Use of the dual construct lowers rod strains in flexion-extension and lateral bending compared to two-rod and two-rod satellite constructs in a cadaveric spine corpectomy model

BACKGROUND CONTEXTComplex spinal reconstructions involving corpectomies, or osteotomies, place spinal implants at extremely high stresses that can lead to pseudoarthrosis and ultimately to rod failure, resulting in revision surgery. Current clinical options to increase the biomechanical strength of a construct include increasing rod diameter, changing rod material, or placing an additional satellite/outrigger rod on a standard two rod construct. Fundamentally, all of these constructs still rely on two longitudinal rods across the reconstruction site and are therefore at risk for rod fracture and loss of alignment. Initially described in 2006, the Dual Construct was developed to address this limitation by utilizing four distinct mechanically independent rods, which allowed for the creation of two separate, and distinct, constructs within each patient. Although there is early clinical evidence to support its efficacy, this is the first biomechanical study to compare the Dual Construct to the two-rod and two-rod with satellite configurations in a cadaveric study.PURPOSETo assess the biomechanical impact of the Dual Construct technique to traditional two-rod and two-rod with satellite rod construct in a cadaveric model.STUDY DESIGN/SETTINGBiomechanical cadaveric studyMETHODSNine fresh-frozen human cadaveric spines (6 males, 3 females, 56 year +/- 9 years) from T9-pelvis were instrumented and tested utilizing all three configurations including two-rod construct, two-rod with satellite construct, and the Dual Construct technique. Biomechanical testing order of the various constructs was randomized to reduce potential effects of order bias. Strain gauges were placed in both the coronal and sagittal planes of the rods to track the strains during flexion-extension and lateral bending while undergoing range of motion testing. Testing was performed using pure-moment flexibility testing protocols.RESULTSIn flexion-extension, the resultant strain in the two-rod construct was an average 600±228 microstrain, the two-rod with satellite rod strain averaged 603±237 microstrain, and the Dual Construct averaged 403±149 microstrain. In lateral bending, the resultant strain in the two-rod construct was an average of 266±134 microstrain, the satellite rod strain was an average of 310±158 microstrain, and the Dual Construct averaged 118±51 microstrain. In both flexion extension and lateral bending, a significant reduction in strain was observed between the Dual Construct condition compared to both the two-rod and satellite configurations. No significant difference was found between the two-rod and two-rod with satellite rod configurations.CONCLUSIONSThe increase in load sharing significantly decreases the strain experienced across the Dual Construct compared to traditional two-rod and two-rod with satellite constructs. Global rod strains on primary rods cannot be reduced by simply increasing the number of satellite rods, but can only be reduce by increasing the actual number of primary rods.     

Evaluation of transforaminal epidural steroid injections for discogenic axial lumbosacral back pain utilizing PROMIS as an outcome measure

