The influence of costal resection on pulmonary function after total en bloc spondylectomy for spine tumor.

BACKGROUND: Total en bloc spondylectomy (TES) is one of the surgical procedures which has been recognized as a complete resection for spine tumors. Although the surgery achieves favorable local control for solitary spinal lesion, performing the procedure in the thoracic spine requires circumferential dissection around the vertebral body and bilateral rib resections which might result in decline of pulmonary function postoperatively. This study aimed to clarify whether the number of rib resections negatively impacts pulmonary function after the procedure. METHODS: This study included 31 patients who underwent vertebrectomy (17 males and 14 females) with a mean age of 54.2 years. Pulmonary function testing (PFT) was performed before surgery and at 1 month, 6 months, and 1 year postoperative visits. Patients with restrictive disorders such as space occupying lesions in the lung, obstructive problems such as a history of asthma, and smoking history were excluded from this study. Associations between the number of rib resections and PFT data were analyzed based on the resected level of the thoracic spine. RESULTS: There was a significant decrease in forced vital capacity (FVC) at 1 month (72% of preoperative value), followed by gradual recovery at 6 months (89%) and 1 year (90%). The percentage of predicted forced expiratory volume in 1 s remained stable. Patients who underwent three pairs of rib resections showed a significant decrease in the FVC (83.5% of the preoperative value) and FEV1 (82.1% of the preoperative value) compared with one or two pairs of rib resections. CONCLUSION: FVC decreased 1 month after vertebrectomy and returned to 90% of preoperative value at 1 year postoperatively. Three pairs of rib resections showed a significant decrease in FVC, suggesting the influence of a greater numbers of rib resections on pulmonary function.

Risk factors that hinder locomotive syndrome improvement following surgery for musculoskeletal diseases in older patients: A multicentre prospective study.

OBJECTIVES: This study aimed to evaluate preoperative and post-operative locomotive syndrome (LS) in older adults undergoing surgical treatment for musculoskeletal diseases of the lumbar spine and lower extremities and identify risk factors that impede LS improvement after surgery. METHODS: The baseline evaluation included 471 patients 65 years or older [276 in the pre-old-age (65-74 years) group; 195 in the old-age (75 years or older) group] and examined the preoperative and post-operative LS data. The second evaluation performed to identify risk factors, including anthropometric measurements, comorbidity, and frailty, that hinder LS improvement after surgery included 378 patients with preoperative LS Stage 3. RESULTS: Preoperatively, 80% of the patients had LS Stage 3; this rate decreased to 40% post-operatively. Half of the patients exhibited post-operative LS improvement. The LS improvement rate was higher in the pre-old-age group than in the old-age group. According to the multiple logistic regression analysis, old age, high body mass index, weak hand grip strength, and high 5-factor modified frailty index score were significant risk factors that hinder LS improvement after surgery. CONCLUSIONS: Ageing, obesity, weak muscle strength, and frailty can hinder LS improvement in older patients who undergo surgery.

[A Case of Postoperative Recurrence of Bilateral Breast Cancer in Which Stable Disease Condition Was Achieved by Olaparib].

The patient is a 51-year-old female with comorbidity of schizophrenia. At the age of 41, she underwent surgery for bilateral breast cancer. Both sides were of the Luminal type, with Stage ⅢC on the right and Stage 0 on the left. She started to receive adjuvant chemotherapy but it was interrupted according to her wish. Approximately 3 years ago, she developed carcinomatous pleuritis, multiple liver metastases, and bone metastases. Despite receiving chemotherapy, her condition worsened. A BRACAnalysis revealed pathogenic variants in BRCA2. Upon initiating treatment with olaparib, both her liver metastases and carcinomatous pleuritis have shown reductions, and her tumor markers have also started to decline. Approximately 5 months after treatment with olaparib, it has been possible to continue without any side effects. Olaparib has shown good results in patients with germline BRCA1/2 mutation-positive HER2-negative advanced/recurrent breast cancer who have a history of receiving anthracycline and taxane-based therapies. It was considered that even in recurrent breast cancer, the presence or absence of BRCA1/2 mutations should be actively sought even in advanced cases, and the administration of olaparib should be considered.

