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.

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.

Incidence and temporal changes in lumbar degeneration and low back pain in child and adolescent weightlifters: A prospective 5-year cohort study.

This study was conducted to investigate the incidence of lumbar degeneration findings and low back pain (LBP) in children and adolescent weightlifters using magnetic resonance imaging (MRI) and medical questionnaires over a 5-year period. Moreover, we aimed to reveal the temporal changes in the lumbar vertebrae caused by long-term weightlifting training during the growth period. Twelve children and adolescent weightlifters who participated in weightlifting for >2 years (six boys, six girls, 11.4±2.0 years) were enrolled. Participants underwent annual medical questionnaire surveys, including data on practice frequency, competition history, presence of LBP, and lumbar examinations using MRI during the 5-year follow-up. Lumbar disc degeneration was detected in all the participants after 4 years, and lumbar disc herniation findings were detected in 33% of participants after 5 years; one underwent herniotomy during the follow-up period. Lumbar spondylolysis was detected in 58% of patients at 5 years. Although there were three participants who had LBP in the final year, none had LBP that prevented them from returning to weightlifting. This 5-year cohort study of 12 children and adolescent weightlifters detected lumbar degeneration in all participants. High frequency weightlifting training over a long period during the growth period may increase the risk of developing current and future LBP.

Prevalence and Risk Factors for the Development of Venous Thromboembolism After Spinal Tumor Surgery.

OBJECTIVE: Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary thromboembolism (PTE), is a deleterious complication that can be fatal. However, the prevalence and underlying risk factors for VTE after spinal tumor surgery remain poorly defined. METHODS: Ninety-six patients undergoing spinal tumor surgery with postoperative screening for DVT and PTE were reviewed. We evaluated the relationship between postoperative VTE and the following factors: age, sex, height, weight, body mass index, location of the tumor, type of tumor (primary or metastasis), type of operation (excisional surgery or palliative surgery), surgical approach (posterior or combined), operative time, intraoperative blood loss, perioperative transfusion, amount of transfusion, duration of postoperative bed rest (<7 days or >7 days), preoperative paralysis, postoperative paralysis, and postoperative neurological worsening. RESULTS: The overall prevalence of VTE was 25.0% (24/96). The rate of DVT and PTE was 20.8% (20/96) and 6.3% (6/96), respectively. PTE only was identified in 4 of 6 PTE-positive patients, and both PTE and DVT were identified in 2. In univariate analysis, the duration of postoperative bed rest of the VTE group was significantly longer than that of the non-VTE group (P = 0.03). In multivariate analysis, only prolonged duration of postoperative bed rest was a significant independent risk factor (P = 0.036). CONCLUSIONS: The prevalence of VTE after spinal tumor surgery was 25.0%. Prolonged duration of postoperative bed rest was a risk factor for postoperative VTE. No DVT was found in 4 of 6 PTE-positive patients, suggesting that screening for PTE itself is also needed in high-risk cases of VTE.

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.

Clinical outcomes and prognostic factors following the surgical resection of renal cell carcinoma spinal metastases.

The efficacy of surgical resection in metastatic renal cell carcinoma is an active and important research field in the postcytokine era. Bone metastases, especially in the spine, compromise patient performance status. Metastasectomy is indicated, if feasible, because it helps to achieve the best clinical outcomes possible compared with other treatments. This study examined the postoperative survival and prognostic factors in patients who underwent metastasectomy of spinal lesions. The retrospective study included 65 consecutive patients with metastatic renal cell carcinomas who were operated on by spinal metastasectomy between 1995 and 2017 at our institution. The cancer-specific survival times from the first spinal metastasectomy to death or the last follow-up (≥3 years) were determined using Kaplan-Meier analysis. Potential factors influencing survival were analyzed using Cox proportional hazard models. Planned surgical resection of all the spine tumors was achieved in all patients. Of these, 38 had complete metastasectomy of all visible metastases, including extraspinal lesions. In all patients, the estimated median cancer-specific survival time was 100 months. The 3-, 5-, and 10-year cancer-specific survival rates were 77%, 62%, and 48%, respectively. The survival times after spinal metastasectomy were similar in both cytokine and postcytokine groups. In multivariate analyses, postoperative disability, the coexistence of liver metastases, multiple spinal metastases, and incomplete metastasectomy were significant risk factors associated with short-term survival. Complete metastasectomy, including extraspinal metastases, was associated with improved cancer-specific survival. Proper patient selection and complete metastasectomy provide a better prognosis in metastatic renal cell carcinoma patients.

