Safety of terminally gamma-ray-sterilized screws coated with fibroblast growth factor 2-calcium phosphate composite layers in non-human primates.

Screws coated with fibroblast growth factor 2 (FGF-2)-calcium phosphate (CP) composite layers exhibit enhanced soft tissue and bone formation and angiogenesis because of the biological activity of FGF-2. Furthermore, the mitogenic activity of the FGF-2 within the composite layers remains unchanged after gamma-ray sterilization, which may improve the storage stability prior to clinical use. However, the in vivo safeties of these screws as spinal implants remain unknown. Here, a randomized controlled trial, involving non-human primates, investigated the safety of using FGF-2-CP composite layer-coated screws after either gamma-ray sterilization or aseptic processing. Titanium alloy screws coated with FGF-2-CP composite layers and subjected to either gamma-ray sterilization at 25 kGy (GS group) or aseptic storage (AS group) were implanted into the vertebral bodies of two cynomolgus monkeys exceeding 12 weeks (day 99). Physiological, histological, and radiographic investigations were performed to evaluate the safeties of the screws. There were no serious adverse events, such as surgical site infection, significant loss of body weight, or abnormal blood test results. No radiolucent areas were observed around the screws from the GS or AS group throughout the study. In the intraosseous region, no significant differences were observed in bone and fibrous tissue apposition rates and rate of bone formation between the two groups (p = 0.49, 0.77, and 0.11, respectively). Neither tumor lesions nor accumulation of lymphocytes and neutrophils were observed in either group. Our data suggest that FGF-2-CP composite layer-coated screws subjected to terminal gamma-ray sterilization are as safe as those fabricated in aseptic processing.

Development of a quantitative method to evaluate pedicle screw loosening after spinal instrumentation using digital tomosynthesis.

BACKGROUND: In general, the diagnosis of pedicle screw (PS) loosening is evaluated qualitatively based on the presence of a radiolucent area around the implant wider than 1 mm on plain radiographs and computed tomography (CT). Digital tomosynthesis is a novel imaging technology that can acquire reconstructed tomographic images of patients in different postures with relatively low radiation. In this study, PS loosening is evaluated quantitatively by measuring the PS displacement angle in the vertebrae using digital tomosynthesis. METHODS: We evaluated 41 patients who underwent posterior spinal fusion surgery using PS. The 72 pedicle screws at the cranial end of the fused segments were evaluated. The patients were divided in two groups, one with PS loosening (7 patients, 12 screws) and the other without PS loosening (34 patients, 60 screws), based on conventional CT findings. All patients underwent tomosynthesis in two different postures during a single CT session. RESULTS: The displacement angles of the PS in patients in a lying position and in a standing position were measured using selected slices of the same cross-sectional view from digital tomosynthesis. The displacement angle was significantly greater in the PS loosening group (5.7°) than in the group without PS loosening (0.6°) (p<0.01). Based on the ROC analysis, the optimal cut-off value of the PS displacement angle for identification of loosened screws was 1.7° with a sensitivity of 100% and specificity of 93% (AUC = 0.98). CONCLUSIONS: This new method using digital tomosynthesis has the potential to aid diagnosis of PS loosening quantitatively and more accurately than conventional evaluations.

Characteristic imaging findings predicting the risk of conservative treatment resistance in fresh osteoporotic vertebral fractures with poor prognostic features on magnetic resonance imaging.

