A Propensity Score-Matched Cohort Study Comparing 3 Different Spine Pedicle Screw Fixation Methods: Freehand, Fluoroscopy-Guided, and Robot-Assisted Techniques

OBJECTIVE

This study aimed to compare the accuracy of robotic spine surgery and conventional pedicle screw fixation in lumbar degenerative disease. We evaluated clinical and radiological outcomes to demonstrate the noninferiority of robotic surgery.

METHODS

This study employed propensity score matching and included 3 groups: robot-assisted mini-open posterior lumbar interbody fusion (PLIF) (robotic surgery, RS), c-arm guided minimally invasive surgery transforaminal lumbar interbody fusion (C-arm guidance, CG), and freehand open PLIF (free of guidance, FG) (54 patients each). The mean follow-up period was 2.2 years. The preoperative spine condition was considered. Accuracy was evaluated using the Gertzbein-Robbins scale (GRS score) and Babu classification (Babu score). Radiological outcomes included adjacent segmental disease (ASD) and mechanical failure. Clinical outcomes were assessed based on the visual analogue scale, Oswestry Disability Index, 36-item Short Form health survey, and clinical ASD rate.

RESULTS

Accuracy was higher in the RS group (p < 0.01) than in other groups. The GRS score was lower in the CG group, whereas the Babu score was lower in the FG group compared with the RS group. No significant differences were observed in radiological and clinical outcomes among the 3 groups. Regression analysis identified preoperative facet degeneration, GRS and Babu scores as significant variables for radiological and clinical ASD. Mechanical failure was influenced by the GRS score and patients' age.

CONCLUSION

This study showed the superior accuracy of robotic spine surgery compared with conventional techniques. When combined with minimally invasive surgery, robotic surgery is advantageous with reduced ligament and muscle damage associated with traditional open procedures.

Clinical course of patients with hepatocellular carcinoma who experienced radiologic complete response after radioembolization

Purpose

The purpose of this study is to elucidate the patterns of recurrence of hepatocellular carcinoma and to analyze factors that can predict recurrence after complete response to radioembolization.

Materials and methods

A total of 289 consecutive patients who underwent radioembolization for the treatment of hepatocellular carcinoma at a single tertiary center were retrospectively reviewed. Baseline characteristics were collected and compared between the group showing complete response and the group showing noncomplete response. Data on recurrence status, time to recurrence, and the patterns of recurrence among the patients who showed radiologic complete response were collected. The group that maintained complete response and the group that experienced recurrence were compared, and the risk factors affecting recurrence were evaluated by logistic regression analysis.

Results

The complete response rate was 24.9% (73/289). Age, sex, tumor markers, maximum tumor diameter, multiplicity, presence of vascular invasion, and target radiation dose were significantly different between the complete response and noncomplete response groups. The recurrence rate after complete response was 38.4% (28/73), and 67.9% (19/28) of recurrences occurred by 8 months after complete response. Eight patients who underwent resection/transplantation after complete response experienced no recurrence. Multiple tumors and a lower target radiation dose were independent risk factors of recurrence after complete response in the multivariate logistic regression.

Conclusion

Hepatocellular carcinoma recurrence following complete response after radioembolization is not uncommon and frequently occurs within 1 year after complete response. Multiple tumors and a lower target radiation dose may be risk factors for recurrence.

Thoracic Duct Embolization for Treatment of Chyle Leakage After Thyroidectomy and Neck Dissection

OBJECTIVE

This study aimed to evaluate the safety and efficacy of intranodal lymphangiography and thoracic duct embolization (TDE) for chyle leakage (CL) after thyroid surgery.

MATERIALS AND METHODS

Fourteen patients who underwent intranodal lymphangiography and TDE for CL after thyroid surgery were included in this retrospective study. Among the 14 patients, 13 underwent bilateral total thyroidectomy with neck dissection (central compartment neck dissection [CCND], n = 13; left modified radical neck dissection (MRND), n = 11; bilateral MRND, n = 2), and one patient underwent left hemithyroidectomy with CCND. Ten patients (76.9%) had high-output CL (> 500 mL/d). Before the procedure, surgical intervention was attempted in three patients (thoracic duct ligation, n = 1; lymphatic leakage site ligation, n = 2). Lymphangiographic findings, technical and clinical successes, and complications were analyzed. Technical success was defined as the successful embolization of the thoracic duct after access to the lymphatic duct via the transabdominal route. Clinical success was defined as the resolution of CL or surgical drain removal.

