Christian Hellum

Surgery with disc prosthesis versus rehabilitation in patients with low back pain and degenerative disc: two year follow-up of randomised study

Objective To compare the efficacy of surgery with disc prosthesis versus non-surgical treatment for patients with chronic low back pain. Design A prospective randomised multicentre study. Setting Five university hospitals in Norway. Participants 173 patients with a history of low back pain for at least one year, Oswestry disability index of at least 30 points, and degenerative changes in one or two lower lumbar spine levels (86 patients randomised to surgery). Patients were treated from April 2004 to September 2007. Interventions Surgery with disc prosthesis or outpatient multidisciplinary rehabilitation for 12-15 days. Main outcome measures The primary outcome measure was the score on the Oswestry disability index after two years. Secondary outcome measures were low back pain, satisfaction with life (SF-36 and EuroQol EQ-5D), Hopkins symptom check list (HSCL-25), fear avoidance beliefs (FABQ), self efficacy beliefs for pain, work status, and patients’ satisfaction and drug use. A blinded independent observer evaluated scores on the back performance scale and Prolo scale at two year follow-up. Results The study was powered to detect a difference of 10 points on the Oswestry disability index between the groups at two years. At two years there was a mean difference of −8.4 points (95% confidence interval −13.2 to −3.6) in favour of surgery. In the analysis of prespecified secondary outcomes, there were significant differences in favour of surgery for low back pain (mean difference −12.2, −21.3 to −3.1), patients’ satisfaction (63% (n=46) v 39% (n=26)), SF-36 physical component score (mean difference 5.8, 2.5 to 9.1), self efficacy for pain (mean difference 1.0, 0.2 to 1.9), and the Prolo scale (mean difference 0.9, 0.1 to 1.6). There were no significant differences in return to work, SF-36 mental component score, EQ-5D, fear avoidance beliefs, Hopkins symptom check list, drug use, and the back performance scale. One serious complication of leg amputation occurred during surgical revision of a polyethylene dislodgement. The drop-out rate was 20% (34) and the crossover rate was 6% (5). Conclusions Surgical intervention with disc prosthesis for chronic low back pain resulted in a significantly greater improvement in the Oswestry score compared with rehabilitation, but this improvement did not clearly exceed the prespecified minimally important clinical difference between groups of 10 points, and the data are consistent with a wide range of differences between the groups, including values well below 10 points. The potential risks of surgery and the substantial amount of improvement experienced by a sizeable proportion of the rehabilitation group also have to be incorporated into overall decision making. Trial registration NCT 00394732.

Comparison of the SF6D, the EQ5D, and the oswestry disability index in patients with chronic low back pain and degenerative disc disease

BackgroundThe need for cost effectiveness analyses in randomized controlled trials that compare treatment options is increasing. The selection of the optimal utility measure is important, and a central question is whether the two most commonly used indexes - the EuroQuol 5D (EQ5D) and the Short Form 6D (SF6D) – can be used interchangeably. The aim of the present study was to compare change scores of the EQ5D and SF6D utility indexes in terms of some important measurement properties. The psychometric properties of the two utility indexes were compared to a disease-specific instrument, the Oswestry Disability Index (ODI), in the setting of a randomized controlled trial for degenerative disc disease.MethodsIn a randomized controlled multicentre trial, 172 patients who had experienced low back pain for an average of 6 years were randomized to either treatment with an intensive back rehabilitation program or surgery to insert disc prostheses. Patients filled out the ODI, EQ5D, and SF-36 at baseline and two-year follow up. The utility indexes was compared with respect to measurement error, structural validity, criterion validity, responsiveness, and interpretability according to the COSMIN taxonomy.ResultsAt follow up, 113 patients had change score values for all three instruments. The SF6D had better similarity with the disease-specific instrument (ODI) regarding sensitivity, specificity, and responsiveness. Measurement error was lower for the SF6D (0.056) compared to the EQ5D (0.155). The minimal important change score value was 0.031 for SF6D and 0.173 for EQ5D. The minimal detectable change score value at a 95% confidence level were 0.157 for SF6D and 0.429 for EQ5D, and the difference in mean change score values (SD) between them was 0.23 (0.29) and so exceeded the clinical significant change score value for both instruments. Analysis of psychometric properties indicated that the indexes are unidimensional when considered separately, but that they do not exactly measure the same underlying construct.ConclusionsThis study indicates that the difference in important measurement properties between EQ5D and SF6D is too large to consider them interchangeable. Since the similarity with the “gold standard” (the disease-specific instrument) was quite different, this could indicate that the choice of index should be determined by the diagnosis.

