage. Therefore, the first choice of treatment should be conservative treatment to achieve bone union, the same for single-level spondylolysis.

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  • Hiroaki Nakashima, Tokumi Kanemura, Kotaro Satake, Kenyu Ito, Satoshi ...
    Article ID: 2020-0191
    Published: 2021
    [Advance publication] Released: February 22, 2021
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    Introduction: Lateral corpectomy has been considered a minimally invasive surgery, allowing a "transdiaphragmatic approach" at the thoracolumbar junction. This approach allows for a small diaphragmatic incision directly in the retroperitoneal space and the affected vertebra. However, its effectiveness in comparison to a conventional approach remains unclear. Thus, in this present study, we compared the surgical outcomes between conventional diaphragmatic detachment and the transdiaphragmatic approach in patients with vertebral fracture at the thoracolumbar junction.

    Methods: In total, 31 patients with a vertebral fracture at the thoracolumbar junction (T12–L2) were included in this study: 17 underwent a conventional approach, whereas 14 underwent a transdiaphragmatic approach, with a minimum 2-year follow-up. The effectiveness of surgery was evaluated in each category of the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ).

    Results: Operative time and estimated blood loss were determined to be significantly shorter in the transdiaphragmatic than in the conventional approach. Perioperative complications were observed in the conventional approach (one atelectasis and one pleural effusion), while no complication was noted in the transdiaphragmatic approach. There were no significant differences in postoperative quality of life as assessed by JOABPEQ in terms of pain-related disorders, lumbar spine dysfunction, gait disturbance, social life dysfunction, or psychological disorders between the conventional and transdiaphragmatic approaches.

    Conclusions: A "transdiaphragmatic approach" using lateral access surgery has been found to be associated with a shorter operative time and less blood loss with fewer complications than the conventional approach. Given that equivalent clinical outcomes were achieved in both conventional and transdiaphragmatic approaches, this "transdiaphragmatic approach" could be useful because of its minimal invasiveness.

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  • Masashi Sato, Yasuhiro Shiga, Naoya Takayama, Masamitsu Sone, Kentaro ...
    Article ID: 2020-0226
    Published: 2021
    [Advance publication] Released: February 22, 2021
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    Introduction: Platelet-rich plasma (PRP) is drawing attention as a substance that can promote bone formation. The growth factors present in PRP are stable for a long time after freeze-drying. However, the effects of PRP are inconsistent, and its effects on bone union in spinal surgery remain controversial. The immortalized megakaryocyte cell lines (imMKCLs) derived from human-induced pluripotent stem cells (hiPSCs) have been developed to produce numerous stable and clinically functional platelets. In this study, growth factors present in freeze-dried hiPSC-derived imMKCLs and platelets (iPS-MK/Plts) were evaluated, and their ability to promote bone formation was examined using a rat lumbar artificial bone grafting model.

    Methods: We prepared freeze-dried iPS-MK/Plts and quantified their growth factors by enzyme-linked immunosorbent assays. Surgical grafting of artificial bone to the lumbar transverse processes was performed in 8-week-old female rats, which were divided into two groups: artificial bone graft (control) and artificial bone graft plus freeze-dried iPS-MK/Plts (iPS group). Transplantation was performed only on the left side. Eight weeks after the surgery, we captured computed tomography images and compared bilateral differences in the bone volume of the graft site in each rat. We also compared the left side/right side bone volume ratio between the two groups.

    Results: The freeze-dried iPS-MK/Plts contained numerous growth factors. While there was no significant increase in bone volume on the transplanted side than that on the non-grafted side in the control group, bone volume significantly increased on the transplanted side in the iPS group, as evidenced by augmented mean left/right bone volume ratio of the iPS group compared with that of the control group. But the new bone observed in the iPS group was histologically normal.

    Conclusions: Freeze-dried hiPSC-derived MKCLs and platelets contain several stable growth factors and have the potential for promoting new bone formation.

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  • Motoya Kobayashi, Yasumitsu Toribatake, Shunpei Okamoto, Satoshi Kato, ...
    Article ID: 2020-0019
    Published: 2021
    [Advance publication] Released: February 09, 2021
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    Introduction:

    Balloon kyphoplasty (BKP) is one of the most frequently used clinical methods to relieve pain caused by osteoporotic vertebral compression fracture (OVCF); it can effectively improve the body height of the vertebra. However, recompression of the augmented vertebra (RAV) is often observed after BKP. This study aimed to report factors that are associated with RAV in terms of cement augmentation.

    Methods:

    A total of 78 patients (women, 60; men, 18) were included in this study. RAV was defined as anterior vertebral height loss (VHL), between immediate postoperation and 3 or 6 months after BKP, of more than 5.0 mm. Cement augmentation ratio (CAR) was calculated as the ratio of the maximal height of polymethylmethacrylate (PMMA) to the maximal distance between both end plates. Age, gender, fracture age, CAR, presence of medication for osteoporosis, intervertebral cleft (IVC), and cement leakage were evaluated using Fisher' s exact test or Mann-Whitney U test to compare between RAV and non-RAV groups. Aforementioned variables were also analyzed using multiple logistic regression test. A P<0.05 was considered statistically significant.

    Results:

    The incidence rates for RAV at 3 and 6 months were 35.9% (28/78) and 38.5% (30/78), respectively. Age (80.1 vs 74.7) was significantly higher in the RAV group, whereas CAR (69.4% vs 77.6%) was lower in the non-RAV group. A multivariate regression analysis revealed that age (odds ratio (OR) =1.12, P=0.001) and CAR (OR=0.91, P=0.001) were independently associated with RAV.

    Conclusions:

    RAV was observed in 38.5% of patients in this study. Older age and low CAR were independently associated with RAV. To prevent RAV, especially in the elderly, augmented PMMA should come in contact with both end plates.

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  • Masaru Tanaka, Masahiro Kanayama, Tomoyuki Hashimoto, Fumihiro Oha, Yu ...
    Article ID: 2020-0203
    Published: 2021
    [Advance publication] Released: February 09, 2021
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    Introduction

    Osteoplastic hemilaminectomy for the treatment of lumbar foraminal nerve root compression is a safe technique as the exiting nerve root can be directly observed during neuroforaminal decompression without spinal fusion. Moreover, this procedure allows anatomical reconstruction of the posterior elements. However, there might be a potential risk for the progression of lumbar segmental instability after performing this procedure. This study aimed to review the radiographic and clinical outcomes of osteoplastic hemilaminectomy for the treatment of lumbar foraminal nerve root compression.

