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Background Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by heterotopic bone formation in the posterior longitudinal ligament of the spine. Although the patients with OPLL are more common in the 60s and 70s, we know that there are markedly young patients (e.g., early 40s). However, to the best of our knowledge, there is few reports characterize young patients with cervical OPLL in terms of the imaging features, subjective symptoms, and ADL problems. Methods This is the multicenter cross-sectional study. Two hundred and thirty-seven Japanese symptomatic patients with cervical OPLL confirmed by standard X-rays collected from 16 institutions belonging to the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament formed by the Japanese Ministry of Health, Labor and Welfare were recruited. Whole spine CT data as well as demographic data such as age, gender, patients-based evaluations, and the 36-item Short Form Health Survey (SF-36) were evaluated. Results Young group (≦ 45 years old) consisted of 23 patients (8 females and 15 males), accounting for 9.7% of the total. Their characteristics were high body mass index (BMI), significant involvement of trauma in the onset and deterioration of symptoms, and the predominance of thoracic OPLL. The patient-based evaluations did not show a significant difference between the young and non-young groups, or between the genders in the young group except for bodily pain (BP) of SF-36. Female patients in young group had significantly lower BP score of SF-36 than that of male in young group. Conclusions Characteristics of young patients with cervical OPLL were high BMI, significant involvement of trauma in the onset and deterioration of symptoms, lower BP score of SF-36 in female, and the predominance of thoracic OPLL.

In Japan, approximately 75% of patients with thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) are treated by posterior decompression with instrumented spinal fusion (PDF) because of its efficacy and safety. To achieve more effective decompression of the spinal cord using a posterior approach, anterior decompression through a posterior approach was developed. However, this technique has a high risk of postoperative paralysis. We have added a couple of ingenuities to this procedure (modified Ohtsuka procedure). This study was performed to report the surgical results of our modified Ohtsuka procedure and to compare them with the results of PDF.This was a retrospective case series. From 2008 to 2018, we surgically treated 32 patients: 20 patients treated by PDF (PDF group) and 12 patients by our modified Ohtsuka procedure (modified Ohtsuka group) as the initial surgery. All patients were followed up for at least 12 months. The degree of surgical invasion and patients' neurological condition were assessed.The operative duration and intraoperative blood loss indicated no significant differences (PDF vs. Ohtuska: 507 ± 103 vs. 534 ± 99 min, 1022 ± 675 vs. 1160 ± 685 ml, respectively). The preoperative Japanese Orthopaedic Association (JOA) score was 4.5 ± 2.0 in the PDF group and 3.3 ± 1.4 in the modified Ohtsuka group (p 0.05). However, the latest JOA score and recovery rate were significantly better in the modified Ohtsuka group than in the PDF group (8.9 ± 1.2 vs. 7.4 ± 2.5 and 70.8 ± 17.6% vs. 44.5 ± 40.2%, respectively). Postoperative paralysis did not occur in the modified Ohtsuka group while four patients had it in the PDF group.The present study clearly indicated the modified Ohtsuka group showed significantly better surgical outcomes than the PDF group with the recovery rate ≥70%.

Introduction: Sacroiliac joint (SIJ) arthrodesis using a minimally invasive technique, particularly the triangular implant system, is performed in patients with SIJ dysfunction in the United States and Europe. We report three-year clinical outcomes of the first minimally invasive SIJ arthrodesis procedures using the implants performed in Japan. Methods: Five patients (one man and four women; age: 56.4±16.9 years) with SIJ pain who underwent SIJ arthrodesis using a triangular implant system in 2017 were included. In addition to operation time and blood loss, pain intensity (visual analog scale [VAS]) and functional impairment (Oswestry disability index [ODI]) were assessed preoperatively and at a 36-month follow-up. Implant loosening and osseous bridging across the joint were evaluated using computed tomography images, and patients' satisfaction with the surgery was also assessed at 12 and 36 months. Results: The surgical time was 67.7±13.1 minutes, and blood loss was 7.4±6.9 mL. The mean VAS value improved significantly from 88.0±8.4 mm to 33.6±31.9 mm at 3 months and was maintained at 46.4±30.9 mm at 36 months (P

