Search

Introduction: Central lumbar spinal stenosis (LSS) is a common cause of pain, reduced function and quality of life in older adults. Current management of LSS includes surgery to decompress the spinal canal and alleviate symptoms. However, evidence supporting surgical decompression derives from unblinded randomised trials with high cross-over rates or cohort studies showing modest benefits. This protocol describes the design of the SUrgery for Spinal Stenosis (SUcceSS) trial -the first randomised placebo-controlled trial of decompressive surgery for symptomatic LSS., Methods and Analysis: SUcceSS will be a prospectively registered, randomised placebo-controlled trial of decompressive spinal surgery. 160 eligible participants (80 participants/group) with symptomatic LSS will be randomised to either surgical spinal decompression or placebo surgical intervention. The placebo surgical intervention is identical to surgical decompression in all other ways with the exception of the removal of any bone or ligament. All participants and assessors will be blinded to treatment allocation. Outcomes will be assessed at baseline and at 3, 6, 12 and 24 months. The coprimary outcomes will be function measured with the Oswestry Disability Index and the proportion of participants who have meaningfully improved their walking capacity at 3 months postrandomisation. Secondary outcomes include back pain intensity, lower limb pain intensity, disability, quality of life, anxiety and depression, neurogenic claudication score, perceived recovery, treatment satisfaction, adverse events, reoperation rate and rehospitalisation rate. Those who decline to be randomised will be invited to participate in a parallel observational cohort. Data analysis will be blinded and by intention to treat. A trial-based cost-effectiveness analysis will determine the potential incremental cost per quality-adjusted life year gained., Ethics and Dissemination: Ethics approval has been granted by the NSW Health (reference:17/247/POWH/601) and the Monash University (reference: 12371) Human Research Ethics Committees. Dissemination of results will be via journal articles and presentations at national and international conferences., Trial Registration Number: ACTRN12617000884303; Pre-results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: The purpose of this study is to investigate if lumbar disc pathology identified on MRI scans is more common in patients with acute, likely discogenic, low back pain than matched controls., Methods: We compared rates of MRI findings between 30 cases with low back pain and 30 pain-free controls. Cases were patients presenting for care with likely discogenic low back pain (demonstrated centralisation with repeated movement testing), of moderate intensity and with minimal past history of back pain. Controls were matched for age, gender and past history of back pain. Cases and controls underwent MRI scanning which was read for the presence of a range of MRI findings by two blinded assessors., Results: The presence of disc degeneration, modic changes and disc herniation significantly altered the odds of a participant being a case or control. For example subjects were 5.2 times more likely to be a case than a control when disc degeneration grade of ≥3 was present, and 6.0 times more likely with modic changes. The presence of a high-intensity zone or annular tear was found to significantly alter odds for one assessor but not the other assessor., Conclusion: MRI findings including disc degeneration, modic changes and herniation are more common in selected people with current acute (likely discogenic) low back pain than in controls without current low back pain. Further investigation of the value of MRI findings as prognostic factors and as treatment effect modifiers is required to assess the potential clinical importance of these findings.

Objective: To investigate (1) whether thoracolumbar posteroanterior (PA) stiffness differs between 2 conditions of ribcage movement: unconstrained and constrained, and (2) whether the effect of ribcage constraint on PA stiffness varies according to where the PA force is applied., Design: Two-factor within-subjects design., Setting: Spinal Mechanics Laboratory, University of Sydney., Intervention: A convenience sample of 41 subjects, asymptomatic for back pain, participated. PA stiffness at T12-L4 was measured in the unconstrained and constrained ribcage conditions with a mechanical device. For the constrained condition, we used a clamping device to apply a force to the subject's lower thorax to reduce movement., Main Outcome Measures: PA stiffness at T12-L4 under both ribcage conditions., Results: PA stiffness at T12-L4 significantly increased when the ribcage was constrained (P<.05). However, the effect of ribcage movement did not depend on the location of the PA force., Conclusions: These findings suggest that the properties of the ribcage influence measures of PA stiffness in the thoracolumbar (T12-L4) spine uniformly. Variations in PA stiffness in segments T12-L4 may reflect the properties of the intervertebral joints.

Objective: To evaluate the reliability and criterion-related validity of a revised version of the reference-based protocol for manually assessing lumbar posteroanterior (PA) stiffness. With the revised protocol, a therapist matched the stiffness of the spine to 1 of 11 stiffness references provided by a mechanical device., Subjects: Two physiotherapists and 41 asymptomatic subjects participated., Methods: Subjects' PA stiffness was assessed by the therapists and the Stiffness Assessment Machine(criterion measure) under standardized conditions. The therapists pressed on the subject's spine and then the mechanical device, the task being to match the stiffness of the back to 1 of the 11 stimuli provided by the device. Each of the 11 stiffness stimuli represented a point on the -5 to +5 stiffness scale. Interrater reliability was evaluated with 2-way analysis of variance (ANOVA) intraclass correlation coefficient for a single rating (ICC [2,1]) and the SEM, whereas criterion-related validity was evaluated with the Pearson product moment correlation (r), including the Fleiss correction., Results: The ICC (2,1) was 0.78 (SEM 0.56), and the criterion-related validity reached 0.74 (Fleiss correction 0.86)., Conclusions: This research shows that therapists can accurately judge asymptomatic subjects' spinal stiffness using a matching task. We believe that this method may allow therapists to quantify lumbar PA stiffness in clinical practice.

