Longitudinal impact of multi-segment spinal fixation surgery on mobility status and clinical outcomes in adult spinal deformity: a multicenter retrospective study.

PURPOSE: To investigate changes in postoperative mobility status in patients with ASD, and the determining factors that influence these changes and their impact on clinical outcomes, including the rate of home discharge and long-term mobility. METHODS: A total of 299 patients with ASD who underwent multi-segment posterior spinal fusion were registered in a multi-center database were investigated. Patient mobility status was assessed using walking aids and classified into five levels (1: independent, 2: cane, 3: walker, 4: assisted, and 5: wheelchair) preoperatively, at discharge, and after 2 years. We determined improvements or declines in the patient's mobility based on changes in the classification levels. The analysis focused on the factors contributing to the deterioration of postoperative mobility. RESULTS: Two years postoperatively, 87% of patients maintained or improved mobility. However, 27% showed decreased mobility status at discharge, associated with a lower rate of home discharge (49% vs. 80% in the maintained mobility group) and limited improvement in mobility status (35% vs. 5%) after 2 years. Notably, postoperative increases in thoracic kyphosis (7.0 ± 12.1 vs. 2.0 ± 12.4°, p = 0.002) and lower lumbar lordosis (4.2 ± 13.1 vs. 1.8 ± 12.6°, p = 0.050) were substantial factors in mobility decline. CONCLUSION: Postoperative mobility often temporarily decreases but generally improves after 2 years. However, an overcorrection in sagittal alignment, evidenced by increased TK, could detrimentally affect patients' mobility status. Transient mobility decline associated with overcorrection may require further rehabilitation or hospitalization. Further studies are required to determine the biomechanical effects of surgical correction on mobility.

Analysis of Calcaneal Avulsion Fractures Treated Surgically and Nonsurgically: A Retrospective Multicenter Study.

Background: Calcaneal avulsion fractures (CAvFs) at the Achilles tendon insertion are among the more challenging fractures to treat. Although rare, they often require reoperation. The optimal treatment, including nonsurgical procedures and better implants for surgical procedures in the treatment of CAvFs, remains to be established. Therefore, our study aimed to (1) perform a descriptive evaluation of CAvFs, including cases managed nonsurgically, and (2) assess surgical procedures, including the incidence of complications and reoperation for surgically treated CAvFs. Methods: In this multicenter retrospective study, we collected data of patients with CAvFs treated at 9 hospitals from 2012 to 2022. We performed a descriptive study of CAvFs and compared postoperative complications and reoperation rates for multiple surgical techniques and implants. The size of the bone fragments was quantified. Results: The data of 70 patients with CAvFs were analyzed; 20 patients were treated nonsurgically, and 50 were treated surgically. The mean age of patients was 68.5 years; 67% of the patients were female. Nineteen percent of the patients had diabetes, and 19% had osteoporosis. The incidence of postoperative complications was 30%, with infection in 14%, necrosis in 26%, and loss of reduction in 18%. The reoperation rate was 22%. Surgical techniques with use of cannulated cancellous screws were performed in 80% of the surgical cases. Cannulated cancellous screw (CCS) fixation alone resulted in a reoperation rate of 35%, whereas additional augmentation, including washers with CCS fixation, resulted in a reoperation rate of 10%. CCS fixation was successfully performed, although suture anchors were used in some cases with smaller fragments. Conclusions: CAvFs occurred more frequently in older women and had a high rate of postoperative complications. A combination of CCS with augmentation was more effective at reducing postoperative complications than CCS fixation alone, even when the bone fragment size was small. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Analysis of spinopelvic parameters in adult patients with lumbosacral transitional vertebrae.