Background contextDiscogenic lumbosacral back pain continues to present a challenging clinical entity with limited, controversial therapeutic options. No study to date has evaluated the efficacy of fluoroscopically guided transforaminal epidural steroid injections (TFESI) in a homogenous patient population with axial lumbosacral back pain from discogenic pathology utilizing strict, explicitly clinical and radiographic criteria. Additionally, there is a paucity of published data utilizing Patient Reported Outcome Measurement Information System (PROMIS) scores as an outcome measure for interventional spine procedures.PurposeEvaluate the therapeutic effect of TFESIs in a specific subset of patients with discogenic axial lumbosacral back pain. Investigate PROMIS as an outcome measure for interventional spine procedures targeting focal degenerative spinal pathology.Study design/settingRetrospective review of patients presenting to a multidisciplinary, tertiary academic spine center.Patient sampleThree thousand eight hundred eighty-one patients were screened for inclusion. A total of 26 patients with discogenic axial low back, based on strict clinical and radiographic criteria, underwent TFESIs. All patients had axial low back pain without radicular pain, ≥3 clinical features of discogenic pain, corroborative radiographic features of active discogenic pathology on lumbar spine magnetic resonance imaging without confounding spinal pathology.Outcome measuresPROMIS Pain Interference (PI) v1.1, PROMIS Physical Function (PF) v1.2/v2.0, and PROMIS Depression (D) v1.0 outcome scores were collected at baseline and postprocedure follow-up.MethodsQuery of an institutional, patient reported outcome database and subsequent retrospective review of electronic medical records was performed. Statistical analysis comparing baseline and postprocedural PROMIS outcome scores and correlation between these instruments was performed. Additionally, an exploratory investigation of minimal clinically important difference achievement rates was performed.ResultsAnalysis determined a statistically significant improvement in PROMIS PI (p=.017, 95% CI=?8.02 to ?1.82) and PROMIS PF (p=.003, 95% CI=0.91–8.72) scores after treatment with TFESIs. At post treatment time points, TFESI had medium effect size on pain (d=0.55) and function (d=0.59). Change in PROMIS D scores (p=.488, 95% CI ?1.74–3.54; d=.08) did not demonstrate statistical significance. Pearson correlation demonstrated a moderate negative correlation (r=?0.544, p=.004) between PROMIS PF with PROMIS PI. Correlation between PROMIS PF (r=?0.239, p=.24) and PROMIS PI (r=0.198, p=.33) with PROMIS D was not significant. Fourteen (53.8%) and 9 (34.6%) subjects achieved minimum clinically important difference (MCID) for PROMIS PI and PROMIS PF, respectively. Nine subjects (34.6%) achieved MCID for PROMIS D despite not otherwise reaching statistical significance otherwise.ConclusionsUtilizing PROMIS as an outcome measure, discogenic axial lumbosacral back pain patients appear to benefit from TFESI in terms of pain and physical function. This study contributes to the growing body of literature utilizing PROMIS scores in patients with clinical sequelae of degenerative spinal pathology; however, prospective studies are needed.     

The impact of both-bone forearm fractures on acute compartment syndrome: An analysis of predisposing factors

ObjectivesAcute compartment syndrome (ACS) is a severe medical condition that, if left untreated, can cause permanent nerve and muscle damage, and may even require amputation. The objective of this study was to identify the risk factors associated with the development of ACS in patients with both-bone fractures of the forearm.MethodsBetween November 2013 and January 2021, a retrospective data collection was conducted on 611 individuals who experienced both-bone forearm fractures at a level 1 trauma center. Among these patients, 78 patients were diagnosed with ACS, while the remaining 533 patients did not have ACS. Based on this division, the patients were categorized into two groups: the ACS group and the non-ACS group. Demographics (including factors such as age, gender, body mass index, crush injury, etc.), comorbidities (including conditions such as diabetes, hypertension, heart disease, anemia, etc.), and admission lab results (including complete blood count, comprehensive metabolic panel, and coagulation profiles, etc.) were analyzed using univariate analysis, logistic regression, and ROC curve analysis.ResultsPredictors of ACS were identified through the final multivariable logistic regression analysis, which revealed that crush injury (p < 0.001, OR = 10.930), the levels of neutrophils (NEU) (p < 0.001, OR = 1.338) and the levels of creatine kinase (CK) (p < 0.001, OR = 1.001) were significant risk factors. Additionally, age (p = 0.045, OR = 0.978) and albumin (ALB) level (p < 0.001, OR = 0.798) were found to provide protective effects against ACS. Furthermore, the receiver operating characteristic (ROC) curve analysis determined cut-off values for NEU and CK to predict ACS: 7.01/L and 669.1 U/L respectively.ConclusionsOur study identified crush injury, NEU, and CK as significant risk factors for ACS in patients with both-bone forearm fractures. We also determined the cut-off values of NEU and CK, allowing for the individualized evaluation of ACS risk and the implementation of early targeted treatments.     