    Methods

    We retrospectively reviewed 51 patients who underwent osteoplastic hemilaminectomy with a minimum follow-up of 2 years. The clinical outcomes were evaluated using the visual analog scale (VAS) for low back pain, leg pain, and numbness and the Japanese Orthopaedic Association (JOA) score. Lumbar segmental instability was evaluated as a radiographic assessment using functional radiography. The mean follow-up period was 65 months.

    Results

    The preoperative VASs for low back pain, leg pain, and numbness were 46 ± 31, 72 ± 26, and 43 ± 34, respectively, which were improved to 24 ± 23, 19 ± 23, and 19 ± 23, respectively. The JOA score was also improved from 14 ± 5 to 22 ± 4. Three patients (5.9%) were reoperated due to recurrent disc herniation within 2 years following surgery. In addition, three patients (5.9%) developed postoperative lumbar segmental instability but did not require additional surgery.

    Conclusions

    The current study revealed that 94.1% of the patients who underwent osteoplastic hemilaminectomy achieved a significant improvement in the clinical outcomes and did not require additional surgery within 2 years following the procedure. Over a 5-year follow-up on average, 5.9% of the subjects developed postoperative lumbar segmental instability; however, they have maintained acceptable clinical conditions.

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  • Shunsuke Fujibayashi, Koichi Murata, Takayoshi Shimizu, Bungo Otsuki, ...
    Article ID: 2020-0204
    Published: 2021
    [Advance publication] Released: February 09, 2021
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    Introduction: Orthopedic surgeons are exposed to ionizing radiation daily. With the increase in the number of minimally invasive surgery performed under X-ray fluoroscopy, radiation exposure to unprotected fingers will increase. Although the effect of high dose radiation exposure is known, the long-term effect of exposure to low doses is unclear. This study aims to investigate damage to the nail and skin on the thumbs of spine surgeons via occupational ionizing radiation exposure.

    Methods: Forty male spine surgeons (group S) and 40 males of the same age group who were not exposed to radiation (controls; group C) were included. Using a scoring system, we evaluated the damage to the fingernail and skin of the bilateral thumb. Scoring was based on fingernail pigmentation (melanonychia), fingernail crack, and periungual dermatitis status. We investigated the number of examinations and operations under radiation exposure in the last 3 months.

    Results: Group S had 17.83 (3–28) years of surgeon experience. In group S, the dominant side scored significantly higher than the non-dominant side; however, there was no dominant vs. non-dominant difference in group C. Only the dominant side had a significantly higher score in group S than in group C. In group S, surgeon experience and the score of the dominant side were significantly correlated; however, for the non-dominant side of group S and both thumbs of group C, no correlation was observed. The kappa coefficients for fingernail pigmentation, fingernail crack, and periungual dermatitis status were 0.458, 0.248, and 0.612, respectively. The average number of examinations and operations under radiation exposure was 11.89 ± 9.04 (0–30) and 26.34 ± 14.67 (1–63), respectively.

    Conclusion: The dominant side in group S had a significantly higher score than the non-dominant side in group S and the dominant side in group C, suggesting the possibility of radiation damage to the dominant side in group S.

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  • Shin Yoshimura, Masahiro Inoue, Takayuki Nakajima, Go Kubota, Yusuke S ...
    Article ID: 2020-0213
    Published: 2021
    [Advance publication] Released: February 09, 2021
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    Introduction In the aging society, fragility fracture of the pelvis (FFP) has become a problem. Although strong and minimally invasive fixation is required in FFP surgery, reports on relevant surgical results are scarce. Crab-shaped fixation (CSF) is a spinopelvic fixation that involves reconstruction of the posterior pelvic ring using spinal instrumentation. This study aimed to evaluate the walking ability and perioperative complications of patients who underwent CSF for FFP.

    Methods We included patients diagnosed with unstable FFPs, including sacral fracture, who required hospitalization. Demographic data, such as age, sex, bone mineral density, and Rommens classification, were evaluated. Surgical findings included estimated blood loss, operation time, and perioperative complications. The improvement in postoperative walking ability was evaluated based on the length of the postoperative period before the initiation of walker training and whether walking aids were required at 6 months post-surgery, compared with those who received conservative treatment for FFP.

    Results Our study included 6 cases that received CSF and 16 cases that received conservative treatment, in which all were females and presented with sacral fractures. The average age of the surgical patients, the operation time, and the estimated blood loss were 79.5 ± 14.7 years, 180.7 ± 28.7 min, and 124.2 ± 29.4 mL, respectively. The average length of the postoperative period prior to the initiation of walker training was 10.8 ± 12.3 days, which was significantly shorter than that of conservative treatment. With regard to perioperative complications, poor reduction of fracture dislocation was observed in one case as well as surgical site infection in another case, but the walking ability improved in all cases.

    Conclusions We evaluated the results of the posterior pelvic ring reconstruction with CSF for patients with vertically unstable FFPs, including sacral fractures. CSF is minimally invasive and would be useful as it allowed walker training during the early postoperative period, which improved patients' walking ability even during the in situ pelvic ring reconstruction.

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  • Kentaro Yamada, Yuichiro Abe, Yasushi Yanagibashi, Takahiko Hyakumachi ...
    Article ID: 2020-0227
    Published: 2021
    [Advance publication] Released: February 09, 2021
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction. Diffuse idiopathic skeletal hyperostosis (DISH) extended to the lumbar segments (L-DISH) reportedly has adverse effects on the surgical outcomes of lumbar spinal stenosis (LSS). However, the risk factors in patients with L-DISH have not been clarified. The purpose of this study was to investigate the long-term risk factors for reoperation at the same level after decompression surgery alone for LSS in patients with L-DISH in a retrospective cohort study.

    Methods. A postoperative postal survey was sent to 1,150 consecutive patients who underwent decompression surgery alone for LSS from 2002 to 2010. Among all respondents, patients who exhibited L-DISH by preoperative total spine X-ray were included in this study. We investigated risk factors for reoperation at the same level as the initial surgery among various demographic and radiological parameters, including the lumbar ossification condition and computed tomography (CT) or magnetic resonance imaging findings.