[A Case of Resection of Right Axillary Accessory Breast Cancer with Skin Invasion].

A 56-year-old female was referred to our hospital for further examination and treatment because of her increasing right axillary mass for 1 year. Based on histological examination diagnosing the right axillary mass as carcinoma and radiological examination showing no evidence of distal metastasis, we decided to perform a radical resection. The patient underwent right axillary mass resection, axillary lymph node dissection, and latissimus dorsi musculocutaneous flap reconstruction. Right-sided breast cancer was diagnosed based on histopathological examination. The diagnosis was similar to that of breast cancer. The patient underwent adjunctive chemotherapy and is currently undergoing endocrine therapy. The incidence of accessory breast cancer is 0.2-0.6% among all breast cancers and is relatively rare. Postoperative adjuvant pharmacotherapy has no consensus. However, endocrine therapy, chemotherapy, and molecular target therapy are performed in cases of conventional breast cancer. Herein, we describe a case of right axillary accessory breast cancer with skin invasion successfully treated with radical resection.

Tumor-Specific Immunoenhancing Effects after Local Cryoablation for Metastatic Bone Tumor in a Mouse Model.

We investigated the abscopal effect after cryoablation (CA) on bone metastasis using a mouse model. Breast cancer cells were implanted in the bilateral tibiae of mice. The left tumor was treated locally with CA, and the right abscopal tumor (AT) was left untreated. The mice were divided into four groups based on the combination of CA and intraperitoneal administration of anti-PD-1 antibody (PD) as treatment interventions (Control, CA, PD, and CA + PD). The reduction ratio of the size of AT, the quantitative immune effects at enzyme-linked immunospot (ELISPOT) assay, and the intensity of infiltration of immune-related cells to AT were compared among the groups. CA alone showed a significant immunoenhancing effect on the volume change ratio of AT from day 0 to day 14 (Control-CA: p < 0.05), ELISPOT assay (Control-CA: p < 0.01), and CD4+ cell count in immunostaining (Control-CA: p < 0.05). CA alone showed no significant immunoenhancing effect on CD8+ and Foxp3+ cell counts in immunostaining, but the combination of CA and PD showed a significant immunoenhancing effect (Control-CA + PD: p < 0.01 [CD8, Foxp3]). The results suggested that the abscopal effect associated with the local cryotherapy of metastatic bone tumors was activated by CA and enhanced by its combination with PD.

Evaluation of locomotive syndrome in patients receiving surgical treatment for degenerative musculoskeletal diseases: A multicentre prospective study using the new criteria.

OBJECTIVES: This study aimed to evaluate the condition of patients with locomotive syndrome (LS) and their improvement after undergoing surgery for degenerative musculoskeletal diseases using the new criteria, including stage 3. METHODS: In total, 435 patients aged ≥40 years (167 middle-aged and 268 older) were divided into four groups based on the disease location: the lumbar (n = 118), hip (n = 191), knee (n = 80), and foot and ankle (n = 46) groups. Patients were evaluated by pre- and 1 year postoperative LS risk tests, including the stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale. RESULTS: The pre- and postoperative prevalence of LS stage 3 were 78% and 29%, respectively. The postoperative LS stage improved in 62% of patients (77% and 53% in the middle-aged and older groups, respectively). Overall, the knee group showed the worst results, and the foot and ankle groups showed the best pre- and postoperative results. The pre- and postoperative prevalence of LS stage 3 according to the 25-Question Geriatric Locomotive Function Scale were comparable to those based on the total assessment. CONCLUSIONS: The new LS stage criteria are appropriate, and the 25-Question Geriatric Locomotive Function Scale is a good option for evaluating patients requiring surgery.

The efficacy of total hip arthroplasty on locomotive syndrome and its related physical function in patients with hip osteoarthritis.

