The Use of NMES With Pelvic Fracture Rehabilitation
Condition: Fractures, Closed
MeSH terms: Fractures, Bone; Hip Fractures; Fractures, Closed
Study type: Interventional

Summary: 
      The purpose of the study is to investigate if using an electrical stimulation machine to see
      if it can help strengthen the muscles around the hip during the first three months post
      pelvic fracture will help with the early stages of rehabilitation. Electrical stimulation is
      a treatment machine that uses an electrical current to cause a single muscle or a group of
      muscles to contract. This contraction helps strengthen injured muscles and helps with the
      healing process. It can also help with pain relief by blocking pain signals from the brain.

      After a pelvic fracture they are surgically fixed and will be advised not to put any weight
      on the operated leg for 10 weeks. During this time hip muscles become very weak as they will
      not be used as much as normal. Bed exercises can help keep muscle strength but this study
      would like to try using electrical stimulation machines alongside bed exercises to see if it
      can improve muscle strength even more. Electrical stimulation machines are already used by
      rehabilitation. Electrical stimulation is a treatment machine that uses an electrical current
      to cause a single muscle or a group of muscles to contract. This contraction helps strengthen
      injured muscles and helps with the healing process. It can also help with pain relief by
      blocking pain signals from the brain.

      After a pelvic fracture they are surgically fixed and will be advised not to put any weight
      on the operated leg for 10 weeks. During this time hip muscles become very weak as they will
      not be used as much as normal. Bed exercises can help keep muscle strength but this study
      would like to try using electrical stimulation machines alongside bed exercises to see if it
      can improve muscle strength even more. Electrical stimulation machines are already used by
      patients to increase muscle strength.

      Participants will be put into one of two groups, both groups will be given an electrical
      stimulation machine but one will be on a placebo setting. Participants will need to use the
      machine twice a day along with their bed exercises and will need to fill in a diary when and
      how many times the machine has been used for 10 weeks until their 12 week appointment with
      the orthopaedic consultant. The participants weight bearing status will change and they will
      be asked to perform a muscle strength test on both the operated and nonoperated leg. They
      will also have their walking quality assessed. The results will compare both groups for
      muscle strength and walking changes.
    

Detailed description: 
      All subjects who wish to enter the study will be fully screened and consented by the Chief
      Investigator, or an appropriate delegate. The Royal London is the largest major trauma centre
      in London and fixes more pelvic fractures than any other hospital. The orthopedic team will
      surgically fix between two and six pelvic fractures per week which should meet the inclusion
      criteria. Pelvic fractures are surgically fixed and then will be instructed to put no weight
      through the operated limb for 10-12 weeks by the orthopedic consultant. The physiotherapist
      will give the patient a bed exercise programme day one post operation as per standard
      practice which consists of hip range of movement exercises and gentle strengthening exercises
      for muscles around the hip and thigh.

      The chief investigator will be part of the patient's normal healthcare team and will identify
      eligible participants. The participants will be recruited one week post operation to give the
      patient time to recover from their surgery but not allow for loss in muscle mass. The
      research assistant will approach the participant 24 hours prior to this and explain the
      demands of the study and what it will involve allowing the participant 24 hours to discuss
      this with family members.

      After the 24 hour period the chief investigator will also be present to answer any questions
      about the study. The participant will be expected to provide written informed consent and
      will be expected to sign the treatment contract which outlines the responsibilities of the
      participant and the chief investigator. On discharge a six week follow up appointment in
      fracture clinic will be arranged in which both the consultant and chief investigator will be
      present to complete the EQ5D questionnaire and monitor compliance within the first six weeks
      of the intervention. At 10 weeks the participant will have a further fracture clinic
      appointment in which they are expected to bring back the machine and make a short journey to
      the human performance laboratory and Queen Mary's University to complete their gait analysis
      and strength testing along with a further EQ5D questionnaire, this will be the end of the
      study and the participants are free to leave.

      Randomisation procedure

      Simple random sampling will be used with a free randomisation computer programme
      (www.sealedenvelopes.co.uk). When the patient has consented to the study the chief
      investigator will enter the participant unique study number into the website whilst the
      participant can read the patient information sheet and treatment contract and it will
      randomly allocate into treatment (NMES) or placebo (TENS) group. If a participant withdrew
      from the study a new participant could not replace this participant but be randomly allocated
      into a group as a new patient.