Background Suture bridge repair has been widely used as one of the standard procedures in the arthroscopic rotator cuff repair. We compared the intratendinous stress distribution between single and double suture passing techniques in the suture bridge repair using a 2-mm tape and clarified the roles of tensioning in this procedure. Methods A board-like model of the supraspinatus tendon and humeral head was used in order to standardize conditions and exclude the influence of anatomical variations between individuals. Reattachment of the supraspinatus tendon to the bone was simulated using both single and double suture passing techniques for the suture bridge repair using a 2-mm tape. A tensile load was applied to the medial end of the tendon, and the stress distribution pattern was observed. Elastic analysis enabled comparison of the von Mises equivalent and maximum principal stresses between the single and double suture passing techniques. The tape configuration was subsequently translated 1 mm toward the insertion points of lateral anchors to simulate the tensioning maneuver. Results Although the distribution pattern of both the equivalent and the maximum principal stresses was similar for both models, areas with a high stress concentration were smaller in the single suture passing model than those in the double suture passing model. The equivalent stress concentrated within the tendon beneath the tapes as well as in the area between the crossing tapes and the lateral end of the tendon, whereas the maximum principal stress concentrated medial to the sites of suture penetration. Conclusions Single suture passing technique can reduce the extent of intratendinous stress concentration compared with double suture passing technique, which might be beneficial to reduce the incidence of type 2 retear after suture bridge repair of rotator cuff tendon using a 2-mm tape.

Background Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by heterotopic bone formation in the posterior longitudinal ligament of the spine. We know that the size and distribution of the ossified lesions in patients with OPLL are different in each case. However, the characteristics of the patients with radiologically severe cervical OPLL remain unknown. Methods The participants of our study were symptomatic patients with cervical OPLL who were diagnosed by standard radiographs of the cervical spine. Whole-spine CT data and demographic data such as age and sex were obtained from 20 institutions belonging to the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. According to the number of the levels involved by OPLL, we stratified the patients into two subgroups: severe group (S-group) and non-severe group (NS-group) to delineate the characteristics of radiologically severe patients with cervical OPLL. We also evaluated the most compressed level and the degree of occupying ratio of cervical spinal canal by OPLL at the most compressed level. Results A total of 234 patients with a mean age of 65 years were recruited. The S-group consisted of 48 patients (21%, 12 females and 36 males) and the NS-group consisted of 92 patients (79%, 22 females and 70 males). The mean age of males in the S-group (68 years old) was significantly higher than that of males in the NS-group (64 years old); however there was no significant difference in the mean age in females between the S-group (69 years old) and the NS-group (66 years old). No significant difference of body mass index, ossification of the nuchal ligament-positivity and presence of diabetes mellitus were found between the S- and the NS-group. Conclusions It is likely that the manner of extension of cervical OPLL is different between male and female patients.

Autophagy is the degradation process of dysfunctional intracellular components and has a crucial function in various human diseases. There are three different types of autophagy: macroautophagy, microautophagy, and chaperone-mediated autophagy (CMA). CMA is a major route for the elimination of cellular aberrant proteins and can provide a cytoprotective effect. The present study investigated the expression of lysosome-associated membrane protein type 2A (LAMP2A), which is the hallmark of CMA activity, in damaged neural tissue after spinal cord injury (SCI) in mice. The number of LAMP2A-expressing cells was significantly increased at the lesion following SCI. The increased number of LAMP2A-positive cells was observed from 24 h and peaked at 3 days after injury. A western blot analysis confirmed that the level of LAMP2A protein was significantly increased in the injured spinal cord compared with the uninjured cord. On double staining for LAMP2A and different neural cell type markers, the increased expression of LAMP2A was observed in neurons, astrocytes, oligodendrocytes, and microglia/macrophages following injury. An electron microscopic analysis showed that secondary lysosomes were increased in damaged neurons at the lesion site. Immunoelectron microscopy revealed that the gold particles with anti-LAMP2A antibody were frequently localized at the secondary lysosomes in the injured site. These findings indicated that CMA was clearly activated in damaged neural tissue after SCI. The activation of CMA may contribute to the elimination of intracellular aberrant proteins and exert a neuroprotective effect following SCI.

