FAcet-joint Injection Clinical and Cost-effective Trial
Condition: Low Back Pain
MeSH terms: Back Pain; Low Back Pain
Study type: Interventional
Phase: Phase 4

Summary: 
      Lumbar facet-joints are small, paired joints in the low back that provide stability,
      integrity and flexibility of movement to the spine. Diseased facet-joints may cause
      persistent low back pain, with significant socioeconomic impact. At present, there is
      insufficient high quality evidence to support the use of lumbar facet-joint injections (FJIs)
      in treating low back pain of less than 12 months' duration; the National Institute for Health
      and Care Excellence (NICE) therefore did not approved their use in their 2009 publication.

      This study will investigate the feasibility of conducting a larger, definitive trial to
      assess lumbar FJIs (a needle is inserted into the facet-joint and steroid injected), by
      comparing it to a dummy or 'sham' procedure (a needle is inserted near the facet-joint but no
      therapeutic substance injected).

      Patients with persistent low back pain, referred to a community or hospital-based pain,
      spinal or musculoskeletal clinic by their general practitioner, will be reviewed and assessed
      by a specialist physician. They will be screened and recruited based on clinical history and
      examination. Participants will receive diagnostic injections (medial branch nerve blocks);
      those with a positive response will randomly receive either FJIs or a sham procedure, under
      x-ray guidance. All participants will receive a combined physical and psychological programme
      recommended by NICE as a strategy to reduce pain and its impact on the person's day-to-day
      life, even if the pain cannot be cured completely.

      Participants will be asked to complete questionnaires comparing a range of pain and
      disability-related issues. These will occur at baseline (before treatment) and at 6 weeks, 3
      months and 6 months after their injections.

      Criteria for the study to be considered successful (and a definitive trial feasible) include
      the abilities to standardise the methods for injection and to recruit and retain sufficient
      participants, and the acceptability of the study design to participants and clinicians.
    

Detailed description: 
      Design

      This study seeks to examine the feasibility of undertaking a fully powered double-blind
      randomised controlled trial. Patients with non-specific low back pain of more than three
      months' duration with confirmed facet-joint disease will be individually randomised 1:1 to
      receive facet-joint injections plus a combined physical and psychological programme
      (intervention group) or to a sham (placebo) procedure plus a combined physical and
      psychological programme (control group).

      Setting

      The feasibility study will be conducted in three hospital-based pain medicine centres: Barts
      Health NHS Trust (formerly Barts and The London NHS Trust), Basildon and Thurrock University
      Hospitals NHS Foundation Trust, and The Walton Centre NHS Foundation Trust.

      Target population

      Patients will be recruited from pain, spinal and musculoskeletal clinics at the three
      participating NHS centres and their associated community clinics. Patients will be referred
      by their general practitioners with low back pain requiring further specialist assessment,
      for reasons such as uncertain diagnosis, failure of conservative treatment, or expectation of
      therapeutic interventions. A screening visit will be used to identify eligible patients i.e.
      pain of at least 3 months' duration and an average pain intensity numerical rating score
      (NRS) of at least 4/10 in the 7 preceding days, signs and symptoms of facet-joint disease
      including bilateral localised paraspinal tenderness at 2 lumbar levels, and have received two
      components of NICE-defined best non-invasive care (education and one of: physical exercise
      programme, acupuncture, or manual therapy).

      Health technologies being assessed

      Facet-joint injections of local anaesthetic and steroid for non-specific low back pain.
      (Delivered in this study as four X-ray guided intra-articular facet-joint injections through
      a spinal needle at two lumbar levels bilaterally, using 0.5ml 0.5% bupivacaine + 20mg
      methylprednisolone per joint, under fluoroscopic guidance.)

      Measurement of costs and outcomes

      The primary outcomes for this feasibility study include: patient recruitment and attrition
      rates, levels of patient completion of outcomes, acceptability of the study design to
      patients and clinicians, fidelity of sham injection and process of blinding, and collection
      of variance outcome data to inform a future sample size calculation.

      The investigators have proposed stopping rules for progression to a main trial. The proposed
      outcomes for the main trial have been selected in accord with IMMPACT recommendations for
      chronic pain trials and include: pain assessment, psychological well-being, health-related
      quality of life, functional disability, health care utilisation including analgesic usage,
      lost productivity and complications/level of adverse events. Outcomes will be collected at
      clinic visits at baseline (pre-randomisation) and at 6 weeks, 3 months, and 6 months
      post-randomisation.

      Sample size

      The investigators will recruit a total of 150 patients who will undergo a diagnostic
      facet-joint injection to determine eligibility to participate (test positive for facet-joint
      disease). Sixty participants (40% of all recruited) are expected to have a positive response
      to the diagnostic test; these 60 patients will be randomly and equally allocated to
      intervention and control groups. Assuming up to a 33% attrition rate, the investigators will
      have >24 complete data sets per arm at the end of the study. This sample size will allow us
      to achieve our various feasibility objectives.

      Project timetables including recruitment rate

      A retrospective audit of patient throughput in participating clinics shows that recruitment
      to achieve 30 patients per treatment arm is readily feasible in the time frame of this study.
      From 1000 new patient attendances for low back pain at the pain services, the investigators
      expect approximately 1 in 4 patients to be eligible to enter the study. This is based on our
      clinical experience and published studies based on responses to controlled diagnostic
      facet-joint injections, performed in accordance with the criteria established by the
      International Association for the Study of Pain. Of these 250 patients, approximately 60%
      (150) will consent to enter the study, of whom approximately 40% (60 patients) are expected
      to have a positive response from diagnostic medial branch nerve blocks.

      The investigators anticipate that the project will take a total of 21 months to complete.
    

Intervention name(s): Active Procedure; Sham procedure
Intervention type(s): Procedure; Procedure
Intervention description(s): If they pass the diagnostic injection with a 50% or more in pain reduction, they are randomised to receive either the active procedure or sham procedure.
Active: 4 X-ray guided intra-articular lumbar facet-joint injections via a spinal needle at 2 bilateral lumbar levels using 0.5ml bupivacaine + 20mg methylprednisolone per joint; If they pass the diagnostic injection with a 50% or more in pain reduction, they are randomised to receive either the active procedure or sham procedure.
Sham: 4 X-ray guided peri-articular injections via a spinal needle at 2 bilateral lumbar levels using 0.5ml of 0.9% sodium chloride per joint.
Other intervention name(s): Active group; 0.5% bupivacaine + 20mg methylprednisolone; Depo-medrone + Bupivacaine; Sham group; 0.9% sodium chloride; normal saline; placebo
Intervention MeSH terms: Methylprednisolone; Methylprednisolone Acetate; Bupivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Patients with persistent low back pain, referred to a community or hospital-based pain clinic by their general practitioner, will be reviewed and assessed by a pain physiotherapist and pain physician. They will be screened and recruited based on clinical history and examination. Participants will receive diagnostic injections (medial branch nerve blocks); those with a positive response will randomly receive either steroid FJIs or a sham procedure, under x-ray guidance.
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Other
Keywords: low back pain; lumbar facet joint pain; feasibility; lumbar facet joint injection