Risk Factor for Poor Patient Satisfaction After Lumbar Spine Surgery in Elderly Patients Aged Over 80 years.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To clarify the poor patient satisfaction after lumbar spinal surgery in elderly patients. SUMMARY OF BACKGROUND DATA: As the global population continues to age, it is important to consider the surgical outcome and patient satisfaction in the elderly. No studies have assessed patient satisfaction in elderly patients undergoing surgical treatment and risk factors for poor satisfaction in elderly patients after lumbar spinal surgery. MATERIALS AND METHODS: A retrospective multicenter survey was performed in 169 patients aged above 80 years who underwent lumbar spinal surgery. Patients were followed up for at least 1 year after surgery. We assessed patient satisfaction from the results of surgery by using a newly developed patient questionnaire. Patients were assessed by demographic data, surgical procedures, complications, reoperation rate, pain improvement, and risk factors for poor patient satisfaction with surgery for lumbar spinal disease. RESULTS: In total, 131 patients (77.5%, G-group) were satisfied and 38 patients (22.5%, P-group) were dissatisfied with surgery. The 2 groups did not differ significantly in baseline characteristics and surgical data. Postoperative visual analog scale score for low back pain and leg pain were significantly higher in the P-group than in the G-group (low back pain: G-group, 1.7±1.9 vs. P-group, 5.2±2.5, P<0.001; leg pain: G-group, 1.4±2.0 vs. P-group, 5.5±2.6, P<0.001). Multivariate regression analysis revealed that postoperative vertebral fracture (P=0.049; odds ratio, 3.096; 95% confidence interval, 1.004-9.547) and reoperation (P=0.025; odds ratio, 5.692; 95% confidence interval, 1.250-25.913) were significantly associated with the patient satisfaction after lumbar spinal surgery. CONCLUSIONS: Postoperative vertebral fracture and reoperation were found to be risk factors for poor patient satisfaction after lumbar spinal surgery in elderly patients, which suggests a need for careful treatment of osteoporosis in addition to careful determination of surgical indication and procedure in elderly patients. LEVEL OF EVIDENCE: Level III.

Short- versus long-segment posterior spinal fusion with vertebroplasty for osteoporotic vertebral collapse with neurological impairment in thoracolumbar spine: a multicenter study.

BACKGROUND: Vertebroplasty with posterior spinal fusion (VP + PSF) is one of the most widely accepted surgical techniques for treating osteoporotic vertebral collapse (OVC). Nevertheless, the effect of the extent of fusion on surgical outcomes remains to be established. This study aimed to evaluate the surgical outcomes of short- versus long-segment VP + PSF for OVC with neurological impairment in thoracolumbar spine. METHODS: We retrospectively collected data from 133 patients (median age, 77 years; 42 men and 91 women) from 27 university hospitals and their affiliated hospitals. We divided patients into two groups: a short-segment fusion group (S group) with 2- or 3-segment fusion (87 patients) and a long-segment fusion group (L group) with 4- through 6-segment fusion (46 patients). Surgical invasion, clinical outcomes, local kyphosis angle (LKA), and complications were evaluated. RESULTS: No significant differences between the two groups were observed in terms of neurological recovery, pain scale scores, and complications. Surgical time was shorter and blood loss was less in the S group, whereas LKA at the final follow-up and correction loss were superior in the L group. CONCLUSION: Although less invasiveness and validity of pain and neurological relief are secured by short-segment VP + PSF, surgeons should be cautious regarding correction loss.