    Results. A total of 57 patients were analyzed. Reoperations at the same level as that of the index surgery were performed in 10 patients (17.5%) and at 11 levels within a mean of 9.2 years. Cox proportional hazard regression analysis indicated that the independent risk factors for reoperation were a sagittal rotation angle ≥ 10° (adjusted hazard ratio: 5.17) and facet opening on CT (adjusted hazard ratio: 4.82). Neither sagittal translation nor the ossification condition in the lumbar segments affected reoperations.

    Conclusions. A sagittal rotation angle ≥ 10° and facet opening on preoperative CT were risk factors for reoperation at the same level as that of the index surgery in patients with L-DISH.The surgical strategy should be carefully considered in those patients.

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  • David Ephraim Bauer, Christoph Johannes Laux, Mazda Farshad
    Article ID: 2020-0193
    Published: 2021
    [Advance publication] Released: January 21, 2021
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Local infection and prolonged fluid discharge account for most complications in lumbar spine surgery. This report is a brief description of a useful technique for revision of complicated, draining wounds with surprisingly positive results that otherwise frequently require multiple surgical interventions.

    Technical Note: We describe the postoperative course of three patients, with prolonged and continuous serosanguineous discharge from the skin incision, who underwent wound revision with multilayered mattress stitches after open decompressive or instrumented spinal surgery. For this purpose, a thick monofilament suture is passed through the skin, subcutaneous fatty tissue, and paravertebral muscle in the fashion of a vertical mattress stitch while the loop above the skin level is augmented using a soft silicone capillary drainage to distribute tension along the wound margin.

    Conclusions: None of the patients treated with the multilayered mattress stitches required further surgical intervention. In this small case series, the multilayered mattress stitches augmented with soft silicone tubing were a useful technique for treating complicated lumbar surgical wounds with prolonged serosanguineous discharge.

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  • Shohei Chatani, Shoichi Haimoto, Yozo Sato, Takaaki Hasegawa, Shinichi ...
    Article ID: 2020-0202
    Published: 2021
    [Advance publication] Released: January 21, 2021
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Preoperative embolization for metastatic spinal cord compression (MSCC) has a risk of spinal ischemia. This study aimed to assess the efficacy and safety of preoperative embolization in patients with MSCC and evaluate the use of computed tomography (CT) angiography for the detection of the radiculomedullary arteries (RMA).

    Methods: This retrospective study included 20 patients (12 men and 8 women; median age, 66 years), who underwent preoperative embolization before a decompression surgery, which corresponded to 22 embolization procedures. The detection ability of RMA was evaluated using angiography and selective CT angiography. Surgical data including intraoperative blood loss and transfusion were also evaluated.

    Results: Six RMAs were identified at the levels of affected vertebrae and one level above and below in the diagnostic spinal angiography. In addition to spinal angiography, adjunctive selective CT angiography allowed visualization of another five RMAs. Overall, 11 RMAs were identified in 9 patients. Preoperative embolization was successfully achieved in all patients. As regards complications related to embolization procedure, palsy exacerbated in one patient (4.5%), which improved postoperatively. During the surgical procedure, the mean intraoperative blood loss was 353.4 ± 254.2 mL without intraoperative transfusion in all patients.

    Conclusion: The present study showed small amounts of intraoperative blood loss without any severe complications related to preoperative embolization. Selective CT angiography was a useful technique to detect RMAs and contributed to the safety of preoperative embolization.

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  • Daisuke Kurosawa, Eiichi Murakami, Toshimi Aizawa, Takashi Watanabe
    Article ID: 2020-0214
    Published: 2021
    [Advance publication] Released: January 21, 2021
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Sacroiliac joint (SIJ) arthrodesis is the last resort for patients with severe SIJ pain. However, this technique does not always provide good outcomes regarding activities of daily living (ADL). This study aims to reveal the preoperative clinical features associated with poor outcomes of SIJ arthrodesis.

    Methods: Twenty-six consecutive patients who underwent SIJ arthrodesis between 2009 and 2018 were evaluated. Good-outcome was defined as ≥30% improvement in ADL, quantified by the Roland-Morris Disability Questionnaire (RDQ). The good-outcome group (17 patients; 10 men and 7 women, 42.5 ± 8.4 years old) and the poor-outcome group (9 patients; 1 man and 8 women, 47.0 ± 17.9 years old) were compared to identify the preoperative clinical features of poor surgical outcomes.

    Results: No significant differences between were observed between the two groups regarding age, preoperative RDQ score, time between onset and the confirmed diagnosis of SIJ pain, and the time between diagnosis and surgical treatment. The following preoperative clinical features associated with poor surgical outcomes were identified: female sex, pain in multiple regions, walking with a cane, and the use of a wheelchair before surgery (P < 0.05).

    Conclusions: The present study demonstrated that poor postoperative outcomes in patients with severe SIJ pain were associated with the following preoperative clinical features: female sex, pain in multiple regions, walking with a cane, or use of a wheelchair. Ample attention is warranted in patients with such features who are indicated for surgical treatments.

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  • Masaaki Chazono, Shintaro Obata
    Article ID: 2020-0176
    Published: 2021
    [Advance publication] Released: January 12, 2021
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    Introduction: Since Little et al. first reported that peak height velocity (PHV) could be described as a reliable clinical marker for the prediction of remaining growth and curve progression of adolescent idiopathic scoliosis (AIS) in clinical practice, much attention has been paid to PHV as a possible predictor of curve progression in patients with AIS. However, PHV itself is only identified retrospectively, so its value is not available at the first outpatient clinic visit. Using the simplified skeletal maturity scale (SSMS) and the thumb ossification composite index (TOCI) staging systems, this study aims to assess skeletal maturity and predict height velocity (HV) in Japanese female patients with AIS.

    Methods: This study involved 95 female patients with AIS, ranging from 9 to 17 years old. A standing AP radiograph of the entire spine and a hand radiograph were retrospectively obtained to establish the skeletal maturity stage in accordance with the SSMS and TOCI systems. Height measurements were recorded at each visit; HV was calculated as the height change (cm) divided by the time interval (years).