Effect of Glucosamine on Pain-Related Disability in Patients With Chronic Low Back Pain and Degenerative Lumbar Osteoarthritis: A Randomized Controlled Trial

CONTEXT Chronic low back pain (LBP) with degenerative lumbar osteoarthritis (OA) is widespread in the adult population. Although glucosamine is increasingly used by patients with chronic LBP, little is known about its effect in this setting. OBJECTIVE To investigate the effect of glucosamine in patients with chronic LBP and degenerative lumbar OA. DESIGN, SETTING, AND PARTICIPANTS A double-blind, randomized, placebo-controlled trial conducted at Oslo University Hospital Outpatient Clinic, Oslo, Norway, with 250 patients older than 25 years of age with chronic LBP (>6 months) and degenerative lumbar OA. INTERVENTIONS Daily intake of 1500 mg of oral glucosamine (n = 125) or placebo (n = 125) for 6 months, with assessment of effect after the 6-month intervention period and at 1 year (6 months postintervention). MAIN OUTCOME MEASURES The primary outcome was pain-related disability measured with the Roland Morris Disability Questionnaire (RMDQ). Secondary outcomes were numerical scores from pain-rating scales of patients at rest and during activity, and the quality-of-life EuroQol-5 Dimensions (EQ-5D) instrument. Data collection occurred during the intervention period at baseline, 6 weeks, 3 and 6 months, and again 6 months following the intervention at 1 year. Group differences were analyzed using linear mixed models analysis. RESULTS At baseline, mean RMDQ scores were 9.2 (95% confidence interval [CI], 8.4-10.0) for glucosamine and 9.7 (95% CI, 8.9-10.5) for the placebo group (P = .37). At 6 months, the mean RMDQ score was the same for the glucosamine and placebo groups (5.0; 95% CI, 4.2-5.8). At 1 year, the mean RMDQ scores were 4.8 (95% CI, 3.9-5.6) for glucosamine and 5.5 (95% CI, 4.7-6.4) for the placebo group. No statistically significant difference in change between groups was found when assessed after the 6-month intervention period and at 1 year: RMDQ (P = .72), LBP at rest (P = .91), LBP during activity (P = .97), and quality-of-life EQ-5D (P = .20). Mild adverse events were reported in 40 patients in the glucosamine group and 46 in the placebo group (P = .48). CONCLUSIONS Among patients with chronic LBP and degenerative lumbar OA, 6-month treatment with oral glucosamine compared with placebo did not result in reduced pain-related disability after the 6-month intervention and after 1-year follow-up. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00404079.

Prognostic Factors of Prolonged Disability in Patients With Chronic Low Back Pain and Lumbar Degeneration in Primary Care: A Cohort Study

Study Design. A cohort study with 1-year follow-up. Objective. To identify prognostic factors in patients with chronic nonspecific low back pain (LBP). Summary of Background Data. The factors (e.g., sociodemographical, low back–related, radiological, and biological) associated with persistent pain and disability for patients with chronic nonspecific LBP are uncertain. Furthermore, sparse information exists about the relationship between biological factors like impaired fasting glucose tolerance and chronic nonspecific LBP. Methods. The participants consisted of 250 patients with nonspecific LBP of more than 6 months duration and degenerative lumbar osteoarthritis. The patients were originally recruited for a randomized controlled trial from the clinics of general practitioners, physiotherapists, and chiropractors. Potential predictors were evaluated at baseline. The outcome was absolute level of pain-related disability (Roland-Morris Disability Questionnaire [RMDQ]) at 1 year. The association between potential prognostic factors and the outcome was analyzed with multivariate linear backward regression. Results. At baseline and 1 year, the RMDQ scores were 9.5 and 5.1 points, respectively. Mean (SD) baseline values for body mass index (BMI), EuroQol (EQ)-index, EQ–visual analogue scale were 25.4 (4.3), 0.60 (0.3), and 61.2 (20.8), respectively. Higher pain-related disability levels (1-year RMDQ score) were associated with 6.1 mmol/L or more fasting glucose level at baseline (&bgr;, 3.7; 95% confidence interval [CI], 1.2–6.1; P = 0.00), baseline pain-related disability (&bgr; 0.2; 95% CI, 0.1–0.4; P = 0.00), BMI (&bgr;, 0.2; 95% CI, 0.1–0.3; P < 0.03), EQ-index (&bgr;, −4.5; 95% CI, 6.9 to 2.1; P = 0.00), and EQ–visual analogue scale (&bgr;, 0.3; 95% CI, −0.6 to −0.0; P = 0.03). However, a limited number of patients had 6.1 mmol/L or more of fasting glucose level at baseline (13/250 patients). The imaging findings, modic changes, and high intensity zones had no predictive ability. Conclusion. Increased pain-related disability at 1 year was seen in patients with impaired fasting glucose tolerance, greater pain-related disability, higher BMI, and lower quality of life at baseline.