PURPOSE: Spinopelvic sagittal alignment is crucial for assessing balance and determining treatment efficacy in patients with adult spinal deformity (ASD). Only a limited number of reports have addressed spinopelvic parameters and lumbosacral transitional vertebrae (LSTV). Our primary objective was to study spinopelvic sagittal parameter changes in patients with LSTV. A secondary objective was to investigate clinical symptoms and quality of life (QOL) in patients with LSTV. METHODS: In this study, we investigated 371 participants who had undergone medical check-ups for the spine. LSTV was evaluated using Castellvi's classification, and patients were divided into LSTV+ (type II-IV, L5 vertebra articulated or fused with the sacrum) and LSTV- groups. After propensity score matching for demographic data, we analyzed spinopelvic parameters, sacroiliac joint degeneration, clinical symptoms, and QOL for these two participant groups. Oswestry Disability Index (ODI) scores and EQ-5D (EuroQol 5 dimensions) indices were compared between the two groups. RESULTS: Forty-four patients each were analyzed in the LSTV + and LSTV- groups. The LSTV + group had significantly greater pelvic incidence (52.1 ± 11.2 vs. 47.8 ± 10.0 degrees, P = 0.031) and shorter pelvic thickness (10.2 ± 0.9 vs. 10.7 ± 0.8 cm, P = 0.018) compared to the LSTV- group. The "Sitting" domain of ODI (1.1 ± 0.9 vs. 0.6 ± 0.7, P = 0.011) and "Pain/Discomfort" domain of EQ-5D (2.0 ± 0.8 vs. 1.6 ± 0.7, P = 0.005) were larger in the LSTV + group. CONCLUSION: There was a robust association between LSTV and pelvic sagittal parameters. Clinical symptoms also differed between the two groups in some domains. Surgeons should be aware of the relationship between LSTV assessment, radiographic parameters and clinical symptoms.

Does global spinal alignment affect the use of walking aids after multi-segment spinal fixation for patients with ASD? A multicenter retrospective study.

PURPOSE: This study aimed to clarify the relation between global spinal alignment and the necessity of walking aid use in patients with adult spinal deformity (ASD) and to investigate the impact of spinal fixation on mobility status after surgery. METHODS: In total, 456 older patients with ASD who had multi-segment spinal fixation surgery and were registered in a multi-center database were investigated. Patients under 60 years of age and those unable to walk preoperatively were excluded. Patients were classified by their mobility status into the independent, cane, and walker groups. Comparison analysis was conducted using radiographic spinopelvic parameters and the previously reported global spine balance (GSB) classification. In addition, preoperative and 2 years postoperative mobility statuses were investigated. RESULTS: Of 261 patients analyzed, 66 used walking aids (canes, 46; walkers, 20). Analysis of preoperative radiographical parameters showed increased pelvic incidence and pelvic incidence-lumbar lordosis mismatch in the walker group and increased sagittal vertebral axis in the cane and walker groups versus the independent group. Analysis of GSB classification showed a higher percentage of walker use in those with severe imbalance (grade 3) in the sagittal classification but not in the coronal classification. While postoperative radiographical improvements were noted, there was no significant difference in the use of walking aids before and 2 years after surgery (P = 0.085). CONCLUSION: A significant correlation was found between "sagittal" spinal imbalance and increased reliance on walking aids, particularly walkers. However, the limitation of improvement in postoperative mobility status suggested that multiple factors influence the mobility ability of elderly patients with ASD.

Preoperative low Hounsfield units in the lumbar spine are associated with postoperative mechanical complications in adult spinal deformity.

