The Effect of Elastic Bandage Compression on Pain and Function in Individuals With Knee Osteoarthritis
Condition: Knee Osteoarthritis
MeSH terms: Osteoarthritis; Osteoarthritis, Knee
Study type: Interventional

Summary: 
      Introduction and Purpose: Compression is a tactile stimulus that can reduce the perception of
      pain by stimulating tactile skin receptors and the speed of nerve conduction. It is highly
      associated with cryotherapy and other non-pharmacological physical agents without
      musculoskeletal pain control. However, there is still a lack of evidence on its possible
      effects on the modulation of this type of pain. This study will evaluate the effect of
      compression by elastic bandages, on pain and on the function of belonging with knee
      osteoarthritis (KO). Methodology: A randomized, blinded controlled clinical trial will be
      conducted. Individuals with KO (n = 90; both sexes; between 40 and 75 years old), will be
      allocated into three groups (n = 30 / group): Compression (submitted to compression by
      elastic bandage on the affected knee, 20 min, in 4 days consecutive); Sham (submitted to the
      same protocol with elastic bandage, but without compression); and Control (waiting list,
      without intervention). All will be taken one day before the start and one day after the last
      intervention. They will also be adopted in the 12th and 24th weeks after the intervention.
      The main outcome will be the pain intensity (Visual Analogue Scale). The Western Ontario &
      McMaster Universities Osteoarthritis (WOMAC) physical function questionnaire, physical
      function tests (step test, sit and stand test in 30s, 40m accelerated walk test), and the
      perception scale global change (GRC). Data analysis: SPSS 24.0 software will be used for
      descriptive analysis and performance of Kolmogorov-Smirnov tests, two-way ANOVA and multiple
      comparison tests. A 95% confidence level and a 5% significance level will be adopted.
    

Detailed description: 
      Study design: The study consists of a randomized controlled clinical trial that meets the
      guidelines recommended by CONSORT (Consolidated Standards of Reporting Trials) for
      non-pharmacological studies TIDieR (Template for Intervention Description and Replication)
      and OARSI recommendations for clinical trials with patients with knee osteoarthritis . The
      procedures will always be carried out at the same times for each volunteer, during the
      intervention and evaluation days, so that the same time interval between interventions and
      evaluations is respected.

      The evaluations will be carried out by a "blind" evaluator with no information about the
      identification of the group to which the volunteer belongs. The evaluator will also be
      trained to maintain balance in discussions and questions raised by individuals regarding the
      research project and the interventions or evaluations used.

      The screening, evaluation and intervention will be carried out at the School Health Unit -
      USE, Federal University of São Carlos (UFSCar), São Carlos. It is a non-probabilistic
      sampling study, for convenience and intentional. Volunteers will be recruited from public
      announcements and waiting lists from local and regional physiotherapy, rehabilitation,
      orthopedics and rheumatology outpatient clinics, as well as from an existing list of
      volunteers diagnosed with knee osteoarthritis, available in our laboratory.

      Participants: 90 individuals will participate in the study, of both sexes, aged between 40
      and 75 years, diagnosed with KO according to the clinical and radiographic criteria of the
      American College of Rheumatology. The individuals will perform a radiographic examination of
      both knees, with lateral, anteroposterior, and axial views. Radiographic exams will be
      performed at the University Hospital, UFSCar. The screening of volunteers will be carried out
      by a physiotherapist specialized in the subject and experienced in the evaluation of
      individuals with knee osteoarthritis.

      Ethical aspects: The project was initially submitted to the Ethics and Research Committee
      involving human beings (Plataforma Brasil), approved under Opinion Number: 3.955.692, and
      submitted to the registration of clinical trials (www.clinicaltrials.gov). Then, the study
      activities will be carried out. Volunteers will receive a verbal and written explanation of
      the objectives and methodology of the study, and those who agree to participate will sign an
      informed consent form.