RESULTS

On lymphangiography, ethiodized oil leakage near the surgical bed was identified in 12 of 14 patients (85.7%). The technical success rate of TDE was 78.6% (11/14). Transabdominal antegrade access was not feasible due to the inability to visualize the identifiable cisterna chyli or a prominent lumbar lymphatic duct. Among patients who underwent a technically successful TDE, the clinical success rate was 90.1% (10/11). The median time from the procedure to drain removal was 3 days (with a range of 1-13 days) for the 13 patients who underwent surgical drainage. No CL recurrence was observed during the follow-up period (ranging from 2-44 months; median, 8 months). There were no complications, except for one case of chylothorax that developed after TDE.

CONCLUSION

TDE appears to be a safe and effective minimally invasive treatment option for CL after thyroid surgery, with acceptable technical and clinical success rates.

Intrawound Vancomycin Powder Application for Preventing Surgical Site Infection Following Cranioplasty

OBJECTIVE

Surgical site infection is the most detrimental complication following cranioplasty. In other surgical fields, intrawound vancomycin powder application has been introduced to prevent surgical site infection and is widely used based on results in multiple studies. This study evaluated the effect of intrawound vancomycin powder in cranioplasty compared with the conventional method without topical antibiotics.

METHODS

This retrospective study included 580 patients with skull defects who underwent cranioplasty between August 1, 1998 and December 31, 2021. The conventional method was used in 475 (81.9%; conventional group) and vancomycin powder (1 g) was applied on the dura mater and bone flap in 105 patients (18.1%; vancomycin powder group). Surgical site infection was defined as infection of the incision, organ, or space that occurred after cranioplasty. Surgical site infection within 1-year surveillance period was compared between the conventional and vancomycin powder groups with logistic regression analysis. Penalized likelihood estimation method was used in logistic regression to deal with zero events. All local and systemic adverse events associated with topical vancomycin application were also evaluated.

RESULTS

Surgical site infection occurred in 31 patients (5.3%) and all were observed in the conventional group. The median time between cranioplasty and detection of surgical site infection was 13 days (range, 4-333). Staphylococci were the most common organisms and identified in 25 (80.6%) of 31 cases with surgical site infections. The surgical site infection rate in the vancomycin powder group (0/105, 0.0%) was significantly lower than that in the conventional group (31/475, 6.5%; crude odds ratio [OR], 0.067; 95% confidence interval [CI], 0.006-0.762; adjusted OR, 0.068; 95% CI, 0.006-0.731; p=0.026). No adverse events associated with intrawound vancomycin powder were observed during the follow-up.

CONCLUSION

Intrawound vancomycin powder effectively prevented surgical site infections following cranioplasty without local or systemic adverse events. Our results suggest that intrawound vancomycin powder is an effective and safe strategy for patients undergoing cranioplasty.

Thermal Grill Illusion in Chronic Lower Back Pain: A Case-Control Study

Purpose

This study aimed to use thermal grill illusion (TGI), an experimental model of pain processing and central mechanisms, to evaluate the perception of TGI-related sensations or pain in patients with chronic lower back pain (CLBP).

Patients and Methods

The perception of TGI (warmth/heat, cold, unpleasantness, pain, burning, stinging, and prickling) was examined in 66 patients with CLBP and compared with that in 22 healthy participants. The visual analog scale (VAS) scores for CLBP, Oswestry Disability Index (ODI), and 12-Item Short Form Survey (SF-12) scores were obtained from the included patients with CLBP.

Results

The CLBP group showed a less intense perception of TGI for sensations of warmth/heat, unpleasantness, and pain than the control group. The CLBP group felt burning sensations lesser than the control (2.77 vs 4.55, P=0.016). In the CLBP group, there were significant correlations between the ODI and the degree of unpleasantness (r=0.381, P=0.002) and prickling sensation (r=0.263, P=0.033). There were also significant correlations between the mental component score of the SF-12 and the degree of warmth/heat (r=-0.246, P=0.046), unpleasantness (r=-0.292, P=0.017), pain (r=-0.292, P=0.017), and burning sensations (r=-0.280, P=0.023).

Conclusion

Our results may be useful for clinicians to evaluate the effectiveness of drugs or interventions to manage centralized LBP.

Balloon Bronchoplasty for the Treatment of Bronchial Stenosis After Lung Transplantation: A Single-Center 10-Year Experience

OBJECTIVE

To assess the safety and efficacy of balloon dilatation under dual guidance using fluoroscopy and bronchoscopy for treating bronchial stenosis following lung transplantation (LT), and to elucidate the factors associated with patency after the procedure.