Segmental mobility, disc height and patient-reported outcomes after surgery for degenerative disc disease: A prospective randomised trial comparing disc replacement and multidisciplinary rehabilitation

This prospective multicentre study was undertaken to determine segmental movement, disc height and sagittal alignment after total disc replacement (TDR) in the lumbosacral spine and to assess the correlation of biomechanical properties to clinical outcomes.A total of 173 patients with degenerative disc disease and low back pain for more than one year were randomised to receive either TDR or multidisciplinary rehabilitation (MDR). Segmental movement in the sagittal plane and disc height were measured using distortion compensated roentgen analysis (DCRA) comparing radiographs in active flexion and extension. Correlation analysis between the range of movement or disc height and patient-reported outcomes was performed in both groups. After two years, no significant change in movement in the sagittal plane was found in segments with TDR or between the two treatment groups. It remained the same or increased slightly in untreated segments in the TDR group and in this group there was a significant increase in disc height in the operated segments. There was no correlation between segmental movement or disc height and patient-reported outcomes in either group.In this study, insertion of an intervertebral disc prosthesis TDR did not increase movement in the sagittal plane and segmental movement did not correlate with patient-reported outcomes. This suggests that in the lumbar spine the movement preserving properties of TDR are not major determinants of clinical outcomes.

Cost-effectiveness of total disc replacement versus multidisciplinary rehabilitation in patients with chronic low back pain: a Norwegian multicenter RCT.

Study Design. Randomized clinical trial with 2-year follow-up. Objective. To evaluate the cost-effectiveness of total disc replacement (TDR) versus multidisciplinary rehabilitation (MDR) in patients with chronic low back pain (CLBP). Summary of Background Data. The existing studies on CLBP report cost-effectiveness of fusion surgery versus disc replacement and fusion versus rehabilitation. This study evaluated the cost-effectiveness of TDR versus MDR. Methods. Between April 2004 and May 2007, 173 patients with CLBP (>1 yr) were randomized to TDR (n = 86) or MDR (n = 87). Treatment effects (Euro Qol 5D [EQ-5D] and Short Form 6D [SF-6D]) and relevant direct and indirect costs at 6 weeks and at 3, 6, 12, and 24 months after treatment were assessed. Gain in quality-adjusted life years (QALYs) after 2 years was estimated. Cost-effectiveness was expressed as an incremental cost-effectiveness ratio. Results. The mean QALYs gained (standard deviation) using EQ-5D was 1.29 (0.53) in the TDR group and 0.95 (0.52) in the MDR group, a significant difference of 0.34 (95% confidence interval 0.18–0.50). The mean total cost per patient in the TDR group was &OV0556;87,622 (58,351) compared with &OV0556;74,116 (58,237) in the MDR group, which was not significantly different (95% confidence interval: −4041 to 31,755). The incremental cost-effectiveness ratio for the TDR procedure varied from &OV0556;39,748 using EQ-5D (TDR cost-effective) to &OV0556;128,328 using SF-6D (TDR not cost-effective). The dropout rate was 20% (15% TDR group, 24% MDR group). Five patients moved from the MDR to the TDR group, whereas 9 patients randomized to TDR declined surgery. Using per-protocol analysis instead of intention-to-treat analysis indicated that TDR was not cost-effective, irrespective of the use of EQ-5D or SF-6D. Conclusion. In this study, TDR was cost-effective compared with MDR after 2 years when using EQ-5D for assessing QALYs gained and a willingness to pay of &OV0556;74,600 (kr500,000/QALY). TDR was not cost-effective when SF-6D was used; therefore, our results should be interpreted with caution. Longer follow-up is needed to accurately assess the cost-effectiveness of TDR. Level of Evidence: 2

Adjacent level degeneration and facet arthropathy after disc prosthesis surgery or rehabilitation in patients with chronic low back pain and degenerative disc: second report of a randomized study.

