Evaluation of outcome measures for neurogenic claudication: A patient-centered approach

Does type 2 diabetes affect the efficacy of therapeutic exercises for degenerative lumbar spinal stenosis?

DESIGN

Propensity-matched retrospective study.

OBJECTIVES

To determine whether type 2 diabetes mellitus (T2D) would affect prognosis in patients with degenerative lumbar spinal stenosis (DLSS) who underwent therapeutic exercises.

METHODS

This study included consecutive patients with or without T2D who underwent therapeutic exercises for symptomatic DLSS from December 2018 to January 2020. Baseline demographics and clinical and radiological data were collected. The 2 groups of patients were further matched in a 1:1 fashion based on the propensity score, balancing the groups on pre-treatment factors including age, sex, leg and back pain, and low back disability. The primary outcomes included self-reported leg pain intensity (Numerical Rating Scale, NRS) and low back disability (Oswestry Disability Index, ODI) and the secondary outcomes included low back pain intensity and walking capacity (self-paced walking test, SPWT) were compared at baseline, 6 weeks, and 12 weeks.

RESULTS

Forty-one pairs of patients were selected by propensity matching. After 6-week therapeutic exercises, patients with T2D achieved a lower improvement in leg pain at 6 weeks (NRS leg change, 1.21 ± 0.40 vs. 1.78 ± 0.52, P = 0.021) and 12 weeks (NRS leg change, 1.52 ± 0.92 vs. 2.18 ± 0.96, P = 0.007) above minimal clinically important difference (MCID), with a significant Group × Time interactions (F_1,80 = 16.32, p < 0.001, ηp2 = 0.053). However, the two groups showed no difference in the improvement of ODI, although the sample had significant improvements at 6 weeks (ODI change 3.02 [95% CI, 2.08 to 2.77], P < 0.001) and 12 weeks ([ODI change 3.82 [95% CI, 4.03 to 4.90], P < 0.001), 46% of the patients achieved an MCID.

CONCLUSION

Six-week therapeutic exercises have an inferior effect on DLSS patients with T2D. Findings from this study will provide an increased understanding of exercise treatment in patients with DLSS.

Lumbar spinal stenosis - surgical outcome and the odds of revision-surgery: Is it all due to the surgeon?

BACKGROUND

Surgical decompression is the intervention of choice for lumbar spinal stenosis (LSS) when non-operative treatment has failed. Apart from acute complications such as hematoma and infections, same-level recurrent lumbar stenosis and adjacent-segment disease (ASD) are factors that can occur after index lumbar spine surgery.

OBJECTIVE

The aim of this retrospective case series was to evaluate the outcome of surgery and the odds of necessary revisions.

METHODS

Patients who had undergone either decompressive lumbar laminotomy or laminotomy and spinal fusion due to lumbar spinal stenosis (LSS) between 2000 and 2011 were included in this analysis. Demographic, perioperative and radiographic data were collected. Clinical outcome was evaluated using numeric rating scale (NRS), the symptom subscale of the adapted version of the german Spinal Stenosis Measure (SSM) and patient-sreported ability to walk.

RESULTS

Within the LSS- cohort of 438 patients, 338 patients underwent decompression surgery only, while instrumentation in addition to decompression was performed in 100 cases (22.3%). 38 patients had prior spinal operations (decompression, disc herniation, fusion) either at our hospital or elsewhere. Thirty-five intraoperative complications were documented with dural tear with CSF leak being the most common (33/35; 94.3%). Postoperative complications were defined as complications that needed surgery and differentiated between immediate postoperative complications (⩽ 3 weeks post operation) and complications that needed revisions surgery at a later date. Within all patients 51 revisions were classified as immediate complications of the index operation with infections, neurological deficits and hematoma being the most common. Within this group only 22 patients had fusion surgery in the first place, while 29 were treated by decompression. Revision surgery was indicated by 53 patients at a later date. While 4 patients decided against surgery, 49 revision surgeries were planned. 28 were performed at the same level, 10 at the same level plus an adjacent level, and 10 were executed at index level with indications of adjacent level spinal stenosis, adjacent level spinal stenosis plus instability and stand-alone instability. Pre- operative VAS score and ability to walk improved significantly in all patients.

CONCLUSIONS

While looking for predictors of revision surgery due to re-stenosis, instability or same/adjacent segment disease none of these were found. Within our cohort no significant differences concerning demographic, peri-operative and radiographic data of patients with or without revision wer noted. Patients, who needed revision surgery were older but slightly healthier while more likely to be male and smoking. Surprisingly, significant differences were noted regarding the distribution of intraoperative and early postoperative complications among the 6 main surgeons while these weren't obious within the intial index group of late revisions.

