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Study Design Retrospective case series.Objectives To investigate the influence of screw size on achieving bone fusion in posterior lumbar interbody fusion (PLIF).Methods In total, 137 consecutive patients with L4 degenerative spondylolisthesis who underwent single-level PLIF at L4-L5 were evaluated. Factors investigated for their contribution to bone fusion included: 1) age, 2) sex, 3) body mass index, 4) bone mineral density, 5) intervertebral mobility, 6) screw diameter, 7) screw length, 8) screw fitness in the pedicle (%fill), 9) screw depth in the vertebra (%depth), 10) screw angle, 11) facetectomy, 12) crosslink connector, and 13) cage material.Results Bone fusion was confirmed in 88.2% of patients. The comparison between fusion (+) and fusion (-) groups showed no significant differences in screw size. The %fill and %length were significantly greater in the fusion (+) group than in the fusion (-) group (%fill: 58.5% ± 7.5% vs 52.3% ± 7.3%, respectively, P= .005; %depth: 59.8% ± 9.7% vs 50.3% ± 13.8%, respectively, P= .025). Multivariate logistic regression analysis revealed that %fill (odds ratio [OR]= 1.11, P= .025) and %depth (OR = 1.09, P= .003) were significant independent factors affecting bone fusion. Receiver operating characteristic curve analyses identified a %fill of 60.0% and a %depth of 54.2% as optimal cutoff values for achieving bone fusionConclusions Screw size should be determined based on the screw fitness in the pedicle (%fill > 60%) and screw insertion depth in the vertebral body (%depth > 54.2%) according to individual vertebral anatomy in L4-L5 PLIF.

Purpose: The importance of coronal alignment is unclear, while the importance of sagittal alignment in the treatment of adult patients with spinal deformities is well described. This study sought to elucidate the impact of global coronal malalignment (GCMA) in surgically treated adult symptomatic lumbar deformity (ASLD) patients. Methods: A multicentre retrospective analysis of a prospective ASD database. GCMA was defined as GCA (C7PL-CSVL) ≥ 3 cm. GCMA is categorized based on the Obeid-Coronal Malalignment Classification (O-CM). Demographic, surgical, radiographic, HRQOL, and complication data were analysed. The risk for postoperative GCMA was analysed by univariate and multivariate analyses. Results: Of 230 surgically treated ASLD patients, 96 patients showed GCMA preoperatively and baseline GCA was correlated with the baseline SRS-22 pain domain score (r= − 30). Postoperatively, 62 patients (27%, O-CM type 1: 41[18%], type 2: 21[9%]) developed GCMA. The multivariate risk analysis indicated dementia (OR 20.1[1.2–304.4]), diabetes (OR 5.9[1.3–27.3]), and baseline O-CM type 2 (OR 2.1[1.3–3.4]) as independent risk factors for postoperative GCMA. The 2-year SRS-22 score was not different between the 2 groups, while 4 GCMA patients required revision surgery within 1 year after surgery due to coronal decompensation (GCMA+ vs. GCMA- function: 3.6 ± 0.6 vs. 3.7 ± 0.7, pain: 3.7 ± 0.8 vs. 3.8 ± 0.8, self-image: 3.6 ± 0.8 vs. 3.6 ± 0.8, mental health: 3.7 ± 0.8 vs. 3.8 ± 0.9, satisfaction: 3.9 ± 0.9 vs. 3.9 ± 0.8, total: 3.7 ± 0.7 vs. 3.7 ± 0.7). Additionally, the comparisons of 2-yr SRS-22 between GCMA ± showed no difference in any UIV and LIV level or O-CM type. Conclusions: In ASLD patients with corrective spine surgery, GCMA at 2 years did not affect HRQOL or major complications at any spinal fusion extent or O-CM type of malalignment, whereas GCA correlated with pain intensity before surgery. These findings may warrant further study of the impact of GCMA on HRQOL in the surgical treatment of ASLD patients.