PURPOSE: To determine the most valid bone health parameter to predict mechanical complications (MCs) following surgery for adult spinal deformity (ASD). METHODS: This multicenter study retrospectively examined the records of patients who had undergone fusion of three or more motion segments, including the pelvis, with a minimum two-year follow-up period. Patients with moderate and severe global alignment and proportion scores were included in the study and divided into two groups: those who developed MCs and those who did not. Bone mineral density (BMD) of the lumbar spine and femoral neck was measured using dual-energy X-ray absorptiometry, and Hounsfield units (HUs) were measured in the lumbar spine on computed tomography. Radiographic parameters were evaluated preoperatively, immediately after surgery, and at final follow-up. RESULTS: Of 108 patients, 30 (27.8%) developed MCs, including 26 cases of proximal junctional kyphosis/failure, 2 of distal junctional failure, 6 of rod fracture, and 11 reoperations. HUs were significantly lower in patients who experienced MCs (113.7 ± 41.1) than in those who did not (137.0 ± 46.8; P = 0.02). BMD did not differ significantly between the two groups. The preoperative and two-year postoperative global tilt, as well as the immediately postoperative sagittal vertical axis, were significantly greater in patients who developed MCs than in those who did not (P = 0.02, P < 0.01, and P = 0.01, respectively). CONCLUSION: Patients who experienced MCs following surgery for ASD had lower HUs than those who did not. HUs may therefore be more useful than BMD for predicting MCs following surgery for ASD.

An appropriate method for predicting the femoral angle on whole-body X-ray images from full-spine X-ray images.

INTRODUCTION: The importance of lower-limb compensation in patients with spinal malalignment due to spinal pathologies has been emphasized. The latest whole-body X-ray images (WBX) have enabled evaluations of whole-body alignment from head to toe. However, WBX is still not commonly available. Thus, the present study aimed to examine an alternative measurement method of the femoral angle on usual full-spine X-ray images (FSX) that approximates the femoral angle on WBX. METHODS: A total of 50 patients (age, 52.8 ± 25.3 years; female, n = 26; male, n = 24) underwent WBX and FSX. The following parameters were measured on lateral view X-rays: WBX and FSX femoral angle (angle between the femoral axis and a perpendicular line); FSX femoral distance (distance from the center of femoral head to the distal femur on FSX); WBX intersection length (length between the center of the femoral head and the intersection point [the point at which the line connecting the center of the femoral head and the midpoint of the femoral condyle intersects the center line of the femur] on WBX). RESULTS: The WBX femoral angle, and FSX femoral angle were 0.16 ± 4.2°, and -0.53 ± 4.1°, respectively. The FSX femoral distance was 102.7 ± 41.1 mm. An ROC curve analysis revealed that the cut-off value of the FSX femoral distance associated with minimal difference in the WBX and FSX femoral angles (<3°) was 73 mm (sensitivity 83.3%, specificity 87.5%, AUC 0.80). The WBX intersection length was 105.3 ± 27.3 mm. CONCLUSION: To calculate the femoral angle on FSX that approximates the WBX femoral angle, the femoral distance on FSX ≥73 mm is preferable. We suggest using the FSX femoral distance within the range of 80 mm-130 mm as a simple numerical value that meets all criteria.

The anatomical relationship between the celiac artery and the median arch ligament in degenerative spinal surgery.

BACKGROUND: This study aimed to characterize the anatomical relationship between the spine, the celiac artery (CA), and the median arcuate ligament using preoperative contrast-enhanced computed tomography (CT) images of patients with spinal deformity who underwent surgical correction. METHODS: This retrospective study included 81 consecutive patients (34 males, 47 females; average age: 70.2 years). The spinal level at which the CA originated, the diameter, extent of stenosis, and calcification were determined using CT sagittal images. Patients were divided into two groups: CA stenosis group and non-stenosis group. Factors associated with stenosis were examined. RESULTS: CA stenosis was observed in 17 (21%) patients. CA stenosis group had significantly higher body mass index (24.9 ± 3.9 vs. 22.7 ± 3.7, p = 0.03). In the CA stenosis group, J-type CA (upward angling of the course by more than 90° immediately after descending) was more frequently observed (64.7% vs. 18.8%, p < 0.001). The CA stenosis group had lower pelvic tilt (18.6 ± 6.7 vs. 25.1 ± 9.9, p = 0.02) than non-stenosis group. CONCLUSIONS: High BMI, J-type, and shorter distance between CA and MAL were risk factors for CA stenosis in this study. Patients with high BMI undergoing fixation of multiple intervertebral corrective fusions at the thoracolumbar junction should undergo preoperative CT evaluation of the anatomy of CA to assess the poteitial risk of celiac artery compression syndrome.