Bipedalism is a unique function in humans. Various investigations in bipedal walking have assessed the kinetic chain from the pelvis to the lower limbs. However, few studies have investigated the functions of the upper body including the psoas major muscles. In the present study, a bipedal-walking human full-body skeletal model, "the bipedal android model", was generated by attaching air cylinder devices to simulate the contraction and relaxation of various muscles required for bipedal walking, including the psoas major muscles. The bipedal-walking principle was discussed using the model.Every part of a human full-body skeletal model was connected by wires or cables to retain the mobility of each joint. Then the psoas major (PM), gluteus minimus (GM), long head of biceps femoris (BF), quadriceps femoris (QF), and semimembranosus (SM) muscles were simulated in the skeletal model using air cylinders. The gait pattern was observed by synchronizing the contraction of PM, GM, QF and SM, and relaxation of BF of the ipsilateral side together with the reversed patterns in the contralateral side, and then switching the phase by every step. The gait pattern in dysfunction of PM or GM muscles was also observed by disconnecting the corresponding air cylinders.The synchronized contraction of PM, GM, QF and SM generates the force to tilt the upper body to ipsilateral side, followed by elevation of the lower limb together with the forward rotation of the pelvis in the contralateral side to swing the leg forward. The next step was generated by reversing the contraction phase at the landing of the swung leg. The dysfunction of PM muscle disabled effective gait in the model, while GM did not.The bipedal android model indicated that the psoas major muscles play a crucial role in bipedal walking in human.

Background: Although diffuse idiopathic skeletal hyperostosis (DISH) is known to coexist with the ossification of spinal ligaments (OSLs), details of the radiographic relationship remain unclear. Methods: We prospectively collected data of 239 patients with symptomatic cervical ossification of the posterior longitudinal ligament (OPLL) and analyzed the DISH severity on whole-spine computed tomography images, using the following grades: grade 0, no DISH, grade 1, DISH at T3–T10, grade 2, DISH at both T3–T10 and C6–T2 and/or T11–L2, and grade 3, DISH beyond C5 and/or L3. Ossification indices were calculated as the sum of vertebral and intervertebral levels with OSL for each patient. Results: DISH was found in 107 patients (44.8%), 65 (60.7%) of whom had grade 2 DISH. We found significant associations of DISH grade with the indices for cervical OPLL (r = 0.45, p &lt, 0.0001), thoracic ossification of the ligamentum flavum (OLF, r = 0.41, p &lt, 0.0001) and thoracic ossification of the supra/interspinous ligaments (OSIL, r = 0.53, p &lt, 0.0001). DISH grade was also correlated with the index for each OSL in the whole spine (OPLL: r = 0.29, p &lt, 0.0001, OLF: r = 0.40, p &lt, OSIL: r = 0.50, p &lt, 0.0001). Conclusion: The DISH grade correlated with the indices of OSL at each high-prevalence level as well as the whole spine.

Background: This study investigated how diffuse idiopathic skeletal hyperostosis (DISH) influences clinical characteristics in patients with cervical ossification of the posterior longitudinal ligament (OPLL). Although DISH is considered unlikely to promote neurologic dysfunction, this relationship remains unclear. Methods: Patient data were prospectively collected from 16 Japanese institutions. In total, 239 patients with cervical OPLL were enrolled who had whole-spine computed tomography images available. The primary outcomes were visual analog scale pain scores and the results of other self-reported clinical questionnaires. Correlations were sought between clinical symptoms and DISH using the following grading system: 1, DISH at T3-T10, 2, DISH at both T3–10 and C6–T2 and/or T11–L2, and 3, DISH beyond the C5 and/or L3 levels. Results: DISH was absent in 132 cases, grade 1 in 23, grade 2 in 65, and grade 3 in 19. There were no significant correlations between DISH grade and clinical scores. However, there was a significant difference in the prevalence of neck pain (but not in back pain or low back pain) among the three grades. Interestingly, DISH localized in the thoracic spine (grade 1) may create overload at the cervical spine and lead to neck pain in patients with cervical OPLL. Conclusion: This study is the first prospective multicenter cross-sectional comparison of subjective outcomes in patients with cervical OPLL according to the presence or absence of DISH. The severity of DISH was partially associated with the prevalence of neck pain.