BACKGROUND: Locomotive syndrome (LS) is a predictive factor of future motor dysfunction. Our aim was to evaluate the change in the total LS grade and, its the association with the Japanese Orthopaedic Association (JOA) hip score after total hip arthroplasty (THA) among patients with hip osteoarthritis. METHODS: This was a prospective case-control study of 72 patients who underwent primary THA. The functional outcomes were measured before, and at 6 and 12 months after THA. LS was evaluated using the following tests: stand-up test, 2-step test, and 25-question Geriatric Locomotive Function Scale (GLFS-25). In addition, factors affecting the improvement of LS grade were examined. RESULTS: Prior to THA, 7% and 93% of patients were classified as LS grades 1 and 2. At 6 months after THA, an improvement in the total LS grade was observed in 57% of patients, with this percentage further increasing to 65% at 1 year. Only the preoperative GLFS-25 was correlated with the preoperative JOA hip scores. The postoperative GLFS-25 and the two-step test were correlated with the postoperative JOA hip scores. The preoperative functional reach test (FRT) was significantly correlated with the total LS grade improvement. CONCLUSIONS: THA can improve the total LS grade in 65% of patients at 1 year postoperatively. Improvement was largely achieved in the first 6 months after THA, with a change from LS grade 2 to grade 1. FRT could be used an indicator of the total LS grade improvement.

The efficacy of surgical treatment on locomotive syndrome and physical function in patients with lumbar spinal canal stenosis.

BACKGROUND: Locomotive syndrome is a condition of reduced mobility due to problems with locomotive organs. Although lumbar spinal canal stenosis is one of the major diseases constituting locomotive syndrome, only few studies have focused on the association between the two pathologies. We aimed to investigate the effect of surgery on lumbar spinal canal stenosis with respect to locomotive syndrome using various physical function tests, including locomotive syndrome risk tests, before and after surgery. METHODS: Clinical data of 101 consecutive patients (male = 46; female = 55; mean age, 69.3 years) who underwent surgery for lumbar spinal canal stenosis at our institute were prospectively collected. Results of physical function tests, including stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale, and the sagittal vertical axis were evaluated before and 1 year after surgery. The association between several parameters and improvement of risk level in locomotive syndrome was evaluated. RESULTS: In the total assessment, 93.1% of cases were in stage 2 and 6.9% in stage 1 preoperatively, while 72.4% were in stage 2, 22.4% in stage 1, and 5.2% in stage 0 at 1 year postoperatively. Postoperative improvement in the total assessment was observed in 28.7% of cases. Several physical function tests and sagittal vertical axis showed significant improvement after surgery. On multiple logistic regression analysis, age >75 years (odds ratio = 10.9, confidence interval = 1.09-109) and postoperative sagittal vertical axis >40 mm (odds ratio = 17.8, confidence interval = 1.78-177) were significant risk factors associated with non-improvement in risk level of locomotive syndrome. CONCLUSIONS: Surgical treatment for lumbar spinal canal stenosis improved physical function, including locomotive syndrome. Risk factors associated with non-improvement of locomotive syndrome were later-stage elderly and postoperative sagittal balance impairment.

Abscopal Effect of Frozen Autograft Reconstruction Combined with an Immune Checkpoint Inhibitor Analyzed Using a Metastatic Bone Tumor Model.

We evaluated the abscopal effect of re-implantation of liquid nitrogen-treated tumor-bearing bone grafts and the synergistic effect of anti-PD-1 (programmed death-1) therapy using a bone metastasis model, created by injecting MMT-060562 cells into the bilateral tibiae of 6-8-week-old female C3H mice. After 2 weeks, the lateral tumors were treated by excision, cryotreatment using liquid nitrogen, excision with anti-PD-1 treatment, and cryotreatment with anti-PD-1 treatment. Anti-mouse PD-1 4H2 was injected on days 1, 6, 12, and 18 post-treatment. The mice were euthanized after 3 weeks; the abscopal effect was evaluated by focusing on growth inhibition of the abscopal tumor. The re-implantation of frozen autografts significantly inhibited the growth of the remaining abscopal tumors. However, a more potent abscopal effect was observed in the anti-PD-1 antibody group. The number of CD8+ T cells infiltrating the abscopal tumor and tumor-specific interferon-γ (IFN-γ)-producing spleen cells increased in the liquid nitrogen-treated group compared with those in the excision group, with no significant difference. The number was significantly higher in the anti-PD-1 antibody-treated group than in the non-treated group. Overall, re-implantation of tumor-bearing frozen autograft has an abscopal effect on abscopal tumor growth, although re-implantation of liquid nitrogen-treated bone grafts did not induce a strong T-cell response or tumor-suppressive effect.