Impact of Obesity, Osteopenia, and Scoliosis on Interobserver Reliability of Measures of the Spinopelvic Sagittal Radiographic Parameters.

Introduction: We investigated the relationships between patient factors, including obesity, osteopenia, and scoliosis, and the reliability of measures of the spinopelvic sagittal parameters using conventional X-radiography (Xp) and slot-scanning Xp devices (EOS) and examined the differences in interobserver measurement reliability between them. Methods: We retrospectively enrolled 55 patients (52.7±25.3 years, 27 females) with conventional whole-spine Xp and EOS images taken within three months. Patients were classified according to obesity (Body mass index≥25 kg/m2), osteopenia (T score<-1), and scoliosis (Cobb angle>20°). The associations between patient factors and reliability of radiological parameter measurements were examined with interobserver intraclass correlation coefficient (ICC), defined as poor, <.40; good, 40-.79; and excellent, ≥.80. Results: All parameters measured with EOS showed excellent reliability except for L4-S (ICC:.760, 95% CI:.295-.927) in the obesity+ group. All parameters measured with conventional Xp were excellent except for those classified as good: L4-S (.608,.093-.868) and pelvic incidence (PI) (.512,.078-.832) in the obese+ group; T1 slope (.781,.237-.952), L4-S (.718,.112-.936), sacral slope (SS) (.792,.237-.955), pelvic tilt (PT) (.787,.300-.952), and center of acoustic meatus and femoral head offset (CAM-HA) (.690,.090-.928) in the osteopenia+ group; and lumbar lordosis (LL, L4-S) (.712,.349-.889), SS (.608,.178-.843), and CAM-HA (.781,.480-.917) in the scoliosis+ group. Conclusions: Reliability of EOS measurements was preferable except for L4-S in patients with obesity. The reliability of conventional Xp measurements of pelvic parameters SS, PT, and PI was affected by patient factors, including obesity, osteopenia, and scoliosis. When evaluating lower lumbar and pelvic parameters in patients with these factors, we recommend substituting thoracic parameters, LL (L1-S), sagittal vertical axis (SVA), and T1 pelvic angle (TPA), or combining computed tomography (CT) measurements.

Lateral Lumbar Interbody Fusion within Three-level for Patients with Neurological Symptoms due to Vertebral Fragility Fractures in the Lumbar Spine.

There is a lack of agreement on whether minimally invasive lateral lumbar intervertebral fusion (LLIF) is a suitable treatment option for vertebral fragility fractures (VFFs). Hence, we sought to evaluate the efficacy and safety of LLIF in the management of VFF with neurological deficits in the lumbar spine. Between April 2015 and March 2020, we conducted a retrospective observational study of patients with VFF treated with three-level or less LLIF. The participants had previously received conservative treatment but had not been able to control their neurological symptoms. To assess the outcomes of the LLIF procedures, the patients were followed up for a minimum of 1 year. Clinical and radiological results, which include the timing and location of the bony fusion, were analyzed. The study involved 19 patients with 23 vertebral fracture levels. The residual height of the fractured vertebra was found to be 57.0 ± 12.3% of the height of the adjacent level. The mean Japanese Orthopedic Association score significantly improved postoperatively. Postoperative radiological parameters were significantly maintained at 1 year, and lumbar lordosis was maintained at the last follow-up (45.0 ± 26.7). In total 31 LLIF levels, bone fusion was observed in four levels at 6 months postoperatively, in 16 levels at 1 year, and in 23 levels at the last follow-up. The facet joint had the highest bony fusion location. LLIF within three levels can be safely performed in certain VFF cases with sufficient residual vertebral height.

Management of Antithrombotic Drugs before Elective Spine Surgery: A Nationwide Web-Based Questionnaire Survey in Japan.

