Facet-joint injections for people with persistent non-specific low back pain (FIS): study protocol for a randomised controlled feasibility trial

Predictors of Pain Recurrence After Lumbar Facet Joint Injections

Introduction

Facet joint injections (FJIs) of anesthetic and corticosteroids are useful for the diagnosis and treatment of low back pain (LBP). In the current study, we evaluated the efficacy of FJI on LBP treatment and the predictive variables of pain recurrence after FJI.

Methods

We included and followed prospectively forty-three consecutive patients with chronic LBP treated with FJI. Clinical assessments were carried out at a baseline 1 week before FJIs and after a 6-month follow-up visit using the visual analog scale (VAS) for pain, Oswestry Disability Index (ODI) for disability-specific measure and MacNab criteria for global effectiveness, and compared through analysis using paired-samples “t” tests. Multiple cox-regression analysis was used to identify the presurgical variables independently associated with pain recurrence anytime during the follow-up. In addition to the demographic, clinical, and surgical data, we also analyzed psychometric scales: Pain Catastrophizing Scale (PCS), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI).

Results

After a 6-month follow-up, thirty-two patients (74.4%) showed a clinically significant reduction of pain and twenty-seven (62.8%) reported a clinically significant improvement of disability. Presurgical catastrophizing (PCS score ≥ 5, adjusted HR 4.4, CI 95% 1.7–11.3, p = 0.002) and smoking (Adjusted HR 12.5, CI 95% 1.1–138.9, p = 0.04) remains associated with pain recurrence.

Conclusion

FJI reduces LBP and disability of patients with unresponsive LBP. Pain-related cognitive and behavioral factors determined by pain catastrophizing and smoking were independently associated with pain recurrence after lumbar FJI. The results support the need of a multidisciplinary approach for presurgical evaluation of patients with chronic pain.

Clinical diagnosis scale for pain lumbar of facet origin: systematic review of literature and pilot study

INTRODUCTION

Lumbar pain affects between 60-90% of people. It is a frequent cause of disability in adults. Pain may be generated by different anatomical structures such as the facet joint. However, nowadays pain produced by the facet joint has no clinical diagnosis. Therefore, the purpose of this article is to propose a clinical diagnostic scale for lumbar facet syndrome.

MATERIALS AND METHODS

The study was conducted by means of 6 phases as follows, Phase 1, a systematic review of the literature was performed regarding the clinical diagnosis of facet-based lumbar pain based on the PRISMA checklist; Phase 2, a list of signs and symptoms proposed for diagnosis lumbar pain of facet origin was made. Phase 3, the list of signs and symptoms found was submitted to a committee of experts to discriminate the most significant signs and symptoms, these were linked to general sociodemographic variables to develop an evaluation questionnaire; Phase 4, the evaluation questionnaire was applied, including those selected signs and symptoms to a group of patients with clinical diagnosis of facet disease lumbar pain and who underwent a selective facet block. Phase 5, under standard technique selective facet block and subsequent postoperative clinical control at 1 month. Phase 6, given pre and postsurgical results associated with signs present in the patients we propose a clinical scale of diagnosis scale. Descriptive statistics and Stata 12.0 were used as statistical software.

RESULTS

A total of 36 signs and symptoms were found for the diagnosis of lumbar facet syndrome that were submitted to the group of experts, where a total of 12 (8 symptoms and 4 signs) were included for the final survey. 31 patients underwent selective lumbar facet blockade, mostly women, with an average of 60±11.5 years, analogous visual scale of preoperative pain of 8/10, postoperative of 1.7/10, the signs and symptoms most frequently found included in a diagnostic scale were: 3 symptoms 1) axial or bilateral axial lumbar pain, 2) improvement with rest, 3) absence of root pattern, may have pseudoradicular pattern, however, the pain is greater lumbar than pain in the leg and 3 clinical signs 1) Kemp sign, 2) pain induced in joint or transverse process, 3) facet stress sign or Acevedo sign.

CONCLUSION

The clinical diagnosis of lumbar facet pain is still debated. Few diagnostic scales have been postulated, with little or no external validity, so the present study proposes a diagnostic scale consisting of 3 symptoms and 3 clinical signs.

Facet joint injections for people with persistent non-specific low back pain (Facet Injection Study): a feasibility study for a randomised controlled trial

BACKGROUND

The National Institute for Health and Care Excellence (NICE) 2009 guidelines for persistent low back pain (LBP) do not recommend the injection of therapeutic substances into the back as a treatment for LBP because of the absence of evidence for their effectiveness. This feasibility study aimed to provide a stable platform that could be used to evaluate a randomised controlled trial (RCT) on the clinical effectiveness and cost-effectiveness of intra-articular facet joint injections (FJIs) when added to normal care.

OBJECTIVES

To explore the feasibility of running a RCT to test the hypothesis that, for people with suspected facet joint back pain, adding the option of intra-articular FJIs (local anaesthetic and corticosteroids) to best usual non-invasive care is clinically effective and cost-effective.

DESIGN

The trial was a mixed design. The RCT pilot protocol development involved literature reviews and a consensus conference followed by a randomised pilot study with an embedded mixed-methods process evaluation.

SETTING

Five NHS acute trusts in England.

PARTICIPANTS

Participants were patients aged ≥ 18 years with moderately troublesome LBP present (> 6 months), who had failed previous conservative treatment and who had suspected facet joint pain. The study aimed to recruit 150 participants (approximately 30 per site). Participants were randomised sequentially by a remote service to FJIs combined with 'best usual care' (BUC) or BUC alone.

INTERVENTIONS

All participants were to receive six sessions of a bespoke BUC rehabilitation package. Those randomised into the intervention arm were, in addition, given FJIs with local anaesthetic and steroids (at up to six injection sites). Randomisation occurred at the end of the first BUC session.

MAIN OUTCOME MEASURES

Process and clinical outcomes. Clinical outcomes included a measurement of level of pain on a scale from 0 to 10, which was collected daily and then weekly via text messaging (or through a written diary). Questionnaire follow-up was at 3 months.

RESULTS

Fifty-two stakeholders attended the consensus meeting. Agreement informed several statistical questions and three design considerations: diagnosis, the process of FJI and the BUC package and informing the design for the randomised pilot study. Recruitment started on 26 June 2015 and was terminated by the funder (as a result of poor recruitment) on 11 December 2015. In total, 26 participants were randomised. Process data illuminate some of the reasons for recruitment problems but also show that trial processes after enrolment ran smoothly. No between-group analysis was carried out. All pain-related outcomes show the expected improvement between baseline and follow-up. The mean total cost of the overall treatment package (injection £419.22 and BUC £264.00) was estimated at £683.22 per participant. This is similar to a NHS tariff cost for a course of FJIs of £686.84.

LIMITATIONS

Poor recruitment was a limiting factor.

CONCLUSIONS

This feasibility study achieved consensus on the main challenges in a trial of FJIs for people with persistent non-specific low back pain.

FUTURE WORK

Further work is needed to test recruitment from alternative clinical situations.

TRIAL REGISTRATION

EudraCT 2014-000682-50 and Current Controlled Trials ISRCTN93184143.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 30. See the NIHR Journals Library website for further project information.