Risk factors for poor outcomes of early rehabilitation after total en bloc spondylectomy: a retrospective chart review of 140 patients.

STUDY DESIGN: A retrospective chart review. OBJECTIVES: Total en bloc spondylectomy (TES) has been reported to decrease the rate of local recurrence and increase survival. Although it is important to achieve early recovery of physical functions after surgery, no studies have evaluated rehabilitation outcomes during the acute phase after TES. This study evaluated ambulatory functions and activities of daily living (ADLs) after surgery and analyzed the prognostic significance of variables affecting rehabilitation outcomes at 1 month after TES. SETTING: University hospital in Kanazawa, Japan. METHODS: This study included 140 patients with spinal tumors who underwent TES between April 2010 and April 2017. Demographic characteristics, neurological functions, perioperative complications functional status as measured by the Functional Independent Measure, and independent indoor walking based on the Spinal Cord Independent Measure were extracted from medical records. Multivariate analyses were performed to assess factors associated with the recovery of ambulation and ADL at 1 month after TES. RESULTS: Preoperative neurological deficits were observed in 51 patients (36%), and postoperative neurological deterioration was found in 41 patients (29%). Multivariate analyses indicated that preoperative neurological deficits (odds ratio [OR], 5.23; 95% confidence interval [CI], 2.07-15.99), postoperative cerebrospinal fluid leakage (OR, 13.42; 95% CI, 2.93-78.82), surgical site infections (OR, 15.27; 95% CI, 2.26-127.7), and postoperative neurological deterioration (OR, 4.86; 95% CI, 1.33-19.99) were risk factors for walking ability and recovery of ADL (P < 0.01). CONCLUSIONS: This study identified preoperative neurological dysfunction and perioperative complications as independent risk factors for poor recovery of ambulation and ADL early after TES.

Improvement of locomotive syndrome with surgical treatment in patients with degenerative diseases in the lumbar spine and lower extremities: a prospective cohort study.

BACKGROUND: The epidemiology, risk factors, and prevention of locomotive syndrome (LS) have been reported. However, the number of clinical studies about the efficacy of LS treatment, including surgery, has been limited. This study aimed to evaluate LS and its improvement in patients undergoing surgeries for degenerative disease of the lumbar spine and lower extremities, and to discuss the effects of surgery on LS and the issues of LS assessment in these patients. METHODS: We enrolled 257 patients aged ≥60 years that underwent surgery for degenerative diseases of the lumbar spine and lower extremities and agreed to participate in the preoperative and 6- and 12-month postoperative LS examinations. According to the disease location, patients were divided into the lumbar (n = 81), hip (n = 106), knee (n = 43), and foot and ankle (n = 27) groups. Patients underwent LS risk tests, including the stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale (GLFS-25) assessment. RESULTS: The preoperative prevalence of LS stage 2 was 95%. Only the hip group showed significant improvements in the stand-up test. The knee group showed the worst results in the stand-up and two-step tests at all time points. All four groups had significant improvements in GLFS-25 scores. Approximately 40% of all patients had improvement in their LS stage postoperatively. However, > 90% of the patients in the knee group had LS stage 2 postoperatively. CONCLUSION: Nearly all elderly patients requiring surgeries for degenerative diseases of the lumbar spine and lower extremities had advanced conditions (LS stage 2). Surgeries could be beneficial in alleviating LS. The LS stage 3 criteria should be established, and the use of the GLFS-25 assessment can be appropriate for advanced LS patients with severe musculoskeletal diseases requiring surgeries.

Characteristics of Scoliosis in Mice Induced by Chondrocyte-specific Inactivation of L-type Amino Acid Transporter 1.