Introduction: The number of patients on antithrombotic drugs for coronary heart disease or cerebrovascular disease has been increasing with the aging of society. We occasionally need to decide whether to continue or discontinue antithrombotic drugs before spine surgery. The purpose of this study is to understand the current perioperative management of antithrombotic drugs before elective spine surgery in Japan. Methods: In 2021, members of the Japanese Society for Spine Surgery and Related Research (JSSR) were asked to complete a web-based questionnaire survey that included items concerning the respondents' surgical experience, their policy regarding discontinuation or continuation of antithrombotic drugs, their reasons for decisions concerning the management of antithrombotic drugs, and their experience of perioperative complications related to the continuation or discontinuation of these drugs. Results: A total of 1,181 spine surgeons returned completed questionnaires, giving a response rate of 32.0%. JSSR board-certified spine surgeons comprised 75.1% of the respondents. Depending on the management policy regarding antithrombotic drugs for each comorbidity, approximately 73% of respondents discontinued these drugs before elective spine surgery, and about 80% also discontinued anticoagulants. Only 4%-5% of respondents reported continuing antiplatelet drugs, and 2.5% reported continuing anticoagulants. Among the respondents who discontinued antiplatelet drugs, 20.4% reported having encountered cerebral infarction and 3.7% reported encountering myocardial infarction; among those who discontinued anticoagulants, 13.6% reported encountering cerebral embolism and 5.4% reported encountering pulmonary embolism. However, among the respondents who continued antiplatelet drugs and those who continued anticoagulants, 26.3% and 27.2%, respectively, encountered an unexpected increase in intraoperative bleeding, and 10.3% and 8.7%, respectively, encountered postoperative spinal epidural hematoma requiring emergency surgery. Conclusions: Our findings indicate that, in principle, >70% of JSSR members discontinue antithrombotic drugs before elective spine surgery. However, those with a discontinuation policy have encountered thrombotic complications, while those with a continuation policy have encountered hemorrhagic complications.

Racial differences in whole-body sagittal alignment between Asians and Caucasians based on international multicenter data.

PURPOSE: To examine inherent differences adjusted for age and clinical score in whole-body sagittal (WBS) alignment involving the lower extremities between Asians and Caucasians, and to determine the relationship between age and WBS parameters by race and sex. METHODS: A total of 317 individuals consisting of 206 Asians and 111 Caucasians participated. WBS parameters including C2-7 lordotic angle, lower lumbar lordosis (lower LL, L4-S), pelvic incidence (PI), pelvic thickness, knee flexion (KF), sagittal vertical axis (SVA), and T1 pelvic angle (TPA) were evaluated radiologically. Propensity score-matching adjustments for age and the Oswestry Disability Index scores for comparative analysis between the two race cohorts and correlation analysis between age and WBS parameters for all subjects by race and sex were conducted. RESULTS: The comparative analysis included 136 subjects (age: Asians 41.1 ± 13.5, Caucasians 42.3 ± 16.2 years, p = 0.936). Racial differences in WBS parameters were observed in C2-7 lordotic angle (-1.8 ± 12.3 vs. 6.3 ± 12.2 degrees, p = 0.001), and lower LL (34.0 ± 6.6 vs. 38.0 ± 6.1 degrees, p < .001). In correlation analysis with age, moderate or more significant correlations with age were found in KF for all groups, and in SVA and TPA for females of both racial groups. Age-related changes in pelvic parameters of PI and pelvic thickness were more significant in Caucasian females. CONCLUSION: Analysis of the correlation between age and WBS parameters suggested that age-related WBS changes vary between races and should be considered during corrective spinal surgery.

Comparative Study of Surgical Outcomes of Occipitocervical and Atlantoaxial Fusion for Retro-Odontoid Pseudotumor.