[Neurogenic intermittent claudication in patients with degenerative lumbar stenosis]

OBJECTIVE

To study the clinical manifestations of neurogenic intermittent claudication (NIC) in patients with degenerative lumbar stenosis (DLS).

MATERIAL AND METHODS

The neurological status, intensity and nature of pain syndrome, and pain-free walking distance were evaluated in 83 NIC patients with DPS, who underwent surgical treatment.

RESULTS

The predominance of the clinical picture of sensorimotor pain (n=30; 36.1%) and isolated pain (n=31; 37.3%) forms of NIC was established. Isolated sensory (n=1; 1.2%), sensorimotor (n=3; 3.6%), and motor-pain (n=4; 4.8%) forms were significantly less common. In 6 (7.2%) patients, there was a pain-free form of NIC. In most patients, surgical treatment led to regression of neurological symptoms and an increase in the distance of pain-free walking. No relationship was found between the demographic and clinical characteristics of patients (gender, age, pain severity, pain-free walking distance), MRI results and the features of NIC clinical picture. In 4 patients, the phenomenon of pacing was revealed in the form of an increase in pain at the beginning of walking and a significant decrease or complete regression as walking continues.

CONCLUSION

The clinical picture of NIC is polymorphic, its pain-free course is possible. The decision on the feasibility of surgical treatment of patients with PLS is possible taking into account the clinical picture of NIC and MRI results.

Differences in Functional Treadmill Tests in Patients With Adult Symptomatic Lumbar Scoliosis Treated Operatively and Nonoperatively

STUDY DESIGN

Prospective longitudinal cohort.

OBJECTIVES

The aim of this study was to determine whether functional treadmill testing (FTT) demonstrates differences between patients treated operatively and nonoperatively for adult symptomatic lumbar scoliosis (ASLS).

SUMMARY OF BACKGROUND DATA

ASLS has become increasingly prevalent as the population ages. ASLS can be accompanied by neurogenic claudication, leading to difficulty walking. FTT may provide a functional tool to evaluate patients with ASLS.

METHODS

One hundred and eighty-seven patients who underwent nonoperative (n = 88) or operative treatment (n = 99) of ASLS with complete baseline and 2-year post-treatment FTTs and concurrent patient-reported outcomes were identified. FTT parameters included maximum speed, time to onset of symptoms, distance ambulated, time ambulated, and Back and Leg pain severity before and after testing.

RESULTS

At baseline, patients treated operatively reported worse post-FTT back pain (4.39 vs. 3.45, P = 0.032) than those treated nonoperatively, despite similar ODI, SRS-22 Pain and Activity domain scores. Mean time ambulated (+2.15 vs. -1.20 P = 0.001), pre-FTT back pain (+0.19 vs. -1.60, P < 0.000) and leg pain (+0.25 vs. -0.54, P = 0.024) improved in the operative group but deteriorated in the nonoperative group. On the 2-year follow-up FTT, both groups showed improvement in post-FTT back pain (-0.53 vs. -2.64, P < 0.000) and leg pain (-0.13 vs. -1.54, P = 0.001) severity but the improvement was statistically significantly greater in the operative compared to the nonoperative group.

CONCLUSION

FTT results at baseline were worse in patients treated operatively than those treated non-operatively. FTT may be a useful adjunct to assess treatment outcomes in patients with ASLS and may help surgeons counsel patients regarding expectations 2 years after operative or nonoperative treatment for ASLS. At 2-year follow-up, time ambulated deteriorated in patients treated nonoperatively but improved in patients treated operatively. Although both groups showed improvement in post-FTT Back and Leg pain at 2 years, the improvement was greater in the operative compared to the nonoperative group.

LEVEL OF EVIDENCE

2.

Understanding the mechanisms of a combined physical and psychological intervention for people with neurogenic claudication: protocol for a causal mediation analysis of the BOOST trial

INTRODUCTION

Conservative treatments such as exercise are recommended for the management of people with neurogenic claudication from spinal stenosis. However, the effectiveness and mechanisms of effect are unknown. This protocol outlines an a priori plan for a secondary analysis of a multicentre randomised controlled trial of a physiotherapist-delivered, combined physical and psychological intervention (Better Outcomes for Older people with Spinal Trouble (BOOST) programme).

METHODS AND ANALYSES

We will use causal mediation analysis to estimate the mechanistic effects of the BOOST programme on the primary outcome of disability (measured by the Oswestry Disability Index). The primary mechanism of interest is walking capacity, and secondary mediators include fear-avoidance behaviour, walking self-efficacy, physical function, physical activity and/or symptom severity. All mediators will be measured at 6 months and the outcome will be measured at 12 months from randomisation. Patient characteristics and possible confounders of the mediator-outcome effect will be measured at baseline. Sensitivity analyses will be conducted to evaluate the robustness of the estimated effects to varying levels of residual confounding.