Background: To date, there is little information available regarding the forces used during mobilization treatment of patients with low back pain (LBP)., Objective: This study measured such forces and investigated whether the force characteristics could be predicted on the basis of physical therapist and patient characteristics., Subjects: Ten physical therapists applied a central posteroanterior (PA) mobilization treatment to 80 patients with LBP, providing data on treatment of 123 lumbar levels., Methods: Physical therapists were required to treat their patients while the patients lay on an instrumented couch. This couch has been shown to be highly accurate in its measurement of force in 3 directions (error <2%) and has demonstrated high test-retest reliability (ICC [2, 1], 99% CI = 0.99-1.00). The forces applied by the physical therapists were recorded over a 10-second period. Data on the characteristics of the physical therapists and patients were collected by means of questionnaires., Results: The force used by physical therapists related not only to patient characteristics but also to physical therapist characteristics. Interestingly, current pain intensity and nature of symptoms did not affect the forces used. The overall patterns of the force characteristics were generally consistent with previous studies performed in asymptomatic subjects. However, the magnitude of the force applied and the frequency of each grade used in the present study are relatively higher than in earlier studies., Conclusion: These preliminary data provide some useful quantitative information about the forces used during mobilization treatment of patients with LBP. Also, the force characteristics described here may provide useful data for both teaching and research in manual therapy.

Movement diagrams are used by physiotherapists to depict the behaviour of resistance through the available range of accessory and physiological joint movement. It is generally accepted that for an asymptomatic joint, the resistance first felt by the therapist (R1) occurs towards the end of range. R1 is considered to be at the transition point between the toe and linear region of a load displacement curve. The aim of this study was to more accurately define R1 from force displacement curves of accessory movement to the spine and peripheral joints using a validated instrument, the Spinal Assessment Machine (SAM). Thirty archived force displacement curves obtained using the SAM, which applied a posteroanterior force of 100N at a frequency of 0.5 Hz to L3 spinous process, were examined. In addition force displacement curves were similarly obtained from the tibiofemoral joint, glenohumeral joint and radiocarpal joint of one asymptomatic individual. In all cases resistance to a PA movement commenced at the beginning of range, the curve ascending as soon as the force was applied. While in most cases there was a low stiffness 'toe' region there was no unambiguous point where it could be said that the toe region ended. It is concluded that for spinal and peripheral accessory movements both the onset of resistance and the toe occurs at the beginning of range. Therapists should therefore depict R1 at the beginning of range not toward the end of range as is current practice., (Copyright 2002 Elsevier Science Ltd.)

Variability in lumbar PA stiffness has been found to relate to many factors. Sagittal pelvic rotation has been suggested as one determinant of lumbar PA stiffness. Previous studies have shown that decreased pelvic rotation is associated with increased lumbar PA stiffness. However, it is not known whether variations in pelvic rotation cause changes in PA stiffness. This study aimed to investigate the role of pelvic rotation in determining lumbar PA stiffness, and to investigate whether this role varies with vertebral level of the applied load. A mechanical device was used to apply PA forces to the skin overlying the spinous processes of L2-L5 with the pelvis constrained and unconstrained in 37 subjects without low back pain. Significantly higher PA stiffness (P<0.05) was found when the pelvis was constrained. The degree of increase in PA stiffness depended upon the vertebral level being loaded, with loads at L5 producing the greatest increase in stiffness (24%) and loads at L2 producing a non-significant increase (6%). The findings indicate that sagittal pelvic rotation plays a significant part in the lumbar PA stiffness at L5 but has a lesser influence at more cephalad vertebral levels., (Copyright 2001 Harcourt Publishers Ltd.)

Although several mechanical devices have been developed to objectively assess posteroanterior (PA) stiffness of the lumbar spine, no standardized testing protocol has been adopted. Two factors that may vary across protocols, and that effect measured stiffness and the comfort of the test subject, are the size of the indenter head used to apply the PA pressure, and indenting frequency. Three variables; PA stiffness, defined as the slope of the stiffness curve (K), the displacement of the indenter at 30N (D30), and rating of perceived comfort, were measured in 36 subjects asymptomatic for low back pain. For each subject nine tests were conducted, using three different indenter head sizes (300mm(2), 720mm(2)and 1564mm(2)) at each of three different testing frequencies (0.25 Hz, 0.5 Hz and 2 Hz). Machine testing with a large indenter head produced a lower K value, an increased D30 value and higher perceived comfort, while a fast testing frequency produced a higher K value and a lower D30 value. An indenter size by frequency interaction showed small indenter heads to be least comfortable at slow speed. The differences found suggest that the indenter head size and the testing frequency should be standardized during mechanical spinal stiffness testing., (Copyright 2000 Harcourt Publishers Ltd.)