      Randomization: The individuals included in the study will be stratified by sex and randomly
      divided using the digital tool (www.randomization.com). Three groups will be randomized, with
      30 individuals each: a) Compression: compression will be applied around the entire knee with
      KO through tensioned elastic bandages; b) Sham will also receive the application of elastic
      bandages around the knee with KO, but without compression; c) Control: patients on the
      waiting list, who will not receive intervention. To avoid selection bias, the confidential
      allocation method will be adopted using an opaque, non-translucent and sealed envelope. In
      addition, the group to which the individual belongs will only be revealed immediately before
      the intervention.

      Sample size: The sample size was calculated preliminarily using the G * Power software
      (version 3.1.3; University of Trier, Germany). Two calculations were performed, the first
      considering pain (assessed by VAS) and the second, function (assessed by the WOMAC
      questionnaire). The calculation was based on the application of an F-test for the difference
      between three independent means (three groups). The effect size considered for this
      calculation, based on a previous study, was d = 0.45 for VAS, and d = 0.39 for WOMAC, which
      after conversion represent respectively f = 0.225 and f = 0.195). The effect sizes of f are
      between small and moderate, and match the rating range for the displayed d values. The level
      of significance was 5% and the power 95%. The calculations indicated a total of 54
      individuals by the VAS and 72 individuals by the WOMAC questionnaire. The calculation to be
      considered will be related to the WOMAC questionnaire, with 24 individuals per group, making
      a total of 72 individuals. Considering a possible dropout rate of 20%, 29 participants must
      be allocated to each group, but to facilitate calculations and randomization, 30 participants
      will be allocated per group, totalling 90 individuals included in the study. A more reliable
      calculation will be performed after a preliminary analysis of the data collected from a pilot
      study.

      Intervention: The elastic bandages used will be (Selecta® 13cm x160 cm, composed of 45%
      cotton, 20% elastodiene and 27% polyamide) involving the entire knee surface, positioned
      considering anatomical aspects: covering the femoral condyles and the anterior tuberosity of
      the tibia. The bandage will involve the knee from the distal (tibial tuberosity) to the
      proximal (femoral condyles), respecting the blood flow of the venous return. The level of
      compression was defined according to recommendations in the literature on compression
      interventions in lymphedema and venous changes, and should be kept between 30 mmHg and 60
      mmHg. The occurrence of any sign of venous stasis (flushing and / or edema) may also indicate
      the need for a reduction in the level of compression or interruption of the procedure.

      To standardize the level of compression presented, a previous reliability study (n = 10) was
      performed, with the aid of a pressure gauge (Stabilizer® - Chattanooga Group), positioned on
      the knee, between the patient's skin and the elastic bandage . The manometer was inflated to
      40mmHg, a value indicated by the manufacturer as the resting pressure of the pneumatic bag47,
      and we then began to wrap the knee with the bandage. The number of turns that the tensioned
      elastic bandage allowed to wrap the knee was collected to reach the indicated compression
      range (30 mmHg ≤ x ≥ 60 mmHg), and if necessary, more than one band could be used. It was
      also evaluated what level of compression the Sham group would receive with the non-tensioned
      bandage. In both groups, the circumference of the knees was collected at three points
      (popliteal fossa, 10 cm above and 10 cm below) and the number of turns that were taken with
      the bandage.

      This first step was performed in the test-retest format, with an interval of seven days, so
      that it was possible to calculate the intra-rater reliability level, which indicated a Kappa
      Coefficient48 of 0.625, considered a substantive agreement. From the reliability study, it
      was possible to calculate the average number of turns that should be performed both in the
      Compression group and in the Sham group so that the level of compression is maintained in the
      stipulated range. In the Compression group, all patients used a bandage, with an average of
      5.7 turns (ranging from 5 to 7 turns) and the pressure level maintained at 48 mmHg (ranging
      from 46 to 52 mmHg). In the Sham group, everyone also used a bandage, with an average of 4
      turns (ranging from 3 to 5 turns) and the pressure level maintained at 00 mmHg.