Study Design. Randomized clinical trial with 2-year follow-up. Objective. To assess the development of adjacent level degeneration (ALD) and index level facet arthropathy (FA) in patients treated with disc prosthesis compared with patients treated with rehabilitation. Summary of Background Data. There is controversy about the natural history of disc degeneration and the development of ALD and FA in patients who undergo disc prosthesis surgery. Methods. The study included 116 patients with a history of low back pain for at least 1 year, Oswestry Disability Index 30 points or more, and degenerative changes in 1 or 2 lower lumbar spine levels. Magnetic resonance imaging was performed before treatment and at the 2-year follow-up. ALD and index level FA were determined on the basis of the majority assessment of 3, independent, experienced radiologists. ALD was assessed by evaluating Modic changes, posterior high intensity zone in the disc, nucleus pulposus signal, disc height, disc contour, and FA. Data were analyzed with Fischer exact test and t test. Results. ALD developed with similar frequencies in patients who were (n = 59) and were not (n = 57) treated with surgery. In patients treated with surgery, index level FA appeared or increased in 20 patients (34%) and decreased in 1 patient. In patients treated with rehabilitation, 2 (4%) had new or increased FA at the index/degenerated disc level and 1 had decreased FA (P < 0.001). The development of ALD and FA was not related to clinical outcome. Conclusion. In this first study that compared the courses of degeneration after treatment with disc prosthesis surgery or rehabilitation, ALD was observed at similar frequencies at the 2-year follow-up. However, the surgery group had increased FA at the implant level.

Reliability of change in lumbar MRI findings over time in patients with and without disc prosthesis--comparing two different image evaluation methods.

ObjectivesTo assess the reliability of change in lumbar magnetic resonance imaging (MRI) findings evaluated retrospectively by direct comparison of images and by non-comparison.Materials and methodsPre-treatment and 2-year follow-up MRI was performed in 126 patients randomized to disc prosthesis surgery or non-surgical treatment. Two experienced radiologists independently evaluated progress and regress for Modic changes, disc findings, and facet arthropathy (FA) at L3/L4, L4/L5, and L5/S1, both by non-comparison and by comparison of initial and follow-up images. FA was evaluated at all levels, and other findings at non-operated levels. We calculated prevalence- and bias-adjusted kappa (PABAK) values for interobserver agreement. The impact of an adjacent prosthesis (which causes artefacts) and image evaluation method on PABAK was assessed using generalized estimating equations.ResultsImage comparison indicated good interobserver agreement on progress and regress (PABAK 0.63−1.00) for Modic changes, posterior high-intensity zone, disc height, and disc contour at L3-S1 and for nucleus pulposus signal and FA at L3/L4; and moderate interobserver agreement (PABAK 0.46−0.59) on decreasing nucleus signal and increasing FA at L4-S1. Image comparison indicated lower (but fair) interobserver agreement (PABAK 0.29) only for increasing FA at L5/S1 in patients with prosthesis in L4/L5 and/or L5/S1. An adjacent prosthesis had no overall impact on PABAK values (p ≥ 0.22). Comparison yielded higher PABAK values than non-comparison (p < 0.001).ConclusionsRegarding changes in lumbar MRI findings over time, comparison of images can provide moderate or good interobserver agreement, and better agreement than non-comparison. An adjacent prosthesis may not reduce agreement on change for most findings.