OBJECTIVE: To compare the surgical and radiographic outcomes of occipitocervical fusion (OCF) with those of atlantoaxial fusion (AAF) in patients with cervical myelopathy caused by retroodontoid pseudotumors (ROPs). METHODS: This retrospective, comparative study included 26 patients; 12 underwent occipitocervical fusion (OCF) (group O) and 14 retroodontoid pseudotumor (AAF) (group A) with a minimum 2-year follow-up. Neurologic outcomes were evaluated using the Japanese Orthopedic Association (JOA) score. Radiologic assessment included the maximum anteroposterior (AP) diameter of the anteroposterior-retroodontoid pseudotumor (AP-ROP), C2-7 angle, O-C2 angle, C1-2 angle, atlantodental interval (ADI), range of motion (ROM) of the ADI, C2-C7 sagittal vertical axis (C2-7 SVA), and T1 slope. Global spinal alignments (pelvic incidence [PI] minus lumbar lordosis [LL] [PI-LL], pelvic tilt, sacral slope, and C7 sagittal vertical axis) were also compared between the groups. RESULTS: Both groups had equally good clinical outcomes with equal complication rates. Three patients had a three-level fusion, 5 cases had a four-level fusion, and 4 cases had more than five-level fusion in group O. All cases had a single-level fusion in group A. Surgical time was significantly shorter in group A. AP-ROP was significantly downsized postoperatively in both groups and was more prominent in group O. C2-7 SVA was significantly increased and C2-7A ROM was significantly reduced in group O at the final follow-up. The PI-LL showed a significant increase in group O at the final follow-up. CONCLUSIONS: Although OCF and AAF were similarly effective for cervical myelopathy with ROP, AAF was less invasive, and spinal alignment was better maintained postoperatively in AAF than OCF.

Differences in Involvement of Whole-Body Compensatory Alignment for Decompensated Spinopelvic Sagittal Balance.

BACKGROUND: The aim of this study was to investigate the differences in the involvement of whole-body compensatory alignment in different conditions of spinopelvic sagittal balance (compensated/decompensated). METHODS: We enrolled 330 individuals who underwent medical checkups and divided them according to sagittal vertical axis (SVA): for the compensated group, this was <4 cm, (group C) and for the decompensated group, it was ≥4 cm, (group D). The correlation between the lack of ideal lumbar lordosis (iLL), which was calculated by using the Schwab formula, and the compensatory radiographic parameters in each group was analyzed. The threshold value of knee flexion (KF) angle, which indicated spinopelvic sagittal imbalance (SVA ≥ 4), was determined by a ROC-curve analysis. RESULTS: The correlation analysis of the lack of iLL and each compensatory parameter showed a strong correlation for pelvic tilt (PT) (r = -0.723), and a weak correlation for thoracic kyphosis (TK) (r = 275) in Group C. In Group D, the correlations were strong for PT (r = -0.796), and moderate for TK (r = 0.462) and KF (r = -0.415). The optimal cutoff value for the KF angle was determined to be 8.4 degrees (sensitivity 89%, specificity 46%). CONCLUSIONS: The present study shows differences between compensated/decompensated spinopelvic sagittal balance in the correlation strength between lack of iLL and whole-body compensatory parameters.

Reduction in CT scan number with the reference frame middle attachment method in intraoperative CT navigation for adolescent idiopathic scoliosis.

PURPOSE: Elucidate whether it is preferable to use the reference frame (RF) middle attachment (RFMA) method over the edge of the planned pedicle screw (PS) insertion area for RF placement in the surgery for adolescent idiopathic scoliosis (AIS) with intraoperative computed tomography (CT) navigation. METHODS: Eighty-six consecutive patients (76 female and 10 male; mean age: 15.9 years) with AIS who underwent posterior spinal fusion using intraoperative CT navigation were enrolled. The group with the RF placed at the most distal part of the CT scan range was defined as the distal group (Group D), with other placements classified into the middle group (Group M). PS perforation rate and surgical outcome were compared between the groups. RESULTS: There was no significant difference in perforation rate between Group M and Group D (3.4% vs. 3.0%, P = 0.754). The mean ± standard deviation number of instrumented vertebrae at the first CT scan was significantly higher in Group M (8.2 ± 1.2 vs. 6.3 ± 1.2, P < 0.001), while mean blood loss was significantly lower (266 ± 185 mL vs. 416 ± 348 mL, P = 0.011). The frequency of needing a second CT scan for PS insertion was significantly lower in Group M (38% vs. 69%, P = 0.04). CONCLUSION: The RFMA method in thoracic scoliosis surgery for AIS with intraoperative CT navigation could significantly decrease the number of CT scans and blood loss while maintaining a comparable PS perforation rate to RF placement at the distal end of the planned PS insertion range.