Effect of bisphosphonates or teriparatide on mechanical complications after posterior instrumented fusion for osteoporotic vertebral fracture: a multi-center retrospective study.

BACKGROUND: The optimal treatment of osteoporosis after reconstruction surgery for osteoporotic vertebral fractures (OVF) remains unclear. In this multicentre retrospective study, we investigated the effects of typically used agents for osteoporosis, namely, bisphosphonates (BP) and teriparatide (TP), on surgical results in patients with osteoporotic vertebral fractures. METHODS: Retrospectively registered data were collected from 27 universities and affiliated hospitals in Japan. We compared the effects of BP vs TP on postoperative mechanical complication rates, implant-related reoperation rates, and clinical outcomes in patients who underwent posterior instrumented fusion for OVF. Data were analysed according to whether the osteoporosis was primary or glucocorticoid-induced. RESULTS: A total of 159 patients who underwent posterior instrumented fusion for OVF were included. The overall mechanical complication rate was significantly lower in the TP group than in the BP group (BP vs TP: 73.1% vs 58.2%, p = 0.045). The screw backout rate was significantly lower and the rates of new vertebral fractures and pseudoarthrosis tended to be lower in the TP group than in the BP group. However, there were no significant differences in lumbar functional scores and visual analogue scale pain scores or in implant-related reoperation rates between the two groups. The incidence of pseudoarthrosis was significantly higher in patients with glucocorticoid-induced osteoporosis (GIOP) than in those with primary osteoporosis; however, the pseudoarthrosis rate was reduced by using TP. The use of TP also tended to reduce the overall mechanical complication rate in both primary osteoporosis and GIOP. CONCLUSIONS: The overall mechanical complication rate was lower in patients who received TP than in those who received a BP postoperatively, regardless of type of osteoporosis. The incidence of pseudoarthrosis was significantly higher in patients with GIOP, but the use of TP reduced the rate of pseudoarthrosis in GIOP patients. The use of TP was effective to reduce postoperative complications for OVF patients treated with posterior fusion.

A comparison of bone conductivity on titanium screws inserted into the vertebra using different surface processing.

PURPOSE: Antibacterial iodine-supported titanium has an anodized oxide layer; thus, it can be expected to have a higher osteoconductivity than untreated titanium. This study aimed to compare the osteoconductivity between untreated titanium (Ti), anodically oxidized titanium (AO-Ti), and iodine-supported titanium (I-Ti) screws. METHODS: The screws were inserted into the vertebral bodies of 30 dogs (12 for the biomechanical, and 18 for the histological examination). The vertebral bodies were analyzed at 4 or 8 weeks after screw insertion. Biomechanically, rotational torque of the screw was measured. Histologically, bone formation index (ratio of the length of the part where the bone directly contacts with the length of the screw) and bone volume density (ratio of the area of the bone tissue to the area between the threads of the screw) were measured. RESULT: At 4 weeks, the torque value was significantly higher in the AO-Ti (0.59 ± 0.16 Nm) and I-Ti (0.72 ± 0.14 Nm) groups than in the Ti group (0.39 ± 0.12 Nm), with the AO-Ti and I-Ti groups showing no significant difference. Bone formation index was significantly higher in the AO-Ti (72.5% ± 0.8%) and I-Ti (73.4% ± 1.5%) groups than in the Ti group (64.6% ±1.7%), with the AO-Ti and I-Ti groups showing no significant difference. Bone volume density did not show a significant difference. At 8 weeks, the results were similar to those at 4 weeks. CONCLUSIONS: I-Ti had a higher osteoconductivity than Ti, indicating that iodine coating did not adversely affect osteoconductivity.

Perioperative Complications and Prognosis of Curative Surgical Resection for Spinal Metastases in Elderly Patients.