ETHICS AND DISSEMINATION

Ethical approval was given on 3 March 2016 (National Research Ethics Committee number: 16/LO/0349). The results of this analysis will be disseminated in peer-reviewed journals and at relevant scientific conferences.

TRIAL REGISTRATION NUMBER

ISRCTN12698674.

Emerging Spine Care Trends and Innovations

The spine is an anchoring structure that is the base for mechanical motion of the body and a protector of neuroelements. Spinal disorders continue to plague generations with issues. Management options continue to evolve, allowing for operative and nonoperative pathways to treat underlying causes. Positive patient outcomes and long-term relief are achieved through evidence-based practice and innovative trends. The future of spine care will continue to push boundaries, allowing patients to return to activity at a much faster rate, with decreased restrictions and lower rates of future complications.

Feasibility of conducting an active exercise prehabilitation program in patients awaiting spinal stenosis surgery: a randomized pilot study

Prehabilitation is defined as the process of augmenting functional capacity before surgery in preparation for the postoperative phase. This study intends to assess the feasibility of conducting a preoperative intervention program in patients with lumbar spinal stenosis and to report on the piloting of the proposed intervention. Patients were allocated to a 6-week supervised preoperative rehabilitation program or a control group. The intervention included supervised exercise sessions aimed to improve strength, muscular endurance, and spinal stabilization. Outcomes were measured at baseline, 6 weeks later and again 6 weeks, 3 months and 6 months after surgery. Sixty-five percent of admissible participants agreed to take part in the study, of which 5% dropped out before the end of the intervention period. Eighty-eight percent of potential training sessions were delivered without adverse event. Improvements were seen in favour of the experimental group at the preoperative assessment for active ranges of motion, leg pain intensity, lumbar extensor muscle endurance and walking capacities. Results show that slight modifications to the choice of outcome measures would increase feasibility of the main study. The absence of adverse events coupled with positive changes seen in dependant outcome measures warrant the conduct of a full-scale trial assessing the effectiveness of the intervention.

Measurement properties of walking outcome measures for neurogenic claudication: a systematic review and meta analysis

BACKGROUND CONTEXT

Selecting a walking outcome measure for neurogenic claudication requires knowledge of its measurement properties.

PURPOSE

To systematically review and appraise the literature on the measurement properties of walking outcome measures for patients with neurogenic claudication.

STUDY DESIGN

A systematic review and meta-analysis.

METHODS

A systematic search was conducted on the following seven databases: PubMed, PsychINFO, Web of Science, Embase, CINAHL, MEDLINE, and Cochrane Central Register of Controlled Trials. Clinical studies that assessed a measurement property of a walking outcome measure for patients with neurogenic claudication were selected. The methodological quality of studies was assessed using the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist. Measurement property results were assessed using the adapted criteria from Terwee et al. (2007).

RESULTS

Twelve studies that evaluated 15 separate walking outcome measures were included. Out of the 12 studies included, half had poor methodological quality. Four measures had acceptable test-retest reliability: the self-paced walking test (intraclass correlation coefficient, or ICC was 0.98, 95% CI: 0.95-0.99), Physical Function Scale (PFS) (pooled analysis ICC = 0.79, 95% CI: 0.77-0.89), PFS walk item (ICC = 0.81, 95% CI: 0.68-0.89), and Oswestry Disability Index (ODI) walk item (ICC = 0.86, 95% CI: 0.76-0.92). Responsiveness was assessed on five walking outcome measures, and three had adequate responsiveness: the ODI walk item (Area under the Curve, or AUC, was 0.76, SD 0.15), Treadmill test (AUC = 0.70), and PFS (AUC = 0.77, SD 0.14). A meta-analysis demonstrated the PFS had adequate test retest reliability (pooled ICC = 0.79, 95% CI: 0.77-0.89) and internal consistency (pooled Cronbach's αlpha (α) = 0.84, 95% CI: 0.81-0.86), but not criterion validity (pooled correlation coefficient = -0.59, 95% CI: -0.71, -0.45). Measures that recorded adequate criterion validity were the ODI walk item (pooled correlation coefficient = -0.71, 95% CI: -0.80, -0.58), Treadmill test (pooled correlation coefficient = 0.86, 95% CI: 0.78-0.91), and self predicted walking item (pooled correlation coefficient = 0.74, 95% CI: 0.63-0.82).

CONCLUSIONS

The results of our systematic review demonstrated that high-quality studies that asses the measurement properties of walking outcome measures for patients with neurogenic claudication are lacking. There was only limited evidence available for each walking measure, which prevented any single outcome from being confirmed as the gold standard measure of neurogenic claudication. Clinicians and researchers are recommended to use the self-paced walking test and ODI walk item until further evidence is available. Future research should focus on producing high-quality studies with excellent methodology and larger sample sizes.