MATERIALS AND METHODS

From September, 2012, to April, 2021, 50 patients (mean age ± standard deviation, 54.4 ± 12.2 years) with bronchial stenosis among 361 recipients of LT were retrospectively analyzed. The safety of balloon dilatation was assessed by evaluating procedure-related complications. Efficacy was assessed by evaluating the technical success, primary patency, and secondary patency. Primary and secondary cumulative patency rates were calculated using the Kaplan-Meier method. The factors associated with patency after the procedure were evaluated using multivariable Cox hazard proportional regression analysis.

RESULTS

In total, 65 bronchi were treated with balloon dilatation in 50 patients. The total number of treatment sessions was 277 and the technical success rate was 99.3% (275/277 sessions). No major procedure-related complications were noted. During the mean follow-up period of 34.6 ± 30.8 months, primary patency was achieved in 12 of 65 bronchi (18.5%). However, the patency rate improved to 76.9% (50 of 65 bronchi) after repeated balloon dilatation (secondary patency). The 6-month, 1-year, 3-year, and 5-year secondary patency rates were 95.4%, 90.8%, 83.1%, and 78.5%, respectively. The presence of clinical symptoms was a significant prognostic factor associated with reduced primary patency (adjusted hazard ratio [HR], 0.465; 95% confidence interval [CI], 0.220-0.987). Early-stage treatment ≤ 6 months (adjusted HR, 3.588; 95% CI, 1.093-11.780) and prolonged balloon dilatation > 5 min (adjusted HR, 3.285; 95% CI, 1.018-10.598) were associated with significantly higher secondary patency.

CONCLUSION

Repeated balloon dilatation was determined to be safe and effective for treating bronchial stenosis following LT. Early-stage treatment and prolonged balloon dilatation could significantly promote long-term patency.

Surgical Strategies and Perioperative Considerations for Cervical Deformity With Cerebral Palsy: A Comprehensive Review of the Literature

The complex nature of the cervical spine makes surgical intervention challenging when treating cervical deformity in patients with cerebral palsy (CDCP). However, few studies have investigated the unique characteristics of cerebral palsy that create the need for surgery, the most effective surgical strategies, and the possible perioperative complications. The intended benefit and the potential risk of postoperative complications must be considered when deciding to operate for CDCP. Because the approach and correction strategy depend on the type of cervical deformity, as well as the patient's comorbidities and functional status, a customized strategy is needed. Perioperatively, botulinum toxin injections and muscle division techniques can help control excessive involuntary movements and improve the spinal fusion success rate. Surgical intervention for CDCP requires a multidisciplinary approach, and the information presented in this article is intended to help in the perioperative management and surgical treatment of CDCP.

Characteristics of CRC01, an investigational CD19 CAR-T product with PD-1 and TIGIT genes silenced by shRNAs

e14514

Background: Currently, CAR-T therapy has been successful in the treatment of certain types of hematological malignancy. However, not all patients benefit from this novel therapy due to various resistance mechanisms, such as suppression of immune cell function by inhibitory immune checkpoint signaling. To overcome this, we have developed a novel two-in-one lentiviral vector system that can efficiently induce shRNA-based silencing of PD-1 and TIGIT genes in CAR-T cells while maintaining robust CAR expression. This PD-1 and TIGIT-silenced CD19 CAR-T, CRC01, showed an enhanced anti-tumor activity in vitro and in vivo, compared to conventional CD19 CAR-T. For the development of CRC01 as an investigational new drug, IND-enabling non-clinical studies have been conducted and CRC01 is currently being evaluated in a clinical trial for r/r LBCL patients (NCT04836507). Methods: T cells were enriched from leukapheresis products of r/r LBCL patients and transduced with the two-in-one lentiviral vector. Transduced T cells were expanded within a semi-closed culture system and formulated for cryopreservation. For phase I clinical trial of CRC01, ten batches of CRC01 were manufactured and characterized in quality. Results: In the manufacturing of ten batches of CRC01, manufacturing time was in the range of 8-14 days and total cells expanded 32-53 folds. In the final product of CRC01, T cell percentage (Live CD3+) and viability were not less than 98% and 85%, respectively. The range of transduction efficiency was 11.3%-28.6% and the range of vector copy number was 1.0-3.5 copies/CAR-T. Generally, CRC01(CAR-positive T cells) showed higher CD4/CD8 ratio than leukapheresis product and CAR-negative T cells, and central memory and effector memory T cell subsets were the main populations of CRC01. All batches of CRC01 released IFN-γ in response to CD19-expressing target cells, but the level of IFN-γ production was quite different from batch to batch. When PD-1 and TIGIT expression levels of CRC01 were analyzed after CD3/CD28 stimulation, CAR-positive T cells were found to express PD-1 and TIGIT much lower than CAR-negative T cells, demonstrating an efficient silencing of PD-1 and TIGIT genes in CRC01. Conclusions: Ten batches of CRC01 were manufactured in GMP facility for CRC01 phase I clinical trial. All batches met acceptance criteria for release, showing that CRC01 manufacturing process is a robust one and that silencing of PD-1 and TIGIT genes via shRNAs, a unique feature of CRC01, was successfully implemented in the investigational products.