OBJECTIVE: The purpose of this study was to evaluate perioperative complications and prognosis associated with curative surgical resection, such as total en bloc spondylectomy, for spinal metastases in elderly patients. METHODS: We retrospectively reviewed 103 consecutive patients who underwent curative surgery between 2010 and 2017 and divided them into group 1 (n = 27, age <50 years), group 2 (n = 47, age ≥50 and <65 years), and group 3 (n = 29, age ≥65 years). Perioperative complication rate and overall survival (OS) after surgery was evaluated. RESULTS: A total of 129 perioperative complications were observed in 76 of 112 surgeries. Among the 3 groups, the total number of complications per person was the highest in group 3, although the difference was not statistically significant. The total number of serious complications per person was the highest in group 3, which was statistically significant. (0.23 vs. 0.51 vs. 0.90; P < 0.05). No significant difference in OS was observed between the groups. In group 3, a significant difference in OS was found between subgroups 1 (renal cell, thyroid, and breast cancer metastasis) and 2 (other primary tumors) (P < 0.01). In group 3, 24 patients (83%) either maintained or had regained their ambulatory capacity at the final follow-up. CONCLUSIONS: Elderly patients who underwent curative surgery had significantly more frequent serious postoperative complications than nonelderly patients. Even in patients with advanced age, curative surgical resection can provide favorable prognosis and local control, especially in those with spinal metastases of renal cell and thyroid cancer.

The factors related to the poor ADL in the patients with osteoporotic vertebral fracture after instrumentation surgery.

PURPOSE: Osteoporotic vertebral fracture (OVF) with nonunion or neurological deficit may be a candidate for surgical treatment. However, some patients do not show improvement as expected. Therefore, we conducted a nationwide multicenter study to determine the predictors for postoperative poor activity of daily living (ADL) in patients with OVF. METHODS: We retrospectively reviewed the case histories of 309 patients with OVF who underwent surgery. To determine the factors predicting postoperative poor ADL, uni- and multivariate statistical analyses were performed. RESULTS: The frequency of poor ADL at final follow-up period was 9.1%. In univariate analysis, preoperative neurological deficit (OR, 4.1; 95% CI, 1.8-10.3; P < 0.001), perioperative complication (OR, 3.4; P = 0.006), absence of preoperative bone-modifying agent (BMA) administration (OR, 2.7; P = 0.03), and absence of postoperative recombinant human parathyroid hormone (rPTH) administration (OR, 3.9; P = 0.006) were significantly associated. In multivariate analysis, preoperative neurological deficit (OR, 4.6; P < 0.001), perioperative complication (OR, 3.4; P = 0.01), and absence of postoperative rPTH administration (OR, 3.9; P = 0.02) showed statistical significance. CONCLUSIONS: Preoperative neurological deficit, perioperative complication, and absence of postoperative rPTH administration were considered as predictors for postoperative poor ADL in patients with OVF. Neurological deficits and complications are often inevitable factors; therefore, rPTH is an important option for postoperative treatment for OVF. These slides can be retrieved under Electronic Supplementary Material.

Indication for anterior spinal cord decompression via a posterolateral approach for the treatment of ossification of the posterior longitudinal ligament in the thoracic spine: a prospective cohort study.

PURPOSE: For ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine, anterior decompression is the most effective method for relieving spinal cord compression. The purpose of this study was to prospectively analyze the surgical outcomes based on our strategy in the treatment of thoracic OPLL. METHODS: This study included 23 patients who underwent surgery for thoracic OPLL based on the following strategy between 2011 and 2017. For patients with a beak-type OPLL in the kyphotic curve with a ≥ 50% canal occupying ratio, circumferential decompression via a posterolateral approach and fusion (CDF) was indicated. For other types of OPLL, posterior decompression and fusion (PDF) was commonly indicated. Posterior fusion without decompression (PF) was applied when the spinal cord was separated from the posterior spinal elements. Clinical and radiological outcomes were compared among the CDF, PDF, and PF groups with a minimum of 20-month follow-up. RESULTS: Ten, eleven, and two patients underwent CDF, PDF, and PF, respectively. The preoperative Japanese Orthopedic Association (JOA) score in the CDF group was significantly lower than that in the PDF group. The average recovery rate, according to JOA score, was 63%, 56%, and 25% in the CDF, PDF, and PF groups, respectively. The result in the CDF group was better than that in the PF group. CONCLUSIONS: Anterior decompression was appropriate for patients with localized spinal cord compression by a large OPLL in the kyphotic curve, and CDF via a posterolateral approach appears to be safe and effective. These slides can be retrieved under Electronic Supplementary Material.