Nationwide Survey of the Surgical Complications Associated with Lateral Lumbar Interbody Fusion in 2015-2020.

Introduction: Lateral lumbar interbody fusion (LLIF) has been introduced in Japan in 2013. Despite the effectiveness of this procedure, several considerable complications have been reported. This study reported the results of a nationwide survey performed by the Japanese Society for Spine Surgery and Related Research (JSSR) on the complications associated with LLIF performed in Japan. Methods: JSSR members conducted a web-based survey following LLIF between 2015 and 2020. Any complications meeting the following criteria were included: (1) major vessel, (2) urinary tract, (3) renal, (4) visceral organ, (5) lung, (6) vertebral, (7) nerve, and (8) anterior longitudinal ligament injury; (9) weakness of psoas; (10) motor and (11) sensory deficit; (12) surgical site infection; and (13) other complications. The complications were analyzed in all LLIF patients, and the differences in incidence and type of complications between the transpsoas (TP) and prepsoas (PP) approaches were compared. Results: Among the 13,245 LLIF patients (TP 6,198 patients [47%] and PP 7,047 patients [53%]), 389 complications occurred in 366 (2.76%) patients. The most common complication was sensory deficit (0.5%), followed by motor deficit (0.43%) and weakness of psoas muscle (0.22%). Among the patient cohort, 100 patients (0.74%) required revision surgery during the survey period. Almost half of the complications developed in patients with spinal deformity (183 patients [47.0%]). Four patients (0.03%) died from complications. Statistically more frequent complications occurred in the TP approach than in the PP approach (TP vs. PP, 220 patients [3.55%] vs. 169 patients [2.40%]; p<0.001). Conclusions: The overall complication rate was 2.76%, and 0.74% of the patients required revision surgery because of complications. Four patients died from complications. LLIF may be beneficial for degenerative lumbar conditions with acceptable complications; however, the indication for spinal deformity should be carefully determined by the experience of the surgeon and the extent of the deformity.

Anatomical Analysis of the Gonadal Veins and Spine in Lateral Lumbar Interbody Fusion.

BACKGROUND: The current study aimed to investigate the anatomical position of the gonadal veins (GVs) from the viewpoint of spine surgery and the risk factors associated with lateral lumbar interbody fusion (LLIF). METHODS: This retrospective study included 99 consecutive patients. The GV locations were divided into the ventral (V), dorsal medial (DM), and dorsal lateral (DL) sides based on lumbar disk levels on axial contrast-enhanced computed tomography images. The DM region surrounded by the vertebral body and psoas muscle had the highest risk of GV injury. The GV at each intervertebral disk level was examined in terms of laterality and sex. The patients were divided into group M (which included those with GV in the DM region at any vertebral level) and group O (which included those without GV in the DM region at any vertebral level). Then, the two groups were compared. RESULTS: In the case of lower lumbar levels and in women, the GVs were commonly observed in the DM region. Group M had a higher incidence of degenerative scoliosis than group O and a significantly larger Cobb angle. CONCLUSIONS: We should pay close attention to the GV location on the preoperative image when using LLIF, particularly in female patients with degenerative scoliosis.

Evaluation of Posterior Ligamentous Complex Injury in Thoracolumbar Burst Fractures: Correlation Analysis of CT and MRI Findings.