PD-1 and TIGIT downregulation distinctly affect the effector and early memory phenotypes of CD19-targeting CAR T cells

CD19-targeting chimeric antigen receptor (CAR) T cells have become an important therapeutic option for patients with relapsed and refractory B cell malignancies. However, a significant portion of patients still do not benefit from the therapy owing to various resistance mechanisms, including high expression of multiple inhibitory immune checkpoint receptors. Here, we report a lentiviral two-in-one CAR T approach in which two checkpoint receptors are downregulated simultaneously by a dual short hairpin RNA cassette integrated into a CAR vector. Using this system, we evaluated CD19-targeting CAR T cells in the context of four different checkpoint combinations-PD-1/TIM-3, PD-1/LAG-3, PD-1/CTLA-4, and PD-1/TIGIT-and found that CAR T cells with PD-1/TIGIT downregulation uniquely exerted synergistic antitumor effects. Importantly, functional and phenotypic analyses suggested that downregulation of PD-1 enhances short-term effector function, whereas downregulation of TIGIT is primarily responsible for maintaining a less differentiated/exhausted state, providing a potential mechanism for the observed synergy. The PD-1/TIGIT-downregulated CAR T cells generated from diffuse large B cell lymphoma patient-derived T cells also showed robust antitumor activity and significantly improved persistence in vivo. The efficacy and safety of PD-1/TIGIT-downregulated CD19-targeting CAR T cells are currently being evaluated in adult patients with relapsed or refractory large B cell lymphoma (ClinicalTrials.gov: NCT04836507).

Laminectomy with instrumented fusion vs. laminoplasty in the surgical treatment of cervical ossification of the posterior longitudinal ligament: A multicenter retrospective study

Laminectomy with instrumented fusion (LF) has demonstrated better prevention of ossification of posterior longitudinal ligament (OPLL) growth compared to laminoplasty (LP). There remains uncertainty, however, as to which surgical approach is more beneficial with respect to clinical outcomes and complications. We retrospectively reviewed 273 cervical OPLL patients of more than 3 levels, from the two institutions' databases, who underwent LF or LP between January 1998 and January 2016. Each 273 patient (85 with LF, 188 with LP) was assessed for postoperative neurologic and radiologic outcomes, complications and reoperations. The mean length of follow-up was 40.11 months. There were baseline differences between cohorts. Overall, postoperative JOA recovery rate at last follow up was significantly better in the LP group with similar improvement in visual analog neck score. Postoperative C2-7 Cobb angle was decreased compared to baseline for both LF and LP cohorts, but there was no significant difference between groups. Complications occurred in 19 (22.35%) LF patients, and 11 (5.85%) LP patients, with higher incidence of C5 palsy and instrumentation failure in the LF group. Four LF patients (4.71%) and five LP patients (2.66%) underwent reoperation during the follow up period.

Factors Affecting Postoperative Complications and Outcomes of Cervical Spondylotic Myelopathy with Cerebral Palsy : A Retrospective Analysis

Objective

Cervical surgery in patients with cervical spondylotic myelopathy (CSM) and cerebral palsy (CP) is challenging owing to the complexities of the deformity. We assessed factors affecting postoperative complications and outcomes after CSM surgery in patients with CP.

Methods

Thirty-five consecutive patients with CP and CSM who underwent cervical operations between January 2006 and January 2014 were matched to 35 non-cerebral palsy (NCP) control patients. Postoperative complications and radiologic outcomes were compared between the groups. In the CP group, the Japanese Orthopaedic Association score; Oswestry neck disability index; modified Barthel index; and values for the grip and pinch, Box and Block, and Jebsen-Taylor hand function tests were obtained preand postoperatively and compared between those with and without postoperative complications.