Reliability of the muscle strength measurement and effects of the strengthening by an innovative exercise device for the abdominal trunk muscles.

OBJECTIVE: We developed an innovative exercise device for the abdominal trunk muscles (ATMs) that has a built-in system to measure muscle strength. We aimed to examine the reliability of the strength measurement as well as the effect of strengthening using the device. METHODS: Twenty healthy adults participated in a reliability study of the muscle strength measurement. The first and second measurement were done in one day with an hour rest interval by raters 1 and 2, and the third by rater 1 following a one-week interval. We calculated the intraclass correlation coefficient (ICC). Another seven healthy men participated in a training program using the device, consisting of strengthening twice a week for 5 weeks. ATM strength was measured before and after the training period, and a positron emission tomography (PET) scan series was performed, consisting of examinations during rest before training (control condition) and during exercise after training (training condition). RESULTS: The intra-rater (ICC = 0.95) and inter-rater (ICC = 0.99) reliability of the strength measurement were excellent. ATM strength was significantly higher after training than before. 18F-fluorodeoxyglucose accumulation within the diaphragm, abdominal rectus, abdominal external and internal oblique, transverse abdominal, and levator ani muscles was significantly higher in the training condition than in the control. CONCLUSIONS: Our innovative device showed excellent reliability to quantify ATM strength. Strengthening using the device increased strength and activated the abdominals, diaphragm, and pelvic floor muscles.

The Large Individual Differences in the Range of Hip Joint Motion Rather Than Lumbar Spine Motion Affect Dynamic Spinopelvic Rhythm.

INTRODUCTION: Global spinal balance and its relationship to the pelvis have received much attention, and various formulae have been used to predict postoperative spinopelvic alignment for spinal surgery. However, previous studies had limitations because no consideration was given to the dynamic factor. METHODS: Fifteen healthy adults without any lumbar disorder (group A) and 9 L4-spondylolisthesis patients (Group B) volunteered to participate in the study. Sequential images were captured with the subjects in the standing position with maximal forward bending followed by backward bending using a dynamic flat panel detector system. Spinopelvic parameters (LL: lumbar lordosis, SA: sacrofemoral angle, SS: sacral slope, PI: pelvic incidence, DP: distance of the horizontal movement of the pelvis) were evaluated. We also investigated the relationship between LL and SA (lumbar/hip [L/H] ratio) as the spinopelvic rhythm. RESULTS: In group A, the mean change in LL was 83.2 ± 9.5°; change in SA, 45.4 ± 16.6°; SS, 42.6 ± 8.9°; PI, 43.2 ± 7.7°; DP, 15.7 ± 3.4 cm, and L/H ratio, 3.6 ± 2.7. However, spinopelvic rhythm changed over time, because the change in LL was larger than the change in SA from the middle of the rising motion to the upright position. In group B, the mean change in LL was 50.3 ± 8.0°; SA, 56.9 ± 16.0°; SS, 27.5 ± 13.5°; PI, 47.4 ± 10.4°; DP, 12.7 ± 6.8 cm; and L/H ratio, 1.0 ± 0.5. CONCLUSIONS: When compared with the change in LL, individual differences were largely noted in the change in SA. These results demonstrated that the range of hip joint motion under physiological conditions, unlike anatomical motion, differed substantially between individuals. Therefore, spinopelvic rhythm is dependent on the change in SA.

Risk Factors for Proximal Junctional Fracture Following Fusion Surgery for Osteoporotic Vertebral Collapse with Delayed Neurological Deficits: A Retrospective Cohort Study of 403 Patients.

