Influence of Placebo on Intratissue Percutaneous Electrolysis in Patellar Tendinopathy

Influence of Placebo on Intratissue Percutaneous Electrolysis (IPE) Treatment in Patients With Patellar Tendinopathy

The main aim of this study is to verify the influence of placebo on the effectiveness of Intratissue Percutaneous Electrolysis (IPE) in patients suffering from with chronic patellar tendinopathy (PT). The secondary aim is to investigate the possible influence of the IPE on pain perception and conditioned pain modulation (CPM) in patients with chronic PT.

The aim of this study is to investigate the influence of placebo on the effectiveness of Intratissue Percutaneous Electrolysis (IPE) in patients with chronic PT. For this purpose a randomized clinical trial will be carried out, with a sample of patients diagnosed of chronic PT based on signs, symptoms and clinical examination. Subjects will be randomly allocated to four different groups: group E1, IPE will be applied, participants will believe they are receiving IPE; group E2, IPE will be applied, participants will believe they are receiving placebo; group P1, IPE will not be applied, participants will believe they are receiving IPE; and group P2, IPE will not be applied, participants will believe they are receiving placebo. IPE treatment will consist of a total of 3 sessions, with a time interval of one week between the 1st and 2nd sessions and 2 weeks between the 2nd and 3rd sessions. To evaluate the effect of intervention, the subjects will be assessed at baseline (V0), one week after the end of the intervention (V1) and 3 weeks after the intervention (V2). In V0, sociodemographic (sex, age, profession, height, body mass index (BMI), sport activity, hours of sport per week) and clinical data (associated pathologies, affected lower limb, dominant lower limb, duration of symptoms) will be registered. In each assessment time information regarding BMI, sports activity, hours of sport per week and location of pain will be obtained. Moreover, in all assessments participants were evaluated for four physical performance tests, pain and functional scales, ultrasound examination, pressure pain thresholds, conditioned pain modulation, and expectations questionnaires.

Participants don't know to which intervention group they belong to. The outcomes assessor doesn't know to which intervention group the patient belongs to.

IPE will be applied following the standard protocol for PT. Participants will believe they are receiving IPE.

IPE will be applied following the standard protocol for PT. Subjects will be led to believe that the intensity of the current is below the threshold necessary to cause changes in the tissue.

The needle will be inserted under the skin but the current will not be passing through. The subjects will see a shame video on the ultrasound screen so they will believe that the IPE is being performed.

The needle will be inserted under the skin, subjects will be led to believe that the intensity of the current is below the threshold necessary to cause changes in the tissue.

Participants will receive a total of 3 sessions of IPE, with a time interval of one week between the 1st and 2nd session and 2 weeks between the 2nd and 3rd session. IPE will be applied following the standard protocol for PT. Participants will believe they are receiving IPE.

Participants will receive a total of 3 sessions of IPE, with a time interval of one week between the 1st and 2nd session and 2 weeks between the 2nd and 3rd session. IPE will be applied following the standard protocol for PT. Subjects will be led to belie

Participants will receive a total of 3 sessions of IPE-placebo, with a time interval of one week between the 1st and 2nd session and 2 weeks between the 2nd and 3rd session. The needle will be inserted under the skin but the current will not be passing th

Participants will receive a total of 3 sessions of IPE-placebo, with a time interval of one week between the 1st and 2nd session and 2 weeks between the 2nd and 3rd session. The needle will be inserted under the skin, subjects will be led to believe that the intensity of the current is below the threshold necessary to cause changes in the tissue.

Knee pain intensity reported by the patient will be assessed using a 100-mm visual analogue scale (VAS, 0-100, 0=minimum score, 100=maximum score). Higher values represent a better outcome (less pain).

Knee pain intensity reported by the patient will be assessed using a 100-mm visual analogue scale (VAS, 0-100, 0=minimum score, 100=maximum score). Higher values represent a better outcome (less pain).

Knee pain intensity reported by the patient will be assessed using a 100-mm visual analogue scale (VAS, 0-100, 0=minimum score, 100=maximum score). Higher values represent a better outcome (less pain).