Full-endoscopic spine surgery diminishes surgical site infections – a propensity score-matched analysis

BACKGROUND CONTEXTSurgical site infections (SSI) are one the most frequent and costly complications following spinal surgery. The SSI rates of different surgical approaches need to be analyzed to successfully minimize SSI occurrence.PURPOSEThe purpose of this study was to define the rate of SSIs in patients undergoing full-endoscopic spine surgery (FESS) and then to compare this rate against a propensity score-matched cohort from the National Surgical Quality Improvement Program (NSQIP) database.DESIGNThis is a retrospective multicenter cohort study using a propensity score-matched analysis of prospectively maintained databases.PATIENT SAMPLEA total of 1277 noninstrumented FESS cases between 2015 and 2021 were selected for analysis. In the nonendoscopic NSQIP cohort we selected data of 55,882 patients.OUTCOME MEASURESThe occurrence of any SSI was the primary outcome. We also collected any other perioperative complications, demographic data, comorbidities, operative details, history of smoking, and chronic steroid intake.METHODSAll FESS cases from a multi-institutional group that underwent surgery from 2015 to 2021 were identified for analysis. A cohort of cases for comparison was identified from the NSQIP database using Current Procedural Terminology of nonendoscopic cervical, thoracic, and lumbar procedures from 2015 to 2019. Trauma cases as well as arthrodesis procedures, surgeries to treat pathologies affecting more than 4 levels or spine tumors that required surgical treatment were excluded. In addition, nonelective cases, and patients with wounds worse than class 1 were also not included. Patient demographics, comorbidities, and operative details were analyzed for propensity matching.RESULTSIn the nonpropensity-matched dataset, the endoscopic cohort had a significantly higher incidence of medical comorbidities. The SSI rates for nonendoscopic and endoscopic patients were 1.2% and 0.001%, respectively, in the nonpropensity match cohort (p-value <.011). Propensity score matching yielded 5936 nonendoscopic patients with excellent matching (standard mean difference of 0.007). The SSI rate in the matched population was 1.1%, compared to 0.001% in endoscopic patients with an odds ratio 0.063 (95% confidence interval (CI) 0.009–0.461, p=.006) favoring FESS.CONCLUSIONSFESS compares favorably for risk reduction in SSI following spinal decompression surgeries with similar operative characteristics. As a consequence, FESS may be considered the optimal strategy for minimizing SSI morbidity.     

Expandable cages increase the risk of intraoperative subsidence but do not improve perioperative outcomes in single level transforaminal lumbar interbody fusion

BACKGROUND CONTEXTExpandable cages (EXP) are being more frequently utilized in transforaminal lumbar interbody fusions (TLIF). EXP were designed to reduce complications related to neurological retraction, enable better lordosis restoration, and improve ease of insertion, particularly in the advent of minimally invasive surgical (MIS) techniques, however they are exponentially more expensive than the nonexpandable (NE) alternative.PURPOSETo investigate the clinical results of expandable cages in single level TLIF.STUDY DESIGN/SETTINGRetrospective review at a single institution.PATIENT SAMPLETwo hundred and fifty-two single level TLIFs from 2012 to 2018 were included.OUTCOME MEASURESClinical characteristics, perioperative and neurologic complication rates, and radiographic measures.METHODSPatients ≥18 years of age who underwent single level TLIF with minimum 1 year follow-up were included. Outcome measures: clinical characteristics, perioperative and neurologic complications. Radiographic analysis included pelvic incidence-lumbar lordosis (PI-LL) mismatch, segmental lumbar lordosis (LL) mismatch, disc height restoration, and subsidence ≥2 mm. Statistical analysis included independent t tests and chi-square analysis. For nonparametric variables, Mann-Whitney U test and Spearman partial correlation were utilized. Multivariate regression was performed to assess relationships between surgical variables and recorded outcomes. For univariate analysis significance was set at p<.05. Due to the multiple comparisons being made, significance for regressions was set at p<.025 utilizing Bonferroni correction.RESULTSTwo hundred and fifty-two TLIFs between 2012 and 2018 were included, with 152 NE (54.6% female, mean age 59.28±14.19, mean body mass index (BMI) 28.65±5.38, mean Charlson Comorbidity Index (CCI) 2.20±1.89) and 100 EXP (48% female, mean age 58.81±11.70, mean BMI 28.68±6.06, mean CCI 1.99±1.66) with no significant differences in demographics. Patients instrumented with EXP cages had a shorter length of stay (3.11±2.06 days EXP vs. 4.01±2.64 days NE; Z=-4.189, p<.001) and a lower estimated blood loss (201.31±189.41 mL EXP vs. 377.82±364.06 mL NE; Z=-6.449, p<.001). There were significantly more MIS-TLIF cases and bone morphogenic protein (BMP) use in the EXP group (88% MIS, p<.001 and 60% BMP, p<.001) as illustrated in Table 1. There were no significant differences between the EXP and NE groups in rates of radiculitis and neuropraxia. In multivariate regression analysis, EXP were not associated with a difference in perioperative outcomes or complications. Radiographic analyses demonstrated that the EXP group had a lower PI-LL mismatch than the NE cage group at baseline (3.75±13.81° EXP vs. 12.75±15.81° NE; p=.001) and at 1 year follow-up (3.81±12.84° EXP vs. 8.23±12.73° NE; p=.046), but change in regional and segmental alignment was not significantly different between groups. Multivariate regression demonstrated that EXP use was a risk factor for intraoperative subsidence (2.729[1.185–6.281]; p=.018).CONCLUSIONSOnce technique was controlled for, TLIFs utilizing EXP do not have significantly improved neurologic or radiographic outcomes compared with NE. EXP increase risk of intraoperative subsidence. These results question the value of the EXP given the higher cost.     