INTRODUCTION: Approximately 3% of osteoporotic vertebral fractures develop osteoporotic vertebral collapse (OVC) with neurological deficits, and such patients are recommended to be treated surgically. However, a proximal junctional fracture (PJFr) following surgery for OVC can be a serious concern. Therefore, the aim of this study is to identify the incidence and risk factors of PJFr following fusion surgery for OVC. METHODS: This study retrospectively analyzed registry data collected from facilities belonging to the Japan Association of Spine Surgeons with Ambition (JASA) in 2016. We retrospectively analyzed 403 patients who suffered neurological deficits due to OVC below T10 and underwent corrective surgery; only those followed up for　≥2 years were included. Potential risk factors related to the PJFr and their cut-off values were calculated using multivariate logistic regression analysis and receiver operating characteristic (ROC) analysis. RESULTS: Sixty-three patients (15.6%) suffered PJFr during the follow-up (mean 45.7 months). In multivariate analysis, the grade of osteoporosis (grade 2, 3: adjusted odds ratio (aOR) 2.92; p=0.001) and lower instrumented vertebra (LIV) level (sacrum: aOR 6.75; p=0.003) were independent factors. ROC analysis demonstrated that lumbar bone mineral density (BMD) was a predictive factor (area under curve: 0.72, p=0.035) with optimal cut-off value of 0.61 g/cm2 (sensitivity, 76.5%; specificity, 58.3%), but that of the hip was not (p=0.228). CONCLUSIONS: PJFr was found in 16% cases within 4 years after surgery; independent risk factors were severe osteoporosis and extended fusion to the sacrum. The lumbar BMD with cut-off value 0.61 g/cm2 may potentially predict PJFr. Our findings can help surgeons select perioperative adjuvant therapy, as well as a surgical strategy to prevent PJFr following surgery.

Surgical outcomes of spinal fusion for osteoporotic vertebral fracture in the thoracolumbar spine: Comprehensive evaluations of 5 typical surgical fusion techniques.

BACKGROUND: A consensus on the optimal surgical procedure for thoracolumbar OVF has yet to be reached due to the previous relatively small number of case series. The study was conducted to investigate surgical outcomes for osteoporotic vertebral fracture (OVF) in the thoracolumbar spine. METHODS: In total, 315 OVF patients (mean age, 74 years; 68 men and 247 women) with neurological symptoms who underwent spinal fusion with a minimum 2-year follow-up were included. The patients were divided into 5 groups by procedure: anterior spinal fusion alone (ASF group, n = 19), anterior/posterior combined fusion (APSF group, n = 27), posterior spinal fusion alone (PSF group, n = 40), PSF with 3-column osteotomy (3CO group, n = 92), and PSF with vertebroplasty (VP + PSF group, n = 137). RESULTS: Mean operation time was longer in the APSF group (p < 0.05), and intraoperative blood loss was lower in the VP + PSF group (p < 0.05). The amount of local kyphosis correction was greater in the APSF and 3CO groups (p < 0.05). Clinical outcomes were approximately equivalent among all groups. CONCLUSION: All 5 procedures resulted in acceptable neurological outcomes and functional improvement in walking ability. Moreover, they were similar with regard to complication rates, prevalence of mechanical failure related to the instrumentation, and subsequent vertebral fracture. Individual surgical techniques can be adapted to suit patient condition or severity of OVF.

Abdominal trunk muscle weakness and its association with chronic low back pain and risk of falling in older women.

