Effect of Pulsed Signal Therapy in Patella Chondromalacia
Condition: Patella Chondromalacia
MeSH terms: Cartilage Diseases; Chondromalacia Patellae
Study type: Interventional

Summary: 
      PST (pulsed signal therapy) is a unique form of pulsed electromagnetic field therapy (PEMF)
      for stimulating healing of damaged structures such as cartilage, bones and soft tissues. The
      physical effect of the pulsed electromagnetic field (PEMF) has been focus of research in
      various studies, with cartilage being the most studied, and which has demonstrated an
      increase in the synthesis of proteoglican and collagen in vitro. This is an randomized,
      controlled and double blind clinical trial. The main objective is to evaluate clinical
      improvement regarding anterior knee pain after PST intervention in patients with patellar
      condropathy.
    

Detailed description: 
      The study was approved by the Research Ethics Committee of the Clinical Hospital (Hospital
      das Clinicas), University of São Paulo (Universidade de São Paulo - USP) under number
      0253/11.

      This patient population is estimated to a total of 40 knees, with the patients meeting the
      following inclusion criteria:

        -  aged between 20 and 50 years;

        -  male or female;

        -  patellofemoral pain syndrome without tibiofemoral and trochlear chondral degeneration
           according to magnetic resonance imaging (MRI);

        -  presence of patellar chondropathy confirmed by MRI;

        -  not having started using direct action drugs on the cartilage in the last 6 months;

        -  absence of prior surgery on the studied knee;

        -  absence of invasive procedures, such as knee infiltration, in the previous 12 months;

        -  absence of disease in the contralateral limb that would cause an excessive burden on the
           studied limb; and

        -  absence of contraindications to performing PST, including a pacemaker, cancer,
           infectious disease activity, severe heart failure, arrhythmias, angina, epilepsy and
           pregnancy.

      The presence of patellofemoral pain is identified by anamnesis and physical examination
      performed by knee surgeons with more than 10 years' experience. The presence of all of the
      following criteria is required for diagnosis: typical complaint of anterior knee pain with a
      duration longer than 3 months (when going up or down stairs, squatting, remaining for long
      periods with bent knees), pain on palpation of the patellar articular surface and pain on
      patellar compression (reproducing the patient's complaint).

      After inclusion in the study, all of the patients will be instructed (for the duration of the
      study) not to use drugs with a direct action on the cartilage (e.g., chondroprotectors, such
      as glucosamine and chondroitin) to avoid confounding biases regarding the effects of the
      treatments. No patients will be included who had started using these drugs in the previous 6
      months to avoid the initial effect of this treatment being a confounder in terms of clinical
      improvement.

      The study is designed so that the patient and the orthopedist evaluating the clinical outcome
      do not know to which group the patient belongs (i.e., a double-blind study).

      After patient inclusion and signing of the terms of free and informed consent, the patients
      will be randomized by a computer into 2 equal groups, i.e., the control and PST groups. The
      patients with both knees included in the study will receive randomization for the right knee,
      and the left will be automatically allocated into the other group. This method was selected
      to best demonstrate any differences between groups. The final distribution of patients into
      groups will be therefore not equalized.

      PST application will be then directed to the patellofemoral joint. The PST application
      protocol is as follows: 9 daily 1-hour applications, with 5 in the first week, a break for
      the weekend, and 4 more the following week.

      The control group patients will be submitted to placebo PST treatment with the same protocol
      and the device connected not generating magnetic pulses. The device operates silently, and it
      is not possible for the patient to determine whether they are receiving the placebo or
      treatment, thus maintaining patient blinding. For patients with both knees included, 9
      sessions of the treatment are performed on one side and 9 more sessions of the placebo on the
      other.

      All of the participants are instructed to maintain their usual level of physical activity.

      The Kujala score will be taken after 3, 6 and 12 months in both groups. If superiority of the
      PST group is observed, it was decided for ethical reasons that the placebo group should
      receive the PST treatment and would again be followed up for 1-year post-treatment, with the
      Kujala score ascertained at 3, 6 and 12 months.

      A sample of approximately 20 patients in each group was used for an alpha of 5% and beta of
      20%. An effect size of 8 to 10 between groups was sought and is considered clinically
      significant in terms of Kujala score.
    

Intervention name(s): PST - Pulsed Signal Therapy; Placebo - Sham PST
Intervention type(s): Device; Device
Intervention description(s): PST application is a painless over-the-skin eletromagnetic field application. 9 sessions of application of electromagnetic therapy - PST - during 60 minutes; Placebo PST will be performed by applying the same device over the patient knee. The machine is not applying the PST but it appears to be on. In this way, patients are blinded to the intervation.
9 sessions of application of Sham PST - during 60 minutes
Other intervention name(s): PST; PEMF; Pulsed Eletromagnetic Field; Placebo
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: knee; chondromalacia; patella; pulsed signal therapy; PST