Background and purpose. Investigating inter-vertebral biomechanics in vivo using end-of-range imaging is difficult due to high intra subject variation, measurement errors and insufficient data. Quantitative fluoroscopy (QF) can reliably measure continuous motion but may suffer from contamination from uncontrolled loading and muscle contraction which compromises comparisons between studies and limits interpretation of results. This study presents the methods used to overcome these limitations. Methods and results. Forty chronic, non-specific low back pain (CNSLPB) patients and 40 matched controls underwent QF using a passive recumbent protocol which standardised the rate and range of trunk rotation, thus reducing intra-subject variation and excluding loading and muscle contraction factors. Left, right, flexion and extension were recorded from L2-5 and vertebral motion registered using image processing algorithms, Resultant continuous inter-vertebral rotation data were normalised to produce proportional contributions of each segment throughout the trunk bend. The expected continuous proportional contributions at each level and direction were determined by calculating reference intervals (mean +/− 2SD) from controls. Prevalence of patients exceeding these ranges was determined and the association with CNSLBP calculated using Chi-squared analysis. Additionally the variance of the normalised data throughout the continuous motion for each direction was determined and summed to produce an combined number. This was used to measure the difference between patients and controls and entered into ROC curve analysis to investigate discrimination between patients and controls. Conclusion. A methodology for assessment of the differences between the continuous in vivo spine kinematics of CNSLBP patients and healthy controls has been developed and will be presented

Background and Purpose of Study:

Differences in regional lumbar angles in sitting have been observed between subgroups of NSCLBP patients exhibiting motor control impairments (MCI) (O'Sullivan, 2005; Dankaerts et al, 2006). However, differences in standing posture and other spinal regions are unknown. This study aimed to compare regional spinal angles in healthy and MCI subgroups in sitting and standing.

Background:. Identification of nerve root involvement (NRI) in patients with low back-related leg pain (LBLP) can be challenging. Diagnostic models have mainly been developed in secondary care with conflicting reference standards and predictor selection. This study aims to ascertain which cluster of items from clinical assessment best identify NRI in primary care consulters with LBLP. Methods:. Cross-sectional data on 395 LBLP consulters were analysed. Potential NRI indicators were seven clinical assessment items. Two definitions of NRI formed the reference standards: (i) high confidence (≥80%) NRI clinical diagnosis (ii) high confidence (≥80%) NRI clinical diagnosis with confirmatory magnetic resonance imaging (MRI) findings. Multivariable logistic regression models were constructed and compared for both reference standards. Model performances were summarised using the Hosmer-Lemeshow statistic and area under the curve (AUC). Bootstrapping assessed internal validity. Results:. NRI clinical diagnosis model retained five items. The model with MRI in the reference standard retained six items. Four items remained in both models: below knee pain, leg pain worse than back pain, positive neural tension tests, neurological deficit (myotome, reflex or sensory). NRI clinical diagnosis model was well calibrated (p=0.17) and discrimination was AUC 0.96 (95%CI: 0.93, 0.98). Performance measures for clinical diagnosis plus confirmatory MRI model showed good discrimination (AUC 0.83, 95% CI: 0.78, 0.86) but poor calibration (p=0.01). Bootstrapping revealed minimal overfitting in both models. Conclusion:. A cluster of items identified NRI in LBLP consulters. These criteria could be used clinically and in research to improve accuracy of identification and homogeneity of this subgroup of low back pain patients

Introduction. Idiopathic scoliosis (IS) has been associated with several genetic loci in varying study populations, reflecting the disorder's genetic complexity. One region of interest is on chromosome 17, flanking regions linked to neurofibromatosis type 1 (NF1). This region is of particular relevance because the most common osseous manifestation in NF1 is scoliosis (10–30% of patients). This alludes to a potential genetic correlation within this region affecting spinal development or stability. The objective of this research is to identify candidate genes within this region that are statistically linked to IS. Methods. An initial population of IS families recruited through approval by the institutional review board (202 families; 1198 individuals) had DNA harvested from blood, and underwent genomic screening, finemapping, and statistical analyses. We identified a specific familial subset: families with males having undergone surgery for scoliosis (17 families, 147 individuals). The initial genome-wide scan indicated that this subset was linked to chromosome 17q.11.2. The most prominent marker, D17s975, (p=0·0003) at 25.12 Mb is adjacent to the NF1 deletional region. We then analysed a custom panel of single-nucleotide polymorphisms (SNPs) extending from 18·30–31·47 Mb for linkage through Taqman SNP assay protocol. With allele specific fluorescent tags, allelic discrimination was done with real-time PCR. Results. Findings show two regions with two or more contiguous SNPs of significance (p<0·05), confirming significant linkage adjacent to the NF1 locus (table). The most significant results lie within the serotonin transporter gene SLC6A4, whose product is a modulator of serotonin (5-HT) activity. Conclusions. IS is a disorder of variable phenotypic expression that has been related to several regions on the genome. Although NF1 has been definitively associated with a region on chromosome 17, the phenotypic expression is not understood at the molecular level. The elucidation of shared genetic variations within this region by two disorders marked by scoliosis has significance for the molecular understanding of the pathogenesis of scoliosis and axial development. The specific gene, SLC6A4, is of particular interest in that as a modulator of serotonin transport, bone mineral content, density, and mechanical strength can be altered. Both NF1 and IS in some patients have been associated with decreased bone mineral density. Future work will focus on replication of these findings and targeted genetic sequencing

Despite the increasing prevalence of sleep apnoea, little information is available regarding its impact on the peri-operative outcome of patients undergoing posterior lumbar fusion. Using a national database, patients who underwent lumbar fusion between 2006 and 2010 were identified, sub-grouped by diagnosis of sleep apnoea and compared. The impact of sleep apnoea on various outcome measures was assessed by regression analysis. The records of 84 655 patients undergoing posterior lumbar fusion were identified and 7.28% (n = 6163) also had a diagnostic code for sleep apnoea. Compared with patients without sleep apnoea, these patients were older, more frequently female, had a higher comorbidity burden and higher rates of peri-operative complications, post-operative mechanical ventilation, blood product transfusion and intensive care. Patients with sleep apnoea also had longer and more costly periods of hospitalisation.

In the regression analysis, sleep apnoea emerged as an independent risk factor for the development of peri-operative complications (odds ratio (OR) 1.50, confidence interval (CI) 1.38;1.62), blood product transfusions (OR 1.12, CI 1.03;1.23), mechanical ventilation (OR 6.97, CI 5.90;8.23), critical care services (OR 1.86, CI 1.71;2.03), prolonged hospitalisation and increased cost (OR 1.28, CI 1.19;1.37; OR 1.10, CI 1.03;1.18).

Patients with sleep apnoea who undergo posterior lumbar fusion pose significant challenges to clinicians.

Cite this article: Bone Joint J 2014;96-B:242–8.

We investigated the spinopelvic morphology and global sagittal balance of patients with a degenerative retrolisthesis or anterolisthesis. A total of 269 consecutive patients with a degenerative spondylolisthesis were included in this study. There were 95 men and 174 women with a mean age of 64.3 years (sd 10.5; 40 to 88). A total of 106 patients had a pure retrolisthesis (R group), 130 had a pure anterolisthesis (A group), and 33 had both (R+A group).

A backward slip was found in the upper lumbar levels (mostly L2 or L3) with an almost equal gender distribution in both the R and R+A groups. The pelvic incidence and sacral slope of the R group were significantly lower than those of the A (both p < 0.001) and R+A groups (both p < 0.001). The lumbar lordosis of the R+A group was significantly greater than that of the R (p = 0.025) and A groups (p = 0.014). The C7 plumb line of the R group was located more posteriorly than that of the A group (p = 0.023), but was no different from than that of the R+A group (p = 0.422). The location of C7 plumb line did not differ between the three groups (p = 0.068). The spinosacral angle of the R group was significantly smaller than that of the A group (p < 0.001) and R+A group (p < 0.001).

Our findings imply that there are two types of degenerative retrolisthesis: one occurs primarily as a result of degeneration in patients with low pelvic incidence, and the other occurs secondarily as a compensatory mechanism in patients with an anterolisthesis and high pelvic incidence.

Cite this article: Bone Joint J 2013;95-B:1244–9.

The revised Tokuhashi, Tomita and modified Bauer scores are commonly used to make difficult decisions in the management of patients presenting with spinal metastases. A prospective cohort study of 199 consecutive patients presenting with spinal metastases, treated with either surgery and/or radiotherapy, was used to compare the three systems. Cox regression, Nagelkerke’s R² and Harrell’s concordance were used to compare the systems and find their best predictive items. The three systems were equally good in terms of overall prognostic performance. Their most predictive items were used to develop the Oswestry Spinal Risk Index (OSRI), which has a similar concordance, but a larger coefficient of determination than any of these three scores. A bootstrap procedure was used to internally validate this score and determine its prediction optimism.

The OSRI is a simple summation of two elements: primary tumour pathology (PTP) and general condition (GC): OSRI = PTP + (2 – GC).

This simple score can predict life expectancy accurately in patients presenting with spinal metastases. It will be helpful in making difficult clinical decisions without the delay of extensive investigations.

Cite this article: Bone Joint J 2013;95-B:210–16.