BACKGROUND: Previous studies have indicated that trunk muscle strength decreases with chronic low back pain, and is associated with poor balance, poor functional performance, and falls in older adults. Strengthening exercises for chronic low back pain are considered the most effective intervention to improve functional outcomes. We developed an innovative exercise device for abdominal trunk muscles that also measures muscle strength. The correlation between muscle weakness, as measured by our device, the presence of chronic low back pain, and decreased physical ability associated with a risk of falling were evaluated in older women. METHODS: Thirty-eight elderly women, who could walk without support during daily activities and attended our outpatient clinic for treatment of chronic low back pain, knee or hip arthritis, or osteoporosis, were included in this study. Anthropometric measurements were performed. Grip power and one-leg standing time with eyes open were measured, and abdominal trunk muscle strength was measured using our device. History of falling in the previous 12 months was noted. Subjects with chronic low back pain (visual analog scale score ≥ 20 mm) for over 3 months were assigned to the low back pain group (n = 21). The remaining subjects formed the non-low back pain group (n = 17). RESULTS: Abdominal muscle strength of subjects in the low back pain group, and with history of falling, was significantly lower compared with that of subjects in the non-low back pain group, and in subjects without a history of falling, respectively. There was a moderate positive correlation between abdominal trunk muscle strength and one-leg standing time with eyes open. CONCLUSION: We measured abdominal muscle strength in older women with chronic low back pain using our device, and it was significantly lower than that of those without chronic low back pain. Muscle weakness was associated with a history and risk of falling.

Fluoroscopy-assisted posterior percutaneous reduction for the management of unilateral cervical facet dislocations after unsuccessful closed reduction: A case report.

INTRODUCTION: In some cases of cervical facet dislocations, open reduction becomes imperative when closed reduction fails. In these cases, posterior open reduction with subsequent posterior fixation has been favored in previous reports as reduction using the posterior approach is less challenging than that using the anterior approach. However, it invades the posterior cervical muscles, is associated with a high risk of postoperative axial neck pain, and is less likely to restore cervical lordosis than anterior surgery. In this report, we describe a novel reduction technique, posterior percutaneous reduction, which can address this dilemma. PRESENTATION OF CASE: An attempt to perform closed reduction in a 19-year-old adolescent with a unilateral facet dislocation at the C4-C5 level was unsuccessful. To preserve the posterior cervical muscles and obtain good cervical alignment, we opted for posterior percutaneous reduction and subsequent anterior cervical discectomy and fusion instead of posterior open reduction and fixation. An elevator was inserted into the locked facet percutaneously with fluoroscopic assistance, and reduction was achieved by lever action. Seven days after the percutaneous reduction, anterior cervical discectomy and iliac bone grafting with plate fixation were performed. There were no complications or neurological deficits postoperatively. DISCUSSION: This report describes the case of a patient who underwent anterior cervical discectomy and fusion after posterior percutaneous reduction with preservation of the posterior cervical muscles for unilateral facet dislocation when closed reduction was unsuccessful. CONCLUSION: Posterior percutaneous reduction could be a useful option for the management of cervical facet dislocations.

Morphologic Changes After Denosumab Therapy in Patients with Giant Cell Tumor of the Spine: Report of Four Cases and a Review of the Literature.

OBJECTIVE: To evaluate the quantitative, radiologic, morphologic, and histologic effects of neoadjuvant denosumab treatment (DT) on 4 patients with spinal giant cell tumor of bone (GCTB) and determine the tumor shrinkage effects of DT for spinal GCTB. METHODS: The morphologic changes in the 4 patients with spinal GCTB who underwent total spondylectomy after neoadjuvant DT at our institution were retrospectively analyzed using computed tomography. Osteolytic tumor volume, vertebral body height, maximum anterior and transverse diameter, and mean area of the spinal canal occupied by the tumor were evaluated. RESULTS: In all patients, osteolytic tumor volume decreased by 81.2% and vertebral body height decreased by 87.4% on average following DT. In 3 of 4 patients with osteolytic lesions and a thin cortical rim, vertebral collapse had progressed after DT. Conversely, vertebral collapse was not observed in one patient with adequate anterior cortical bone. Two patients showed a mean decrease of 96.7% in the maximum transverse diameter, whereas 2 had a mean increase of 109% due to vertebral collapse. The mean area of the spinal canal occupied by the tumor reduced from 56.1% to 15.1%. CONCLUSIONS: In all patients, osteolytic tumor volume decreased after DT. This tumor shrinkage effect of DT may increase the mechanical stress on the thin cortical rim, leading to the acute collapse of the affected vertebral body if it consists mostly of osteolytic lesions. The presence of adequate anterior cortical bone could prevent acute vertebral collapse after DT.