BACKGROUND Oral support during feeding was clinically provided to patients with severe motor and intellectual disabilities (SMID) for the prevention of dysphasia. The present study anatomically and functionally investigated the advantages of oral support. METHODS A videofluoroscopic swallowing study was conducted on nine patients with SMID (age = 5-41 years; mean age = 15.0; four males, five females) and twenty-four healthy adults (age = 26-67 years; mean age = 44.3; 16 males, eight females). The movements of the hyoid bone and mandible during pharyngeal swallowing were tracked, and the pharyngeal residues were evaluated. The temporal and spatial features of the movements were compared between patients with and without oral support as well as healthy adults. RESULTS The mandible moved downward earlier and showed larger displacement in the patients with SMID. The patients also had insufficient anterior displacement of the hyoid, which was associated with pharyngeal residue. This displacement was enhanced, and the pharyngeal residue decreased with oral support. CONCLUSIONS Oral support to hold the mandible successfully improved hyoid excursion and reduced pharyngeal residue during swallowing, which is a simple and reliable strategy for the prevention of dysphasia in patients with SMID.

Experiments are conducted on a planar ramp in high-enthalpy flow, with gaseous hydrogen injected through a porthole at the ramp surface. The ramp is covered in a thin layer of temperature-sensitive luminescent paint, originally intended to allow surface heat-flux measurements; however, anomalous transient features are identified in high-speed recorded images of the paint emission, which are postulated as originating from excitation by OH* chemiluminescence produced during hydrogen combustion. By assuming the OH*-induced emission to occur on much shorter timescales than surface temperature changes, it is possible to extract this pseudo-OH* signal, allowing time-resolved combustion features to be investigated. Two cases are examined, the first exhibiting marginal combustion and the second with more robust ignition. For the first, the weak OH* excitation allows concurrent temperature and heat-flux distributions to be derived. In both cases, the time-averaged combustion distribution shows intense ignition in the immediate vicinity of the injection hole, with extended fingers of weaker combustion extending downstream; the latter are assumed to be associated with the main counter-rotating vortex pair produced by the injection. By examining shorter timescales, however, it is revealed that these combustion fingers are not steady features but rather the time-integrated result of more localized ignition streaks convecting downstream. Overall, the presence of combustion is associated with higher surface heat fluxes. The pseudo-OH* visualization method is a possible alternative to conventional OH* chemiluminescence for wall-bounded combusting flows, allowing a conventional visible-wavelength camera to be employed in place of a UV-sensitive imaging system.

Introduction Laminoplasty is a common surgery for cervical myelopathy. Previous studies have analyzed the reoperation rates in posterior decompression surgeries of the cervical spine. However, few studies have solely focused on midline-splitting laminoplasty (MSL) using a large number of patients. This aims to analyze the reoperation rates after MSL using the survival function method. Methods Between 1988 and 2013, 4,208 MSLs were performed as a primary operation for cervical myelopathy and enrolled in our spinal surgery registration system. The Kaplan-Meier survival function method was used to analyze the rates of reoperation. Results Of 4,208 patients with primary MSL, 40 underwent reoperation for neurological complications. The overall reoperation rate was 0.26%, 0.64%, 0.83%, 0.93%, and 0.95% at 1, 5, 10, 20, and >20 years, respectively. The causes of reoperation were postoperative cervical radiculopathy in 10 patients, stenosis at an adjacent level in 8, stenosis due to failed "open-door" lamina in 6, instability of the cervical spine in 4, cervical disc herniation in 3, elongation of ossification of the posterior longitudinal ligament in 3, spinal cord injury in 1, fracture of the cervical spine in 1, postoperative scar formation in 1, ossification of anterior longitudinal ligament in 1, and unknown in 2. The number of patients with surgical site infection (SSI) who needed surgical debridement was 34 (0.81%). Conclusions Excluding reoperations for SSI, the reoperation rate of MSL was approximately 1.0% at the maximum of 26 years after surgery. MSL was determined to be a reliable surgical procedure regarding postoperative complications requiring additional surgeries.

