The Effect of Multiple Injection of Platlet-rich Plasma in Chronic Patellar Tendinopathy

Study Overview
=================
Brief Summary
-----------------
According to previous studies, the effect of PRP to patellar tendinopathy could last longer. However, the type, concentration, time and frequent of injection are still debated。 This study is to understand the effect of multiple injection of platlet-rich plasma in chronic patellar tendinopathy and to analyze the relation between efficacy of PRP and the growth factor in PRP.

Detailed Description
-----------------
Patellar tendinopathy, also known as jumper's knee，is clinically common characterised by anterior knee pain, activity-related pain、local tenderness over inferior pole of patella. The discomfort can result in decreasing athletic performance and be one of the most challenge for sports medicine doctor. The patellar tendon suffer from repetitive microtrauma，result in reactive patellar tendinopathy. The overload tendon combining with risk factors of patellar tendinopathy will not recover timely and progress to chronic patellar tendinopathy. Hence, to reverse the progression is our aim. According to previous studies, several nonsurgical treatment options have been proposed such as medication, eccentric exercise, corticosteroid injection, shockwave and platelet-rich plasma (PRP). Among all the options, the effect of PRP could last longer. However, the type, concentration, time and frequent of injection are still debated。Moreover, there is no study about the relationship between efficacy and the ratio and concentration of growth factor in the PRP. The aim of this study is to understand (1) The effect of multiple injection of platlet-rich plasma in chronic patellar tendinopathy. (2) The effect of leukocyte-rich PRP in chronic patellar tendinopathy (3) Analyze the relation between efficacy of PRP and the growth factor in PRP.

Official Title
-----------------
The Effect of Multiple Injection of Platlet-rich Plasma in Chronic Patellar Tendinopathy

Conditions
-----------------
Tendinopathy

Intervention / Treatment
-----------------
* Biological: Platlet-rich plasma


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Chronic patellar tendinopathy Exclusion Criteria: Corticosteroid injections within 12 months Previous knee surgery Any confounding diagnosis to the knee joint Arthritis Rheumatoid arthritis Diabetes Infections of knee joint NSAIDs in the 10 days before the procedure

Ages Eligible for Study
-----------------
Minimum Age: 20 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PRP injection, once<br>PRP injection, once | Biological: Platlet-rich plasma<br>* Multiple Platlet-rich plasma injection.<br>|
| Experimental: PRP injection, twice<br>PRP injection, twice, 2 weeks apart | Biological: Platlet-rich plasma<br>* Multiple Platlet-rich plasma injection.<br>|
| Experimental: PRP injection, 3 times<br>PRP injection, 3 times, 2 weeks apart | Biological: Platlet-rich plasma<br>* Multiple Platlet-rich plasma injection.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline Victorian Institute of Sport Assessment (VISA-P) score to 36 weeks | Clinical evaluation for patellar tendinopathy minimum score: 0(worse outcome) maximum score: 100(better outcome) | 36 weeks | 
| Change from baseline modified Blazina Scale to 36 weeks | Clinical evaluation for patellar tendinopathy Stage 0 - No pain Stage 1 - Pain only after intense sports activity; no undue functional impairment Stage 2 - Pain at the beginning and after sports activity; still able to perform at a satisfactory level Stage 3 - Pain during sports activity; increasing difficulty in performing at a satisfactory level Stage 4 - Pain during sports activity; unable to participate in sport at a satisfactory level Stage 5 - Pain during daily activity; unable to participate in sport at any level | 36 weeks | 
| Change from baseline thickness of patellar tendon to 36 weeks | Sonographic evaluation for patellar tendinopathy to measure the thickness of proximal patellar tendon. | 36 weeks | 
| Change from baseline Visual analogue score(VAS) to 36 weeks | evaluation for pain(minimal score:0, maximal score:10) | 36 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between Platlet derived growth factor (PDGF) and VISA-P score | Aim: To find the relationship between treatment effect(VISA-P score) and concentration of growth factor(PDGF) | 36 weeks | 
| Correlation between Transforming growth factor beta 1 (TGF beta 1) and VISA-P score | Aim: To find the relationship between treatment effect(VISA-P score) and concentration of growth factor(TGF beta 1) | 36 weeks | 
| Correlation between Epithelial growth factor (EGF) and VISA-P score | Aim: To find the relationship between treatment effect(VISA-P score) and concentration of growth factor(EGF) | 36 weeks | 
| Change from baseline Victorian Institute of Sport Assessment (VISA) score to 104 weeks | To evaluate the longterm effect of multiple PRP injection | 104 weeks |