Total disc replacement versus multidisciplinary rehabilitation in patients with chronic low back pain and degenerative discs: 8-year follow-up of a randomized controlled multicenter trial

BACKGROUND CONTEXT Lumbar total disc replacement (TDR) is a treatment option for selected patients with chronic low back pain (LBP) that is non-responsive to conservative treatment. The long-term results of disc replacement compared with multidisciplinary rehabilitation (MDR) have not been reported previously. PURPOSE We aimed to assess the long-term relative efficacy of lumbar TDR compared with MDR. DESIGN We undertook a multicenter randomized controlled trial at five university hospitals in Norway. PATIENT SAMPLE The sample consisted of 173 patients aged 25-55 years with chronic LBP and localized degenerative changes in the lumbar intervertebral discs. OUTCOME MEASURES The primary outcome was self-reported physical function (Oswestry Disability Index [ODI]) at 8-year follow-up in the intention-to-treat population. Secondary outcomes included self-reported LBP (visual analogue scale [VAS]), quality of life (EuroQol [EQ-5D]), emotional distress (Hopkins Symptom Checklist [HSCL-25]), occupational status, patient satisfaction, drug use, complications, and additional back surgery. METHODS Patients were randomly assigned to lumbar TDR or MDR. Self-reported outcome measures were collected 8 years after treatment. The study was powered to detect a difference of 10 ODI points between the groups. The study has not been funded by the industry. RESULTS A total of 605 patients were screened for eligibility, of whom 173 were randomly assigned treatment. Seventy-seven patients (90%) randomized to surgery and 74 patients (85%) randomized to rehabilitation responded at 8-year follow-up. Mean improvement in the ODI was 20.0 points (95% confidence interval [CI] 16.4-23.6, p≤.0001) in the surgery group and 14.4 points (95% CI 10.7-18.1, p≤.0001) in the rehabilitation group. Mean difference between the groups at 8-year follow-up was 6.1 points (95% CI 1.2-11.0, p=.02). Mean difference in favor of surgery on secondary outcomes were 9.9 points on VAS (95% CI 0.6-19.2, p=.04) and 0.16 points on HSCL-25 (95% CI 0.01-0.32, p=.04). There were 18 patients (24%) in the surgery group and 4 patients (6%) in the rehabilitation group who reported full recovery (p=.002). There were no significant differences between the groups in EQ-5D, occupational status, satisfaction with care, or drug use. In the per protocol analysis, the mean difference between groups was 8.1 ODI points (95% CI 2.3-13.9, p=.01) in favor of surgery. Forty-three of 61 patients (70%) in the surgery group and 26 of 52 patients (50%) in the rehabilitation group had a clinically important improvement (15 ODI points or more) from baseline (p=.03). The proportion of patients with a clinically important deterioration (six ODI points or more) was not significantly different between the groups. Twenty-one patients (24%) randomized to rehabilitation had crossed over and had undergone back surgery since inclusion, whereas 12 patients (14%) randomized to surgery had undergone additional back surgery. One serious adverse event after disc replacement is registered (<1%). CONCLUSIONS Substantial long-term improvement can be expected after both disc replacement and MDR. The difference between groups is statistically significant in favor of surgery, but smaller than the prespecified clinically important difference of 10 ODI points that the study was designed to detect. Future research should aim to improve selection criteria for disc replacement and MDR.

Risk factors for surgical site infections among 1,772 patients operated on for lumbar disc herniation: a multicentre observational registry-based study

BackgroundThere are no previous studies evaluating risk factors for surgical site infections (SSIs) and the effectiveness of prophylactic antibiotic treatment (PAT), specifically for patients operated on for lumbar disc herniation.MethodThis observational multicentre study comprises a cohort of 1,772 consecutive patients operated on for lumbar disc herniation without laminectomy or fusion at 23 different surgical units in Norway. The patients were interviewed about SSIs according to a standardised questionnaire at 3 months’ follow-up.ResultsThree months after surgery, 2.3% of the patients had an SSI. Only no PAT (OR = 5.3, 95% CI = 2.2–12.7, p< 0.001) and longer duration of surgery than the mean time (68 min) (OR = 2.8, 95% CI = 1.2–6.6, p = 0.02) were identified as independent risk factors for SSI. Numbers needed to have PAT to avoid one SSI was 43.ConclusionsIn summary, this study clearly lends support to the use of PAT in surgery for lumbar disc herniation. Senior surgeons assisting inexperienced colleagues to avoid prolonged duration of surgery could also reduce the occurrence of SSI.