STUDY DESIGN: A mouse study of the Slc7a5 gene using conditional knockout to assess the effects of its inactivation on spinal deformity. OBJECTIVES: This study aimed to investigate whether the mice with scoliosis [induced by chondrocyte-specific inactivation of L-type amino acid transporter 1 (LAT1)] show a developmental process similar to that of pediatric scoliosis and to examine the relationship between reduced bone mineral density (BMD) and scoliosis. Furthermore, we aimed to obtain insights into elucidating the etiology and pathophysiology of scoliosis. SUMMARY OF BACKGROUND DATA: The etiology and pathogenesis of scoliosis are not fully understood despite substantial investigative efforts. LAT1 is an amino acid transporter that mediates the cellular uptake of large neutral amino acids. A recent study revealed that chondrocyte-specific inactivation of LAT1 in mice results in scoliosis (Col2a1-Cre;Slc7a5fl/fl mice: "Sko mice"). MATERIALS AND METHODS: Body length, body weight, Cobb angle, vertebral body rotation angle, and BMD at 1, 2, 4, 6, and 8 weeks of age were examined and statistically compared with those of normal control mice. Pathologic and morphologic evaluation was performed on specimens from 10-week-old euthanized mice. RESULTS: The Sko mice developed thoracic scoliosis in infancy without congenital malformations. This spinal deformity progressed rapidly during growth, with diverse curve patterns and hypoplastic vertebral bodies. Pathologic examination revealed thickening of the growth plates and decreased osteoblasts, suggesting that impaired endochondral ossification was the cause of the scoliosis. Sko mice were also observed to have decreased BMD and degraded bone microstructure. Reduced BMD and bone quality may not be the causes of the onset and progression of scoliosis in the Sko mice. CONCLUSIONS: In Sko mice, the characteristics of scoliosis and vertebral pathology showed many similarities with syndromic scoliosis in humans. Endochondral ossification defects may impair growth, leading to scoliosis and decreased BMD.

Characteristics and risk factors of instrumentation failure following total en bloc spondylectomy.

AIMS: The aim of this study was to investigate the incidence and characteristics of instrumentation failure (IF) after total en bloc spondylectomy (TES), and to analyze risk factors for IF. METHODS: The medical records from 136 patients (65 male, 71 female) with a mean age of 52.7 years (14 to 80) who underwent TES were retrospectively reviewed. The mean follow-up period was 101 months (36 to 232). Analyzed factors included incidence of IF, age, sex, BMI, history of chemotherapy or radiotherapy, tumour histology (primary or metastasis; benign or malignant), surgical approach (posterior or combined), tumour location (thoracic or lumbar; junctional or non-junctional), number of resected vertebrae (single or multilevel), anterior resection line (disc-to-disc or intravertebra), type of bone graft (autograft or frozen autograft), cage subsidence (CS), and local alignment (LA). A survival analysis of the instrumentation was performed, and relationships between IF and other factors were investigated using the Cox regression model. RESULTS: A total of 44 patients (32.4%) developed IF at a median of 31 months (interquartile range 23 to 74) following TES. Most IFs were rod fractures preceded by a mean CS of 6.1 mm (2 to 18) and LA kyphotic enhancement of 10.8° (-1 to 36). IF-free survival rates were 75.8% at five years and 56.9% at ten years. The interval from TES to IF peaked at two to three years postoperatively and continued to occur over a period of time thereafter; the early IF-developing group had greater CS at one month postoperatively (CS1M) and more lumbar TES. CS1M ≥ 3 mm and sole use of frozen autografts were identified as independent risk factors for IF. CONCLUSION: IF is a common complication following TES. We have demonstrated that robust spinal reconstruction preventing CS, and high-quality bone grafting are necessary for successful reconstruction.Cite this article: Bone Joint J 2023;105-B(2):172-179.

Clinical Outcomes of Total En Bloc Spondylectomy for Previously Irradiated Spinal Metastases: A Retrospective Propensity Score-Matched Comparative Study.

This study aimed to investigate the clinical outcomes of total en bloc spondylectomy (TES) for spinal metastases previously treated with radiotherapy (RT). This study enrolled 142 patients who were divided into two groups: those with and those without an RT history. Forty-two patients were selected from each group through propensity score matching, and postoperative complications, local recurrence, and overall survival rates were compared. The incidence of postoperative complications was significantly higher in the group with an RT history than in the group without an RT history (57.1% vs. 35.7%, respectively). The group with an RT history had a higher local recurrence rate than the group without an RT history (1-year rate: 17.5% vs. 0%; 2-year rate: 20.8% vs. 2.9%; 5-year rate: 24.4% vs. 6.9%). The overall postoperative survival tended to be lower in the group with an RT history; however, there was no significant difference between the two groups (2-year survival: 64.3% vs. 66.7%; 5-year survival: 47.3% vs. 57.1%). When planning a TES for irradiated spinal metastases, the risk of postoperative complications and local recurrence should be fully considered.

