Study purpose and background. Kinematic variables have been identified as potential biomarkers for low back pain patients; however, an in-depth comparison between chronic (n=22), acute (n=15), and healthy controls (n=136) has not been done. This retrospective data analysis compared intervertebral lumbar motion parameters, angular range of motion, translation, maximum disc height, motion share inequality (MSI) and variability (MSV), and laxity, between these groups. Methods and results. Kinematic parameters were determined using video tracking techniques utilising quantitative fluoroscopy (QF), during both weight-bearing and recumbent controlled sagittal bending tasks. Data was analysed for normality, and appropriate statistical tests were applied to determine differences between groups. There were no significant differences between the groups for age, height, weight and sex. Whilst few differences were found between acute and healthy groups, differences were shown between both chronic and healthy, and acute and chronic groups for all six parameters. Of particular note were examples of differences in the motion share parameters between the acute and chronic populations, with an increased MSI in the chronic group during recumbent flexion, and MSV during recumbent extension, and inversely an increase in MSV in the acute group during weight-bearing flexion. Conclusion. Analysis of intervertebral lumbar motion provides valuable insights into kinematic differences between chronic, acute, and healthy control populations. These findings suggest that there is variation between the groups which is knowledge that may benefit management strategies. Further exploration of the time varying data is warranted to explore how such differences may relate to the motion share inequalities and variability shown. Conflicts of Interest. No conflicts of interest. Sources of Funding. No funding obtained

Purpose and background. Recent research has identified possible functional biomarkers in chronic, nonspecific back pain (CNSLBP) based on intervertebral kinematics. Although excessive IV-RoM is no longer regarded as a clear motion abnormality, some studies have found subtle kinematic measures such as mid-range laxity and motion sharing inequality to be greater in CNSLBP patients. We studied a group of such patients who were investigated following failed interventions in terms of these subtle measures. Methods. Thirty-seven patients (mean age 47.5 years SD10.87, F14, M23) with CNSLBP that had recently failed to respond to a range of treatments and 37 healthy controls received passive recumbent lumbar intervertebral flexion assessments following a standardised quantitative fluoroscopy (QF) protocol. Groups were compared for motion sharing inequality (MSI) and variability (MSV) (L2-S1), for level by level laxity and translation, and with reference ranges of these from a separate group of healthy controls (n=54). Results. Patients had significantly higher MSI values than controls (p=0.01), but not MSV (p=0.79). Laxity and translation above normative reference limits were not more prevalent in patients. Eleven patients had had surgical or interventional procedures, 10 had spondylolisthesis or pars defects and 16 no disruptive elements. Those who had received invasive procedures (e.g. disc replacement, fusion) had significantly higher median MSI values than those with spondylolistheses/pars defects (p=0.02) or no disruption (p=0.001). Conclusion. Reduced individual level intervertebral restraint during passive recumbent motion was not associated with pain in treatment resistant patients, but uneven restraint between levels (MSI) appeared to be. Future work should investigate the reasons for this. No conflicts of interest. No funding obtained

Background. Dynamic measurement of continuous intervertebral motion in low back pain (LBP) research in-vivo is developing. Lumbar motion parameters with the features of biomarkers are emerging and show promise for advancing understanding of personalised biometrics of LBP. However, measurement of changes over time inevitably involve error, due to subjects' natural variation and/or variation in the measurement process. Thus, intra-subject repeatability of parameters to measure changes over time should be established. Methods. Seven lumbar spine motion parameters, measured using quantitative fluoroscopy (QF), were assessed for intra-subject repeatability: Intervertebral range-of-motion (IV-RoM), laxity, motion sharing inequality (MSI), motion sharing variability (MSV), flexion translation and flexion disc height. Intra-subject reliability (ICC) and minimal detectable change (MDC95) of baseline and 6-week follow-up measurements were obtained for 109 healthy volunteers (54 coronal and 55 sagittal). Results. Reliability was substantial to excellent for repeated measurements of IV-RoM, laxity, flexion translation and disc height during recumbent passive motion (ICC:0.69–0.95) and during active weight-bearing motion (ICC:0.64–0.92). MSI was moderate to excellent across both positions (ICC:0.43–0.91). The reliability of MSV was generally poorer for both positions (0.14–0.65). For all parameters, measurement error exceeded 42%. Conclusion. Recumbent IV-RoM, laxity and disc height demonstrated the best repeatability at 6-weeks suggesting they may be better outcome moderators in clinical studies than other variables. However measurement errors for all parameters were higher than the minimal changes of interest. These results are limited to healthy controls and should be regarded as reference values. Similar studies in CNSLBP patients are required. No conflicts of interest. Sources of Funding: Dr Rebecca Hemming received a Seedcorn Bursary from the Cardiff Institute of Tissue Engineering and Repair (CITER) and Professor Alan Breen received a project grant from the European Chiropractors Union Research Fund (ECURF)

Background and Purpose:. The inability of intervertebral joints to resist perturbation due to laxity is traditionally measured in cadaveric specimens as their neutral zones (NZ). However in patients, quantitative fluoroscopic (QF) examinations substitute the Initial Attainment Rate for this. If these two measures correspond sufficiently, a clinical method for measuring segmental instability is possible. This study explored this by determining the criterion validity of the Initial Attainment Rate against the Dynamic NZ in an unloaded multilevel porcine spine. Methods and Results:. A 5-segment porcine spine was prepared and mounted on a motorised horizontal motion platform fitted with a digital force gage. Left and right bending moments were calculated about each intervertebral joint for 10 repeated side bends using an inverse dynamics method. The Dynamic NZs and Initial Attainment Rates in the first 10° of platform motion at each level were correlated. The Initial Attainment Rates were comparable to those found in vivo in healthy controls. Substantial and highly significant levels of correlation between these and Dynamic NZs were found for left (rho= 0.75, p=0.0002) and combined left-right bending (rho=0.72, p=0.0001) and moderate for right bending alone (rho=0.55, p=0.0012). Conclusion:. This study found good correlation between the Initial Attainment Rate and the Dynamic NZ indicating the feasibility of assessing intervertebral laxity using QF in clinical studies. Confirmatory studies with multiple specimens adding sagittal and axial plane rotations are needed

Aims

To determine the effectiveness of prone traction radiographs in predicting postoperative slip distance, slip angle, changes in disc height, and lordosis after surgery for degenerative spondylolisthesis of the lumbar spine.

Aims

Diagnosis of cauda equina syndrome (CES) remains difficult; clinical assessment has low accuracy in reliably predicting MRI compression of the cauda equina (CE). This prospective study tests the usefulness of ultrasound bladder scans as an adjunct for diagnosing CES.

Transarticular screw fixation with autograft is an established procedure for the surgical treatment of atlantoaxial instability. Removal of the posterior arch of C1 may affect the rate of fusion. This study assessed the rate of atlantoaxial fusion using transarticular screws with or without removal of the posterior arch of C1. We reviewed 30 consecutive patients who underwent atlantoaxial fusion with a minimum follow-up of two years. In 25 patients (group A) the posterior arch of C1 was not excised (group A) and in five it was (group B). Fusion was assessed on static and dynamic radiographs. In selected patients CT imaging was also used to assess fusion and the position of the screws. There were 15 men and 15 women with a mean age of 51.2 years (23 to 77) and a mean follow-up of 7.7 years (2 to 11.6). Stable union with a solid fusion or a stable fibrous union was achieved in 29 patients (97%). In Group A, 20 patients (80%) achieved a solid fusion, four (16%) a stable fibrous union and one (4%) a nonunion. In Group B, stable union was achieved in all patients, three having a solid fusion and two a stable fibrous union. There was no statistically significant difference between the status of fusion in the two groups. Complications were noted in 12 patients (40%); these were mainly related to the screws, and included malpositioning and breakage. The presence of an intact or removed posterior arch of C1 did not affect the rate of fusion in patients with atlantoaxial instability undergoing C1/C2 fusion using transarticular screws and autograft.

Cite this article: Bone Joint J 2013;95-B:972–6.

This prospective study of 136 children with progressive infantile scoliosis treated under the age of four years, and followed up for nine years, shows that the scoliosis can be reversed by harnessing the vigorous growth of the infant to early treatment by serial corrective plaster jackets.

In 94 children (group 1), who were referred and treated in the early stages of progression, at a mean age of one year seven months (6 to 48 months) and with a mean Cobb angle of 32° (11° to 65°), the scoliosis resolved by a mean age of three years and six months. They needed no further treatment and went on to lead a normal life. At the last follow-up, their mean age was 11 years and two months (1 year 10 months to 25 years 2 months), 23 (24.5%) were at Risser stages 4 and 5 and 13 girls were post-menarchal.

In 42 children (group 2), who were referred late at a mean age of two years and six months (11 to 48 months) and with a mean Cobb angle of 52° (23° to 92°), treatment could only reduce but not reverse the deformity. At the last follow-up, at a mean age of ten years and four months (1 year 9 months to 22 years 1 month), eight children (19%) were at Risser stages 4 and 5 and five girls were post-menarchal. Fifteen children (35.7%) had undergone spinal fusion, as may all the rest eventually.

We reviewed seven children with torticollis due to refractory atlanto-axial rotatory fixation who were treated in a halo vest. Pre-operative three-dimensional CT and sagittal CT imaging showed deformity of the superior articular process of C2 in all patients. The mean duration of halo vest treatment was 67 days (46 to 91). The mean follow-up was 34 months (8 to 73); at the latest review six patients demonstrated remodelling of the deformed articular process. The other child, who had a more severe deformity, required C1-2 fusion.

We suggest that patients with atlanto-axial rotatory fixation who do not respond to conservative treatment and who have deformity of the superior articular process of C2 should undergo manipulative reduction and halo-vest fixation for two to three months to induce remodelling of the deformed superior articular process before C1-2 fusion is considered.