BACKGROUND: Recent studies have reported that confined high-intensity and diffuse low-intensity on sagittal T2-weighted magnetic resonance imaging (MRI) are distinctive features that are highly predictive of delayed union or nonunion on osteoporotic vertebral fracture (OVF). The objective of this study was to identify the characteristics of imaging findings predicting the risk for requiring surgical treatment in fresh OVF with poor prognostic features on MRI. METHODS: We conducted a retrospective study of 74 patients (17 men and 57 women with a mean age of 81.1 years) of OVF with the poor prognostic MRI findings. We compared the imaging findings between the surgery group (16 patients) and the conservative group (58 patients): vertebral instability defined as the difference between the vertebral collapse ratio in dynamic X-rays, and the grade of posterior wall injury (Grade I, no spinal canal encroachment; Grade II, <2 mm; Grade III, ≥2 mm) as well as the presence or absence of pedicle fracture (Grade I, none; Grade II, unilateral; Grade III, bilateral) on computed tomography. RESULTS: The mean vertebral instability was 24.0% ± 10.1% in the surgery group and 13.0% ± 7.8% in the conservative group, which was significantly different. Posterior wall injury in the surgery and conservative groups was Grade I in 0 and 29 cases, Grade II in 5 and 21 cases, and Grade III in 11 and 8 cases, respectively, constituting a significant difference. Pedicle fracture in the surgery and conservative groups was Grade I in 5 and 55 cases, Grade II in 6 and 2 cases, and Grade III in 5 and 1 case, respectively, also constituting a significant difference. CONCLUSIONS: The most high-risk OVF patients with poor prognostic MRI findings who required surgical treatment were those who exhibited greater vertebral instability as well as either more severe posterior wall injury or pedicle fracture. STUDY DESIGN: Retrospective clinical study.

Exercise training using hybrid assistive limb (HAL) lumbar type for locomotive syndrome: a pilot study.

BACKGROUND: With a rapidly aging population in Japan, locomotive syndrome is becoming an increasingly serious social problem. Exercise therapy using the lumbar type HAL, which is a wearable robot suit that can assist voluntary hip joint motion, would be expected to cause some beneficial effects for people with locomotive syndrome. The purpose of this study was to assess whether the deterioration of low back pain and any other adverse events would occur following HAL exercise therapy. Moreover, the changes of motor ability variables were evaluated. METHODS: We enrolled 33 participants (16 men, 17 women) with locomotive syndrome in this study. They received exercise training (sit-to-stand, lumbar flexion-extension, and gait training) with HAL (in total 12 sessions). We assessed the change of low back pain (lumbar VAS). More than 50% and 25 mm increase compared to baseline was defined as adverse events. One-leg standing time (OLST), 10-m walking test (10MWT), Timed Up and Go test (TUG), 1-min sit-to-stand test (1MSTS), FIM mobility scores and EQ-5D were measured. RESULTS: Of the 33 participants, 32 (16 men, 16 women) (97.0%) completed all 12 exercise training sessions using the lumbar type HAL. One woman aged 82 years withdrew because of right upper limb pain after the second session regardless of the use of HAL. There was no participant who had deterioration of low back pain. Any other adverse events including external injuries and/or falling, skin disorders, uncontrollable cardiovascular or respiratory disorders, and other health disorders directly related to this exercise therapy did not occur. Several outcome measures of motion ability including OLST, TUG and 1MSTS, EQ VAS and lumbar pain improved significantly after this HAL training. CONCLUSIONS: Almost all patients with locomotive syndrome completed this exercise training protocol without any adverse events related to HAL. Furthermore, balance function variables including OLST, TUG and 1MSTS improved after this HAL exercise therapy even though mobility function variables including 10MWT and FIM mobility scores did not show any significant change. These findings suggest that the exercise therapy using the lumbar type HAL would be one of the options for the intervention in locomotive syndrome.

Correlation between osteoarthritis of the atlantoaxial facet joint and a high-riding vertebral artery.

BACKGROUND: A high-riding vertebral artery (HRVA) is an intraosseous anomaly that narrows the trajectory for C2 pedicle screws. The prevalence of a HRVA is high in patients who need surgery at the craniovertebral junction, but reports about HRVAs in subaxial cervical spine disorders are limited. We sought to determine the prevalence of HRVAs among patients with subaxial cervical spine disorders to elucidate the potential risk for VA injury in subaxial cervical spine surgery. METHODS: We included 215 patients, 94 were with a main lesion from C3 to C7 (subaxial group) and 121 were with a main lesion from T1 to L5 (thoracolumbar group). A HRVA was defined as a maximum C2 pedicle diameter of < 3.5 mm on axial CT. The sex, age of patients, body mass index (BMI), osteoarthritis of the atlantoaxial (C1-2) facet joints, and prevalence of a HRVA in the 2 groups were compared and logistic regression was used to identify the factors correlated with a HRVA. RESULTS: The patients in the subaxial group were younger than those in the thoracolumbar group, but their sex and BMI did not differ significantly between the 2 groups. The mean osteoarthritis grade of the C1-2 facet joints of patients in the subaxial group was significantly higher than that in those in the thoracolumbar group. A HRVA was found in 26 patients of 94 (27.7 %) in the subaxial group and in 19 of 121 (15.7 %) in the thoracolumbar group. The prevalence of a HRVA in the subaxial group was significantly higher and osteoarthritis of C1-2 facet joints correlated significantly with a HRVA. CONCLUSIONS: The prevalence of a HRVA in patients with subaxial cervical spine disorders is higher than in those without and osteoarthritis of the C1-2 facet joints is correlated with a HRVA.

