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Background: The penetrating end plate screw (PES) technique improved the fixation strength of the pedicle screw by penetrating the end plate in posterior fusion. The "double" PES, which is a trajectory that penetrates both the upper end plate of the corresponding vertebra and the lower end plate of the upper adjacent vertebral body, provides a stronger tricortical fixation but requires a stricter trajectory. The purpose of this study was to measure the cephalad angles from T7-L5 that would allow a safe trajectory for "double" PES., Methods: We analyzed 1078 pedicles of 539 vertebral bodies of 50 consecutive cases (27 males and 23 females, mean age, 63.3 years) who underwent computed tomography (CT) myelography for evaluation of spinal disorders. The mean cephalad angle to obtain the double PES trajectory of each vertebra was examined, except for cases in which the appropriate trajectory would perforate the pedicles., Results: The cephalad angle for the appropriate trajectory of "double" PES ranged from 23.4 to 37.6 degrees in the thoracic spine and 34.8 to 40.8 degrees in the lumbar spine. The ratio of pedicle perforation was significantly higher at T7 (16%), L4 (26%), and L5 (52%)., Conclusions: It is important to measure the optimal cephalad angle by preoperative computed tomography imaging according to the vertebral level. In L4 and L5, "double" PES should be avoided because it is often unsafe., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Percutaneous endoscopic discectomy (PED) has been reported to be an effective procedure and minimally invasive surgical therapy for various spinal pathologies., Objective: To evaluate the clinical outcome of patients with pyogenic spondylitis who were treated with PED., Methods: Twenty-four patients with pyogenic spondylitis who underwent PED were evaluated for medical history, level of the affected intervertebral space, mode of onset, plain radiographs, epidural or psoas abscesses on MRI, results of blood and intraoperative sample cultures, preoperative C-reactive protein (CRP) level, time until postoperative CRP normalization (CRP < 0.3), and any additional surgery. Patients who underwent additional surgery and showed uncontrollable inflammation were considered to have "failed" PED for pyogenic spondylitis. To elucidate the factors that were significantly associated with a failure of PED for pyogenic spondylitis, statistical analyses were conducted by univariate analysis., Results: Control of inflammation was achieved in 19 of 24 patients (76%) after PED for pyogenic spondylitis. The remaining five patients failed to achieve infection control by PED. One such patient was not able to control the infection after PED, and another patient developed an epidural abscess 2 weeks after PED. Remaining three "failed" patients had exacerbations of their infections during the postoperative course and required additional surgery. Univariate analyses demonstrated that diabetes mellitus (DM; p = 0.05), hemodialysis due to DM-induced renal failure ( p = 0.02), concomitant malignant disease ( p = 0.09), and acute onset ( p = 0.05) were possibly correlated with PED failure. Stepwise logistic regression analysis revealed that hemodialysis due to DM-induced renal failure was an independent factor associated with PED failure ( p = 0.03)., Conclusions: PED might be considered as one of the alternative therapeutic options before invasive radical surgeries for pyogenic spondylitis after failure of standard conservative therapy. Even by less invasive PED, pyogenic spondylitis patients with DM-hemodialysis showed poor outcome.

After spine fusion surgery, it is difficult to evaluate the spinal canal and nerve roots using magnetic resonance imaging (MRI) because of metallic implant-related artifacts. Digital tomosynthesis is a new radiographic technique that can acquire tomographic images with reduced metallic artifact effects compared with MRI. We report a case demonstrating the visualization of nerve roots nearby metallic implants using dynamic tomosynthesis-radiculography (DTRG) after spinal fusion surgery. A 77-year-old man, who 3 years earlier underwent spine fusion surgery at L3-L5, presented complaining of newly-onset low back pain and radicular symptoms in the right fifth lumbar (L5) nerve root area. His symptoms were exacerbated when he stood upright. We suspected right L5 nerve root radiculopathy, but MRI could not depict any lesion of the nerve root because of metallic implant-related artifacts. We performed DTRG at the right L5 nerve root with the patient in both prone and upright positions. The right L5 nerve root was detected clearly, and nerve root compression at the foramina when the patient was upright was exacerbated more than when the patient was in a prone position. DTRG is helpful to diagnose lumbar foraminal stenosis nearby metallic implants after spine fusion surgery., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