    Results: The TOCI stage rating increased identically to the SSMS stage rating increase. The chi-square test showed that there was a significant correlation between the two scoring systems (χ2 = 720.4). The Cramer V correlation also demonstrated a very strong correlation (Cramer V = 0.62). Regarding the relationship between HV and each SSMS and TOCI stage, HV decreased as SSMS and TOCI stages increased. η2 equaled to 0.67 in both groups and displayed a strong correlation between HV and SSMS and TOCI stages.

    Conclusions: These findings suggest that evaluation of the rate of HV using these radiological assessments is of supreme importance for determining the status of pubertal maturity and predicting the remaining amount of adolescent growth at the outpatient clinic visit.

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  • Brian Fiani, Imran Siddiqi, Daniel Chacon, Ryan Arthur Figueras, Prest ...
    Article ID: 2020-0179
    Published: 2021
    [Advance publication] Released: January 12, 2021
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Lumbosacral interbody fusion is a mainstay of surgical treatment for degenerative spinal pathologies causing chronic pain and functional impairment. However, the optimal technique for this procedure remains controversial. Well-established open approaches, including anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), and transforaminal lumbar interbody fusion (TLIF), have historically been the standard of practice. A recent paradigm shift in spinal surgery has led to the investigation of minimally invasive approaches to mitigate tissue damage without compromising outcomes. This extensive review aims to examine current clinical and biomechanical evidence on the paracoccygeal transsacral approach to an axial lumbosacral interbody fusion. Since this technique was first described in 2004, accumulating evidence suggests it results in high fusion rates, consistent improvements in pain and function, reduced perioperative morbidity, and low rates of complication. Although early clinical outcomes have been promising, there is a paucity of comparative data investigating outcomes of the paracoccygeal transsacral approach to traditional alternatives and other minimally invasive techniques. Here, we summarize current evidence and discuss pertinent topics for the spinal surgeon considering this novel approach, including indications, advantages, relevant anatomy, contraindications, and technical considerations.

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  • Yasuchika Aoki, Masahiro Inoue, Hiroshi Takahashi, Go Kubota, Atsuya W ...
    Article ID: 2020-0189
    Published: 2021
    [Advance publication] Released: January 12, 2021
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction. Previous studies have reported differences in lumbopelvic alignment between standing and supine positions. Computed tomography (CT) images taken in the supine position are often used for clinical studies in addition to standing radiographs, although not frequently. Our study aims to clarify normative values of CT-evaluated lumbopelvic parameters and the characteristics of age- and gender-related lumbopelvic alignment in the supine position.

    Methods. Patients undergoing CT scans of abdominal or lumbar regions for reasons other than low back disorders were included (n = 581). Sagittal multiplanar reconstruction CT images were obtained, and lumbar lordosis (LL), L5–S1 angle, and sacral slope (SS) were measured. Mean values of the parameters in patients aged 59 years and under, 60–69, 70–79, and 80 and over, and in males and females, were calculated. Age- and gender-related differences in these parameters were statistically analyzed.

    Results. Among the four age groups, patients 80 years and over showed significantly lower LL and SS than patients aged 70–79. Females 80 years and over showed significantly lower LL and SS than all other age groups, but those in males did not. The comparison between males and females showed no significant differences in LL and SS; however, the L5–S1 angle was significantly higher in males than in females. In patients 80 years and over, females showed significantly lower LL and SS than in males.

    Conclusion. This study provides normative CT-evaluated lumbopelvic parameters, such as LL, L5–S1 angle, and SS, which will be utilized for comparisons in future studies. The present study first revealed that pelvic retroversion and lumbar kyphosis occur in elderly females in the supine position, which raised a possibility that age-related decrease of LL and SS in females occurs at an older age in the supine position than in the standing position.

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  • Kosei Ono, Bungo Otsuki, Shunsuke Fujibayashi, Takayoshi Shimizu, Koic ...
    Article ID: 2020-0212
    Published: 2021
    [Advance publication] Released: January 12, 2021
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION
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  • Shereen I. Fawaz, Mohamed A. Elgebeily, Heba G. Saber, Hany El Zahlawy
    Article ID: 2020-0121
    Published: 2020
    [Advance publication] Released: December 05, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: The modified Japanese Orthopaedic Association (mJOA) score is considered to be among the most comprehensive scores in the assessment of patients with cervical myelopathy. Hence, providing reliable, translated, and cross-culturally adapted versions in different languages is required to standardize the evaluation of patients. This study aimed to translate a reliable Arabic version of the mJOA score.

    Methods: A total of 65 patients of variable age and with etiologies for compressive cervical myelopathy were recruited. Both forward and backward translations were performed. Then, intraobserver and interobserver reliabilities were measured using the intraclass correlation coefficient and Cronbach's alpha coefficient.

    Results: The mean age of the patients was 58.08 years, and most of them were male (69.2%). The intraobserver and interobserver reliabilities were almost in perfect agreement for the different sections and the total score, which were 96.8% and 97.4%, respectively.

    Conclusion: In this study, a reliable, cross-culturally adapted Arabic version of the mJOA score for patients with cervical myelopathy is provided. Although the study was conducted on Egyptian patients, we believe that it could be implemented in majority of the Arabic-speaking population.

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  • Yasushi Fujiwara, Shinji Kotaka, Ryo Ohta, Yasuo Arakawa, Yutaka Kadon ...
    Article ID: 2020-0144
    Published: 2020
    [Advance publication] Released: December 05, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction

    Surgeons need precise information about motor deterioration risk during surgery for intramedullary spinal cord tumors (IMSCTs). However, the conventional TcMsEP alarm criterion provides limited information with a less than or a more than single alarm criterion without any grades in between, resulting in false-negative and false-positive outcomes.

    Therefore, we developed a "seven-color TcMsEP grading system" for neuromonitoring to provide more graded information. This study investigates the system's efficacy.

    Methods

    This study included 60 patients that underwent resection surgeries for IMSCTs. TcMsEP outcomes were classified into seven grades: Grade "D-0 Green" includes a wave amplitude decrease of 0%–50% compared with the baseline amplitude. Grade "D-1 Lime" includes a 50%–70% decrease. Grade "D-2 Yellow" includes a 70%–90% decrease. Grade "D-3 Orange" includes a more than 90% decrease with a clearly visible waveform. Grade "D-4 Red" includes a minimal and abnormally shaped wave. The severest, grade "D-5 Black," includes a wave that has completely disappeared. The additional grade "D-X Gray" includes cases in which the baseline wave is undetectable.