Characteristics of relief and residual low back pain after discectomy in patients with lumbar disc herniation: analysis using a detailed visual analog scale.

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.

Thoracic kyphosis and pelvic anteversion in patients with adult spinal deformity increase while walking: analyses of dynamic alignment change using a three-dimensional gait motion analysis system.

PURPOSE: To determine dynamic changes of spinopelvic alignment while walking using a three-dimensional (3D) gait motion analysis in adult spinal deformity (ASD) patients. METHODS: This study included 20 ASD patients. The 3D gait motion analysis (Vicon) was performed during continuous walking to their limit. Dynamic parameters were obtained using reflective markers on the spinous processes, which were segmented into thoracic (T-), lumbar (L-), and whole spine (S-), sagittal spinal distance (SVA) and coronal one (CVA), sagittal spinal angle to the vertical axis (SA) and coronal one (CA), sagittal pelvic angle to the horizontal axis (P-SA) and coronal (P-CA), and thoracic limited spinal angle to the pelvic angle (T-P SA) and lumbar one (L-P SA). The dynamic variables at the final lap were compared with those at the first lap of an oval walkway. RESULTS: Spinal kyphotic deformity deteriorated significantly. As for pelvic angle, the mean P-SA parameters (first lap/final lap) were 3.2°/5.2°. Anteversion of pelvic sagittal angle increased significantly after continuous walking to their limit. In particular, regarding limited spinal angle to the pelvic angle, the mean T-P SA parameters were 30.5°/36.2° and L-P SA parameters were 6.4°/6.8°. Thoracic kyphotic angle increased significantly, but lumbar kyphotic angle did not change. CONCLUSION: Decrease of thoracic kyphosis and pelvic retroversion has been recognized as a compensation for ASD on standing radiograph. Our 3D gait motion analysis to determine spinal balance found thoracic kyphosis and pelvic anteversion increased significantly in patients with ASD after continuous walking to the limit of their endurance until they were fatigued, indicating a failure of compensation for ASD. These slides can be retrieved under Electronic Supplementary Material.

Posterolateral lumbar spine fusion with unidirectional porous beta-tricalcium phosphate in a canine model.

We investigated the use of the autologous iliac bone and unidirectional porous beta-tricalcium phosphate (UDPTCP) in posterolateral lumbar spine fusion (PLF). Ten canine PLF models were prepared. Using only the autologous bone as the control group, 100%, 75%, 50%, and 25% groups were prepared according to the mixing ratios of UDPTCP. Radiological evaluation and histological analysis were performed 12 weeks after surgery. Bone fusion was evaluated according to anteroposterior plain X-rays and coronal reconstruction CT views using four grades: 0 = no osteogenesis, 1 = only slight discontinuous osteogenesis between transverse processes, 2 = discontinuous osteogenesis between transverse processes, and 3 = continuous osteogenesis between transverse processes. Bone fusion determined by X-ray was 2.8 ± 0.5 in the control group, 0 in the 100% UDPTCP group (p = 0.02), 1.8 ± 0.5 (p = 0.03) in the 75% UDPTCP group, 2.5 ± 0.6 (p = 0.54) in the 50% UDPTCP group, and 2.8 ± 0.5 (p = 1.0) in the 25% UDPTCP group. The bone fusion score was significantly lower in the 75% and 100% UDPTCP groups than in the control group. Bone fusion determined by CT was 2.8 ± 0.5 in the control group, 1.0 ± 0.8 (p = 0.01) in the 100% UDPTCP group, 2.0 ± 0.0 (p = 0.02) in the 75% UDPTCP group, 2.5 ± 0.6 (p = 0.54) in the 50% UDPTCP group, and 2.8 ± 0.5 (p = 1.0) in the 25% UDPTCP group. Similar to the bone fusion determination by X-ray, the bone fusion score was significantly lower in the 75% and 100% UDPTCP groups. These data suggest that, in a canine PLF model, the appropriate mixing ratio of UDPTCP is 50% or less.

