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.

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).

Methods

Fifty-four healthy controls (F=22, M=23) received passive recumbent and active weight bearing QF screenings during controlled motion, plus still fluoro imaging in neutral, flexion and extension. The translatory slip of all levels from L2-S1 was determined for each condition using bespoke image tracking codes (Matlab) and pooled to provide means and ranges of variation (+/-1.96SD). The pooled measurement error, or minimal detectable change (MDC₉₅), reflecting the intra subject repeatability over 6 weeks was calculated. Ranges of translation for each level (L2-S1), for each type of motion were also calculated.

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).

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).

Methods and Results:

Fifty-seven consecutive referrals were reviewed. Patients underwent passive recumbent and/or weight-bearing active examinations in either the sagittal or both the sagittal and coronal planes. Data were extracted from anonymised QF reports and analysed for patient characteristics, reason for referral, working diagnosis at referral, level(s) of interest, previous surgical procedures and findings reported. Reports were also thematically analysed for key findings.

Most patients had chronic back conditions of moderate or severe intensity. Most (38/57) were male, mean age 47 (SD 13.1) and mean complaint duration 5.4 years (0.3–32 years). They were referred mainly to investigate segmental instability (19/54) or spondylolisthesis (13/54) to inform either surgical referral or conservative management. Instability was reported in only 8/57 cases, but restricted and hypermobile levels in the same patient was also common (13/57). In 11 cases no mechanical abnormality was found.

Methods and Results:

Forty-five patient referrals to the upright MRI Department at the AECC for weight bearing lumbar spine scans between November 1^st 2014 and June 30^th 2015, and the resulting radiologists' reports were reviewed. Age, gender, clinical history, summary of findings, type of weight bearing scanning performed (sitting, standing, flexion, extension) were abstracted. All patients were scanned in a 0.5T Paramed MRopen scanner and all also received supine lumbar spine sagittal and axial scans.

The patients comprised 18 females and 27 males, mean age 52 years, (SD 15.5). Thirty had leg pain, 6 of which was bilateral. In 15, a stenotic lesion was suspected. Other reasons for referral were; possible malignancy (1), effects of degenerative change (4), spondylolisthesis (2), fracture, (1), previous surgery (3), trauma (1), sacroiliitis (1) and instability (3).

In 12/45 cases, reportable findings were more prominent, and sometimes only identifiable, on weight bearing scans, while in a further 4, the reverse was true. All but one of these involved disruption of the spinal or root canals. Eight of them also involved positional alignment.

Methods and Results:

Participants underwent passive recumbent examinations in the sagittal and coronal planes. Values based on were developed for both maximum and continuous motion in controls (n=40). Fishers exact test was used to analyse proportions of patients whose IV-RoMs exceeded reference values.

For maximum IV-RoM in patients, there were no statistically significant differences between groups for the lower value. Only flexion at L4/5 significantly exceeded the upper value (p=0.03). For continuous IV-RoM, left L3/4 (p=0.01) and right L4/5 (p=0.01) were significantly below the lower cut off values. Both flexion L4/5 (p=0.05) and left L3/4 (p=0.01) were significantly above the upper cut off values.

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.