Patients with spinal kyphosis were radiographically evaluated while standing. However, the spino-pelvic alignment during walking is different. This study examined the spino-pelvic-lower extremity alignment during walking by a three-dimensional (3D) motion analysis.Twenty-six patients with a sagittal vertical axis of ≥4 cm (male: female, 5:21; average age, 66 years) were evaluated. Using a 3D motion capture system, the trunk and pelvic anterior inclination angles, hip and knee joint angles were measured during a 3-min walk. The correlation coefficient between the change of the trunk anterior inclination angle and each parameter at the beginning of walking was calculated, and those parameters were compared with radiographic measurements.The patients were divided into two groups according to the change of the trunk anterior inclination angle: the large change group included 14 patients with an increase of ≥5° between the beginning and end of the 3-min walk; the small change group included 12 patients with an increase of5°. The pelvic anterior inclination angle showed a significant difference between the two groups at the first gait cycles. The pelvic anterior inclination angle and the hip joint angle in the large change group showed a significant difference between the first and last cycles. The correlation coefficient revealed a significant association between the change in the trunk anterior inclination angle and the pelvic anterior inclination angle at the beginning of walking. There were no significant differences between the two groups in any radiographic spino-pelvic parameters.There were two types of patients with spinal kyphosis: patients with a small pelvic anterior inclination angle at the beginning of walking showed slight progression in their trunk anterior inclination, whereas those with a large pelvic angle showed a large degree of progression in their pelvic and trunk inclination during walking.

Background: The purpose of this study was to clarify the clinical features of ossification of the posterior longitudinal ligament (OPLL) and extreme ossification at multiple sites. Methods: This prospective study involved patients with a diagnosis of cervical OPLL at 16 institutions in Japan. Patient-reported outcome measures, including responses on the Japanese Orthopaedic Association (JOA) Cervical Myelopathy Evaluation Questionnaire (JOA-CMEQ), JOA Back Pain Evaluation Questionnaire (JOA-BPEQ), and visual analog scale pain score, were collected to investigate clinical status. In each patient, the sum of the levels at which OPLL was located (OP index) was evaluated on whole-spine computed tomography, along with ossification of other spinal ligaments including the anterior longitudinal ligament (OALL), ligament flavum (OLF), supra- and intraspinous ligaments (SSL), and diffuse idiopathic skeletal hyperostosis (DISH). The distribution of OP index values in the study population was investigated, and the clinical and radiologic characteristics of patients in the top 10% were assessed. Results: In total, 236 patients (163 male, 73 female; mean age 63.5 years) were enrolled. Twenty-five patients with OP index ≥ 17 were categorized into a high OP index group and the remainder into a moderate/low OP index group. There were significantly more women in the high OP index group. Patients in the high OP index group also had significantly poorer scores for lower extremity function and quality of life on the JOA-CMEQ and in each domain but not for body pain on the JOA-BPEQ compared with those in the moderate/low OP index group. Patients in the high OP index group had more OALL in the cervical spine and more OLF and SSL in the thoracic spine. The prevalence of DISH was also significantly higher in the high OP index group. In the high OP index group, interestingly, OPLL was likely to be present adjacent to DISH in the cervicothoracic and thoracolumbar spine, especially in men, and often coexisted with DISH in the thoracic spine in women. Conclusion: This prospective cohort registry study is the first to demonstrate the clinical and radiologic features of patients with OPLL and a high OP index. In this study, patients with a high OP index had poorer physical function in the lumbar spine and lower extremities and were also predisposed to extreme ossification of spinal ligaments other than the OPLL.

BackgroundIn this study, we aimed to identify the gene abnormality responsible for pathogenicity in an individual with an undiagnosed neurodevelopmental disorder with megalencephaly, ventriculomegaly, hypoplastic corpus callosum, intellectual disability, polydactyly and neuroblastoma. We then explored the underlying molecular mechanism.MethodsTrio-based, whole-exome sequencing was performed to identify disease-causing gene mutation. Biochemical and cell biological analyses were carried out to elucidate the pathophysiological significance of the identified gene mutation.ResultsWe identified a heterozygous missense mutation (c.173C>T; p.Thr58Met) in theMYCNgene, at the Thr58 phosphorylation site essential for ubiquitination and subsequent MYCN degradation. The mutant MYCN (MYCN-T58M) was non-phosphorylatable at Thr58 and subsequently accumulated in cells and appeared to induce CCND1 and CCND2 expression in neuronal progenitor and stem cells in vitro. Overexpression of Mycn mimicking the p.Thr58Met mutation also promoted neuronal cell proliferation, and affected neuronal cell migration during corticogenesis in mouse embryos.ConclusionsWe identified a de novo c.173C>T mutation inMYCNwhich leads to stabilisation and accumulation of the MYCN protein, leading to prolonged CCND1 and CCND2 expression. This may promote neurogenesis in the developing cerebral cortex, leading to megalencephaly. While loss-of-function mutations inMYCNare known to cause Feingold syndrome, this is the first report of a germline gain-of-function mutation inMYCNidentified in a patient with a novel megalencephaly syndrome similar to, but distinct from, CCND2-related megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome. The data obtained here provide new insight into the critical role of MYCN in brain development, as well as the consequences of MYCN defects.