Factors related to length of hospital stay after two-stage corrective surgery for adult spinal deformity in elderly Japanese

BackgroundPostoperative recovery of activities of daily living after surgery in elderly patients often takes a longer time because of their frailty. However, it is unclear how long it takes for patients with adult spinal deformity (ASD) to recover their abilities to live their daily lives in their home after corrective fusion surgery. This study aimed to investigate the length of hospital stay required to perform activities of daily living (ADL) in patients undergoing two-stage corrective fusion surgery for ASD in our institution and to detect factors associated with the length of hospital stay.MethodsThirty-four consecutive female ASD patients (median age, 70 years) who underwent two-stage corrective fusion surgery (lateral lumbar interbody fusion at the first stage and posterior corrective fusion at the second stage) from T9 or T10 to the pelvis were included. The length of hospital stay from admission to return home was determined, and correlations between length of hospital stay and demographics, skeletal muscle mass, operative invasion and perioperative complications, and spino-pelvic alignment were investigated.ResultsThe median length of hospital stay was 51 days, exceeding 100 days in 25% of cases. Age at surgery (ρ = 0.545, p = 0.001), estimated glomerular filtration rate (ρ = ?0.603, p < 0.001), age-adjusted Charlson comorbidity index (ρ = 0.437, p = 0.01), and preoperative pelvic incidence (ρ = 0.356, p = 0.04) were correlated with length of hospital stay. Preoperative skeletal muscle mass, preoperative spinal imbalance, perioperative changes in spino-pelvic alignment, operative invasion, and perioperative complications were not correlated with length of hospital stay.ConclusionsAfter >50 days, ADL performance of each patient reached the extent required for daily living to return home after two-stage corrective fusion surgery for ASD. Factors related to length of hospital stay were age and indices related to frailty.     