Clinical Trial for the Safety and Feasibility of Pedicle Screws Coated with a Fibroblast Growth Factor-2-Apatite Composite Layer for Posterior Cervical Fusion Surgery.

To solve the instrument loosening problem, we developed a fibroblast growth factor-2-calcium phosphate composite layer as a novel coating material to improve screw fixation strength. The primary aim of the present study was to demonstrate the safety and feasibility of screws coated with the FGF-2-calcium phosphate composite layer for posterior instrumented surgery of the cervical spine. The trial design was a single-arm, open-label, safety and feasibility study. Patients receiving fusion of the cervical spine from C2 (or C3) to C7 (or T1) were recruited. The primary endpoint to confirm safety was any screw-related adverse events. Seven patients who underwent posterior fusion surgery of the cervical spine were enrolled in the present study. The coated pedicle screws were inserted bilaterally into the lowest instrumented vertebrae. There was only one severe adverse event unrelated with the coated screw. Three out of the fourteen coated screws showed loosening. The present results prove the safety and feasibility of pedicle screws coated with the FGF-2-calcium phosphate composite layer for fusion surgery in the cervical spine. This is the first step to apply this novel surface coating in the field of spine surgery.

Spinal Epidural Lipoma on the Ventral Dura Side and Intervertebral Foramen Causing Lumbar Radiculopathy.

A 56-year-old obese man with a body mass index of 30.9 kg/m2 presented with left sciatica and intermittent claudication. Computed tomography scans showed a posterior vertebral scalloping change in L3, L4, and L5. Meanwhile, magnetic resonance imaging revealed epidural mass posterior to the L3, L4, and L5 vertebral bodies. The solitary mass was isosignal to subcutaneous fat and asymmetrically compressed to the left side of the dural sac and L4 nerve root, as observed on axial T1- and T2-weighted images. To the best of our knowledge, there have been few reports of a solitary epidural lipoma causing lumbar radiculopathy. The patient underwent transforaminal lumbar interbody fusion at L4-L5, and his symptoms then resolved. Thus, we recommend decompression and fixation as appropriate management for lumbar radiculopathy caused by epidural lipoma located on the ventral side of the dura and intervertebral foramen.

Surgical Apgar Score and Controlling Nutritional Status Score are significant predictors of major complications after cervical spine surgery.

Nutritional screening scores, including Controlling Nutritional Status (CONUT) Score and Surgical Apgar Score (SAS), which reflect intraoperative hemodynamics, have been reported to be useful for predicting major postoperative complications in various kinds of surgery. We assessed independent risk factors for major complications after cervical spine surgery using those scoring measurements. We retrospectively reviewed medical records of patients who underwent cervical spine surgery at our institution from 2014 to 2019. Baseline clinical information, including the CONUT Score, and surgical factors, including the SAS, were assessed as risk factors for major postoperative complications. We analyzed 261 patients. Major postoperative complications occurred in 40 cases (15.3%). In the multivariate analysis, SAS (odds ratio [OR], 0.42; P < 0.01), CONUT (OR, 1.39; P < 0.01), and operative time (OR, 1.42; P < 0.01) were significant independent risk factors of major complications. The area under the SAS curve was 0.852 in the receiver operating characteristic curve analysis. Postoperative hospitalization duration was significantly longer in major complications group. Evaluating preoperative nutritional condition and intraoperative hemodynamics with CONUT score and SAS was useful for predicting major postoperative complications of cervical spine surgery. In addition, both scoring measurements are easily calculated, objective evaluations. Perioperative management utilizing those scoring measurements may help prevent them.

