Risk factors for sleep disturbance in patients with cervical myelopathy and its clinical significance: a cross-sectional study

BACKGROUND CONTEXTSleep disturbance is highly prevalent in patients with spinal cord injury and is one of the most important clinical issues affecting their quality of life. However, it has not been properly measured or treated in patients with cervical myelopathy (CM), although most typical or atypical symptoms of CM are known to be risk factors for sleep disturbance. In addition, previous studies identified that the presence of sleep disturbance is unintentionally missed under the current evaluation process for degenerative spinal disease without direct investigation using validated tools for sleep. Therefore, studies about sleep disturbances in patients with CM are essential.PURPOSEThe purpose of this study was to investigate the prevalence of sleep disturbance in patients with CM using validated tools and to understand its mechanism by identifying high-risk patients.STUDY DESIGN/SETTINGCross-sectional study.PATIENT SAMPLEConsecutive patients diagnosed with CM.OUTCOME MEASURESPittsburgh sleep quality index.METHODSThis study was performed on patients diagnosed with CM. Sleep disturbance was determined using the Pittsburgh sleep quality index. Variables associated with sleep disturbance including demographics, lifestyle, medical history, and radiologic parameters were investigated. Independent risk factors related to sleep disturbance were identified using multivariate logistic regression analysis.RESULTSA total of 203 patients with CM were included in our study. Among them, 126 patients (62.1%) were men, and the mean age was 63.0 years. Despite male predominance, sleep disturbance was identified in 71.4% of patients (145 of 203). Multivariate analysis identified a worse depression scale score, a lower modified Japanese Orthopedic Association score, chronic shoulder joint pain, smaller spinal cord area, and decreased cervical range of motion as independent risk factors for sleep disturbance.CONCLUSIONSIn patients with CM, sleep disturbance was associated with a more severe type of myelopathy. Further studies including polysomnography and measurement of melatonin will be helpful to identify the mechanisms of the sleep disturbance in patients with CM and to improve their quality of life and clinical outcomes.     

Risk factors for postoperative ileus after oblique lateral interbody fusion: a multivariate analysis

Background ContextOblique lateral interbody fusion (OLIF)–has become a widely used, efficient surgical tool for various degenerative lumbar conditions. Postoperative ileus (POI) is a relatively common complication after anterior lumbar interbody fusion due to the manipulation of the intestine during the surgical approach. However, to our knowledge, little is known about POI following OLIF even though it also involves bowel manipulation during a surgical procedure.PurposeTo assess the incidence of POI and identify independent risk factors for POI development after OLIF.Study Design/SettingRetrospective cohort study.Patient SampleAll consecutive patients who underwent OLIF and percutaneous pedicle screw instrumentation from August 2012 until October 2019 at a single institutionOutcome MeasuresPatient demographics (sex, age, body weight, height, and body mass index), comorbidities (diabetes mellitus, gastroesophageal reflux disease, antithrombotic medication, previous abdominal surgery, and previous lumbar surgery), and perioperative details (preoperative diagnosis, number of levels fused, inadvertent endplate fracture during cage insertion, type of interbody graft, intraoperative estimated blood loss, duration of surgery and anesthesia, the amount of intraoperative remifentanil and propofol used as anesthetic agents, the total postoperative retroperitoneal closed-suction drainage output, and the cumulative opioid dosage administered in the first 72 hours postoperatively).MethodsPOI was defined as 2 or more of the following at 72 hours postoperatively: (1) ongoing nausea or vomiting postoperatively, (2) the absence of flatus over last 24-hour period, (3) inability to tolerate an oral diet over last 24-hour period, (4) ongoing abdominal distention postoperatively, and (5) radiological confirmation. The subjects were divided into 2 groups: patients with POI and those without POI. Binary logistic regression analyses were performed on demographics, comorbidities, and perioperative factors to identify independent risk factors for POI.ResultsEighteen (3.9%) of 460 patients experienced POI after OLIF and percutaneous pedicle screw instrumentation. Patients with POI had a significantly longer postoperative length of hospital stay than those without POI (8.61 ± 2.66 vs 6.48 ± 2.64, p = .001). Multivariate logistic regression analysis identified inadvertent endplate fracture (adjusted odds ratio = 6.017, p = .001) and the amount of intraoperative remifentanil (adjusted odds ratio = 1.057, p = .024) as independent risk factors for the occurrence of POI following OLIF.ConclusionThis study identified inadvertent endplate fracture and the amount of intraoperative remifentanil as independent risk factors for the development of POI after OLIF.     

A clinical calculator for predicting intraoperative blood loss and transfusion risk in spine tumor patients

BACKGROUND CONTEXTSurgery for vertebral column tumors is commonly associated with intraoperative blood loss (IOBL) exceeding 2 liters and the need for transfusion of allogeneic blood products. Transfusion of allogeneic blood, while necessary, is not benign, and has been associated with increased rates of wound complication, venous thromboembolism, delirium, and death.PURPOSETo develop a prediction tool capable of predicting IOBL and risk of requiring allogeneic transfusion in patients undergoing surgery for vertebral column tumors.STUDY DESIGN/SETTINGRetrospective, single-center study.PATIENT SAMPLEConsecutive series of 274 patients undergoing 350 unique operations for primary or metastatic spinal column tumors over a 46-month period at a comprehensive cancer centerOUTCOME MEASURESIOBL (in mL), use of intraoperative blood products, and intraoperative blood products transfused.METHODSWe identified IOBL and transfusions, along with demographic data, preoperative laboratory data, and surgical procedures performed. Independent predictors of IOBL and transfusion risk were identified using multivariable regression.RESULTSMean age at surgery was 57.0±13.6 years, 53.1% were male, and 67.1% were treated for metastatic lesions. Independent predictors of IOBL included en bloc resection (p<.001), surgical invasiveness (β=25.43 per point; p<0.001), and preoperative albumin (β=?244.86 per g/dL; p=0.011). Predictors of transfusion risk included preoperative hematocrit (odds ratio [OR]=0.88 per %; 95% confidence interval [CI, 0.84, 0.93]; p<0.001), preoperative MCHgb (OR=0.88 per pg; 95% CI [0.78, 1.00]; p=0.048), preoperative red cell distribution width (OR=1.32 per %; 95% CI [1.13, 1.55]; p<0.001), en bloc resection (OR=3.17; 95%CI [1.33, 7.54]; p=0.009), and surgical invasiveness (OR=1.08 per point; [1.06; 1.11]; p<0.001). The transfusion model showed a good fit of the data with an optimism-corrected area under the curve of 0.819. A freely available, web-based calculator was developed for the transfusion risk model (https://jhuspine3.shinyapps.io/TRUST/).CONCLUSIONSHere we present the first clinical calculator for intraoperative blood loss and transfusion risk in patients being treated for primary or metastatic vertebral column tumors. Surgical invasiveness and preoperative microcytic anemia most strongly predict transfusion risk. The resultant calculators may prove clinically useful for surgeons counseling patients about their individual risk of requiring allogeneic transfusion.     

Representative dynamic ranges of spinal alignment during gait in patients with mild and severe adult spinal deformities

BACKGROUND CONTEXTSurgical correction strategies for adult spinal deformity (ASD) relies heavily on radiographic alignment goals, however, there is often debate regarding degree of correction and how static alignment translates to physical ability in daily life. Kinematic analysis has the potential to improve the concept of ideal spinal alignment by providing clinically meaningful estimates of dynamic changes in spinal alignment during activities of daily life.PURPOSEEstimate representative dynamic ranges of spinal alignment during gait among ASD patients using 3D motion tracking; compare dynamic alignment between mild and severe deformity patients and to healthy adults.STUDY DESIGN/SETTINGRetrospective review at a single institution.PATIENT SAMPLEFifty-two ASD patients and 46 healthy adults.OUTCOME MEASURESRadiographic alignment, kinematic spine motion, spatiotemporal gait measures, patient reported outcomes (VAS pain, ODI, SRS-22r).METHODSSpinal alignment was assessed radiographically and during standing and overground walking tests. Dynamic alignment was initialized by linking radiographic alignment to kinematic alignment during standing and at initial heel contact during gait. Dynamic changes in maximums and minimums during gait were made relative to initial heel contact for each gait cycle. Total range-of-motion (RoM) was measured for both ASD and healthy subjects. Dynamic alignment measures included coronal and sagittal vertical axes (CVA, SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), and pelvic tilt (PT). ASD patient's deformities were classified as either Mild or Severe based on the SRS-Schwab ASD classification.RESULTSSevere ASD patients had significantly larger dynamic maximum and minimums for SVA, TPA, LL, and PT (all p<.05) compared with Mild ASD patients. ASD patients exhibited little difference in dynamic alignment compared with healthy subjects. Only PT had a significant difference in dynamic RoM compared with healthy (p<.001).CONCLUSIONSMild and Severe ASD patients exhibited similar global dynamic alignment measures during gait and had comparable RoM to healthy subjects except with greater PT and reduced spatiotemporal performance which may be key compensatory mechanisms for dynamic stabilization.     

