Methods: Nineteen volunteers (16 men, three women) lifted a 60-kg doll from a seated position to a standing position. The first transfer was performed without the HAL for Care Support, and the second was performed with the HAL for Care Support assistive robot. We evaluated transfer performance, the visual analog scale (VAS) score for lumbar fatigue, and electromyogram analyses of the trunk and hip. Results: Four participants (two men, two women) succeeded with the HAL for Care Support even though they were unable to perform the task without it. The mean lumbar fatigue VAS score for all participants without the HAL for Care Support was 62 mm, while that with it was 43 mm. With lumbar assistance from the HAL for Care Support, subjective lumbar fatigue during the transfer decreased significantly. A power analysis indicated adequate statistical power to detect a difference in the VAS score for lumbar fatigue (0.99). The activity of the left gluteus maximus alone increased significantly during transfers with the HAL for Care Support. No adverse events occurred during use of the HAL for Care Support for transfers. Conclusions The HAL for Care Support was able to reduce lumbar load in a simulated patient transfer.

Calcification of the ligamentum flavum (CLF), which is a rare disorder that can potentially cause myelopathy, occurs uncommonly in the thoracic spine. Here, we report a rare case of thoracic myelopathy caused by CLF in a 78-year-old man. Magnetic resonance imaging (MRI) showed posterior spinal cord compression by a hypo-signal intense mass, and computed tomography (CT) revealed CLF and vacuum disc phenomenon at T10/11. After undergoing posterior decompression and instrumented fusion (T9–T12), the patient’s gait difficulties improved. The pathogenesis of CLF is largely unknown; however, it involves accumulation of calcium pyrophosphate dehydrate crystals (CPPD), and CLF from CPPD deposition tends to occur within a thickened and hypertrophic ligament. CLF occurs predominantly in the cervical spine and less frequently in the lumbar spine, with few cases involving the thoraco-lumbar spine. The thoracic spine is characterized by hypomobility; however, the thoraco-lumbar spine has a mobile segment which may potentiate CLF formation. Decompression with fusion surgery can be useful for treating patients with thoraco-lumbar CLF.

Objective: Whether or not emergent decompression/fusion surgery for paralysis caused by metastatic spinal tumors of unknown origin improves patient neurological outcome and survival remains unclear. This study aimed to evaluate the clinical outcomes of emergent decompression/fusion surgery for paralysis caused by spinal tumors of unknown or not previously diagnosed origin.Patients and Methods: Data from the medical records of 11 patients with spinal tumors of unknown origin (study group) were compared with those of 15 patients with metastatic spinal tumors of known origin (control group). The outcome measures were postoperative performance status, motor function evaluated with the Frankel grade, and actual survival after surgery as compared with the estimated survival calculated using the Tokuhashi score. χ2 analyses were performed to evaluate differences between the groups.Results: The mean performance status was 3.6 preoperatively, which improved to 2.9 postoperatively (P<0.05), in the unknown origin group and 3.6 preoperatively, which improved to 2.7 postoperatively (P<0.05), in the control group. Seven patients (64%) in the unknown origin group showed improvement in paralysis by ≥1 Frankel grade. By contrast, only 4 patients (27%) in the control group showed improvement in paralysis. The unknown origin group tended to show better improvement (P=0.05). All the patients in the unknown origin group underwent adjuvant therapy after definitive diagnosis following surgery. The unknown origin group showed a slight tendency toward better survival than toward the estimated survival.Conclusion: Emergent decompression/fusion surgery for patients with paralysis caused by metastatic tumors of unknown origin is potentially useful for diagnosing tumor origin and improving neurological outcomes and performance status, and thus for extending survival.

Objective: To treat vertebral fractures with posterior wall injury in the elderly, vertebral bone grafting is generally performed through a posterior transpedicular approach, combined with pedicle screw fixation. An autologous bone is ideal to treat this disorder. However, harvesting autologous bones from the elderly with osteoporosis is limited by the amount and quality of available autologous bone. Thus, we developed a bone-grafting substitute. The newly developed unidirectional porous β-tricalcium phosphate, with a porosity of 57% (UDPTCP; Affinos®, Kuraray Co., Ltd., Tokyo, Japan), is used in the bone-grafting procedure. This is the first report of UDPTCP used as an artificial bone graft in patients with an acute vertebral burst fracture.Materials and Methods: UDPTCP (mean: 4.2 g) was implanted through the pedicle, and posterior instrumentation was achieved with pedicle screws in five elderly patients. Resorption of UDPTCP and substitution with the autologous bone were evaluated on computed tomography (CT) and plain X-ray performed immediately and at 3, 6, and 12 months after the operation.Results: In case 1, the pedicle screws did not loosen, and UDPTCP was completely resorbed and replaced with the autologous bone at 3 postoperative months. In the other four cases, although the pedicle screws or the caudal part loosened because of osteoporosis, resorption of UDPTCP was observed at 3 postoperative months. At 6 postoperative months, progressive substitution with the autologous bone was confirmed, and at 12 postoperative months, formation of the good autologous bone was confirmed.Conclusion: This preliminary case series demonstrated that the newly developed UDPTCP shows good clinical potential as a bone-graft substitute for acute vertebral burst fractures in the elderly, including patients with osteoporosis.

Purpose: This study aimed to examine the characteristics of lumbar spondylolysis with acute lumbar spondylolysis on one side and pseudoarthrotic spondylolysis on the other, relative to acute lumbar spondylolysis on one side only.Patients and Methods: Short-tau inversion recovery images obtained through magnetic resonance imaging were used to diagnose 58 patients with acute lumbar spondylolysis with bone marrow edema on one side only. A total of 20 patients who had pars defects on the contralateral side (terminal-stage pseudoarthrotic spondylolysis) were included in the contralateral pseudoarthrosis group (P group). The remaining 38 patients with normal images for the contralateral pars interarticularis were included in the unilateral lesion group, in which the contralateral side was normal (U group). We investigated the union rate, age, sex, lesion laterality, vertebral level, pathological stage, and existing spina bifida occulta in both groups.Results: The P group was characterized by a higher proportion of right-side cases, L5 lesions, more progressed pathological stage, and spina bifida occulta and a significantly lower union rate than the U group.Conclusion: The union rate in patients with lumbar spondylolysis with acute lumbar spondylolysis on one side and pseudoarthrotic spondylolysis on the opposite side was only 15%. We should inform patients with acute unilateral spondylolysis lesions and contralateral pseudoarthrosis about this poor union rate and urge them to choose their therapy accordingly.