Can Proximal Junctional Kyphosis after Surgery for Adult Spinal Deformity Be Predicted by Preoperative Dynamic Sagittal Alignment Change with 3D Gait Analysis? A Case-Control Study.

BACKGROUND: Severe spinal deformity is a risk factor for proximal junctional kyphosis (PJK) in surgery for adult spinal deformity (ASD). However, standing X-ray imaging in patients with dynamic spinal imbalance can underestimate the risk of PJK because of compensation mechanisms. This study aimed to investigate whether preoperative dynamic spinal alignment can be a predictive factor for PJK. METHODS: We retrospectively included 27 ASD patients undergoing three-dimensional (3D) gait analysis before surgery. Dynamic spinal parameters were obtained using a Nexus motion capture system (Vicon, Oxford, UK). The patients were instructed to walk as long as possible around an oval walkway. The averaged dynamic parameters in the final lap were compared between patients with PJK (+) and with PJK (-). RESULTS: PJK occurred in seven patients (26%). The dynamic angle between the thoracic spine and pelvis was larger in patients with PJK (+) than in those with PJK (-) (32.3 ± 8.1 vs. 18.7 ± 13.5 °, p = 0.020). Multiple logistic regression analysis identified this angle as an independent risk factor for PJK. CONCLUSIONS: Preoperative thoracic anterior inclination exacerbated by gait can be one of preoperative independent risk factors for PJK in patients undergoing corrective surgery for ASD.

Paravertebral foramen screw fixation for posterior cervical spine surgery: clinical case series.

OBJECTIVE: The goal of this study was to clarify the clinical utility of paravertebral foramen screws (PVFSs) and to determine intraoperative indicators for appropriate screw placement during posterior cervical fusion surgery to improve its safety. METHODS: The authors included data from 46 patients (29 men and 17 women, mean age 61.7 years) who underwent posterior cervical spine surgery with 94 PVFSs. Of the 94 PVFSs, 77 were used in C6, 9 in C3, 5 in C4, and 3 in C5. According to the cervical lateral radiographic view, the authors divided the 94 PVFSs into 3 groups as follows: a longer group, in which the tip of PVFS was located anteriorly from the line of the posterior wall of the vertebral body (> +0 mm); an intermediate group, in which the screw tip was located up to 2 mm posteriorly to the posterior wall of the vertebral body (-2 to 0 mm); and a shorter group, in which the screw tip was located more than 2 mm posteriorly (< -2 mm). The accuracy of screw placement was assessed using CT imaging in the axial plane, and the proportion of screws penetrating a vertebral foramen or a transverse foramen was compared between the 3 groups. Screw loosening was defined as a lucent zone around the screw evaluated on cervical radiography at 1 year after surgery. Complications related to PVFS insertion and revision surgery related to PVFS were evaluated. RESULTS: The authors classified 25 PVFSs into the longer group, 43 into the intermediate group, and 26 into the shorter group. The proportion of screws penetrating a vertebral foramen was largest in the shorter group, and the proportion penetrating a transverse foramen was largest in the longer group. Screw loosening was confirmed for 3 of 94 PVFSs. One PVFS inserted in C6 unilaterally within a long construct from C2 to C7 showed loosening, but it did not cause clinical symptoms. Revision surgery was required for 2 PVFSs inserted in C3 bilaterally as the lower instrumented vertebra in occiput-cervical fusion because they pulled out. There was no neurovascular complication related to PVFS insertion. CONCLUSIONS: PVFSs are useful for posterior cervical fusion surgery as alternative anchor screws, and the line of the posterior wall of the cervical body on lateral fluoroscopic images is a potential intraoperative reference to indicate an appropriate trajectory for PVFSs.

Sudden, Transient Intraoperative Hypotension During the Use of the Cantilever Technique for Correction of Adult Spine Deformity.