Victorian Institute of Sport Assessment-Patellar Tendon (VISA-P, 0-100, 0=minimum score, 100=maximum score) will aso be used to evaluate function of the patellar tendon. A score between 80-100 points is considered as the optimal outcome.

Victorian Institute of Sport Assessment-Patellar Tendon (VISA-P, 0-100, 0=minimum score, 100=maximum score) will aso be used to evaluate function of the patellar tendon. A score between 80-100 points is considered as the optimal outcome.

Victorian Institute of Sport Assessment-Patellar Tendon (VISA-P, 0-100, 0=minimum score, 100=maximum score) will aso be used to evaluate function of the patellar tendon. A score between 80-100 points is considered as the optimal outcome.

Physical performance of the knee will be assessed by the Single Leg Decline squat (SLDS), which consists of performing a squat with one leg on a decline board with an angle of 25º.

Physical performance of the knee will be assessed by the Single Leg Decline squat (SLDS), which consists of performing a squat with one leg on a decline board with an angle of 25º.

Physical performance of the knee will be assessed by the Single Leg Decline squat (SLDS), which consists of performing a squat with one leg on a decline board with an angle of 25º.

The presence (yes/no) and amount (0=no vascularity, 1=low fow, 2=mild flow, 3=high flow) of neovascularity of the patellar tendon will be measured by ultrasonography.

The amount (0=no vascularity, 1=low fow, 2=mild flow, 3=high flow) of neovascularity of the patellar tendon will be measured by ultrasonography.

The amount (0=no vascularity, 1=low fow, 2=mild flow, 3=high flow) of neovascularity of the patellar tendon will be measured by ultrasonography.

The amount (0=no vascularity, 1=low fow, 2=mild flow, 3=high flow) of neovascularity of the patellar tendon will be measured by ultrasonography.

PPTs will be recorded using an electronic algometer at the ipsilateral (affected) patellar tendon, the contralateral patellar tendon and the ipsilateral upper trapezius. Higher values represent a better outcome.

PPTs will be recorded using an electronic algometer at the ipsilateral (affected) patellar tendon, the contralateral patellar tendon and the ipsilateral upper trapezius. Higher values represent a better outcome.

PPTs will be recorded using an electronic algometer at the ipsilateral (affected) patellar tendon, the contralateral patellar tendon and the ipsilateral upper trapezius. Higher values represent a better outcome.

Patients' expectations with the treatment will be registered using an add-hoc questionnaire consisting of 2 questions: "What do you think will be the intensity of your pain when this intervention takes effect?" (NPRS, 0-10, 10 severe pain, 0=no pain) and "Do you expect to have more pain, less pain or the same intensity of pain after treatment?" (more pain, less pain, same pain).

Participants' will rate the results/outcomes obtained with the treatment by the Global rating of change scale (GROC) ((-7)-(+7), -7= very great deal worse, +7= very great deal better).

Participants' will rate the results/outcomes obtained with the treatment by the Global rating of change scale (GROC) ((-7)-(+7), -7= very great deal worse, +7= very great deal better).

Self-perceived pain after treatment will be assessed by the question "What do you think your pain is like now (after treatment): more pain, less pain or the same pain intensity compared to before treatment?" (more pain, less pain, same pain).

Self-perceived pain after treatment will be assessed by the question "What do you think your pain is like now (after treatment): more pain, less pain or the same pain intensity compared to before treatment?" (more pain, less pain, same pain).

Inclusion Criteria: 18 years old or older presenting the following signs and symptoms of patellar tendinopathy: pain when jumping, landing, running o changing direction, pain at the inferior pole of the patella, Victorian Institute of Sport Assessment-Patella (VISA-P) score <80, symptoms duration of at least 3 months. Exclusion Criteria: prior knee surgery patients having received local corticosteroids injection in the tendon within the preceding 6 months patients presenting any inflammatory disease, metabolic bone disease, type II diabetes, fibromyalgia, hypercholesterolemia, pregnancy or chemotherapy within the 3 months prior to the study.