The Impact of Frailty on Postoperative Complications in Total En Bloc Spondylectomy for Spinal Tumors.

Total en bloc spondylectomy (TES) is an effective treatment for spinal tumors. However, its complication rate is high, and the corresponding risk factors remain unclear. This study aimed to clarify the risk factors for postoperative complications after TES, including the patient's general condition, such as frailty and their levels of inflammatory biomarkers. We included 169 patients who underwent TES at our hospital from January 2011-December 2021. The complication group comprised patients who experienced postoperative complications that required additional intensive treatments. We analyzed the relationship between early complications and the following factors: age, sex, body mass index, type of tumor, location of tumor, American Society of Anesthesiologists score, physical status, frailty (categorized by the 5-factor Modified Frailty Index [mFI-5]), neutrophil-to-lymphocyte ratio, C-reactive protein/albumin ratio, preoperative chemotherapy, preoperative radiotherapy, surgical approach, and the number of resected vertebrae. Of the 169 patients, 86 (50.1%) were included in the complication group. Multivariate analysis showed that high mFI-5 scores (odds ratio [OR] = 2.99, p < 0.001) and an increased number of resected vertebrae (OR = 1.87, p = 0.018) were risk factors for postoperative complications. Frailty and the number of resected vertebrae were independent risk factors for postoperative complications after TES for spinal tumors.

Safety and Efficacy of a Bodyweight Exercise Training Program in Symptomatic Patients With Severe Aortic Valve Stenosis.

Conventional exercise therapy including aerobic and resistance training is desirable for cardiovascular disease, whereas it is generally considered contraindicated for symptomatic severe aortic valve stenosis (AS). This study aimed to evaluate the safety and efficacy of bodyweight resistance exercise training (BRET), which is low-intensity exercise training in symptomatic patients with severe AS. A BRET program consisting of 8 exercises was performed 3 times a week by patients with AS with physical therapists. For the 78 symptomatic patients with severe AS, the median aortic valve area and mean transaortic valve pressure gradient were 0.56 cm2 and 48.9 mm Hg, respectively; none showed any harmful changes in blood pressure or heart rate in 11 sessions of the BRET program. There were no adverse events during hospitalization. Meanwhile, Barthel's Index score significantly improved at the time of hospital discharge. In conclusion, the BRET program in this study did not appear to cause harmful changes in hemodynamics during the program or adverse events during hospitalization, and it improved activities of daily living in symptomatic patients with severe AS, allowing doctors and physical therapists to conduct it safely, with less emotional stress, for cardiac rehabilitation for such patients.

Morphology Control of Monomer-Polymer Hybrid Electron Acceptor for Bulk-Heterojunction Solar Cell Based on P3HT and Ti-Alkoxide with Ladder Polymer.

We report the morphology control of a nano-phase-separated structure in the photoactive layer (power generation layer) of organic-inorganic hybrid thin-film solar cells to develop highly functional electronic devices for societal applications. Organic and inorganic-organic hybrid bulk heterojunction solar cells offer several advantages, including low manufacturing costs, light weight, mechanical flexibility, and a potential to be recycled because they can be fabricated by coating them on substrates, such as films. In this study, by incorporating the carrier manager ladder polymer BBL as the third component in a conventional two-component power generation layer consisting of P3HT-the conventional polythiophene derivative and titanium alkoxide-we demonstrate that the phase-separated structure of bulk heterojunction solar cells can be controlled. Accordingly, we developed a discontinuous phase-separated structure suitable for charge transport, obtaining an energy conversion efficiency higher than that of the conventional two-component power generation layer. Titanium alkoxide is an electron acceptor and absorbs light with a wavelength lower than 500 nm. It is highly sensitive to LED light sources, including those used in homes and offices. A conversion efficiency of 4.02% under a 1000 lx LED light source was achieved. Hence, high-performance organic-inorganic hybrid bulk heterojunction solar cells with this three-component system can be used in indoor photovoltaic systems.