      After the completion of the evaluations, the individuals of the three groups will receive
      face-to-face training, consisting of therapeutic exercises recommended for the treatment of
      knee osteoarthritis (KO), as well as a booklet with the proposed exercises, prepared by our
      research group, so that they can also perform the exercises without supervision. After
      completing the evaluations, participants in the Sham and Control groups will be able to
      receive the same treatment available to the Compression group, if they so request. In
      addition, they will remain on our list of volunteers for further studies in KO. The
      applications of the interventions will be performed by a physiotherapist previously trained
      on these procedures performed on the knee joint. The therapist will also be trained to
      maintain balance in explaining the study's general outlook, in discussions and questions
      raised by individuals about the research project and about the interventions or assessments
      used.

      Data analysis: The registration of the data collected in the evaluations will be carried out
      through digital forms (Google Forms) and automatically stored in an electronic database in
      the Cloud (Google Drive), protected by password, to guarantee the security of the data and
      the participants. After completion of the collections, the data will be analysed by a "blind"
      biostatistician, with no information on the identification of the groups, using the SPSS 24.0
      software (SPSS Inc, Chicago, IL).

      The independent variables of interest in the study are group (Compression, Sham and Control)
      and time [pre- (assessment 1) and post-intervention (assessments 2, 3 and 4)]. The dependent
      variables are VAS (pain intensity), WOMAC (total score), Step test (seconds), Sit and stand
      test in 30 seconds (number of repetitions), and 40 m accelerated walk test (speed in m / s).
      The data distribution, or normality, will be tested by the Kolmogorov-Smirnov test and,
      according to the result, parametric or non-parametric tests will be used.

      Initially, descriptive analyses will be performed, using measures of central tendency and
      dispersion: mean and standard deviation when following a normal distribution, and the median,
      minimum and maximum, when non-normal distribution. For normal data, the two-way ANOVA with
      mixed design will be the parametric test chosen to compare the means of the dependent
      variables, considering both factors simultaneously, one from repeated measurements (pre- and
      post-intervention, and follow up of 12 and 24 weeks) and another of independent samples
      (Compression, Sham and Control). If significant differences are found, tests of multiple
      comparisons (Post-Hoc) will be performed to assess the differences. For distribution of
      non-normal data, the possible reasons for non-normality, analysis of possible correction and
      then non-parametric tests can be applied, using both repeated (time) and non-repeated
      (groups) comparisons with Bonferroni adjustments or similar.

      For all variables, a 95% confidence level will be determined and a significance level of 5%
      will be considered statistically significant. Added to this, the difference between the
      groups will be compared to the MDCI values defined for each variable. When the MDCI values
      are not available, Cohen's d coefficient will be calculated (effect size:> 0.8 large, close
      to 0.5 moderate and ≤ 0.2 small). Finally, to preserve the benefit of randomization, allowing
      for a balanced distribution of prognostic factors in the compared groups and, consequently,
      the observed effect, an intention-to-treat analysis will be adopted using the
      expectation-maximization imputation method.
    

Intervention name(s): Elastic bandage compression
Intervention type(s): Other
Intervention description(s): The compression will be applied with the volunteer in the supine position on a stretcher, with both lower limbs extended and relaxed. The intervention in the Compression group will be with elastic bandages involving the entire surface of the knee, positioned considering anatomical aspects: femoral condyles and the anterior tibial tuberosity. The level of compression must be maintained between 30 mmHg and 60 mmHg, according to the researched literature. The variations within these values will be stipulated according to the volunteer's self-report (comfortable and painless compression). The Shan Group will have the bandage wrapped around the knee without any compression force being exerted. The intervention will be carried out for 20 minutes, once a day, for 4 consecutive days. The Control group will be composed of volunteers who make up a study waiting list and will carry out the evaluations at the same time intervals as the other groups, but will not receive any type of intervention.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Randomized controlled clinical trial following guidelines from CONSORT (Consolidated Standards of Reporting Trials), TIDieR (Template for Intervention Description and Replication) and OARSI recommendations for clinical trials with patients with knee osteoarthritis.
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Physiotherapy; Rehabilitation; Compression; Analgesia