    Postoperative motor deterioration was evaluated in the upper limbs (PUMD) and lower limbs (PLMD) individually.

    Results

    PLMD only occurred in cases with more than a 90% wave amplitude decrease (from D-3 to D-5) and with the undetectable baseline wave (D-X). The PLMD rate increased according to the severity of the amplitude decreases (29% in D-3, 67% in D-4, 80% in D-5). Most PUMD occurred in cases with more than a 90% decrease, but one case with grade D1 had PUMD.

    Conclusions

    The seven-color graded alarm criterion supports surgeons' decisions on how to treat the wave amplitude decrease during surgery. It provides motor deterioration risk in each grade without false negatives. Moreover, the corresponding colors enable quick comprehension of the risks.

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  • Shinji Takahashi, Hidetomi Terai, Hiromitsu Toyoda, Masatoshi Hoshino, ...
    Article ID: 2020-0185
    Published: 2020
    [Advance publication] Released: December 05, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Because of adolescent idiopathic scoliosis (AIS), most surgeons use rod rotation on the concave side for Lenke types 1 and 2 curves. Nevertheless, the accurate placement of pedicle screws within dysplastic pedicles, especially on the concave side, is sometimes challenging. Conversely, there is a concern that apical rotation might be exacerbated after convex rod rotation maneuver (RRM) because the rod is rotated in the same direction as vertebral rotation. This study aims to demonstrate the surgical technique and outcomes of a convex RRM with direct vertebral rotation (DVR) for the correction of AIS.

    Technical Note: Multilevel pedicle screws were inserted into the vertebrae. The pre-bent pure titanium rod was set on the convex side and then derotated to nearly 90°. DVR was conducted for the desired vertebrae. Another pre-bent titanium alloy rod, for placement on the concave side, was contoured the same as the rod on the convex side. Using a reduction tube that allowed easier capture of the rod, the rod was connected to the concave side screws. DVR was again conducted for the desired vertebrae. Among the 59 patients, the correction rate of the main thoracic curve in Lenke types 1 and 2 AIS was 75.1% and 65.0%, respectively. The absolute value of the change in apical vertebral rotation between pre- and post-operative computed tomography (CT) scans in Lenke types 1 and 2 curves was 4.8° and 4.2°, respectively.

    Conclusions: The convex RRM improved vertebral rotation in Lenke types 1 and 2 AIS. This procedure should be regarded as one of the surgical options for AIS, especially in patients with a narrow pedicle width on the concave side.

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  • Gen Inoue, Takashi Kaito, Yukihiro Matsuyama, Toshihiko Yamashita, Mam ...
    Article ID: 2020-0083
    Published: 2020
    [Advance publication] Released: November 20, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Chronic low back pain (CLBP) is a leading cause of disability, yet there is limited high-quality evidence to identify the most suitable pharmacological therapy. The purpose of this Japanese nationwide, multicenter, prospective study was to compare the effectiveness of four representative drug therapies—acetaminophen, celecoxib, loxoprofen, and a tramadol and acetaminophen (T+A) combination drug—to establish evidence for a drug of choice for CLBP.

    Methods: Patients with CLBP (N = 471) received one of the four treatments and were evaluated, prospectively and comprehensively, once every month for six months using a visual analog scale (VAS) for LBP, the Japanese Orthopedic Association (JOA) score, the JOA Back Pain Evaluation Questionnaire (JOABPEQ), the Roland–Morris Disability Questionnaire (RDQ), the EuroQol five-dimensions three-levels (EQ-5D-3L), and the Short Form-8 item health survey (SF-8). We conducted multivariable linear regression analyses of the four drugs at 1 and 6 months after drug allocation. Differences with P < 0.05 were considered statistically significant.

    Results: Patients who received acetaminophen showed a significant improvement from baseline in the mental health subscale of the JOABPEQ at one month (P = 0.02) and the JOA score at six months (P < 0.01). None of the other outcome measures among the four drugs differed significantly. Across groups, all outcome measures, except the mental component summary (MCS) score of the SF-8, improved equivalently, although most measurements showed no obvious cumulative effect over six months. The MCS score of the SF-8 decreased gradually over six months in all groups.

    Conclusions: Most of the outcome measures among the treated groups were not significantly different, indicating similar treatment effects of the four drugs for CLBP. Our study indicated the limit of each outcome measure for evaluating the patient status, suggesting that a single outcome measure is insufficient to reflect treatment effectiveness.

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  • Hideaki Nakajima, Arisa Kubota, Yasuhisa Maezawa, Shuji Watanabe, Kazu ...
    Article ID: 2020-0126
    Published: 2020
    [Advance publication] Released: November 20, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Intradiscal chondroitin sulfate ABC endolyase (condoliase) injection for lumbar disc herniation (LDH) is an intermediate between conservative treatment and surgery. This approach can only be performed once in a lifetime; therefore, understanding the factors that determine the indication for the use of condoliase and predict outcomes is important. The aim of this study was to review clinical and imaging findings in patients after intradiscal condoliase injection, and to assess the short-term outcomes and factors associated with therapeutic effects.

    Methods: The subjects were 42 patients with LDH who underwent intradiscal condoliase injection. Patients with and without a ≥50% improvement from baseline of leg pain at 3 months after injection were defined as responders and non-responders, respectively. Clinical features and radiological findings were compared between these groups.

    Results: Of the 42 patients, 32 (76.2%) were responders and 10 (23.8%) were non-responders. Of 8 patients with a history of discectomy at the same level as LDH, 6 (75.0%) were responders. Non-responders had a significantly longer time from onset to treatment, smaller herniated volume before treatment, lower percentage reduction of herniated mass, and less intervertebral disc degeneration before treatment. There were no significant differences in LDH types (subligamentous extrusion or transligamentous extrusion types), high-intensity area within the herniation, changes in disc height, and region of condoliase injection between the two groups.

    Conclusions: Intradiscal condoliase injection had a good short-term therapeutic effect in patients with LDH, including in transligamentous extrusion-type and revision cases as well as subligamentous extrusion-type cases. Administration of intradiscal condoliase injection may be most effective in patients with a larger herniated mass volume before treatment, and least effective in cases with a longer time and less intervertebral disc degeneration before treatment.