Intraoperative hypotension is a common but critical complication of spinal surgery. However, it is uncommon to experience sudden transient intraoperative hypotension in patients undergoing surgery for adult spine deformity (ASD) without the presence of major vascular injury, spinal cord injury, or cardiac events. We report a patient who experienced sudden transient intraoperative hypotension during the use of the cantilever technique for correction of an ASD. A 58-year-old woman underwent two-stage surgery (anterior correction followed by posterior fusion) for an ASD that caused low back pain. During the posterior fusion procedure, she experienced sudden transient intraoperative hypotension during the use of a cantilever technique. As soon as we paused the use of this technique, her hypotension resolved. Postoperative radiography revealed excessive segmental lordosis at the L4/5 level, suggesting an accidental rupture of the anterior longitudinal ligament (ALL). We believe that the mechanism of our patient's sudden hypotension was a decrease in venous return due to compression and stretching of the inferior vena cava at the time of rod application when the use of the cantilever technique caused ALL rupture. Sudden hypotension during posterior spinal correction surgery is possible, especially in patients with a ruptured ALL.

Imaging-Based Diagnosis of Epiconus Syndrome From the Distance of the Lesion to Where the Spinal Cord Terminates Not From the Disc Level: A Case Series.

Objective This study aimed to analyze the neurological symptoms caused by thoracolumbar lesions according to their distance from where the spinal cord terminates for a better description of epiconus syndrome. Methods We retrospectively reviewed cases of patients with neurological symptoms caused by a thoracolumbar lesion in a single institute. Neurological symptoms were analyzed according to the distance from the proximal end of the lesion to where the spinal cord terminates using MRI or CT myelograms. The symptoms were classified into epiconus syndrome, thoracic myelopathy, and conus medullaris syndrome. The distance was described regarding the length of a vertebral body (VB). Results We included 19 patients in this series. The spinal cord terminates were at the lower third of the L1 vertebra most frequently (32%) in the range of T12 to L2 vertebra. The border between thoracic myelopathy and epiconus syndrome was 2VB proximal from where the spinal cord terminates, and that between epiconus syndrome and conus medullaris syndrome was 1VB. Mean disease duration until symptoms changed was 2.4 months in epiconus syndrome, while it was 25 months in thoracic myelopathy, and 10.3 months in conus medullaris syndrome. Conclusion Epiconus syndrome is caused by lesion 1-2VB proximal to where the spinal cord terminates. This study may provide further helpful information for clinical practice in the treatment of epiconus syndrome.

Severe, rigid cervical kyphotic deformity associated with SAPHO syndrome successfully treated with three-stage correction surgery combined with C7 vertebral column resection: a technical case report.

STUDY DESIGN: Case report. OBJECTIVES: To describe the first reported use of corrective surgery combined with C7 vertebral column resection (VCR) to treat an extremely rare case of severe, rigid cervical kyphotic deformity associated with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. BACKGROUND DATA: Spinal lesions reportedly occur in 32-45% in SAPHO syndrome. However, bone and joint lesions are usually repaired such that severe joint destruction is rare. Therefore, there have been few reported cases of surgical treatment for spinal lesions. METHODS: A 22-year-old woman had been diagnosed with cervical kyphotic deformity associated with SAPHO syndrome. She had difficulty looking upward. On radiography, the C4-C7 vertebral bodies were fused and exhibited severe rigid kyphotic deformity. Right convex scoliosis with a Cobb angle of 22° was apparent at C5-T2, and the C2-C7 angle of kyphosis was 75°. Corrective three-stage surgery was carried out from the anterior, posterior, and anterior, with C7 VCR. RESULTS: The C2-T1 angle improved to 21° and the patient was capable of looking up. At present, 2 years postoperatively, complete bony fusion has been achieved. Her cervical spine function and quality of life were markedly improved. CONCLUSION: Only a very limited number of patients have a deformity sufficiently severe that VCR of cervical vertebra is required, but as this is the technique that provides the greatest multiplanar alignment correction, its choice in the present case was appropriate. LEVEL OF EVIDENCE: IV.

Exercise Therapy Using the Lumbar-Type Hybrid Assistive Limb Ameliorates Locomotive Function after Lumbar Fusion Surgery in an Elderly Patient.