肿瘤间质比及联合免疫评分对预测脊柱脊索瘤患者生存预后的意义

目的:分析脊柱脊索瘤中肿瘤间质比(tumor-stroma ratio,TSR)、免疫评分(immunescore,IS)与患者预后之间的关系,探讨TSR及其联合IS在预测患者预后中的临床价值。方法:回顾性分析77例脊柱脊索瘤患者的临床资料,其中男性54例,女性23例。由2位病理科医师对病理切片中的TSR进行独立评估,利用X-tile软件获得局部无复发生存期(local relapse-free survival,LRFS)及总体生存时间(overall survival,OS)具有最小对数秩P值的点,利用该点将患者分为高TSR组和低TSR组;应用免疫组化法对77例脊索瘤标本进行CD3+和CD8+肿瘤浸润性淋巴细胞(tumor-infiltrating lymphocytes,TILs)子集的检测,再对其进行自动图像分析,得出IS,并将患者分为高IS组和低IS组。采用Kaplan-Meier方法对临床和病理参数(年龄、性别、肿瘤大小、位置、术前复发、周围组织浸润、级别、分期、切除方式、出血和坏死情况、TSR和IS)与患者结局(LRFS、OS)的关系进行单因素生存分析;纳入单因素分析有显著统计学意义的变量,使用Cox比例风险模型分析患者LRFS和OS的独立危险因素;Pearson′s相关性分析两个连续变量之间的关系。应用受试者工作特征(receiver operating characteristic, ROC)曲线比较TSR联合IS和TSR或IS单独使用时的预测能力。应用Bland-Altman一致性分析评估两位评估者之间TSR测量的一致性。结果:两位评估者在TSR评估方面存在很强的相关性(r=0.924,P0.001);Bland-Altman证实两位评估者之间TSR数据的平均差异较小,有良好的一致性(P=0.292)。单变量分析显示TSR、IS、年龄、周围肌肉浸润、手术切除方式与LRFS存在相关性(P0.05)。TSR、IS、周围肌肉浸润、肿瘤分期、手术切除方式与OS存在相关性(P0.05)。TSR与IS呈正相关(P0.05),高IS预示着良好的临床预后,而低TSR和低IS患者存活率最低。LRFS的多变量Cox分析显示周围肌肉浸润、TSR和IS可独立预测预后(P0.05),OS的多变量Cox分析显示TSR是OS的唯一预测因素(P=0.011)。ROC分析显示TSR在预测LRFS和OS方面的能力与IS相当[LRFS:AUC(TSR)=0.565,AUC(IS)=0.630;OS:AUC(TSR)=0.632,AUC(IS)=0.648];将TSR纳入IS系统中可提高TSR对疾病复发和生存率预测的准确性[LRFS:AUC(TSR+IS)=0.709;OS:AUC(TSR+IS)=0.727]。结论:TSR与患者的生存率相关,且是LRFS和OS的预测因素。在生存分析中纳入TSR可提高其预测预后的能力,将TSR纳入IS系统中可提高IS对疾病复发和生存率预测的准确性。     

Therapeutic effect of co-culture of rat bone marrow mesenchymal stem cells and degenerated nucleus pulposus cells on intervertebral disc degeneration

BackgroundAfter non-contact co-culture of bone marrow mesenchymal stem cells (BMSCs) with nucleus pulposus cells (NPCs), exosomes secreted by BMSCs were able to ameliorate the degree of disc degeneration. The reason for this is, at least in part, that exosomes from BMSCs achieve by affecting the level of autophagy in NPCs, while the components in exosomes are diverse and their specific mechanism of action is still unclear.PurposeHere, we aimed to explore the therapeutic effect of co-culture of BMSCs and NPCs on NPCs and explore its specific mechanism of action.Study design/SettingIn vitro study.MethodsRat NPCs and BMSCs were isolated and cultured in vitro. The serum deprivation experiment (using oxygen, glucose, and serum deprivation [OGD]) simulates the pathological state of low blood supply of the intervertebral disc in vivo. We used apoptotic cell staining and flow cytometry to study the effect of BMSCs on the apoptosis rate of rat NPCs, and the apoptotic proteins active-caspase-3, active-caspase-9, autophagy marker proteins LC3 and Beclin 1 were further detected using Western blot analysis. The expression levels of the pro-apoptotic protein Bax and the apoptosis-inhibiting protein Bcl2 were measured. The differentially expressed miRNAs were screened in a gene expression profiling chip. Then qRT-PCR was used to detect the effect of different treatment methods on miR-155 expression. The effect of anti-miR-155 antibodies on autophagy was studied by flow cytometry and transmission electron microscopy. A luciferase reporter assay was used to study the direct interaction between miR-155 and BACH1 mRNA, which was analyzed by TargetScan software, and the results were verified by Western blotting.ResultsCompared with the OGD group, the expression level of miR-155 and the NPC autophagy level significantly increased; the HO-1 protein expression increased; and the Bach1 protein expression, degeneration index, and apoptosis index all significantly decreased in the co-culture group. After BMSCs transfected with anti-miR-155 were co-cultured with NPCs, the miR-155 expression in the cells was significantly reduced, the HO-1 protein expression and the level of cell autophagy was reduced. However, Bach1 protein expression, NPC degeneration index, and apoptosis index increased. After being inhibited by the autophagy inhibitor wortmannin, the cell degeneration index and apoptosis rate significantly improved.ConclusionIn the OGD model, BMSCs can significantly increase the viability, the level of autophagy, and reduce the level of apoptosis in rat NPCs. BMSC exosomes increase miR-155 expression in NPCs, which targets Bach1 and in turn upregulates HO-1 expression, activates autophagy in NPCs, inhibits the apoptosis level, and improves intervertebral disc degeneration.Clinical SignificanceOur experiment shows that it is maybe feasible to treat disc degeneration with drugs. At the same time, compared with BMSC injection method of treatment, side effects of drug therapy are smaller, and can be controlled, it also provides a new way for intervertebral disc degeneration drug treatment.     