      Blinding/ Emergency unblinding

      The independent assessor will be blinded to participant allocation when testing at 10 weeks
      for both the gait analysis and peak torque measurements. All participants will be blinded to
      group allocation and will all be given identical machines on different settings. The
      principle investigator will complete the randomisation procedure and will be aware of group
      allocation for monitoring and safety purposes.

      Treatment/intervention plan and rationale

      Patients allocated to the NMES group will be given an information booklet on NMES machines
      and the principle researcher will explain and demonstrate how to use the machines. The Cefar
      Compex three electrical stimulator will be used and demonstrates valid results from previous
      studies (Billot et al 2010., Gondin et al 2005., and Maffiuletti et al., 2002).

      Participants are expected to use the NMES machine for half an hour and complete bed exercises
      twice daily. They will be activating two of their muscles at the same time and will not be
      expected to complete the bed exercises and NMES together. Patients should relax during the
      NMES as completing both does not demonstrate better results, due to unsynchronised activation
      of the NMES (Gregory & Bickel, 2005). Using the machine once daily will allow for the
      recovery of the muscle. A voluntary contraction would normally be 20-30Hz but due to the high
      intensities of the NMES (35-75Hz) it can cause muscle fatigue (Maffiuletti, 2011).

      Participants will use the muscle reinforcement rehabilitation protocol below which increases
      from 4Hz to 85Hz allowing slow and fast twitch muscle fibre recruitment. This protocol is
      used for participants who have had minimal loss of muscle bulk and starts with small currents
      and slowly builds up as the patient becomes accustom to the sensation of the machine.
      Patients are expected to increase the intensity, as higher intensity can increase activation
      of more muscle fibres (Stevens-Lapsley et al, 2012).

      Additional treatment/ interventions

      The placebo group will act as the control group. They will be expected to complete the same
      regime as previously described above, however these machines will be on TENS setting
      (80-100Hz) as even low Hz can trigger motor stimulation (Paillard 2008). This setting is
      designed as a sensory stimulus therefore will have no effects on muscle strength however the
      patient will feel a small twitch sensation. This setting is not painful and will have no
      effect on muscle fatigue. The patient will not be expected to complete the bed exercises and
      the TENS session together.

      Experts within orthopedic rehabilitation concluded a 20% difference between operated and
      non-operated post intervention would be of clinical relevance. A randomized feasibility study
      was completed previously in which the results were used to calculate a power calculation for
      this specific trial. The value of 0.25 represents the standard deviation achieved when
      comparing the NMES and the placebo group in the previous study. The 0.2 is 20% calculated
      into a ratio which is needed to achieve clinical relevance. This power calculation indicates
      25 participants are needed for each group to achieve statistical significance 50 participants
      in total. The orthopedic team will surgically fix between two and six pelvic fractures per
      week which should meet the inclusion criteria. Dropout rates will be small as it is a six
      week intervention. Patients will receive weekly phone calls and text reminders monitoring
      compliance.

      N= (1.96+0.84)2 x 2 x 0.252 0.22 = 25 per group (50 in total)

      0.2/ 0.25 = the standard deviation achieved when comparing treatment to placebo in peak
      torque differences

      0.2 = is the ratio / 20% difference between the treatment and placebo group in abductors

      An independent experimental design using an independent test will be suitable to assess the
      data for this study. Both the placebo and NMES group will have different interventions and
      will therefore not be measured using a pre and post design. Due to the adequate sample size
      it will be appropriate to use a parametric statistical test. A Paired T-test will be used to
      analyse the data from the EQ5D questionnaire as they are taken at six and 12 weeks during the
      intervention with the same participants.

      A Spearman's rank correlation test will be used to compare changes with compliance levels in
      both bed exercises and NMES use in the NMES group and compared to the changes in peak torque
      to assess the relationship between the two variables. The same will be completed between the
      intensity level of the NMES and the changes in peak torque within the NMES group. Variables
      can be seen in table format below:
    

Intervention name(s): Treatment NMES; Placebo NMES
Intervention type(s): Device; Device
Intervention description(s): Muscle stimulation to reproduce an active muscle contraction. CE marked used for intended purpose.; TENS machine to mimic an active muscle contraction. CE marked used for intended purpose.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment