Showing papers in "European Spine Journal in 2015"

Impact on health related quality of life of adult spinal deformity (ASD) compared with other chronic conditions.

Abstract: Medical and health policy providers should be aware of the impact of adult spinal deformity (ASD) on health-related quality of life (HRQL). The purpose of this study was to compare the relative burden of four chronic conditions with that of ASD. The International Quality of Life Assessment project gathered data from 24,936 people and published the SF-36 scores of patients with self-reported arthritis, chronic lung disease, diabetes and congestive heart failure from 8 industrialized countries (3 continents) Alonso et al. (Qual Life Res Int J Qual Life Asp Treat Care Rehabil 13:283–298, 2004). We compared these with the SF-36 baseline data of consecutive patients with ASD enrolled in a prospective multicentre international database with the following inclusion criteria: age >18 years and scoliosis >20°, sagittal vertical axis >5 cm, pelvic tilt >25° or thoracic kyphosis >60°. Four ASD groups were considered: all ASD patients, surgical candidates (preop HRQL scores), and non-surgical candidates with and without previous surgery. Adjusted estimates of the impact of chronic disease were calculated using separate multivariate linear regression models. Individuals without chronic conditions were used as the reference group. Coefficients for each chronic condition and ASD represent the difference compared with this healthy group. 766 patients (mean age 45.8 years) met the inclusion criteria for ASD. The scores on all SF-36 domains were lower in ASD patients than in any other chronic condition. Differences between ASD and the other chronic conditions were always greater than the reported minimal clinically important differences. When compared with individuals reporting no medical conditions, SF-36 scores from the population with self-reported chronic conditions ranged from −2.5 to −14.1. Comparable scores for patients with ASD ranged from −10.9 to −45.0. Physical function, role physical and pain domains showed the worst scores. Surgical candidates with ASD displayed the worst HRQL scores (−17.4 to −45.0) and patients previously operated the best (−10.9 to −33.3); however, even the latter remained worse than any scores for the other self-reported chronic conditions. The global burden of ASD was huge compared with other self-reported chronic conditions in the general population of eight industrialized countries. The impact of ASD on HRQL warrants the same research and health policy attention as other important chronic diseases.

Core outcome domains for clinical trials in non-specific low back pain

Abstract: Purpose Inconsistent reporting of outcomes in clinical trials of patients with non-specific low back pain (NSLBP) hinders comparison of findings and the reliability of systematic reviews. A core outcome set (COS) can address this issue as it defines a minimum set of outcomes that should be reported in all clinical trials. In 1998, Deyo et al. recommended a standardized set of outcomes for LBP clinical research. The aim of this study was to update these recommendations by determining which outcome domains should be included in a COS for clinical trials in NSLBP.

Incidence of traumatic spinal cord injury worldwide: a systematic review

Abstract: Traumatic spinal cord injuries (TSCI) are among the most devastating conditions in developed and developing countries, which can be prevented. The situation of TSCI around the world is not well understood which complicates the preventive policy decision making in fight against TSCI. This study was aimed to gather the available information about incidence of TSCI around the world. A systematic search strategy was designed and run in Medline and EMBASE, along with extensive grey literature search, personal communications, website searching, and reference checking of related papers. Overall, 133 resources including 101 papers, 17 trauma registries, 6 conference proceedings, 5 books, 2 theses and 2 personal communication data were retrieved. Data were found for 41 individual countries. The incidence of TSCI ranges from 3.6 to 195.4 patients per million around the world. Australia, Canada, US, and high-income European countries have various valuable reports of TSCI, while African and Asian countries lack the appropriate epidemiologic data on TSCI. Data of epidemiologic information in TSCI are available for 41 countries of the world, which are mostly European and high-income countries. Researches and efforts should be made to gather information in developing and low-income countries to plan appropriate cost-effective preventive strategies in fight against TSCI.

Pedicle screw loosening: a clinically relevant complication?

Abstract: Literature studies showed a very wide range of pedicle screw loosening rates after thoracolumbar stabilization, ranging from less than 1 to 15 % in non-osteoporotic patients treated with rigid systems and even higher in osteoporotic subjects or patients treated with dynamic systems. Firstly, this paper aims to investigate how much this complication is affecting the success rate of pedicle screw fixation, in both non-osteoporotic and osteoporotic patients, and to discuss the biomechanical reasons which may be related to the variability of the rates found in the literature. The secondary aim was to summarize and discuss the published definitions and conventions about screw loosening from a clinical and radiological point of view. Narrative literature review. Screw loosening appears to be a minor problem for fixation and fusion of healthy, non-osteoporotic bone. Pedicle screw fixation in osteoporotic bone is believed to be at risk of loosening, but clinical data are actually scarce. Both expandable and augmented screws may be a viable option to reduce the risk of loosening, but clinical evidence is missing. Posterior motion-preserving implants seems to have a significant risk of screw loosening. Standardization appears to be lacking regarding the radiological assessment. Marked differences in the loosening rates found based either on planar radiography or on CT scanning were observed. Reported loosening rates primarily depended on the protocol used for the clinical examination during follow-up and on the conventions used for the radiological assessment. Aiming to a better comparability of published data, we recommend the authors of clinical studies to describe which criteria were used to assess a loosened screw, as well as the protocol of the clinical follow-up examination. Low-dose CT should be used for the assessment of screw loosening whenever possible.

Pelvic incidence-lumbar lordosis mismatch predisposes to adjacent segment disease after lumbar spinal fusion

Abstract: Several risk factors and causes of adjacent segment disease have been debated; however, no quantitative relationship to spino-pelvic parameters has been established so far. A retrospective case–control study was carried out to investigate spino-pelvic alignment in patients with adjacent segment disease compared to a control group. 45 patients (ASDis) were identified that underwent revision surgery for adjacent segment disease after on average 49 months (7–125), 39 patients were selected as control group (CTRL) similar in the distribution of the matching variables, such as age, gender, preoperative degenerative changes, and numbers of segments fused with a mean follow-up of 84 months (61–142) (total n = 84). Several radiographic parameters were measured on pre- and postoperative radiographs, including lumbar lordosis measured (LL), sacral slope, pelvic incidence (PI), and tilt. Significant differences between ASDis and CTRL groups on preoperative radiographs were seen for PI (60.9 ± 10.0° vs. 51.7 ± 10.4°, p = 0.001) and LL (48.1 ± 12.5° vs. 53.8 ± 10.8°, p = 0.012). Pelvic incidence was put into relation to lumbar lordosis by calculating the difference between pelvic incidence and lumbar lordosis (∆PILL = PI−LL, ASDis 12.5 ± 16.7° vs. CTRL 3.4 ± 12.1°, p = 0.001). A cutoff value of 9.8° was determined by logistic regression and ROC analysis and patients classified into a type A (∆PILL <10°) and a type B (∆PILL ≥10°) alignment according to pelvic incidence-lumbar lordosis mismatch. In type A spino-pelvic alignment, 25.5 % of patients underwent revision surgery for adjacent segment disease, whereas 78.3 % of patients classified as type B alignment had revision surgery. Classification of patients into type A and B alignments yields a sensitivity for predicting adjacent segment disease of 71 %, a specificity of 81 % and an odds ratio of 10.6. In degenerative disease of the lumbar spine a high pelvic incidence with diminished lumbar lordosis seems to predispose to adjacent segment disease. Patients with such pelvic incidence-lumbar lordosis mismatch exhibit a 10-times higher risk for undergoing revision surgery than controls if sagittal malalignment is maintained after lumbar fusion surgery.

Sagittal parameters of global cervical balance using EOS imaging: normative values from a prospective cohort of asymptomatic volunteers

Abstract: To define reference parameters for analyzing sagittal balance of the cervical spine in asymptomatic volunteers. Prospective study after Bioethics Committee approval. Imaging performed using a low-dose radiographic system (EOS Imaging, Paris, France). The absence of pain was assessed using the Oswestry Questionnaire and VAS. 106 subjects were included of whom 55.66 % were men. The parameters measured were: pelvic incidence, pelvic tilt, sacral slope, thoracic and lumbar curvature, C7 plumb line position and the spino-sacral angle. The C7 slope and new parameters were measured: cranial incidence, defined in relation to the McGregor line and the sella turcica allowing to define cranial slope and tilt, and the spino-cranial angle (SCA). This study demonstrated a close correlation between the C7 slope and the cranio-cervical system. Economic sagittal balance in the asymptomatic population was defined by a constant SCA angle of 83° ± 9°. To maintain this balance, a spine with a marked C7 slope will present lordosis and vice versa. Cranial incidence is an anatomical parameter characteristic of the cranio-cervical system which makes it possible to analyze the spatial positioning of the head and to predict the desired value of cervical lordosis which is closely correlated to cranial slope. The C7 slope has a predictive value of the shape of the cervical spine in the sagittal plane. One-third of the asymptomatic population had cervical kyphosis. Our results could be used to study sagittal balance before and after arthrodesis, or cervical prosthesis.

Pathobiology of cervical spondylotic myelopathy

Abstract: In this narrative review, we aim to outline what is currently known about the pathophysiology of cervical spondylotic myelopathy (CSM), the most common cause of spinal cord dysfunction. In particular, we note the unique factors that distinguish it from acute spinal cord injury. Despite its common occurrence, the reasons why some patients develop severe symptomatology while others have few or no symptoms despite radiographic evidence confirming similar degrees of compression is poorly understood. Neither is there a clear understanding of why certain patients have a stable clinical myelopathy and others present with only mild myelopathy. Moreover, the precise molecular mechanisms which contribute to the pathogenesis of the disease are incompletely understood. The current treatment method is decompression of the spinal cord but a lack of clinically relevant models of CSM have hindered the understanding of the full pathophysiology which would aid the development of new therapeutic avenues of investigation. Further elucidation of the role of ischemia, currently a source of debate, as well as the complex cascade of biomolecular events as a result of the unique pathophysiology in this disease will pave the way for further neuroprotective strategies to be developed to attenuate the physiological consequences of surgical decompression and augment its benefits.

Methods to determine pedicle screw placement accuracy in spine surgery: a systematic review

Abstract: Systematic review. The aims of this systematic review were: (1) to determine the most commonly used methods for assessing pedicle screw placement accuracy, and (2) assess the difference in pedicle screw placement accuracy between navigation and free-hand techniques according to the classification method. Pedicle screw fixation and spine surgery have almost become synonymous. However, there is currently no gold standard method to assess pedicle screw placement accuracy. We reviewed the literature to determine current techniques used by spine surgeons for the assessment of pedicle screw accuracy. We systematically reviewed the medical literature (OVID Medline, Embase, PubMed) to identify all articles published between 2010 and 2013 that have assessed pedicle screw placement accuracy in humans. Two independent reviewers with a third independent mediator performed study screening, selection and data extraction using a blinded and objective protocol. A total of 68 relevant articles were included in this systematic review, for a total of 3442 patients, 60 cadavers and 43,305 pedicle screws. The most widely used method (37 articles) was based on 2 mm breach increments measured on computer tomography images. The second most widely used method consisted of an “in” or “out” classification system (16 articles). The remaining 15 articles used variable classification systems. Our result suggests that an average of 91.4 % of pedicle screws placed with free-hand or fluoroscopy technique where within the safe zone (<2 mm breach) in comparison to an average of 97.3 % of pedicle screws using navigation (p < 0.001) for the 2 mm increment method. Similarly, the in or out classification also showed statistically significant difference between free-hand and navigated techniques (p < 0.001). The grading system based on 2 mm increments seems to be the most widely accepted method for determining pedicle screw placement accuracy. All grading systems were based on imaging alone without taking into account the direction of the breach or patient’s symptoms.

Anterior vertebral body tethering for immature adolescent idiopathic scoliosis: one-year results on the first 32 patients

Abstract: This retrospective chart review evaluates the clinical and radiographic outcomes of anterior vertebral body tethering (VBT) at 1-year follow-up. Anterior VBT offers a fusionless treatment option for skeletally immature patients with adolescent idiopathic scoliosis. It is a growth-modulation technique, which utilizes patients’ growth to attain progressive scoliosis correction. Numerous animal models support its promise; however, clinical data remain sparse. Clinical and radiographic data were retrospectively analyzed. We reviewed 32 patients who underwent thoracic VBT with a minimum one-year follow-up. Pertinent clinical and radiographic data were collected. ANOVA, Student’s t test and Fisher’s exact test were utilized to compare different time points. 32 patients with thoracic idiopathic scoliosis (72 % female) with a minimum one-year follow-up were identified; mean age at surgery was 12 years. All patients were considered skeletally immature pre-operatively; mean Risser score 0.42, mean Sanders score 3.2. Patients underwent tethering of an average of 7.7 levels (range 7–11). Median blood loss was 100 cc. The mean pre-operative thoracic curve magnitude was 42.8° ± 8.0° which corrected to 21.0° ± 8.5° on first erect and 17.9° ± 11.4° at most recent. The pre-operative lumbar curve of 25.2° ± 7.3° demonstrated progressive correction (first erect = 18.0° ± 7.1°, 1 year = 12.6° ± 9.4°, p < 0.00001). Thoracic axial rotation measured 13.4° pre-operatively and 7.4° at the most recent measurement (p < 0.00001). One patient experienced prolonged atelectasis which required a bronchoscopy; otherwise, no major complications were observed. Our early results indicate that anterior VBT is a safe and potentially effective treatment option for skeletally immature patients with idiopathic scoliosis. These patients experienced an improvement of their scoliosis with minimal major complications. However, longer term follow-up of this cohort will reveal the true benefits of this promising technique. IV.

Predictors of outcome in patients with degenerative cervical spondylotic myelopathy undergoing surgical treatment: results of a systematic review.

Abstract: Purpose To conduct a systematic review of the literature to determine important clinical predictors of surgical outcome in patients with cervical spondylotic myelopathy (CSM). Methods A literature search was performed using MEDLINE, MEDLINE in Process, EMBASE and Cochrane Database of Systematic Reviews. Selected articles were evaluated using a 14-point modified SIGN scale and classified as either poor (\7), good (7‐9) or excellent (10‐14) quality of evidence. For each study, the association between various clinical factors and surgical outcome, evaluated by the (modified) Japanese Orthopaedic Association scale (mJOA/JOA), Nurick score or other measures, was defined. The results from the EXCELLENT studies were compared to the combined results from the EXCELLENT and GOOD studies which were compared to the results from all the studies. Results The initial search yielded 1,677 citations. Ninetyone of these articles, including three translated from Japanese, met the inclusion and exclusion criteria and were graded. Of these, 16 were excellent, 38 were good and 37 were poor quality. Based on the excellent studies alone, a longer duration of symptoms was associated with a poorer outcome evaluated on both the mJOA/JOA scale and Nurick score. A more severe baseline score was related with a worse outcome only on the mJOA/JOA scale. Based on the GOOD and EXCELLENT studies, duration of symptoms and baseline severity score were consistent predictors of mJOA/JOA, but not Nurick. Age was an insignificant predictor of outcome on any of the functional outcomes considered. Conclusion The most important predictors of outcome were preoperative severity and duration of symptoms. This review also identified many other valuable predictors including signs, symptoms, comorbidities and smoking status.

Minimally invasive versus open transforaminal lumbar interbody fusion for treatment of degenerative lumbar disease: systematic review and meta-analysis

Abstract: While open TLIF (O-TLIF) remains the mainstay approach, minimally invasive TLIF (MI-TLIF) may offer potential advantages of reduced trauma to paraspinal muscles, minimized perioperative blood loss, quicker recovery and reduced risk of infection at surgical sites. This meta-analysis was conducted to provide an updated assessment of the relative benefits and risks of MI-TLIF versus O-TLIF. Electronic searches were performed using six databases from their inception to December 2014. Relevant studies comparing MI-TLIF and O-TLIF were included. Data were extracted and analysed according to predefined clinical end points. There was no significant difference in operation time noted between MI-TLIF and O-TLIF cohorts. The median intraoperative blood loss for MI-TLIF was significantly lower than O-TLIF (median: 177 vs 461 mL; (weighted mean difference) WMD, −256.23; 95 % CI −351.35, −161.1; P < 0.00001). Infection rates were significantly lower in the minimally invasive cohort (1.2 vs 4.6 %; relative risk (RR), 0.27; 95 %, 0.14, 0.53; I 2 = 0 %; P = 0.0001). VAS back pain scores were significantly lower in the MI-TLIF group compared to O-TLIF (WMD, −0.41; 95 % CI −0.76, −0.06; I 2 = 96 %; P < 0.00001). Postoperative ODI scores were also significantly lower in the minimally invasive cohort (WMD, −2.21; 95 % CI −4.26, −0.15; I 2 = 93 %; P = 0.04). In summary, the present systematic review and meta-analysis demonstrated that MI-TLIF appears to be a safe and efficacious approach compared to O-TLIF. MI-TLIF is associated with lower blood loss and infection rates in patients, albeit at the risk of higher radiation exposure for the surgical team. The long-term relative merits require further validation in prospective, randomized studies.

Prevalence of cervical spondylotic myelopathy

Abstract: Patients with signs and/or symptoms of cervical spondylotic myelopathy are frequently encountered in spinal practice. Exact numbers of prevalence or incidence are not known. A literature search was performed by an experienced librarian in Pubmed, Embase, and Scopus. After selection of articles based on titles and abstracts, a full text review was performed. The prevalence of people needing surgical treatment was also estimated in a neurosurgical practice with a population adherence of 1.7 million people and a known referral pattern of the neurologists; all patients operated upon because of cervical spondylotic myelopathy between July 2009 and July 2012 were collected and prevalence calculated. The search of the literature did not reveal any article reporting an incidence or prevalence of cervical spondylotic myelopathy. Eighty of 5,992 patients were operated upon because of a cervical spondylotic myelopathy: 1.6 per 100,000 inhabitants. Surprisingly, an extensive search of the literature did not reveal exact data about the incidence or prevalence of cervical spondylotic myelopathy. The prevalence of surgically treated cervical spondylotic myelopathy was estimated as 1.6 per 100,000 inhabitants. Although the population adherence to the surgical practice is reasonably fixed and referral patterns are known, this estimate will still be too low for various reasons. At best, this estimate is the minimal prevalence of cervical spondylotic myelopathy that has been operated upon. To address the exact incidence or prevalence of cervical spondylotic myelopathy in general or needing surgical treatment, other investigations are warranted.

Comparison of anterior approach versus posterior approach for the treatment of multilevel cervical spondylotic myelopathy

Abstract: The purpose of this study is to evaluate the clinical outcomes, complications, and surgical trauma between anterior and posterior approaches for the treatment of multilevel cervical spondylotic myelopathy (CSM). Systematic review and meta-analysis. Randomized controlled trials or non-randomized controlled trials published up to November 2014 that compared the clinical effectiveness of anterior and posterior surgical approaches for the treatment of multilevel CSM were acquired by a comprehensive search in four electronic databases (PubMed, EMBASE, Cochrane Controlled Trial Register and MEDLINE). Exclusion criteria were non-controlled studies, combined anterior and posterior surgery and cervical myelopathy caused by ossification of the posterior longitudinal ligament. The main end points included: recovery rate; Japanese Orthopedic Association (JOA) score; complication rate; reoperation rate; blood loss; operation time and length of stay. A total of ten studies were included in the meta-analysis; none of which were randomized controlled trials. All of the selected studies were of high quality as indicated by the Newcastle–Ottawa scale. In six studies involving 467 patients, there was no significant difference in the preoperative JOA score between the anterior surgery group and the posterior group [P > 0.05, WMD −0.00 (−0.50, 0.50)]. In four studies involving 268 patients, the postoperative JOA score was significantly higher in the anterior surgery group compared with the posterior surgery group [P 0.05, WMD 2.73 (−8.69, 14.15)]. In nine studies involving 804 patients, the postoperative complication rate was significantly higher in the anterior surgery group compared with the posterior surgery group [P = 0.009, OR 1.65 (1.13, 2.39)]. In five studies involving 294 patients, the reoperation rate was significantly higher in the anterior surgery group compared with the posterior surgery group [P = 0.0001, OR 8.67 (2.85, 26.34)]. In the four studies involving 252 patients, the intraoperative blood loss and operation time was significantly higher in the anterior surgery group compared with the posterior surgery group [P < 0.05, WMD −40.25 (−76.96, −3.53) and P < 0.00001, WMD 61.3 (52.33, 70.28)]. In the three studies involving 192 patients, the length of stay was significantly lower in the anterior surgery group compared with the posterior surgery group [P < 0.00001, WMD −1.07 (−2.23, −1.17)]. In summary, our meta-analysis suggested that a definitive conclusion could not be reached regarding which surgical approach is more effective for the treatment of multilevel CSM. Although anterior approach was associated with better postoperative neural function than posterior approach in the treatment of multilevel CSM, there was no apparent difference in the neural function recovery rate between the two approaches. Higher rates of surgery-related complication and reoperation should be taken into consideration when anterior approach is used for patients with multilevel CSM.

Fusion rate following extreme lateral lumbar interbody fusion.

Abstract: Lumbar fusion has been found to be a clinically effective procedure in adult patients. The lateral transpsoas approach allows for direct visualization of the intervertebral space, significant support of the vertebral anterior column, while avoiding the complications associated with the posterior procedures. The aim of this study is to determine the fusion rate of inter body fusion using computed tomography in patients treated by extreme lateral intersomatic fusion (XLIF) technique. All patients intervened by XLIF procedure between 2009 and 2013 by a single operating team at a single institution were recruited for this study. A clinical evaluation and a CT scan of the involved spinal segments were then performed with at least 1-year follow-up following the standard clinical practice in the center. A total of 77 patients met inclusion criteria, of which 53 were available for review with a mean follow-up of 34.5 (12–62) months. A total of 68 (87.1 %) of the 78 operated levels were considered as completely fused, 8 (10.2 %) were considered as stable, probably fused, and 2 (2.6 %) of the operated levels were diagnosed as pseudarthrosis. When stratified by type of graft material complete fusion was obtained in 75 % of patients in which autograft was used to fill the cages, compared to 89 % of patients in which calcium triphosphate was used, and 83 % of patients in which Attrax™ was used. Reports of XLIF fusion rate in the literature vary from 85 to 93 % at 1-year follow-up. Fusion rate in our series corroborates data from previous publications. The results of this series confirm that anterior inter body fusion by means of XLIF approach is a technique that achieves high fusion rate and satisfactory clinical outcomes.

Effectiveness of posterior decompression techniques compared with conventional laminectomy for lumbar stenosis

Abstract: To compare the effectiveness of techniques of posterior decompression that limit the extent of bony decompression or to avoid removal of posterior midline structures of the lumbar spine versus conventional facet-preserving laminectomy for the treatment of patients with degenerative lumbar stenosis. A comprehensive electronic search of the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Web of Science, and the clinical trials registries ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform was conducted for relevant literature up to June 2014. A total of four high-quality RCTs and six low-quality RCTs met the search criteria of this review. These studies included a total of 733 participants. Three different techniques that avoid removal of posterior midline structures are compared to conventional laminectomy; unilateral laminotomy for bilateral decompression, bilateral laminotomy and split-spinous process laminotomy. Evidence of low or very low quality suggests that different techniques of posterior decompression and conventional laminectomy have similar effects on functional disability and leg pain. Only perceived recovery at final follow-up was better in patients that underwent bilateral laminotomy compared with conventional laminectomy. Unilateral laminotomy for bilateral decompression and bilateral laminotomy resulted in numerically fewer cases of iatrogenic instability, although in both cases, the incidence of instability was low. The difference in severity of postoperative low back pain following bilateral laminotomy and split-spinous process laminotomy was significantly less, but was too small to be clinically important. We found no evidence to show that the incidence of complications, length of the procedure, length of hospital stay and postoperative walking distance differed between techniques of posterior decompression. The evidence provided by this systematic review for the effects of unilateral laminotomy for bilateral decompression, bilateral laminotomy and split-spinous process laminotomy compared with conventional laminectomy on functional disability, perceived recovery and leg pain is of low or very low quality. Therefore, further research is necessary to establish whether these techniques provide a safe and effective alternative for conventional laminectomy. Proposed advantages of these techniques regarding the incidence of iatrogenic instability and postoperative back pain are plausible, but definitive conclusions are limited by poor methodology and poor reporting of outcome measures among included studies.

Impaired bone mineral density as a predictor of graft subsidence following minimally invasive transpsoas lateral lumbar interbody fusion.

Abstract: The LLIF procedure is a useful stand-alone and adjunct surgical approach for many spinal conditions. One complication of LLIF is subsidence of the interbody graft into the vertebral bodies, resulting in severe pain, impaired arthrodesis and potentially fracture of the body. Low bone density, as measured by T score on DEXA scanning, has also been postulated to increase the risk of subsidence. A retrospective review of prospectively collected data was performed on all patients who underwent LLIF at this institution consisting of 712 levels in 335 patients. Patients with subsidence following LLIF were recorded. We utilized the T score obtained from the femoral neck DEXA scans, which is used to determine overall fracture risk. The T score of patients with subsidence was compared to those without subsidence. 20 of 57 (35 %) patients without subsidence had a DEXA T score between −1.0 and −2.4 consistent osteopenia, one patient (1.8 %) exhibited a T score less than −2.5, consistent with osteoporosis. 13 patients of 23 (57 %) with subsidence exhibited a T score between −1.0 and −2.4, consistent with osteopenia, five (22 %) exhibited a T score of −2.5 or less, consistent with osteoporosis. The mean DEXA T score in patients with subsidence was −1.65 (SD 1.04) compared to −0.45 (SD 0.97) in patients without subsidence (p < 0.01). The area under the receiver operating characteristic curve for patients with a T score of −1.0 or less was 80.1 %. Patients with DEXA T scores less than −1.0 who undergo stand-alone LLIF are at a much higher risk of developing graft subsidence. Further, they are at an increased risk of requiring additional surgery. In patients with poor bone quality, consideration could be made to supplement the LLIF cage with posterior instrumentation.

Prevalence of C5 nerve root palsy after cervical decompressive surgery: a meta-analysis.

Abstract: To investigate the epidemiological prevalence of C5 palsy in patients following cervical decompressive surgery. We searched the PUBMED database for relevant studies that mentioned the incidence of C5 palsy after cervical surgery. We also manually screened reference lists for additional qualified articles. Relevant prevalence estimates were calculated by an appropriate meta-analysis. Subgroup analysis, sensitivity analysis, and publication bias assessment were also performed, respectively. Finally, a total of 79 studies, with 704 C5 palsy cases in 13,621 patients, were included in our meta-analysis. The overall pooled prevalence of C5 palsy was 5.3 % (95 % CI 4.6–6.0 %). Individuals after posterior cervical surgery (5.8 %) had a slightly higher prevalence than those after anterior surgery (5.2 %), and a similar trend was observed between ossification of posterior longitudinal ligament (OPLL) (5.8 %) and cervical spondylotic myelopathy (CSM) (4.5 %). The highest prevalence (11.0 %) was found in patients who underwent laminectomy and fusion (LIF), while those who received anterior cervical discectomy and fusion (ACDF) had the lowest prevalence (3.3 %). Other intermediate prevalence estimates increased gradually, from cervical laminoplasty-only (CLP-only) (5.1 %), to CLP plus other posterior procedures (6.5 %) and anterior cervical corpectomy and fusion (ACCF) (7.5 %). The prevalence was significantly higher in male (5.2 %) than in female (2.2 %) patients. In most cases, C5 palsy was unilateral and transient, and diagnosed within 3 days (3.4 %). Cervical surgery is associated with high risk of C5 palsy, particularly in patients who received LIF and in male patients. These figures may be useful in the estimation of the probability of C5 palsy following cervical surgery.

Sacropelvic fixation in adult spinal deformity (ASD); a very high rate of mechanical failure.

Abstract: Sacropelvic fixation (SPF) is an integral part of ASD surgery. Literature suggests that combination of S1 and iliac screws may be associated with lowest rate of complications. To analyze the rate and potential factors of mechanical failure associated with SPF in adult spinal deformity surgery. Of 504 patients enrolled in a prospective multicentric database, 239 were treated conservatively and 265 were treated surgically. Forty-five of those who had sacroiliac fixations and with >6 months (or to failure) f/up constitute the population. Type of iliac fixation was S2 alar/iliac (S2AI) screws in 20 (44.4 %) and iliac screws with lateral connectors (IwL) in 25 (55.6 %). Diagnoses were degenerative in 20, failed back in 11 and other in 14. Average instrumentation length was 11.6 ± 4.0 levels. Cases with failure were compared to those without using Fisher’s Exact and Mann–Whitney U tests. A total of 16 implant related complications were identified (35.6 %). Failures were identified on an average of 224.1 days (8–709) following index surgery. Failure rate of S2AI screws was 35 vs. 12 % for IwL screws (p > 0.05). All broken screws were associated with S2AI technique with polyaxial screws. Comparison of failed cases to others revealed that failed cases had inadequate restoration of Lumbar Lordosis but this was not statistically insignificant. Only age was a significantly different, patient with failure being older. Pelvic fixation is still associated with a very high rate of mechanical failure. Major risk factors appear to be age and type of fixation. Although could not be shown to be statistically significant, failure to restore the optimal sagittal balance may be a contributing factor as well. So in conclusion, in cases with suboptimal sagittal plane correction, S2AI with polyaxial screws seem to have higher risk of short-term acute failure compared to IwL.

Surgical treatment of sacral chordoma: prognostic variables for local recurrence and overall survival

Abstract: Purpose Sacral chordomas (SC) are rare, locally invasive, malignant neoplasms. Despite surgical resection and adjuvant therapies, local recurrence (LR) is common and overall survival (OS) is poor. The objective of this study was to identify prognostic factors that have an impact on the local recurrence-free survival (LRFS) and OS of patients with SC.

MIS lateral spine surgery: a systematic literature review of complications, outcomes, and economics

Abstract: Over the past decade, the minimally disruptive lateral transpsoas approach for lumbar interbody fusion (MI-LIF) is increasingly being used as an alternative to conventional surgical approaches. The purpose of this review was to evaluate four primary questions as they relate to MI-LIF: (1) Is there an anatomical justification for MI-LIF at L4–5? (2) What are the complication and outcome profiles of MI-LIF and are they acceptable with respect to conventional approaches? (3) Given technical and neuromonitoring differences between various MI-LIF procedures, are there any published clinical differences? And, (4) are modern minimally disruptive procedures (e.g., MI-LIF) economically viable? Through a MEDLINE and Google Scholar search, a total of 237 articles that discussed MI-LIF were identified. Of those, topical areas included anatomy (22), biomechanics/testing (17), technical descriptions (11), case reports (40), complications (30), clinical and radiographic outcomes (43), deformity (23), trauma or thoracic applications (10), and review articles (41). In answer to the questions posed, (1) there is a high strength of evidence showing MI-LIF to be anatomically justified at all levels of the lumbar spine from L1–2 to L4–5. The evidence also supports the use of advanced neuromonitoring modalities. (2) There is moderate strength evidence in support of reproducible and reasonable complication, side effect, and outcome profiles following MI-LIF which may be technique dependent. (3) There is low-strength evidence that shows elevated neural complication rates in non-traditional (e.g., shallow-docking approaches and/or those without specialized neuromonitoring) MI-LIF, and (4) there is low- to moderate-strength evidence that modern minimally disruptive surgical approaches are cost-effective. There is considerable published evidence to support MI-LIF in spinal fusion and advanced applications, though the results of some reports, especially concerning complications, vary greatly depending on technique and instrumentation used. Additional cost-effectiveness analyses would assist in fully understanding the long-term implications of MI-LIF.

Symptomatic epidural hematoma after lumbar decompression surgery

Abstract: Postoperative symptomatic epidural hematoma (SEH) is a serious complication of lumbar spine surgery. Despite its rarity, this uncommon complication may result in devastating neurological sequelae, including lower limb weakness. A retrospective study was made to identify possible risk factors of postoperative spinal epidural hematoma by reviewing the clinical cases of this rare complication and analyzing the postoperative evaluations of patients. From 2002 to 2010, out of 15,562 who underwent lumbar decompression procedure with/without instrumentation, 25 patients required reoperation for epidural hematoma after the initial spinal surgery. For the control group, another 75 patients were randomly selected from the pool of patients who received lumbar decompression surgery during the same period of time. The medical records of preoperative, intraoperative and postoperative factors were collected to determine possible risk factors by comparing between the cases and controls, and the postoperative evaluations of muscle power, intractable pain, saddle anesthesia, time to detection and time to evacuation were analyzed to find if there is any significant relation within the case group. Mann–Whitney U test, two-sample t test, χ 2 test and Fisher’s exact test were used for statistical analysis. The incidence of postoperative symptomatic epidural hematoma is 0.16 %. After the initial procedure, 20 (80 %) patients developed progressive decrease in muscle power (MP ≤ 3), 14 (56 %) patients had intractable pain (VAS ≥ 7), and 19 (76 %) patients had saddle anesthesia. Preoperative diastolic blood pressure, intraoperative use of gelfoam for dura coverage and postoperative drain output were statistically significant risk factors (p < 0.01). Within the SEH case group, postoperative symptom of decreased muscle power had significant relation with blood loss, laminectomy level and fusion level (p = 0.016, 0.021, 0.010). If the symptom of decreased muscle power or perianal anesthesia was not improved after hematoma evacuation, there was a tendency for permanent leg weakness after 1-year follow-up (p = 0.001, 0.003). The findings suggest that preoperative diastolic blood pressure, intraoperative use of gelfoam for dura coverage and postoperative drain output are risk factors for symptomatic epidural hematoma after lumbar decompression surgery. Major blood loss and multilevel surgical procedure could result in poor recovery of muscle power. After spine decompression surgery, early detection and evacuation of hematoma are the key to avoid neurologic deterioration and have better clinical outcomes.