An excessive lumbar load with snow-shoveling is a serious problem in snowfall areas. Various exoskeletal robots have been developed to reduce lumbar load in lifting work. However, few studies have reported the attempt of snow-shoveling work using exoskeletal robots. The purpose of the present study was to test the hypothesis that the HAL for Care Support robot would reduce lumbar load in repetitive snow-shoveling movements. Nine healthy male volunteers performed repetitive snow-shoveling movements outdoors in a snowfall area for as long as possible until they were fatigued. The snow-shoveling trial was performed under two conditions: with and without HAL for Care Support. Outcome measures were defined as the lumbar load assessed by the VAS of lumbar fatigue after the snow-shoveling trial and the snow-shoveling performance, including the number of scoops, and snow shoveling time and distance. The mean of VAS of lumbar fatigue, the number of scoops, and snow-shoveling time and distance without HAL for Care Support were 75.4 mm, 50.3, 145 s, and 9.6 m, while with HAL for Care Support were 39.8 mm, 144, 366 s, and 35.4 m. The reduction of lumbar fatigue and improvement of snow-shoveling performance using HAL for Care Support were statistically significant. There was no adverse event during snow-shoveling with HAL for Care Support. In conclusion, the HAL for Care Support can reduce lumbar load in repetitive snow-shoveling movements., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Spinal alignment in patients with adult spinal deformity (ASD) changes between rest and during gait. However, it remains unclear at which point the compensated walking posture breaks down and how muscles respond. This study used time-synchronized electromyography (EMG) to investigate the relationship between dynamic spinal alignment and muscle activity during maximum walking duration to reveal compensation mechanisms. Methods: This study collected preoperative three-dimensional gait analysis data from patients who were candidates for corrective surgery for ASD from April 2015 to May 2019. We preoperatively obtained dynamic spinal alignment parameters from initiation to cessation of gait using a motion capture system with time-synchronized surface integrated EMG (iEMG). We compared chronological changes in dynamic spinal alignment parameters and iEMG values 1) immediately after gait initiation (first trial), 2) half of the distance walked (half trial), and 3) immediately before cessation (last trial). Results: This study included 26 patients (22 women, four men) with ASD. Spinal sagittal vertical axis distance during gait (SpSVA) increased over time (first vs. half vs. last, 172.4 ± 74.8 mm vs. 179.9 ± 76.8 mm vs. 201.6 ± 83.1 mm; P < 0.001). Cervical paravertebral muscle (PVM) and gluteus maximus activity significantly increased (P < 0.01), but thoracic and lumbar PVM activity did not change. Dynamic spinal alignment showed significant correlation with all muscle activity (cervical PVM, r = 0.41–0.54; thoracic PVM, r = 0.49–0.66; gluteus maximus, r = 0.54–0.69; quadriceps, r = 0.46–0.55) except lumbar PVM activity. Conclusion: Spinal balance exacerbation occurred continuously in patients with ASD over maximum walking distance and not at specific points. To maintain horizontal gaze, cervical PVM and gluteus maximus were activated to compensate for a dynamic spinal alignment change. All muscle activities, except lumbar PVM, increased to compensate for the spinal malalignment over time. [ABSTRACT FROM AUTHOR]

Background: Several authors have reported favorable results in low back pain (LBP) for patients with lumbar disc herniation (LDH) treated with discectomy. However, detailed changes over time in the characteristics and location of LBP before and after discectomy for LDH remain unclear. To clarify these points, we conducted an observational study to determine the detailed characteristics and location of LBP before and after discectomy for LDH, using a detailed visual analog scale (VAS) bilaterally.Methods: We included 65 patients with LDH treated by discectomy in this study. A detailed VAS for LBP was administered with the patient under 3 different conditions: in motion, standing, and sitting. Bilateral VAS was also administered (affected versus opposite side) for LBP, lower extremity pain (LEP), and lower extremity numbness (LEN). The Oswestry Disability Index (ODI) was used to quantify clinical status. Changes over time in these VAS and ODI were investigated. Pfirrmann grading and Modic change as seen by magnetic resonance imaging (MRI) were reviewed before and 1 year after discectomy to determine disc and endplate condition.Results: Before surgery, LBP on the affected side while the patients were in motion was significantly higher than LBP while they were sitting (p = 0.025). This increased LBP on the affected side in motion was improved significantly after discectomy (p < 0.001). By contrast, the residual LBP while sitting at 1 year after surgery was significantly higher than the LBP while they were in motion or standing (p = 0.015). At 1 year following discectomy, residual LBP while sitting was significantly greater in cases showing changes in Pfirrmann grade (p = 0.002) or Modic type (p = 0.025).Conclusions: Improvement of LBP on the affected side while the patient is in motion suggests that radicular LBP is improved following discectomy by nerve root decompression. Furthermore, residual LBP may reflect increased load and pressure on the disc and endplate in the sitting position. [ABSTRACT FROM AUTHOR]

When ossification of the yellow ligament (OYL) occurs in the lumbar spine and extends to the lateral wall of the spinal canal, facetectomy is required to remove all of the ossified lesion and achieve decompression. Subsequent posterior fixation with interbody fusion will then be necessary to prevent postoperative progression of the ossification and intervertebral instability. The technique of lateral lumbar interbody fusion (LLIF) has recently been introduced. Using this procedure, surgeons can avoid excess blood loss from the extradural venous plexus and detachment of the ossified lesion and the ventral dura mater is avoidable. We present a 55-year-old male patient with OYL at L3/4 and anterior spondylolisthesis of L4 vertebra, with concomitant ossification of the posterior longitudinal ligament, who presented with a severe gait disturbance. He underwent a 2-stage operation without complications: LLIF for L3/4 and L4/5 was performed at the initial surgery, and posterior decompression fixation using pedicle screws from L3 to L5 was performed at the second surgery. His postoperative progress was favorable, and his interbody fusion was deemed successful. Here, we present the first reported case of LLIF for OYL of the lumbar spine. This procedure can be a good option for OYL of the lumbar spine. [ABSTRACT FROM AUTHOR]