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  • Motoya Kobayashi, Junichi Ohya, Yuki Onishi, Junichi Kunogi, Naohiro K ...
    Article ID: 2020-0153
    Published: 2020
    [Advance publication] Released: November 20, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction:

    Reportedly, the medialization of the common carotid artery (MCCA) to be a vascular anomaly with a potential risk of intraoperative carotid artery injury. Nevertheless, among spine surgeons, the presence of MCCA has not been well recognized.

    Methods:

    We retrospectively reviewed consecutive patients who underwent cervical radiographs and magnetic resonance imaging (MRI) examinations in a single spine center. Using MRI, the MCCA grade was classified into grades 1 to 3 in order of severity. Radiographic measurement included C2–C7 angles as cervical lordosis, cervical sagittal vertical axis (C-SVA), T1 slope (T1S), and T1S-cervical lordosis mismatch. We compared each patient's background and radiographic parameters between patients with each of the three MCCA grades. The continuous variables were compared using the Jonckheere–Terpstra trend test and the proportions were compared using the Cochran–Armitage trend test to investigate the trend of variables in three grades.

    Results:

    The present study included data from 133 eligible patients (65 males and 68 females) with a mean age of 63.7 (±14.2) years. The details of MCCA grading were as follows: grade 1, n = 101; grade 2, n = 27; and grade 3, n = 5. With an increasing MCCA grade, age (61.9 ± 14.0, 68.2 ± 13.8, and 76.4 ± 9.4 years for grades 1, 2, and 3, respectively, p = 0.005) and proportion of female (p < 0.001) had an increasing trend, whereas cervical lordosis had a decreasing trend (11.7 ± 13.5°, 7.0 ± 14.5°, and −10.0 ± 19.2° for grades 1, 2, and 3, respectively, p = 0.011).

    Conclusions:

    Several patient backgrounds including the female gender, older age, and kyphotic alignment were determined as MCCA risk factors. Careful preoperative neck vasculature assessment would avoid a catastrophic complication during anterior cervical surgery.

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  • Chad E Cook, Alessandra N Garcia, Christopher Shaffrey, Oren Gottfried
    Article ID: 2020-0156
    Published: 2020
    [Advance publication] Released: November 20, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Employment status plays an essential role as a social determinant of health. Unemployed are more likely to have a longer length of hospital stay and a nearly twofold greater rate of 30 day readmission than those who were well employed at the time of back surgery. This study aimed to investigate whether employment status influenced post-surgery outcomes and if so, the differences were clinically meaningful among groups.

    Methods: This retrospective observational study used data from the Quality Outcomes Database Lumbar Registry. Data refinement was used to isolate individuals 18 to 64 who received primary spine surgeries and had a designation of employed, unemployed, or disabled. Outcomes included 12 and 24 month back and leg pain, disability, patient satisfaction, and quality of life. Differences in descriptive variables, comorbidities, and outcomes measures (at 12 and 24 months) were analyzed using chi-square and linear mixed-effects modeling. When differences were present among groups, we evaluated whether they were clinically significant or not.

    Results: Differences (between employed, unemployed, and disabled) among baseline characteristics and comorbidities were present in nearly every category (p < 0.01). In all cases, those who were disabled represented the least healthy, followed by unemployed, and then employed. Clinically meaningful differences for all outcomes were present at 12 and 24 months (p < 0.01). In post hoc analyses, differences between each group at nearly all periods were found.

    Conclusion: The findings support that the health-related characteristics are markedly different among employment status groups. Group designation strongly differentiated outcomes. These findings suggest that disability and unemployment should be considered when determining prognosis of the individual.

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  • Koichi Yoshikane, Katsuhiko Kikuchi, Teiyu Izumi, Ken Okazaki
    Article ID: 2020-0159
    Published: 2020
    [Advance publication] Released: November 20, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Revision surgery for recurrent lumbar disc herniation after surgical treatment is at times challenging due to epidural adhesions and scar. This study aimed to review the clinical results and safety of full-endoscopic lumbar discectomy via interlaminar (FELD-IL) and transforaminal (FELD-TF) approaches for revision surgery.

    Methods: We conducted a retrospective study including 52 lumbar disc herniation revision patients (mean age, 51.8 years; male/female, 13/39), with 17 FELD-IL and 35 FELD-TF cases. Complication incidences were assessed by reviewing surgical videos and postoperative magnetic resonance images of nerve decompression outcomes. Patients' responses to Japan Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and numerical rating scales (NRS) for lumbar pain, leg pain, and leg numbness were recorded before and during follow-up. The Wilcoxon-signed rank tests were utilized to compare pre- and postoperative group variables.

    Results: The average operation time was 33.0 min in FELD-IL and 31.7 min in FELD-TF. Seven FELD-IL cases required lamina excavation with high-speed drill bars for scar tissue dissection from the lamina. Dura injury occurred during the excavation in one case. No complication was noted in the FELD-TF group. Successful decompression of the nerve was achieved in all cases. Complete sets of JOABPEQ and NRS were obtained in 64.5% of FELD-IL and in 82.9% of FELD-TF. The mean follow-up period was 18.6 months. All the subdomain of JOABPEQ and NRS improved significantly postoperative in both groups. There was no difference regarding the improvement of scores between the procedures except NRS for lumbar pain, which was more favorable in FELD-IL. Recurrence of herniation occurred in one patient (6%) after FELD-IL and two patients (6%) after FELD-TF.

    Conclusions: Both FELD-IL and FELD-TF are safe and effective revision procedures for recurrent lumbar disc herniation. FELD-TF could be performed employing the same procedure as primary surgery in revisions, regardless of the previous surgical approach.

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  • Maho Okamura, Wataru Saito, Masayuki Miyagi, Eiki Shirasawa, Takayuki ...
    Article ID: 2020-0170
    Published: 2020
    [Advance publication] Released: November 20, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Intraoperative hypothermia is associated with perioperative complications such as blood loss and wound infection. Thus, perioperative heat retention methods to prevent perioperative hypothermia such as providing a warmed blanket and active patients' warming are important. Although major surgery and pediatric patient age are noted as risk factors, only a few studies focus on hypothermia as an intraoperative complication in pediatric scoliosis surgery. The aim of this study is to investigate the incidence of intraoperative hypothermia in pediatric scoliosis surgery and the associated preoperative risk factors.