Results

Sixteen patients (16/35%) in the CP group and seven (7/35%) in the NCP group (p=0.021) had postoperative complications. Adjacent segment degeneration (p=0.021), postoperative motor weakness (p=0.037), and revisions (p=0.003) were significantly more frequent in the CP group than in the NCP group; however, instrument-related complications were not significantly higher in the CP group (7/35 vs. 5/35, p=0.280). The number of preoperative fixed cervical deformities were significantly higher in CP with postoperative complications (5/16 vs. 1/19, p=0.037). In the CP group, clinical outcomes were almost similar between those with and without postoperative complications.

Conclusion

The occurrence of complications during the follow-up period was high in patients with CP. However, postoperative complications did not significantly affect clinical outcomes.

The diagnostic value of phase angle, an integrative bioelectrical marker, for identifying individuals with dysmobility syndrome: the Korean Urban-Rural Elderly study

Low phase angle, a non-invasive bioimpedance marker, is associated with elevated odds of dysmobility syndrome and its components. Phase angle (estimated cutoffs: < 4.8° in men; < 4.5° in women) can be used to detect dysmobility syndrome in community-dwelling older adults as a simple, integrative screening tool.

INTRODUCTION

Dysmobility syndrome uses a score-based approach to predict fracture risk that incorporates the concepts of osteoporosis, sarcopenia, and obesity. Low phase angle (PhA), a simple, non-invasive bioelectrical impedance marker, was associated with low lean mass, high fat mass, and poor muscle function. We aimed to investigate the association between PhA and dysmobility syndrome, with the exploration of the diagnostic cutoffs.

METHODS

In a community-dwelling Korean older adult cohort, dysmobility syndrome was defined as the presence of ≥ 3 of the following components: osteoporosis, low lean mass, falls in the preceding year, low grip strength, high fat mass, and poor timed up and go performance.

RESULTS

Among the 1825 participants (mean age 71.6, women 66.7%), subjects were classified into sex-stratified PhA tertiles. The prevalence of dysmobility syndrome increased from the highest PhA tertile group to the lowest (15.50 to 2.45% in men; 33.41 to 12.25% in women, P for trend < 0.001). The mean PhA values decreased as the dysmobility score increased (5.33° to 4.65° in men; 4.76° to 4.39° in women, P for trend < 0.001). Low PhA (cutoff: < 4.8° in men; < 4.5° in women) was associated with twofold elevated odds of dysmobility syndrome after adjusting for age, sex, and conventional risk factors. Low PhA improved the identification of individuals with dysmobility syndrome when added to the conventional risk model (area under the curve, 0.73 to 0.75, P = 0.002).

CONCLUSION

Low PhA was associated with dysmobility syndrome and its components, independent of age, sex, body mass index, nutritional status, and inflammation.

Preoperative Cognitive Impairment as a Predictor of Postoperative Outcomes in Elderly Patients Undergoing Spinal Surgery for Degenerative Spinal Disease

Cognitive status has been reported to affect the peri-operative and post-operative outcomes of certain surgical procedures. This prospective study investigated the effect of preoperative cognitive impairment on the postoperative course of elderly patients (n = 122, >65 years), following spine surgery for degenerative spinal disease. Data on demographic characteristics, medical history, and blood analysis results were collected. Preoperative cognition was assessed using the mini-mental state examination, and patients were divided into three groups: normal cognition, mild cognitive impairment, and moderate-to-severe cognitive impairment. Discharge destinations (p = 0.014) and postoperative cardiopulmonary complications (p = 0.037) significantly differed based on the cognitive status. Operation time (p = 0.049), white blood cell count (p = 0.022), platelet count (p = 0.013), the mini-mental state examination score (p = 0.033), and the Beck Depression Inventory score (p = 0.041) were significantly associated with the length of hospital stay. Our investigation demonstrated that improved understanding of preoperative cognitive status may be helpful in surgical decision-making and postoperative care of elderly patients with degenerative spinal disease.

Predictors of neurologic outcome after surgery for cervical ossification of the posterior longitudinal ligament differ based on myelopathy severity: a multicenter study

OBJECTIVE

The purpose of this retrospective multicenter study was to compare prognostic factors for neurological recovery in patients undergoing surgery for cervical ossification of the posterior longitudinal ligament (OPLL) based on their presenting mild, moderate, or severe myelopathy.