Relationships between anthropometric adiposity indexes and bone mineral density in a cross-sectional Chinese study

Background ContextPrevious studies have reported conflicting results for the relationships between anthropometric adiposity indexes and bone mineral density, based on dual-energy X-ray absorptiometry (DXA). However, few studies were published based on quantitative computed tomography (QCT), especially for Chinese population.PurposeTo evaluate the associations of spine bone mineral density (BMD) with body mass index (BMI), waist circumstance (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and a body shape index (ABSI) using QCT.Study Design/SettingA Cross-sectional study.Patient SampleAround 3,457 participants in multiple communities across 7 administrative regions of China.Outcome MeasuresSpine BMD was measured using QCT, and the classification of osteoporosis was defined as follows: 1) osteoporosis if BMD <80mg/cm³, 2) osteopenia if BMD 80–119 mg/cm³, and 3) normal bone mass if BMD≥120 mg/cm³.MethodsThis study was conducted using convenient sampling between 2013 and 2017. Multivariable linear regression model and logistic regression models were used for the associations of continuous and categorical BMD, respectively.ResultsAround 3,405 participants were included in the final analyses, including 1,272 males and 2,133 females, with spine BMD of 111.00±35.47 mg/cm³ and 99.38±40.60 mg/cm³, respectively. Spine BMD decreased significantly with the increase of ABSI in females (adjusted β, ?5.74; 95% confidence interval [CI], ?8.50 to ?2.98), and this trend also was kept in females aged at less than 60 years (adjusted β, ?14.54; 95% CI, ?20.40 to ?8.68), and females with age ≥60 years (adjusted β, ?7.59; 95% CI, ?10.91 to ?4.28). However, this inverse association was observed only in males with age ≥ 60 years (adjusted β, ?5.19; 95% CI, ?10.08 to ?0.29). Except ABSI, negative associations of Spine BMD with WC (adjusted β, ?0.46; 95% CI, ?0.77 to ?0.15), WHR (adjusted β, ?6.25; 95% CI, ?10.63 to ?1.86), WHtR (adjusted β, ?6.80; 95% CI, ?11.63 to ?1.97) were shown in females aged at <60 years, and positive association with BMI in males with age ≥60 years (adjusted β, 0.92; 95% CI, 0.29–1.55).ConclusionsABSI had more remarkable association with spine BMD, compared with the other four indexes.     

Role of Rho-associated coiled-coil containing protein kinase in the spinal cord injury induced neuropathic pain