The goal of this study is to perform correlation analysis of Computed tomography (CT) and magnetic resonance imaging (MRI) results in posterior ligament complex (PLC) injury and define the morphological traits of thoracolumbar (TL) burst fractures connected to PLC injury. Forty patients with surgically repaired TL burst fractures between January 2013 and December 2020 were retrospectively analyzed. The patients were split into two groups for comparison based on MRI (Group P: patients with a confirmed or suspected PLC injury; Group N: patients with PLC injury denied). The radiographic morphological examination based on CT scans and clinical evaluation was performed and compared between two groups. The thoracolumbar injury classification and severity score (TLICS), the load sharing classification (LSC) scores, and the number of patients with neurological impairments were considerably greater in Group P. Loss of height of the fracture (loss height), local kyphosis of the fracture (local kyphosis), and supraspinous distance were significantly higher in Group P and significantly associated with PLC injuries indicating severe vertebral body destruction and traumatic kyphosis in multivariate logistic analysis [odds ratio: 1.90, 1.06, and 1.13, respectively]. Cutoff value for local kyphosis obtained from the receiver operating characteristic curve was 18.8. If local kyphosis is greater than 18.8 degrees on CT scans, we should take into account the probability of the highly damaged burst fracture associated with PLC injury. In this situation, we should carefully assess MRI to identify the spinal cord injury or spinal cord compression in addition to PLC injury because these instances likely present with neurological abnormalities.

Current status and future prospects of the Japanese orthopaedic association national registry (JOANR), Japan's first national registry of orthopaedic surgery.

The Japanese Orthopaedic Association National Registry (JOANR) is Japan's first national registry of orthopaedic surgery, which has been developed after having been selected for the Project for Developing a Database of Clinical Outcome approved by the Health Policy Bureau of the Ministry of Health, Labour and Welfare. Its architecture has two levels of registration, one being the basic items of surgical procedure, disease, information on surgeons, surgery-related information, and outcome, and the other being detailed items in the affiliated registries of partner medical associations. It has a number of features, including the facts that, because it handles medical data, which constitute special care-required personal information, data processing is conducted entirely in a cloud environment with the imposition of high-level data security measures; registration of the implant data required to assess implant performance has been automated via a bar code reader app; and the system structure enables flexible collaboration with the registries of partner associations. JOANR registration is a requirement for accreditation as a core institution or partner institution under the board certification system, and the total number of cases registered during the first year of operation (2020) was 899,421 registered by 2,247 institutions, providing real-world evidence concerning orthopaedic surgery.

Comparative Study of Anterior Transvertebral Foraminotomy and Anterior Cervical Discectomy and Fusion for Unilateral Cervical Spondylotic Radiculopathy.

OBJECTIVE: To study the compared surgical and radiographic outcomes of Transvertebral foraminotomy (TVF) with anterior cervical discectomy and fusion (ACDF) in patients with unilateral cervical spondylotic radiculopathy (CSR). METHODS: We performed a retrospective comparative study of 72 consecutive patients with 1- or 2-level CSR treated with ACDF or TVF. 27 patients who underwent TVF (group T) and 45 patients who underwent ACDF (group A) with a minimum 2-year follow-up were enrolled. We evaluated clinical outcomes and radiological assessment. Clinical outcome included Visual analog scale (VAS) scores for axial, arm pain at preoperatively and final follow-up. VAS score for painful swallowing was also evaluated 1 week after surgery. Radiological assessment included C2-7 sagittal Cobb angle (C2-7 CA), range of motion (ROM) of C2-7 CA, the height, angle and ROM of the functional spinal unit (FSU), and tip of the spinous process of the operated segment. We also evaluated the disc height, FSU angle, and ROM of the FSU at the cranial adjacent segment. RESULTS: Both groups had good clinical outcomes. Soft tissue swelling was significantly less prominent in group T than that for group A. VAS scores for painful swallowing is lower in group T without significant difference. The ROM of C2-7 CA, FSU, and spinous processes demonstrated a significant reduction in group A compared with group T.(P < 0.05). Disc height at the cranial adjacent segment was maintained in group T. CONCLUSIONS: TVF is as effective as ACDF for unilateral CSR and preserves whole cervical spine and segmental alignment.