METHODS

The study included 372 consecutive patients with OPLL who underwent surgery for cervical myelopathy between 2006 and 2016 in East Asian countries with a high OPLL prevalence. Baseline and postoperative clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA) myelopathy score and recovery ratio. Radiographic assessment included occupying ratio, cervical range of motion, and sagittal alignment parameters. Patient myelopathy was classified as mild, moderate, or severe based on the preoperative JOA score. Linear and multivariate regression analyses were performed to identify patient and surgical factors associated with neurological recovery stratified by baseline myelopathy severity.

RESULTS

The mean follow-up period was 45.4 months (range 25-140 months). The mean preoperative and postoperative JOA scores and recovery ratios for the total cohort were 11.7 ± 3.0, 14.5 ± 2.7, and 55.2% ± 39.3%, respectively. In patients with mild myelopathy, only age and diabetes correlated with recovery. In patients with moderate to severe myelopathy, older age and preoperative increased signal intensity on T2-weighted imaging were significantly correlated with a lower likelihood of recovery, while female sex and anterior decompression with fusion (ADF) were associated with better recovery.

CONCLUSIONS

Various patient and surgical factors are correlated with likelihood of neurological recovery after surgical treatment for cervical OPLL, depending on the severity of presenting myelopathy. Older age, male sex, intramedullary high signal intensity, and posterior decompression are associated with less myelopathy improvement in patients with worse baseline function. Therefore, myelopathy-specific preoperative counseling regarding prognosis for postoperative long-term neurological improvement should include consideration of these individual and surgical factors.

Defining an international cut-off of two-legged countermovement jump power for sarcopenia and dysmobility syndrome

We aimed to establish jump power cut-offs for the composite outcome of either sarcopenia (EWGSOP2) or dysmobility syndrome using Asian and Caucasian cohorts. Estimated cut-offs were sex specific (women: < 19.0 W/kg; men: < 23.8 W/kg) but not ethnicity specific. Jump power has potential to be used in definitions of poor musculoskeletal health.

PURPOSE

Weight-corrected jump power measured during a countermovement jump may be a useful tool to identify individuals with poor musculoskeletal health, but no cut-off values exist. We aimed to establish jump power cut-offs for detecting individuals with either sarcopenia or dysmobility syndrome.

METHODS

Age- and sex-matched community-dwelling older adults from two cohorts (University of Wisconsin-Madison [UW], Korean Urban Rural Elderly cohort [KURE], 1:2) were analyzed. Jump power cut-offs for the composite outcome of either sarcopenia defined by EWGSOP2 or dysmobility syndrome were determined.

RESULTS

The UW (n = 95) and KURE (n = 190) cohorts were similar in age (mean 75 years) and sex distribution (68% women). Jump power was similar between KURE and UW women (19.7 vs. 18.6 W/kg, p = 0.096) and slightly higher in KURE than UW in men (26.9 vs. 24.8 W/kg, p = 0.050). In UW and KURE, the prevalence of sarcopenia (7.4% in both), dysmobility syndrome (31.6% and 27.9%), or composite of either sarcopenia or dysmobility syndrome (32.6% and 28.4%) were comparable. Low jump power cut-offs for the composite outcome differed by sex but not by ethnicity (< 19.0 W/kg in women; < 23.8 W/kg in men). Low jump power was associated with elevated odds of sarcopenia (adjusted odds ratio [aOR] 4.07), dysmobility syndrome (aOR 4.32), or the composite of sarcopenia or dysmobility syndrome (aOR 4.67, p < 0.01 for all) independent of age, sex, height, and ethnicity.

CONCLUSION

Sex-specific jump power cut-offs were found to detect the presence of either sarcopenia or dysmobility syndrome in older adults independent of Asian or Caucasian ethnicity.

Novel C-arm based planning spine surgery robot proved in a porcine model and quantitative accuracy assessment methodology

BACKGROUND

We assessed pedicle screw accuracy utilizing a novel navigation-based spine surgery robotic system by comparing planned pathways with placed pathways in a porcine model.

METHODS

We placed three mini screws per vertebra for accuracy evaluation and used a reference frame for registration in four pigs (46 screws in 23 vertebrae). We planned screw paths and performed screw insertion under robot guidance. Using C-arm and CT images, we evaluated accuracy by comparing the 3D distance of the placed screw head/tip from the planned screw head/tip and 3D angular offset.