The number of elderly people who undergo lumbar fusion surgery (LFS) has been increasing. Postoperative rehabilitation for them can be problematic due to lumbar stiffness. This is the first case report describing exercise therapy using the lumbar-type hybrid assistive limb (HAL) after multiple LFS in an elderly patient. An 83-year-old man underwent LFS at L4-S1. Additional fusion surgery at L2-3 for adjacent segment disease was performed 2 years after the primary surgery. Although the patient's leg pain declined, he had severe locomotive dysfunction at 3 months after his final surgery. He started exercise therapy using the lumbar-type HAL including sit-to-stand training and squat training 4 months after his final surgery. He performed 3 sets of 20 sit-to-stand and 20 squat repetitions with adequate rests in between sets. The HAL training was safely conducted every day for 12 weeks without adverse event. Timed up and go test (TUG), 1-minute sit to stand test (1MSTS), one-leg stand test (OLST), and Berg balance scale (BBS) were assessed as locomotive function measurement. Before HAL therapy, TUG, 1MSTS, OLST, and BBS were 18.1 sec, 20 times, less than 1 sec, and 47, respectively. He could not walk without assistance. After the exercise therapy with the lumbar-type HAL, his locomotive function dramatically improved. TUG, 1MSTS, OLST, and BBS were 12.2 sec, 25 times, 3.9 sec, and 52, respectively. Moreover, the patient could walk 60 meters continuously without assistance. The unique characteristics of the lumbar-type HAL to prevent the lumbar overload and assist the voluntary hip joint motion during exercise therapy may be effective for this patient with lumbar stiffness after LFS. Sit-to-stand training and squat training using the lumbar-type HAL are promising options to improve locomotive function in elderly patients after LFS.

Accidental anterior longitudinal ligament rupture during lateral lumbar interbody fusion disclosed after posterior corrective fusion surgery resulting in local hyper-lordosis.

Objective: To report a case of anterior longitudinal ligament (ALL) injury that was not noticeable during lateral lumbar interbody fusion and was disclosed after posterior corrective fusion surgery. Case presentation: After performing lateral lumbar interbody fusion followed by posterior corrective fusion surgery, we observed an anterior longitudinal ligament rupture that required additional surgery. Postoperative pain in the left lower limb and muscle weakness due to nerve traction appeared, but this was improved by stabilization between the vertebral bodies. Conclusion: Unidentified anterior longitudinal ligament rupture can result in unexpected local lordosis during posterior surgery, possibly related to lower extremity palsy. Therefore, checking for possible rupture during and after anterior surgery is important. If the ALL damage is disclosed before posterior surgery, the proper surgical strategy for the posterior surgery must be considered.

A Case of Cardiac Arrest during C1 Laminectomy for Irreducible Atlantoaxial Subluxation.

We report a case of cardiac arrest, which occurred during C1 laminectomy for irreducible atlantoaxial subluxation, with return of spontaneous circulation (ROSC) upon interruption of the laminectomy. A 60-year-old woman with rheumatoid arthritis presented with neck pain, bilateral finger numbness, and bladder-rectal disturbance. Simple radiograph images showed that the atlantodental interval (ADI) was enlarged to 8 mm, and magnetic resonance imaging revealed severe spinal stenosis at C1. She was diagnosed with cervical spondylotic myelopathy due to atlantoaxial subluxation. Cardiac arrest occurred twice during the C1 laminectomy and occipito-cervical fusion (Occ-C3), and ROSC occurred without any treatment. There was no postoperative worsening of neurological symptoms, and the improvement of sensory and motor palsy was favorable. The pathogenic mechanism was presumed to be trigeminocardiac reflex. Cardiac arrest during upper cervical spine surgery is an important intraoperative complication of which operators should be made aware.

Successful Use of the Hybrid Assistive Limb for Care Support to Reduce Lumbar Load in a Simulated Patient Transfer.

STUDY DESIGN: Prospective experimental study in humans. PURPOSE: To determine whether the hybrid assistive limb (HAL) for Care Support can reduce lumbar load during a patient transfer. OVERVIEW OF LITERATURE: The prevalence of work-related low back pain (LBP) among nurses is high. In particular, transferring patients poses a high risk for LBP due to the large lumbar load. Attempts to reduce the lumbar load are crucial to avoid the risk of LBP. Therefore, we investigated the effects of the HAL for Care Support. 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.