    Methods: We retrospectively reviewed the records of pediatric patients who underwent posterior spinal fusion at a single institution between 2015 and 2019. We recorded the background data, perioperative data, lowest recorded core temperature, and perioperative complications. Patients were divided into those whose temperature decreased below 36°C (Group H) and those who maintained a temperature of 36°C or greater (Group N) during surgery. We compared the two groups and performed multivariate analysis to identify preoperative risk factors for intraoperative hypothermia.

    Results: A total of 103 patients underwent posterior spinal fusion; 56 for adolescent idiopathic scoliosis and 47 for neuromuscular scoliosis. Hypothermia was observed in 40 patients (38.8%). Group H had more non-adolescent idiopathic scoliosis (AIS) patients, lower mean body mass index, greater mean blood loss, greater number of fused vertebrae, larger preoperative Cobb angle, and lower initial core body temperature (immediately after induction of anesthesia). On multivariate analysis, a diagnosis of neuromuscular scoliosis, a lower body mass index, and a lower initial core body temperature were identified as independent risk factors for intraoperative hypothermia.

    Conclusion: The incidence of hypothermia in pediatric posterior scoliosis surgery is 38.8%. Diagnosis of non-AIS, lower body mass index, and lower core body temperature at the time of anesthesia induction are preoperative risk factors for intraoperative hypothermia.

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  • Tsunehiko Konomi, Shinjiro Kaneko, Amir Fariz Zakaria, Kanehiro Fujiyo ...
    Article ID: 2020-0134
    Published: 2020
    [Advance publication] Released: October 22, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction:

    An anterior surgical approach for severe infectious spondylodiscitis in the lumbar region is optimal but not always atraumatic. The aim of this study was to evaluate the efficacy and safety of a minimal anterior-lateral retroperitoneal approach, also known as a surgical approach for oblique lumbar interbody fusion, for cases with severe infectious spondylodiscitis with osseous defects.

    Methods:

    Twenty-four consecutive patients who underwent anterior debridement and spinal fusion with an autologous strut bone graft for infectious spondylodiscitis with osseous defects were reviewed retrospectively. Eleven patients underwent the minimal retroperitoneal approach (Group M), and 13 underwent the conventional open approach (Group C). Peri- and postoperative clinical outcomes, that is, estimated blood loss (EBL), operative time (OT), creatine kinase (CK) level, visual analog scale (VAS), and rates of bone union and additional posterior instrumentation, were evaluated, and the differences between both groups were assessed statistically.

    Results:

    Mean EBL, serum CK on the 1st postoperative day, and VAS on the 14th postoperative day were 202.1 mL, 390.9 IU/L, and 9.5 mm in Group M and 648.3 mL, 925.5 IU/L, and 22.3 mm in Group C, respectively, with statistically significant differences between the groups. There were no statistically significant intergroup differences in OT and rates of bone union and additional posterior instrumentation.

    Conclusions:

    Anterior debridement and spinal fusion using the minimal retroperitoneal approach is a useful and safe surgical technique. Although a preponderance of the minimal approach regarding early bone union is not validated, this technique has the advantages of conventional open surgery, but reduces blood loss, muscle injury, and pain postoperatively.

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  • Keisuke Masuda, Hideki Shigematsu, Masato Tanaka, Sachiko Kawasaki, Yu ...
    Article ID: 2020-0149
    Published: 2020
    [Advance publication] Released: October 22, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Compared with the conventional posterior lumbar decompression surgery,the spinous process splitting approach for lumbar spinal stenosis is less invasive. There are currently two types of the spinous process splitting approach that are performed. First is the lumbar spinous process splitting laminectomy (LSPSL), which involves the detachment of the spinous process from the lamina. Second is the modified Marmot method, which involves leaning of the spinous process without detachment from the lamina. To the best of our knowledge, this is the first study comparing the 2-year surgical outcomes of the modified Marmot method and LSPSL in cases of lumbar spinal canal stenosis.

    Methods: We recruited 69 patients who underwent decompression surgery. A total of 32 patients underwent the modified Marmot method (M group), and 37 patients underwent LSPSL (S group). We compared the clinical results, laboratory data of surgical invasion, wound pain, and safety.

    Results: No significant difference was observed in terms of the demographic data and operative time between the two groups. The number of decompressed segments and intraoperative and postoperative blood loss volume in the M group were greater than that in the S group. In the S group, the postoperative Japanese Orthopedic Association scores and recovery rates were significantly greater compared with those in the M group. Perioperative complications did not significantly differ between the two groups. On postoperative day 1, the Postoperative Visual Analog Scale scores at rest in the M group were lower than those in the S group.

    Conclusions: In clinical practice, we believe that posterior lumbar decompression surgery is safe, effective, and minimally invasive. Although the modified Marmot method may be less invasive and result in the reduction of wound pain during early postoperative periods, the clinical results did not exhibit greater long-term improvements with regard to surgical complications and neurological improvement, when compared with LSPSL.

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  • Takeshi Sasagawa, Yosuke Takeuchi, Ikuo Aita
    Article ID: 2020-0152
    Published: 2020
    [Advance publication] Released: October 22, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction Some reports revealed that hidden blood loss (HBL) during surgery for traumatic thoracolumbar fracture cannot be ignored, even when using a percutaneous approach. Using percutaneous pedicle screws (PPS) for traumatic thoracolumbar fracture, this study aimed to compare estimate blood loss (EBL), including HBL, between early and late fixation.

    Methods This investigation was a retrospective study. In the present study, data from 39 patients who underwent posterior spinal stabilization using PPS for single-level thoracolumbar fracture have been included. We divided the patients into an early group (group E) (n = 20) in whom surgery was conducted within 3 days of fracture and a late group (group L) (n = 19) in whom surgery was conducted more than 3 days after fracture. We evaluated hemoglobin (Hb) on the day of injury, and 1, 3 or 4, and 7 days after surgery, EBL, HBL, and transfusion requirement.