Validation and comparison of trunk muscle activities in male participants during exercise using an innovative device and abdominal bracing maneuvers.

BACKGROUND: Abdominal bracing is effective in strengthening the trunk muscles; however, assessing performance can be challenging. We created a device for performing abdominal trunk muscle exercises. The effectiveness of this device has not yet been evaluated or comparedOBJECTIVE: We aimed to quantify muscle activity levels during exercise using our innovative device and to compare them with muscle activation during abdominal bracing maneuvers. METHODS: This study included 10 men who performed abdominal bracing exercises and exercises using our device. We measured surface electromyogram (EMG) activities of the rectus abdominis (RA), external oblique, internal oblique (IO), and erector spinae (ES) muscles in each of the exercises. The EMG data were normalized to those recorded during maximal voluntary contraction (%EMGmax). RESULTS: During the bracing exercise, the %EMGmax of IO was significantly higher than that of RA and ES (p< 0.05), whereas during the exercises using the device, the %EMGmax of IO was significantly higher than that of ES (p< 0.05). No significant difference was observed in the %EMGmax of any muscle between bracing exercises and the exercises using the device (p= 0.13-0.95). CONCLUSIONS: The use of our innovative device results in comparable activation to that observed during abdominal bracing.

Associations between Abdominal Trunk Muscle Weakness and Future Osteoporotic Vertebral Fracture in Middle-Aged and Older Adult Women: A Three-Year Prospective Longitudinal Cohort Study.

Potential risk factors associated with future osteoporotic vertebral fracture (OVF) were prospectively investigated in middle-aged and older adult women. We enrolled 197 female patients aged ≥50 years who were scheduled to undergo surgery for lower-extremity degenerative diseases. Patient anthropometric and muscle strength measurements, a bone mineral density measurement of the lumbar spine (L-BMD), and full-spine standing radiographs to examine the presence of old OVFs and spinopelvic sagittal parameters were obtained preoperatively. We evaluated 141 patients who underwent full-spine standing radiographs three years postoperatively to identify new OVFs. We excluded 54 patients who did not undergo a second radiographic examination and 2 with new traumatic OVFs. Univariate and multivariate analyses were performed to identify risk factors associated with new non-traumatic OVF occurrence. Ten (7.1%) patients developed new non-traumatic OVFs during the study period (fracture group). The fracture group had less abdominal trunk muscle strength, lower L-BMD, smaller sacral slopes, and larger pelvic tilt than the non-fracture group. The fracture group showed a higher prevalence of old OVFs preoperatively than the non-fracture group. Abdominal trunk muscle weakness, low L-BMD, and the presence of old OVFs were identified as significant risk factors for OVF occurrence. In middle-aged or older adult women, abdominal trunk muscle weakness, low L-BMD, and old OVFs were associated with future OVF.

Risk Factors for Progressive Spinal Sagittal Imbalance in the Short-Term Course after Total Hip Arthroplasty: A 3 Year Follow-Up Study of Female Patients.

Total hip arthroplasty (THA) for patients with hip osteoarthritis improves hip flexion contracture, subsequently improving spinal sagittal balance. However, in some cases, spinal sagittal imbalance develops in the course after THA, and its risk factors remain unknown. We aimed to investigate the risk factors of progressive spinal sagittal imbalance after THA. This retrospective cohort study of a prospectively maintained database included female patients aged ≥50 years who underwent THA. Before performing THA, we obtained each patient's anthropometric and muscle strength measurements and whole-spine radiographs. Three years postoperatively, patients underwent whole-spine radiography to examine changes in the spinal sagittal balance. Patients were assigned into groups on the basis of their preoperative and 3 year postoperative sagittal vertical axis (SVA) values. Patients with 3 year postoperative SVA values ≥40 mm with an increase ≥30 mm were categorized into the imbalance group; the other patients were categorized into the non-imbalance group. Of 103 patients, 11 (10.7%) were in the imbalance group. In multiple logistic regression analysis, preoperative weak abdominal trunk muscle strength (ATMS) (p = 0.007) and small sacral slope (SS) (p = 0.005) were significant risk factors for progressive spinal sagittal imbalance. In conclusion, risk factors for progressive spinal sagittal imbalance after THA were weak preoperative ATMS and small SS.