Study Design Retrospective studyObjectives The combination of oblique lateral interbody fusion (OLIF) with grade 2 posterior column osteotomy (PCO) is an effective treatment for adult spinal deformity. However, grade 2 PCO may lead to pseudoarthrosis because it involves complete removal of the bilateral posterior facet joints. The main study objective was to determine the achievement rate of anterior and posterolateral fusion resulting in circumferential fusion in patients who underwent combined OLIF and grade 2 PCO.Methods This retrospective study included consecutive patients who underwent OLIF and grade 2 PCO. The group comprised a long fusion group, with fusion from the thoracic level to the ilium, and a short fusion group, with fusion within the lumbar region. The OLIF with percutaneous pedicle screw insertion group was also used for reference. The Brantigan–Steffee–Fraser classification was used to assess interbody fusion and Lenke classification for assessment of posterolateral fusion.Results Sixty-six patients with 109 lumbar levels were included in the study. We observed 100% anterior fusion in all 3 groups. The fusion rate for posterolateral fusion between the OLIF-grade 2 PCO group was 97%, with very low (3%) non-circumferential fusion (pseudoarthrosis only at the osteotomy site). In most cases, solid posterolateral fusions (Lenke A) occurred within 24 months.Conclusions The combination of OLIF and grade 2 PCO resulted in circumferential fusion for most (97%) of the cases within 24 months. OLIF and grade 2 PCO are considered a good combination treatment to achieve sufficient lumbar lordosis and solid bone fusion.

Study design: Retrospective comparative study. Objective: This study aimed to determine whether the degree of preoperative gait disturbance remains following surgical resection in patients with intradural extramedullary spinal cord tumors (IDEMSCTs), and to investigate any factors that may influence poor improvement in postoperative gait disturbance. Setting: The single institution in Japan. Methods: In total, 78 IDEMSCTs patients who required surgical excision between 2010 and 2019 were included. According to the degree of preoperative gait disturbance using modified McCormick scale (MMCS) grade, they were divided into the Mild and Severe groups. The mean postoperative follow-up period was 50.7 ± 17.9 months. Data on demographic and surgical characteristics were compared between the two groups. Results: There was no significant difference in terms of age at surgery, sex, tumor size, surgical time, estimated blood loss, tumor histopathology, and postoperative follow-up period between the Mild and Severe groups. At the final follow-up, 84.6% of IDEMSCTs patients were able to walk without support. Gait disturbance improved after surgery in most of the patients with preoperative MMCS grades II–IV, but remained in approximately half of patients with preoperative MMCS grade V. Age at surgery was correlated with poor improvement in postoperative gait disturbance in the Severe group. Conclusions: Regardless of the degree of preoperative gait disturbance, it improved after tumor resection in most of the IDEMSCTs patients. However, in the preoperative MMCS grade III–V cases, older age at surgery would be an important factor associated with poor improvement in postoperative gait disturbance.

Retrospective cohort study. The purpose of the current study was to examine the effectiveness of late decompression surgery for traumatic cervical spinal cord injury (CSCI) with pre-existing cord compression. Murayama Medical Center, National Hospital Organization, Tokyo, Japan. In total 78 patients with traumatic CSCI without bone injury hospitalized in 2012–2015 in our institute for rehabilitation after initial emergency care were divided into four groups according to the compression rate (CR) of the injured level and whether or not decompression surgery was performed. Neurological status was evaluated by American Spinal Injury Association impairment scale (AIS), Barthel index, and Spinal Cord Independence Measure (SCIM). In the severe compression group (CR ≥ 40%), >2 grade improvement in the AIS was observed in 30% of patients with surgical treatment, although it was not observed in any patient without surgery. The SCIM improvement rate at discharge was 60% in the surgical treatment group and 20% in the non-surgical treatment group. In the minor compression group (CR < 40%), >2 grade improvement in the AIS was observed in 18% of patients with surgical treatment and in 11% without surgery. The SCIM improvement rate at discharge was 52% in the surgical treatment group and 43% in the non-surgical treatment group. These results indicate that surgical treatment has an advantage for patients following traumatic CSCI with severe cord compression. In contrast, surgical efficacy is not proved for CSCI patients without severe cord compression.

No study has assessed the incidence or predictors of postoperative shoulder imbalance (PSI) in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS) who underwent selective anterior spinal fusion (ASF). This study evaluated the incidence and predictors of shoulder imbalance after selective ASF for Lenke type 5C AIS.