Minimally invasive transforaminal lumbar interbody fusion using the biportal endoscopic techniques versus microscopic tubular technique

BACKGROUND CONTEXTMinimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) with microscopic tubular technique is an established surgical procedure with several potential advantages, including decreased surgical-related morbidity, reduced length of hospital stay, and accelerated early rehabilitation. A recently introduced biportal endoscopic technique for spine surgery presents familiar surgical anatomy and can be conducted using a conventional approach with a minimal footprint; it is also applicable to TLIF.PURPOSETo compare the clinical and radiological outcomes of biportal endoscopic technique transforaminal lumbar interbody fusion (BE-TLIF) and microscopic tubular technique transforaminal lumbar interbody (MT-TLIF) in patients with single- or two-segment lumbar spinal stenosis with or without spondylolisthesis.STUDY DESIGNA retrospective cohort study.PATIENT SAMPLEOne hundred two participants with neurogenic intermittent claudication or lumbar radiculopathy with single- or two-level lumbar spinal stenosis with or without spondylolisthesis.OUTCOME MEASURESClinical outcomes were assessed using the visual analog scale (VAS) score for the back and leg pain, Oswestry Disability Index (ODI), and the Short Form-36 health survey Questionnaire (SF-36). Demographic data, operative data (total operation time, estimated blood loss, amount of surgical drain, postoperative transfusion, and length of hospital stay), and laboratory results (plasma hemoglobin, serum creatine phosphokinase, and C-reactive protein) were also evaluated. The fusion rate was assessed using the Bridwell interbody fusion grading system. Postoperative complications were also noted.METHODSPatients were divided into two groups: group A (BE-TLIF) and group B (MT-TLIF). The clinical outcomes, including VAS-Back and VAS-Leg, ODI, and SF-36 scores, were evaluated at 1 month, 6 months, and 1 year after surgery. Differences in demographics, operative data, and the laboratory and radiological results were assessed between the two groups. The fusion rate was assessed using standard standing lumbar radiographs and computed tomography scans conducted 1 year after surgery.RESULTSSeventy-nine patients were analyzed in this study, 47 from group A and 32 from group B. Demographic and operative data were comparable for both the groups. The VAS-Back and SF-36 scores were more significantly improved in group A than in group B at 1 month after surgery. However, there were no significant differences between groups for the mean VAS-Back, VAS-Leg, ODI, and SF-36 scores at 1year after the surgery. Although the total operation time was significantly longer in group A, the estimated blood loss and the amount of surgical drainage was significantly higher in group B (p < .001). There were no between-group differences for the fusion rate and postoperative complications.CONCLUSIONBoth BE-TLIF and MT-TLIF provided equivalent and favorable clinical outcomes and fusion rates. Further large-scale, randomized, controlled trials with long-term follow-ups are warranted.