Objectives Dysphagia is linked to mortality risk among patients with profound intellectual and multiple disabilities (PIMD); the present study therefore aimed to clarify the characteristics of hyoid movements during swallowing and to examine the mechanism of dysphagia in patients with PIMD. Methods A retrospective video fluoroscopic swallowing study was conducted on 43 patients with PIMD (mean age = 25.4; 25 males, 18 females) and 24 healthy adults (mean age = 44.3; 16 males, 8 females). The movements of the hyoid bone and mandible were tracked frame by frame in the video footage, and their range of movements and trajectories were analyzed. Results Most patients showed atypical movement trajectories of the hyoid, such as insufficient anterior movement and increased range of mandibular downward movement, compared with normal adults. Moreover, the mechanism of dysphagia was revealed by structural equation modeling, indicating that insufficient anterior movement could lead to pharyngeal residue in the pyriform sinus. Conclusion The insufficient anterior movement of the hyoid could be caused by weak ventral suprahyoid muscles and atypical head and neck posture characteristic of patients with PIMD. It may be useful to predict pharyngeal residue from the range of hyoid movements and trajectories for the prevention of aspiration.

OBJECTIVE Various surgical procedures are used to manage thoracic myelopathy due to ossification of the posterior longitudinal ligament (OPLL). However, the outcomes of surgery for thoracic OPLL are generally unfavorable in comparison to surgery for cervical OPLL. Previous studies have shown a significant risk of perioperative complications in surgery for thoracic OPLL. Thus, a safe and secure surgical method to ensure better neurological recovery with less perioperative complications is needed. The authors report a novel concept of anterior decompression through a posterior approach aimed at anterior shift of the OPLL during surgery rather than extirpation or size reduction of the OPLL. This surgical technique can securely achieve anterior shift of the OPLL using a curved drill, threadwire saw, and curved rongeur. The preliminary outcomes were investigated to evaluate the safety and efficacy of this technique. METHODS This study included 10 consecutive patients who underwent surgery for thoracic OPLL. Surgical outcomes, including the ambulatory status, Japanese Orthopaedic Association (JOA) score, and perioperative complications, were investigated retrospectively. In this surgery, pedicle screws are introduced at least three levels above and below the corresponding levels. The laminae, facet joints, transverse processes, and pedicles are then removed bilaterally at levels wherein subsequent anterior decompression is performed. For anterior decompression, the OPLL and posterior portion of the vertebral bodies are partially resected using a high-speed drill with a curved burr, enabling the removal of osseous tissues just ventral to the spinal cord without retracting the dural sac. To securely shift the OPLL anteriorly, the intact PLL and posterior portion of the vertebral bodies cranial and caudal to the lesion are completely resected using a threadwire saw and/or curved rongeur. Rods are connected to the screws, and bone grafting is performed for posterolateral fusion. RESULTS Five patients were nonambulatory before surgery, but all were able to walk at the final follow-up. The average JOA score before surgery and at the final follow-up was 3.2 and 8.8 points, respectively. Notably, the mean recovery rate of JOA score was 72%. Furthermore, no patients showed neurological deterioration postoperatively. CONCLUSIONS The surgical technique is a useful alternative for safely achieving sufficient anterior decompression through a posterior approach and may consequently reduce the risk of postoperative neurological deterioration and improve surgical outcomes in patients with thoracic OPLL.