SUMMIT-07: a randomized trial of NKTR-181, a new molecular entity, full mu-opioid receptor agonist for chronic low-back pain

NKTR-181, a new molecular entity, mu-opioid receptor agonist with an inherently slow rate of central nervous system (CNS) entry, was designed to provide analgesia while reducing abuse potential. This phase 3, enriched-enrollment, randomized-withdrawal trial evaluated the analgesic efficacy, safety, and tolerability of NKTR-181 in patients with chronic low-back pain (CLBP). Adults with moderate-to-severe CLBP refractory to nonopioid analgesics achieving an analgesic NKTR-181 dosage (100-400 mg twice daily) during the open-label titration period were randomized to continued NKTR-181 treatment, double-blind, or switched to placebo. The study was conducted at 55 sites in the United States. Of 1189 patients exposed to NKTR-181 during the titration period, 610 were randomized to NKTR-181 100 to 400 mg every 12 hours or placebo for 12 weeks. The primary outcome measure was change in weekly pain score (scale, 0-10) at 12 weeks from randomization baseline. Secondary outcome measures included responder rates defined by ≥30% and ≥50% improvement in pain score from screening to 12 weeks. Among 610 randomized patients, the mean pain score decreased from 6.73 to 2.32 during open-label titration. After randomization, the least-squares mean change in pain score was +0.92 for NKTR-181 vs +1.46 for placebo (P = 0.002). The ≥30%-improvement responder rate of NKTR-181 vs placebo was 71.2% vs 57.1% (P < 0.001), and the ≥50%-improvement responder rate was 51.1% vs 37.9% (P = 0.001). NKTR-181 was well tolerated with a low incidence (<3%) of CNS-related adverse events during the randomized treatment phase. In patients with moderate-to-severe CLBP, NKTR-181 demonstrated significant analgesic efficacy and a favorable safety/tolerability profile, with a low incidence of CNS adverse events.

Why are there no drugs indicated for sciatica, the most common chronic neuropathic syndrome of all?

This review examines the stark contrast between the successes and failures of the clinical development of analgesics for different types of chronic low back pain (CLBP) syndrome over the past three decades. Multiple drugs with differing mechanisms of action have been developed for nonspecific axial-predominant low back syndromes and yet not a single therapy is indicated for any neuropathic low back pain syndrome (e.g., sciatica). Clinician findings have informed the entry criteria for neuropathic low back pain clinical trials, whereas entry criteria of axial CLBP trials have prioritized only patient reports of pain. This key difference could account for the lack of success in developing therapies for neuropathic low back pain in an era marked by successful development of analgesics for other types of CLBP as well as many chronic pain syndromes associated with nerve injury, such as post-herpetic neuralgia (PHN).

Validation of the baseline severity stratification of objective functional impairment in lumbar degenerative disc disease

OBJECTIVE

The Timed Up and Go (TUG) test is a simple, objective, and standardized method to measure objective functional impairment (OFI) in patients with lumbar degenerative disc disease (DDD). The objective of the current work was to validate the OFI baseline severity stratification (BSS; with levels of “none,” “mild,” “moderate,” and “severe”).

METHODS

Data were collected in a prospective IRB-approved 2-center study. Patients were assessed with a comprehensive panel of scales for measuring pain (visual analog scale [VAS] for back and leg pain), functional impairment (Roland-Morris Disability Index [RMDI] and Oswestry Disability Index [ODI]), and health-related quality of life (HRQOL; EQ-5D and SF-12). OFI BSS was determined using age- and sex-adjusted cutoff values.

RESULTS

A total of 375 consecutive patients scheduled for lumbar spine surgery were included. Each 1-step increase on the OFI BSS corresponded to an increase of 0.53 in the back pain VAS score, 0.69 in the leg pain VAS score, 1.81 points in the RMDI, and 5.93 points in the ODI, as well as to a decrease in HRQOL of −0.073 in the EQ-5D, −1.99 in the SF-12 physical component summary (PCS), and −1.62 in the SF-12 mental component summary (MCS; all p < 0.001). Patients with mild, moderate, and severe OFI had increased leg pain by 0.90 (p = 0.044), 1.54 (p < 0.001), and 1.94 (p < 0.001); increased ODI by 7.99 (p = 0.004), 12.64 (p < 0.001), and 17.13 (p < 0.001); and decreased SF-12 PCS by −2.57 (p = 0.049), −3.63 (p = 0.003), and −6.23 (p < 0.001), respectively.

CONCLUSIONS

The OFI BSS is a valid measure of functional impairment for use in daily clinical practice. The presence of OFI indicates the presence of significant functional impairment on subjective outcome measures.