Visceral, vascular, and wound complications following over 13,000 lateral interbody fusions: a survey study and literature review

Abstract: Minimally invasive lateral interbody fusion (MIS-LIF) has become a popular less invasive treatment option for degenerative spinal disease, deformity, and trauma. While MIS-LIF offers several advantages over traditional anterior and posterior approaches, the procedure is not without risk. The purpose of this study was to evaluate the incidence of visceral, vascular, and wound complications following MIS-LIF performed by experienced surgeons. A survey was conducted by experienced (more than 100 case experience) MIS-LIF surgeons active in the society of lateral access surgery (SOLAS) to collect data on wound infections and visceral and vascular injuries. Of 77 spine surgeons surveyed, 40 (52 %) responded, including 25 (63 %) orthopedic surgeons and 15 (38 %) neurosurgeons, with 20 % practicing at an academic institution and 80 % in community practice. Between 2003 and 2013, 13,004 patients were treated with MIS-LIF by the 40 surgeons who responded to the survey. Of those patients, 0.08 % experienced a visceral complication (bowel injury), 0.10 % experienced a vascular injury, 0.27 % experienced a superficial wound infection, and 0.14 % experienced a deep wound infection. The incidence of surgical site infections and vascular and visceral complications following MIS-LIF in this large series was low and compared favorably with rates for alternative interbody fusion approaches. Although technically demanding, MIS-LIF is a reproducible approach for interbody fusion with a low risk of vascular and visceral complications and infections.

Comparison of MIS vs. open PLIF/TLIF with regard to clinical improvement, fusion rate, and incidence of major complication: a meta-analysis

Abstract: Purpose Meta-analysis was conducted to estimate whether MiTLIF could reduce the complication rate while maintaining the similar clinical result to that of open procedures.

Reproducibility and repeatability of a new computerized software for sagittal spinopelvic and scoliosis curvature radiologic measurements: Keops ®

Abstract: The purpose of this study was to evaluate the inter- and intra-observer variability of the computerized radiologic measurements using Keops® and to determine the bias between the software and the standard paper measurement. Four individuals measured all frontal and sagittal variables on the 30 X-rays randomly selected on two occasions (test and retest conditions). The Bland–Altman plot was used to determine the degree of agreement between the measurement on paper X-ray and the measurement using Keops® for all reviewers and for the two measures; the intraclass correlation coefficient (ICC) was calculated for each pair of analyses to assess interobserver reproducibility among the four reviewers for the same patient using either paper X-ray or Keops® measurement and finally, concordance correlation coefficient (rc) was calculated to assess intraobserver repeatability among the same reviewer for one patient between the two measure using the same method (paper or Keops®). The mean difference calculated between the two methods was minimal at −0, 4° ± 3.41° [−7.1; 6.4] for frontal measurement and 0.1° ± 3.52° [−6.7; 6.8] for sagittal measurement. Keops® has a better interobserver reproducibility than paper measurement for determination of the sagittal pelvic parameter (ICC = 0.9960 vs. 0.9931; p = 0.0001). It has a better intraobserver repeatability than paper for determination of Cobbs angle (rc = 0.9872 vs. 0.9808; p < 0.0001) and for pelvic parameter (rc = 0.9981 vs. 0.9953; p < 0.0001). We conclude that Keops® has no bias compared to the traditionally paper measurement, and moreover, the repeatability and the reproducibility of measurements with this method is much better than with similar standard radiologic measures done manually in both frontal and sagittal plane and that the use of this software can be recommended for clinical application. Diagnostic, level III.

Sagittal deformities of the spine: factors influencing the outcomes and complications.

Abstract: Degenerative changes have the potential to greatly disrupt the normal curvature of the spine, leading to sagittal malalignment. This phenomenon is often treated with operative modalities, such as osteotomies, though even with surgery, only one-third of patients may reach neutral alignment. Improvement in surgical outcomes may be achieved through better understanding of radiographic spino-pelvic parameters and their association with defor- mity. Methodical surgical planning, including selection of levels of instrumentation and site of the osteotomy, is crucial in determining the optimal plan for a patient's specific pathology and may minimize risk of developing postoperative proximal junctional kyphosis/failure. While sagittal alignment is essential in operative strategy, the coronal plane should not be overlooked, as it may affect the osteotomy technique. The concepts of sagittal balance and alignment are further complicated in patients with neuro- muscular diseases such as Parkinson's disease, and appre- ciation of the interplay between anatomic and postural deformities is necessary to properly treat these patients. Finally, given the importance of sagittal alignment and the role of osteotomies in treatment for deformity, the need for future research becomes apparent. Novel intraoperative measurement techniques and three-dimensional analysis of the spine may allow for vastly improved operative cor- rection. Furthermore, awareness of the relationship between alignment and balance, the soft tissue envelope, and compensatory mechanisms will provide a more com- prehensive conception of the nature of spinal deformity and the modalities with which it is treated.

Sagittal spinopelvic alignment in 654 degenerative spondylolisthesis

Abstract: Purpose Degenerative spondylolisthesis (DS) is common degenerative spinal disease. Recent studies highlighted relationship between DS and high pelvic incidence (PI). Moreover, impact of spinopelvic alignment on clinical outcomes has been emphasized. We aimed at describing epidemiologic and sagittal spinopelvic parameters in patients with DS, comparing them with asymptomatic volunteers, and determining a classification of DS patients.