    Results Hb on day 1 (group E: 12.2 ± 1.7 g/dL, group L: 12.3 ± 1.6 g/dL) was significantly less than that on the injured day (group E: 14.2 ± 1.7 g/dL, group L: 13.9 ± 1.7 g/dL) in both groups. The values of Hb and EBL were not significantly different at any time between the two groups. HBL (group E: 487 ± 266 mL, group L: 386 ± 305 mL) was not significantly different between the two groups. No patients required transfusion in either group.

    Conclusions EBL in early fixation using PPS for traumatic thoracolumbar fracture is not significantly different compared with that in late surgery from days 1 to 7 postoperatively. Early fixation using PPS for traumatic thoracolumbar fracture does not result in negative outcomes any more than those in late surgery in terms of blood loss.

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  • Takeshi Sainoh, Sumihisa Orita, Manato Horii, Jiro Hirayama, Miyako Su ...
    Article ID: 2020-0099
    Published: 2020
    [Advance publication] Released: September 23, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION
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  • Kumiko Yotsuya, Tomohiko Hasegawa, Yu Yamato, Go Yoshida, Sho Kobayash ...
    Article ID: 2020-0120
    Published: 2020
    [Advance publication] Released: September 23, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Background: Since 1929, only 171 epidural hemangioma cases have been reported. We report five epidural hemangiomas and review cases reported over the past decade in terms of radiological features and clinical findings.

    Methods: Among patients operated on for spinal tumors at our hospital between 2009 and 2020, five had epidural hemangiomas. We retrospectively examined patient records and images and reviewed relevant English literature in PubMed from 2009 to 2019. Eighty-seven epidural hemangioma cases were reported in the last 10 years.

    Results: Among 87 cases, the average age was 49.58 years; 43 and 44 cases were male and female, respectively. The most common lesion level was thoracic (59.8%), while common symptoms were back pain (42.5%); numbness, hypoesthesia, or anesthesia (37.9%); paraparesis (34.5%); and radicular pain (20.7%). On magnetic resonance imaging (MRI), 77.1% showed hypo-isointensity on T1-weighted image (WI), hyperintensity on T2WI, and homogenous enhanced patterns with contrast. Total resection was performed in most cases, with good clinical outcomes. Preoperative embolization was performed in four cases, with good surgical outcomes. The median follow-up duration of postoperative MRI was 16 months, and no case had recurrence.

    Conclusions: Epidural hemangiomas are extremely rare and may be difficult to diagnose preoperatively. They should be considered if a dumbbell-shaped or epidural hypervascular lesion is noted. The treatment of choice for epidural hemangioma is total resection, with most cases having good clinical outcomes. Preoperative embolization may be useful for reducing bleeding. Although there were almost no recurrences after resection, careful follow-up for longer periods is required.

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  • Kenyu Ito, Kei Ando, Kazuyoshi Kobayashi, Hiroaki Nakashima, Yukihiro ...
    Article ID: 2020-0123
    Published: 2020
    [Advance publication] Released: September 23, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION

    Introduction. Recent research has shown that spinal sagittal alignment plays a critical role in health-related quality of life. However, most of these studies were cross-sectional in nature, and longitudinal studies of lumbar lordosis (LL) in healthy subjects were few. This study aims to evaluate the change in lumbar sagittal parameters during a 10-year period.

    Methods. The study population included 45 individuals (mean age, 65.7 years; male, n = 20; female, n = 25) who underwent sagittal lumbar radiography and a basic health checkup during a 10-year period. The radiologic parameters were LL, disc angle, sacral slope angle (SS), and pelvic incidence (PI). The change of LL during the 10-year period was defined as ΔLL. The subjects were divided into the LL maintenance group (n = 33) and the LL non-maintenance group (n = 12) based on their LL values.

    Results. The radiologic baseline/final parameters were as follows: LL, 45/34 degrees (P < 0.001); L1/L2 disc angle, 4.5/2.5 degrees; L2/L3 disc angle, 5.5/2.7 degrees; L3/L4 disc angle, 6.2/4.2 degrees; L4/L5 disc angle, 8.1/5.1 degrees; L5/S disc angle, 14.2/12.2 degrees; and SS, 32.0/32.1 degrees.

    The mean PI (50.5 degrees) was tended to be associated with the final LL (R = 0.31, P = 0.044) and was correlated with the ΔLL (R = 0.43, P < 0.01).

    The data of the LL maintenance/non-maintenance groups were as follows: age, 65.0/67.0; primary LL, 43.2/50.2 degrees (P < 0.05); final LL, 36.2/27.8 degrees (P < 0.05); and PI, 52.8/43.8 degrees (P < 0.01).

    Conclusions. During the 10-year study period, the LL in middle-aged and elderly volunteers decreased by 11 degrees. The factor of maintenance of LL was PI.

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  • Toru Funayama, Kentaro Mataki, Kohei Murakami, Yuki Mataki, Hiroshi No ...
    Article ID: 2020-0127
    Published: 2020
    [Advance publication] Released: September 23, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION
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  • Yoshinori Ishikawa, Naohisa Miyakoshi, Michio Hongo, Yuji Kasukawa, Da ...
    Article ID: 2020-0106
    Published: 2020
    [Advance publication] Released: August 31, 2020
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  • Masayuki Tanabe, Satoshi Ogihara, Shunpei Iida, Satoshi Ikemune, Jun K ...
    Article ID: 2020-0111
    Published: 2020
    [Advance publication] Released: August 31, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION
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  • Yuma Suga, Hideki Shigematsu, Jin Iida, Nobuhisa Sato, Masato Tanaka, ...
    Article ID: 2020-0014
    Published: 2020
    [Advance publication] Released: August 20, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION
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  • Ryo Ogaki, Eijiro Okada, Satoshi Suzuki, Satoshi Nori, Osahiko Tsuji, ...
    Article ID: 2020-0066
    Published: 2020
    [Advance publication] Released: August 20, 2020
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  • Taiki Yasukawa, Junichi Ohya, Naohiro Kawamura, Yuki Onishi, Yuichi Yo ...
    Article ID: 2020-0085
    Published: 2020
    [Advance publication] Released: August 20, 2020
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  • Yoshiyuki Takahashi, Kota Watanabe, Mitsuru Yagi, Satoshi Suzuki, Sato ...
    Article ID: 2020-0087
    Published: 2020
    [Advance publication] Released: August 20, 2020
    JOURNALS OPEN ACCESS ADVANCE PUBLICATION
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