Objective: One explanation for the poor reliability of manual judgments of posteroanterior (PA) stiffness may be that if manual therapists use different forces when testing, different stiffness is perceived. This study was conducted to examine measurements of lumbar PA stiffness obtained using a device programmed to generate different loading forces., Subjects: Twenty-five subjects with no history of low back pain and a mean age of 23.5 yr were measured., Methods: Measures of lumbar PA stiffness were obtained using a mechanical device that applied a testing force of 200 N to the skin overlying the L3 spinous process. Six stiffness coefficients were determined from the force/displacement curve obtained from each subject by performing linear regressions from 30-80 N, 30-150 N, 30-200 N, and from 30-83.3 N, 83.3-136.7 N, and 136.7-200 N. Intraclass correlation coefficients and repeated measures analysis of variance were used to analyze the data., Results: Although moderate reliability [ICC 2,1 = 0.67] was found for stiffness measures arising from increasingly wide force-interval regressions (30-80 N, 30-150 N, 300-200 N), poor reliability [ICC (2,1) = 0.39] was found for stiffness measures arising from same-width, higher force regressions (30-83.3 N, 83-137 N, 137-200 N). In both cases there were significant differences between the obtained K stiffness values corresponding to different force intervals., Conclusion: These results show that if therapists push harder, different stiffnesses will be felt. Studies using instrumental measurement of spinal stiffness to obtain 'K' values should report the force intervals used. Also, revised protocols for manually judging PA stiffness should ensure that stiffness is assessed by sampling specified force intervals rather than the raters determining their own force limits.

Objective: Characterization of the responses to spinal posteroanterior loading has involved measuring the gradient of the linear region of the force-displacement relationship between 30 N and 100 N of applied force. However, forces applied during manual assessment of stiffness may reach 300 N. This study investigated whether the force-displacement relation remains linear above 100 N., Design: A single-case-study design with replication was used., Subjects: Two male subjects, with no history of low back pain requiring treatment over the preceding twelve months, participated in this study., Methods: Posteroanterior loads of 275 N were applied to the 1.3 vertebra of both subjects using a mechanical device. The force-displacement responses in these subjects were measured and analyzed to examine the linearity of the data., Results: The responses from the two subjects were similar. In both cases, the responses were approximately linear at all levels of load up to 275 N. Because of the small degree of nonlinearity, there was a tendency for the stiffness to show moderate increases as the load increased. Stiffness was approximately 25% greater when calculated between 30 N and 275 N than when calculated between 30 N and 100 N., Conclusion: In these two subjects, the force-displacement relation was approximately linear for all three force intervals considered, although there was some increasing stiffness with increasing force.

Objective: To investigate the relationship between low back pain (LBP) and lumbar posteroanterior (PA) stiffness., Design: A repeated-measures design was used to measure lumbar posteroanterior stiffness on two occasions in subjects with and without LBP., Subjects: Twenty-five subjects with acute or subacute LBP and twenty-five pain-free subjects participated. Pain subjects reported pain on the application of a manual PA force to the lumbar spine and had no contraindication to PA stiffness testing. Pain-free subjects reported no history of LBP requiring treatment, and obtained a score of 0 on the McGill Pain Questionnaire., Methods: PA stiffness was measured in subjects with LBP when (a) they first presented with pain and (b) when pain had resolved by more than 80%. Pain-free subjects, matched with pain subjects on gender, age, vertebral level to be tested and time between tests, were also measured on two occasions, to control for the effects of repeated stiffness testing and the passing of time., Results: In subjects with low back pain stiffness decreased by 1.21 N/mm between test 1 and test 2. A paired t test found a significant difference between the tests (t = 3.04, df = 24, p = .006). In subjects without pain, there was an increase in stiffness of 0.74 N/mm between test 1 and test 2; a paired t test found no significant difference between the tests (t = -1.673, df = 24, p = .107)., Conclusions: Subjects with LBP showed increased PA stiffness compared with when they had little or no pain, whereas pain-free subjects showed unchanged PA stiffness over time.

Background and Purpose: This study determined the test-retest reliability of measurements of responses to posteroanterior (PA) forces made using a recently developed instrument., Subject: Twenty-two subjects with nonspecific low back pain participated., Methods: The length of the low- stiffness or "toe" region and the slope of the linear portion of the force-displacement curve were measured on two occasions. Reliability of repeated measurements was evaluated by intraclass correlation coefficients and percentage-of-agreement scores. The presence of a systematic change in the response to PA forces was evaluated by a paired-samples t test., Results: High reliability coefficients were obtained for both indices of the response to PA forces. The t test revealed no systematic change with repeated testing., Conclusion and Discussion: The new device provides highly reliable measurement of the lumbar PA force-displacement relationship and may prove useful in evaluating theories that have suggested a relationship between spinal symptoms and abnormal PA stiffness.