RESULTS

Mean registration deviation between the preoperative 3D space (C-arm) and postoperative CT scans was 0.475 ± 0.119 mm. The average offset from preoperative plan to final placement was 4.8 ± 2.0 mm from the head (tail), 5.3 ± 2.3 mm from the tip and 3.9 ± 2.4 degrees of angulation.

CONCLUSIONS

Our spine surgery robot showed good accuracy in executing an intended planned trajectory and screw path. This faster and more accurate robotic system will be applied in future studies, first in cadavers and subsequently in the clinical field.

Does serum vitamin D level affect the association between cardiovascular health and cognition? Results of the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) study

BACKGROUND AND PURPOSE

Few studies have assessed the role of vitamin D in the association between cardiovascular risk factors and cognitive function. Here, the aim was to investigate the association between cardiovascular health (CVH) and cognitive function according to vitamin D level in a middle-aged Korean population.

METHODS

This cross-sectional study included 840 men and 1811 women (mean age 57.2 years) from the Cardiovascular and Metabolic Diseases Etiology Research Center study baseline enrolment (2013-2018). Life's Simple 7 tools from the American Heart Association were used to assess CVH. Cognitive function was evaluated using the Mini-Mental State Estimation for Dementia Screening (MMSE-DS), and the serum 25-hydroxyvitamin D level was measured.

RESULTS

In the adjusted generalized linear regression models, no significant association between a high Life's Simple 7 score (4-7 metric at optimal level) and MMSE-DS score (β = 0.01, P = 0.93) was found. Amongst men with a high vitamin D level, the high Life's Simple 7 score group showed a significantly higher MMSE-DS score (β = 0.48, P = 0.03). However, amongst men in the low vitamin D group, the association was opposite with no statistical significance (β = -0.23, P = 0.08). In women, the results were similar, but both strata according to vitamin D level showed no statistical significance.

CONCLUSIONS

Our findings suggest that vitamin D is an effect modifier in the association between CVH and cognition, especially in men.

Feasibility of Using the Epidural Space Detecting Device (EPI-DetectionTM) for Interlaminar Cervical Epidural Injection

Cervical epidural injection (CEI), which is widely used for the treatment of cervical radiculopathy, sometimes has been associated with post-operative complications. Recently, EPI-Detection^TM, which detects the negative pressure of the epidural space and notifies the proceduralist by flashing a light and producing a beeping sound, was introduced. We assumed that the newly developed device could be as safe and efficient as the conventional loss of resistance (LOR) method. Therefore, we aimed to evaluate the effectiveness of the EPI-Detection^TM and compare it to that of the conventional LOR method. We randomly assigned 57 patients to the LOR and EPI-Detection groups (29 and 28 patients, respectively). Subjects were treated with interlaminar CEI (ILCEI) using one of two methods. The measured parameters, i.e., operation time and radiation dose were lower in the EPI-Detection^TM group (4.6 ± 1.2 min vs. 6.9 ± 2.1 min; and 223.2 ± 206.7 mGy·cm² vs. 380.3 ± 340.9 mGy·cm², respectively; all p < 0.05) than in the LOR group. There were no complications noted in either group. Both the EPI-Detection^TM and LOR methods were safe and effective in detecting the epidural space, but the former was superior to the latter in terms of operation time and radiation exposure. The EPI-Detection^TM may help perform ILCEI safely.

Association of Frailty and Self-Care Activity With Sagittal Spinopelvic Alignment in the Elderly

OBJECTIVE

To assess the relationship between frailty, activities of daily living (ADL), instrumental ADL (IADL), and sagittal spinopelvic parameters in the elderly.

METHODS

To compare the characteristics based on the FRAIL scale status (robust, prefrail, frail), continuous variables were analyzed using ANOVA with Tukey post hoc tests, and categorical variables were analyzed using χ² and Fisher's exact test. Multivariate linear regression was used to investigate cross-sectional association between sagittal alignment and FRAIL status.

RESULTS

Comparison analysis of the 3 groups (robust, prefrail, frail) demonstrated that frailty scale had significant correlations with T1 pelvic angle (T1PA, P = 0.019), pelvic tilt (PT, P = 0.004), pelvic incidence minus lumbar lordosis (PI-LL, P = 0.004) and ADL (P = 0.017). Multiple regression analysis that controlled for confounding factors confirmed the correlations between frailty scale and spinopelvic parameters (C7 sagittal vertical axis [SVA], B = 17.49, P = 0.028; T1PA, B = 4.83, P = 0.029; PT, B = 4.62, P = 0.003; PI-LL value, B = 7.11, P = 0.005). In addition, the ADL was associated with T1PA (B = 4.06, P = 0.006); whereas the IADL was correlated with C7 SVA (B = 11.38, P = 0.005), T1PA (B = 3.36, P = 0.003), and PI-LL (B = 3.13, P = 0.018).