BACKGROUND CONTEXTSpinal cord injury (SCI) can lead to increased phosphorylation of p38 in spinal cord microglia. This is one of the main causes for the development of persistent pain. Recently, we reported our study on the activation of p38 mitogen-activated protein kinases (MAPK) in spinal microglia, which has been considered the key molecule for the onset and maintenance of neuropathic pain after peripheral nerve injury, using a rat model. We also reported that the RhoA/Rho-associated coiled-coil containing protein kinase (ROCK) pathway mediates p38 activation in spinal microglia in peripheral nerve injury. But the precise mechanisms of neuropathic pain induced by SCI are still unclear.PURPOSEThis study aimed to examine the activation of microglia and the p38 MAPK expression in the lumbar spinal cord after thoracic SCI in rats, and the correlation to the therapeutic effect of ROCK inhibitor ripasudil in rats with SCI.STUDY DESIGNMale Sprague–Dawley rats underwent thoracic (T10) spinal cord contusion injury using an Infinite Horizon impactor device. SCI rats received ROCK inhibitor ripasudil (24 nmol/day or 240 nmol/day) from just before SCI to 3 days after SCI.METHODSThe mechanical threshold in the rat's hind paws was measured over four weeks. Morphology of microglia and phosphorylation of p38 (p-p38) in the lumbar spinal cord and were analyzed using immunohistochemistry.RESULTSThe p-p38 positive cell and Iba1 (a maker of microglia) positive area were significantly increased at the lumbar spinal dorsal horn (L4–5) 3 days and 7 days after SCI compared with the sham-control (p<.05), whereas phosphorylated p38 was co-localized with microglia. Three days after SCI, the intensity of phosphorylated p38 and Iba1 immunoreactive cells in the dorsal horn was significantly lower in the ripasudil treated groups than in the saline group. However, administration of ROCK inhibitor did not affect the numbers of microglia. Moreover, the withdrawal threshold of the ripasudil-treated rats was significantly higher than that of the saline-injected rats on 14 days and 28 days after SCI.CONCLUSIONSOur results suggest that activation of ROCK in spinal cord microglia is likely to have an important role in the activation of p38 MAPK, which has been considered as a key molecule that switches on neuropathic pain after SCI. Inhibition of ROCK signaling may offer a means in developing a novel neuropathic pain treatment after SCI. It may help patients with neuropathic pain after SCI.CLINICAL SIGNIFICANCEThe findings in the present study regarding intracellular mechanisms suggest that modulation of ROCK signaling may be a focus for novel treatment for neuropathic pain after SCI.     

Does obesity affect long-term outcomes of extreme lateral interbody fusion with posterior stabilization?

Background ContextObese patients can pose significant challenges to spine surgeons in lumbar fusion procedures. The increased risk of complications has led surgeons to be wary in pursing operative interventions in these patients. Since the advent of minimally-invasive techniques in lumbar fusion, surgeons are turning to these procedures in an attempt to minimize operative time, blood loss and overall cost. With an increased proportion of obese patients in the population, it is imperative to understand the long-term outcomes in these minimally-invasive approaches.PurposeThe purpose of this study was to evaluate the long-term safety and efficacy of extreme lateral interbody fusion (XLIF) in the obese.Study Design/SettingRetrospective cohort study.Patient SampleA total of 115 patients (53 nonobese and 62 obese) who underwent XLIF with a minimum of 5-year follow-up.Outcome Measures(1) Patient reported outcome scores: Visual Analog Scale (VAS) for back pain, Oswestry Disability Index (ODI), (2) Reoperation rate, (3) Pelvic incidence (PI)- Lumbar lordosis (LL) mismatch correction, (4) Graft subsidence and fusion rateMethodsA retrospective review was performed to identify patients who underwent XLIF with percutaneous posterior stabilization since 2007 with a minimum follow-up of 5 years. Demographics including BMI were recorded and patients were subdivided into 2 cohorts: nonobese (BMI <30 kg/m²) and obese (BMI ≥30 kg/m²). Functional outcomes were assessed by comparing pre- and postoperative VAS and ODI scores. Reoperation rates were compared between cohorts. PI-LL mismatch was calculated from both pre- and postoperative radiographs. Rates of graft subsidence and fusion were measured at final follow-up.ResultsA total of 115 consecutive patients were included (53 nonobese and 62 obese) with a mean follow up of 95.3 months. Mean BMI was 25.3 in the nonobese group and 35.3 in the obese group (p<.001). There were more females in nonobese cohort. VAS scores decreased by a mean of 5.7 in the nonobese cohort, and 5.4 in the obese cohort (p=.213). ODI improvement was also similar between the groups. 5.6% of nonobese patients required reoperation compared to 9.6% of obese patients (p=.503). Graft subsidence rates at final follow-up were 5.66% and 8.06% for the nonobese and obese groups, respectively (p=.613). Rates of successful fusion were 96.23% and 98.39% for the nonobese and obese groups, respectively (p=.469). Both cohorts achieved a similar proportion of PI-LL mismatch correction, 85% in obese versus 78% in nonobese patients (p=.526).ConclusionObese patients have similar surgical outcomes to nonobese patients with respect to functional outcome scores, reoperation rates, graft subsidence and correction of PI-LL mismatch after long-term follow-up. With similar outcome and reoperation profiles, minimally-invasive approaches to the spine, such as XLIF, may be an acceptable alternative to traditional open procedures in obese patients.