Osteoporosis is a common disease in elderly populations and is a major public health problem worldwide. It is not uncommon for spine surgeons to perform spinal instrumented fusion surgeries for osteoporotic patients. However, in patients with severe osteoporosis, instrumented fusion may result in screw loosening, implant failure or nonunion because of a poor bone quality and decreased pedicle screw stability as well as increased graft subsidence risk. In addition, revision surgeries to correct failed instrumentation are becoming increasingly common in patients with osteoporosis. Therefore, techniques to enhance the fixation of pedicle screws are required in spinal surgeries for osteoporotic patients. To date, various instrumentation methods, such as a supplemental hook, sublaminar taping and sacral alar iliac screws, and modified screwing techniques have been available for reinforcing pedicle screw fixation. In addition, several materials, including polymethylmethacrylate and hydroxyapatite stick/granules, for insertion into prepared screw holes, can be used to enhance screw fixation. Many biomechanical tests support the effectiveness of these augmentation methods. We herein review the current therapeutic strategies for screw fixation and augmentation methods in the surgical treatment of patients with an osteoporotic spine.

This study aimed to reveal how the COVID-19 stay-at-home period has affected the quality of life (QOL) of children with neurodevelopmental disorders and their parents and to identify possible factors that enabled them to maintain their QOL. We enrolled 136 school-aged children (intellectual quotient ≥ 50) and their parents and administered QOL questionnaires to assess the maladaptive behavior of the children; depression, anxiety, and stress of the parents; and activities of their daily lives. The relationship between their QOL and clinical features was examined. The decrease in QOL of children and parents was associated with the mother’s limited job flexibility. Decreased QOL was also associated with changes in the sleep rhythms of the children. Maladaptive behaviors in children were associated with parental stress. However, maintained QOL of some families who faced these same conditions of job stress and sleep disorders was associated with less parental stress, less parental depression and anxiety, and milder maladaptive behavior in children. Both mothers with limited job flexibility and changes in the sleep rhythm of children were associated with reduced QOL of children and their parents. Low parental stress was associated with decreased maladaptive behavior in children and with maintained QOL of the family.

The sacroiliac joint (SIJ) is burdened with variant loads. However, no methods have allowed to measure objectively how the SIJ deforms during bipedal walking. In this study, in-vivo walking conditions were replicated in a kinematic model combining the finite element method with 3D walking analysis data divided into five phases in order to visualize the load transition on the SIJ and clarify the role of the SIJ. Both models with and without inclusion of the SIJ were investigated. In models with bilateral SIJs, the displacement differed greatly between the sacrum and both hip bones on the SIJ as the boundary. The movements of the sacrum involved a nutation movement in the stance phase and a counter-nutation in the swing phase relative to the ilium. In models without SIJs, the displacement of the pelvis and loads of pelvic ligaments decreased, and the equivalent stress of the SIJs increased compared to the model with SIJs. The walking loads cause distortion of the entire pelvis, and stress concentration at the SIJ are seen due to the morphology of the pelvic ring. However, the SIJs help dissipate the resulting stresses, and the surrounding ligaments are likewise involved in load transmission.

BackgroundCongenital central hypoventilation syndrome (CCHS) is a rare disease characterized by sleep apnea. Anoxia often occurs soon after birth, and it is important to prevent anoxia-mediated central nervous system complications; however, data on the relationship between respiratory management and the prognosis for intellectual development of patients with CCHS is not well yet investigate.MethodsWe performed a retrospective chart review cohort study of patients with CCHS in Japan. We investigated the risk and prognostic factors for developmental outcomes and examined the disease in terms of its symptoms, diagnosis, complications, and treatment.ResultsOf the 123 patients with CCHS included in the survey, 88 patients were 6 years old and older. They were divided into two group based on their intelligence quotient. Those treated using positive-pressure ventilation via tracheostomy in the first three months of life had a better developmental prognosis than those managed via tracheostomy after three months of age and those treated by ventilation using mask (OR = 3.80; 95% CI: 1.00–14.37, OR = 4.65; 95% CI: 1.11–19.37). There was no significant difference in physical development (P = 0.64).ConclusionsThe best respiratory treatment for patients with CCHS is ventilation via tracheostomy, initiated ideally before the age of three months.