Little is known regarding the incidence of the shoulder instability in Japan. The aim of this study was to evaluate the incidence of traumatic shoulder instability among Japanese military cadets. A prospective cohort study was performed to capture all traumatic shoulder instability events between 2009 and 2012 among cadets in a military educational academy of the Japan Self Defense Forces. The total number of cadets in the cohort was 5,402 (average age 20.6 years). The incidence of instability events, including dislocation or subluxation, was calculated. Chronicity, demographics of participants, mechanism of injury, and athletic events were also evaluated. The incidence of traumatic dislocation was 4.1/1,000 person-years and that of subluxation was 6.1/1,000 person-years. The incidence of primary dislocation or subluxation was 5.4/1,000 person-years and that of recurrent dislocation or subluxation was 4.7/1,000 person-years. Of first dislocations or subluxations, 92% occurred during sports activities, including after-school sports activities, military training, and gym classes. In conclusion, the overall incidence of shoulder instability events among Japanese military cadets was 10.3/1,000 person-years, and was extremely high. Most shoulder instability events occurred during sports activities, and a program to prevent such injuries during sports activities is necessary for young participants.

The Omicron variant of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) was identified in Japan in November 2021. This variant contains up to 36 mutations in the spike protein, the target of neutralizing antibodies, and can escape vaccine-induced immunity. A booster vaccination campaign began with healthcare workers and high-risk groups. The safety and immunogenicity of the three-dose vaccination against Omicron remain unknown.

A morphometric measurement of cortical bone trajectory (CBT) for the lumbar pedicle screw insertion using computed tomography (CT).

There is no well-established treatment for osteoporosis in male patients with leprosy, because no clinical trials have examined the efficacy of treatment on bone mineral density (BMD) or fracture incidence in patients with leprosy. In this study, we report a case of osteoporosis in a man with leprosy, treated by oral administration of risedronate and alfacalcidol. An 82-year-old man with leprosy presented to our hospital with chronic back pain, due to osteoporosis, in July 2002. To prevent the progession of osteoporosis, oral administration of risedronate and alfacalcidol was started for this patient. An increase in forearm BMD and a decrease in the level of urinary crosslinked N-telopeptides of type I collagen (NTx) were observed in January 2003. The patient suffered a trochanteric fracture of the proximal femur at the end of March 2003. Surgical treatment with a sliding-screw plate was performed 5 days after the injury. Complete bony union of the right proximal femur was confirmed by radiography in July 2003. The above findings suggested that the treatment with risedronate and alfacalcidol contributed to the increase in BMD; however, the treatment did not prevent fracture due to osteoporosis in this male patient with leprosy.

Cervical malalignment occurring after conventional laminectomy or laminoplasty is caused by intraoperative injuries to the posterior extensor mechanism, including the deep extensor muscles. To minimize such injuries, we developed a technique for muscle-preserving double-door laminoplasty below C2 (TEMPL) and TEMPL for the axis (TEMPLA) in treating patients with multisegmental cervical myelopathy. In these procedures, the posterior arches, which were sagittally split in the midline, can be opened. This leaves untouched the semispinalis cervicis and multifidus muscle attachments to each split half of the spinous process below C2, and of all five muscles to each split half of the C2 spinous process. In review of short-term surgical outcomes from 41 patients who underwent the procedures, neurological improvement was demonstrated in each patient. Postoperative kyphosis development was identified in one patient only, in whom delayed fracture occurred at the bilateral C2 laminar hinge. TEMPL and TEMPLA, in which the deep extensor musculature is preserved as an important stabilizer of the cervical spine, are effective procedures to prevent postoperative cervical malalignment. Les laminectomies et les laminoplasties du rachis cervical se compliquent souvent de déformations en rapport avec le traumatisme musculaire opératoire. Dans le traitement des myélopathies cervicales par ossification du ligament longitudinal postérieur, les auteurs ont développé une technique de laminoplastie dite « double door » pour préserver les muscles de la région. La technique est différente pour C2 (TEMPLA) et au-dessous de C2 (TEMPL). Dans cette technique, l'arc postérieur de la vertèbre coupé en son milieu peut être ouvert, laissant intacte l'attache musculaire. La revue à court terme de 41 patients opérés par cette technique a montré une amélioration neurologique constante. Aucune cyphose post-opératoire n'a été remarquée sauf chez un patient où une fracture différée des lames de C2 a été mise en évidence. La technique TEMPLA et TEMPL, qui préserve les muscles extenseurs du cou est efficace et prévient des déformations post-opératoires du rachis cervical.