CONCLUSIONS

Higher frailty score was associated with higher grades of sagittal spinopelvic malalignment and ADL in the elderly. Furthermore, higher ADL and IADL scores were associated with higher grades of sagittal spinopelvic malalignment. Frailty, ADL, IADL, and sagittal spinopelvic parameters were closely related to each other in the elderly.

Comparison of the effectiveness and safety of bioactive glass ceramic to allograft bone for anterior cervical discectomy and fusion with anterior plate fixation

Recently, a bioactive glass ceramic (BGC) has been developed for use as intervertebral cages for anterior cervical discectomy and fusion (ACDF). However, the effectiveness and safety of BGC cages remain to be evaluated. We completed a retrospective comparison of the radiological and clinical outcomes of 36 patients (52 levels) who underwent ACDF with a BGC cage and 35 patients (54 levels) using allograft bone. The following variables were compared between the two groups: the visual analog (VAS) neck and arm pain score and the neck disability index (NDI), measured before surgery and 1 year after; the change in Cobb's angle, between the C2 and C7 vertebrae, the global sagittal angle, and disc height compared from before surgery to 1 year after; and the rate of spinal fusion and cage subsidence at 1 and 2 years after surgery. The VAS and NDI scores were not different between the two groups. Similarly, the spinal fusion rate was not different between the BGC and allograft bone group at 1 year (73% and 87%, respectively; p = 0.07) and 2 years (94% and 91%, respectively; p = 0.54) after surgery. However, the rate of cage subsidence was higher in the allograft bone (43%) than the BGC (19%) group (p = 0.03), as was the rate of instrument-related failure (p = 0.028), with a specifically higher incidence of implant fracture or failure in the allograft bone group (p = 0.025). Overall, our findings indicate that BGC cages provide a feasible and safe alternative to allograft bone for ACDF.

Performance of deep learning-based algorithm for detection of ileocolic intussusception on abdominal radiographs of young children

The purpose of this study was to develop and test the performance of a deep learning-based algorithm to detect ileocolic intussusception using abdominal radiographs of young children. For the training set, children (≤5 years old) who underwent abdominal radiograph and ultrasonography (US) for suspicion of intussusception from March 2005 to December 2017 were retrospectively included and divided into control and intussusception groups according to the US results. A YOLOv3-based algorithm was developed to recognize the rectangular area of the right abdomen and to diagnose intussusception. For the validation set, children (≤5 years old) who underwent both radiograph and US from January to August 2018 with the suspicion of intussusception were included. Diagnostic performances of an algorithm and radiologists were compared. Total 681 children including 242 children in intussusception group were included in the training set and 75 children including 25 children in intussusception group were included in the validation set. The sensitivity of the algorithm was higher compared with that of the radiologists (0.76 vs. 0.46, p = 0.013), while specificity was not different between the algorithm and the radiologists (0.96 vs. 0.92, p = 0.32). Deep learning-based algorithm can aid screening of intussusception using abdominal radiography in young children.

Identifying key gait features associated with the radiological grade of knee osteoarthritis

PURPOSE

Knee osteoarthritis (KOA) is characterized by pain and decreased gait function. This study assessed key features that can be used as mechanical biomarkers for KOA severity and progression. The identified features were validated statistically and were further examined by developing a classification model based on a machine-learning algorithm.

METHODS

The study included 227 volunteers with various grades of KOA. The severity of KOA was graded using the Kellgren-Lawrence (KL) system. A total of 165 features were extracted from the gait data. The key features were selected using neighborhood component analysis. The selected features were validated using the t-test. Then, the features were examined by building a classification model using a random forest algorithm.

RESULTS

Twenty features were identified that could discriminate the grade of KOA, including nine features extracted from the knee joint, seven from the hip, two from the ankle and two from the spatiotemporal gait parameters. The t-test showed that some features differed significantly between health and sever group, while some were significantly different among the severe group, and others were significantly different for all KL grades. The areas under the receiver operating characteristic curves for classification were 0.974, 0.992, 0.845, 0.894, and 0.905 for KL grades 0 through 4, respectively.

CONCLUSION

Key gait features reflecting the grade of KOA were identified. The results of the statistical analysis and machine-learning algorithm show that the features can discriminate the severity of disease according to the KL grade.