Clinical results and limitations of indirect decompression in spinal stenosis with laterally implanted interbody cages: results from a prospective cohort study.

Abstract: Purpose The lateral approach for anterior interbody fusion allows placement of a large footprint intervertebral spacer to indirectly decompress the neural elements through disc height restoration and resultant soft tissue changes. However, it is not well understood under what circumstances indirect decompression in lateral approach surgery is sufficient. This report aimed to evaluate clinical scenarios where indirect decompression was and was not sufficient in symptom resolution when using lateral interbody fusion.

Radiographic outcomes of anterior column realignment for adult sagittal plane deformity: a multicenter analysis

Abstract: Anterior column reconstruction (ACR) is a minimally invasive technique for the treatment of sagittal plane deformity. ACR uses a lateral transpsoas approach with ALL release and the application of an interbody device to achieve correction. Here, we present 1-year radiographic results from a multicenter study of adult spinal deformity (ASD) patients. A multicenter database was queried from 2005 to 2013 for ASD patients treated with ACR. Demographics, surgical data, and radiographic measurements were collected and retrospectively analyzed. Radiographic time points included preoperative (pre-op), postoperative (post-op; first visit prior to 3 months), and last follow-up (last FU; minimum of 1 year). Sagittal radiographic measurements included regional lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), T1 spinopelvic inclination (T1SPi), and segmental lordosis (disc angle). Mean patient age was 67.4 years (range 46.5–80.0) and 11 patients (32.4 %) were male. Twenty patients (58.8 %) had previous lumbar surgery. All patients had a minimal of one-level ACR with ALL release (mean 1.7; range 1–4). Mean number of lateral interbody fusion (LLIF) levels without ALL release per patient was 0.7 (range 0–3). Thirty-three patients (97.1 %) received supplemental posterior fixation and 1 patient (2.9 %) had lateral fixation only. In 26 patients (76.5 %), supplemental posterior fixation was performed using an open approach, and 7 patients (20.6 %) were treated with percutaneous placement. Mean of number of levels fused was 7.1 (range 2–16). There was a significant improvement in LL (p < 0.001), PI-LL mismatch (p < 0.001), and PT (p = 0.03) from pre-op to post-op, and pre-op to last FU. There was no change in T1SPi, SS, or PI. Segmental lordosis improved at ACR levels from mean of −2.2° pre-op to −16.0° post-op (p < 0.01) and −16.3° at last FU (p < 0.001). The addition of posterior column osteotomy increased the change in segmental lordosis with ACR by 72.7 % (p < 0.001). LLIF without ALL release led to significant improvement in segmental lordosis from pre-op (−2.4°) to post-op (−7.1°; p < 0.01) but not from pre-op to last FU (−5.7°; p = 0.06). ACR successfully restores lumbar lordosis in ASD patients with sagittal imbalance. ACR results in greater segmental correction than is achieved with LLIF alone. Supplementing with posterior osteotomies allows for even greater correction. The ability to achieve the desired radiographic goals is expected to improve as technical nuances are refined and patient selection is optimized.

Postoperative wound infection after posterior spinal instrumentation: analysis of long-term treatment outcomes

Abstract: Postoperative spinal implant infection (PSII) places patients at risk for pseudarthrosis, correction loss, spondylodiscitis, adverse neurological sequelae, and even death; however, prognostic factors that predict long-term treatment outcomes have not been clearly investigated. In addition, few studies concerning the feasibility of reconstructing the failed spinal events have been published. We performed a cohort study of 51 patients who contracted PSII in the posterolateral thoracolumbar region at a single tertiary center between March 1997 and May 2007. Forty-seven patients (92.2 %) had one or more medical problems. Isolated bacterial species, infection severity, treatment timing, and hosts’ defense response were evaluated to assess their relationship with management outcomes. The use of implant salvage, or removal subsequent with a revision strategy depended on the patient’s general conditions, infection control, and implant status for fusion. The most common infective culprit was Staphylococcus spp. found in 35 of 60 (58.3 %) isolates, including 20 methicillin-resistant species. Gram-negative bacilli and polymicrobial infection were found significantly in patients presenting early-onset, deep-site infection and myonecrosis. Prompt diagnosis and aggressive therapy were responsible for implant preservation in 41 of 51 cases (80.4 %), while implant removal noted in 10 cases (19.6 %) was attributed to delayed treatment and uncontrolled infection with implant loosening, correction loss, or late infection with spondylodesis. The number of employed debridements alone was not significantly correlated with successful implant preservation. Delayed treatment for infection >3 months significantly led to implant removal (p < 0.05) and a higher number of failed spinal events. Patients with significant comorbidities, malnutrition, severe trauma, neurological deficits, long-level instrumentation, and delayed treatment had poor outcomes. Sixteen patients (31.4 %) exhibited probable nonunion or pseudarthrosis, and eight symptomatic patients among them underwent successful revision surgery. Retention of the mechanically sound implants in early-onset infection permits fusion to occur, while delayed treatment, severe malnutrition and multiple comorbidities will most likely result in a lack of effectiveness in eradicating the infecting pathogens. Restoring optimal physiological conditions is imperative in high-risk patients to allow for further healing. When loosened screws cause peridiscal erosion and incapacitating motion pain, premature implant removal possibly results in failed fusion and correction loss. Reconstruction for a failed spinal event is feasible following infection control.

Can triggered electromyography monitoring throughout retraction predict postoperative symptomatic neuropraxia after XLIF? Results from a prospective multicenter trial.

Abstract: Purpose This multicenter study aims to evaluate the utility of triggered electromyography (t-EMG) recorded throughout psoas retraction during lateral transpsoas interbody fusion to predict postoperative changes in motor function.