Condition category
Musculoskeletal Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status
Results overdue

Plain English Summary

Background and study aims
Jumpers knee (patellar tendinopathy) is an inflammation or injury of the tendon that joins the kneecap (patella) to the shin bone (tibia). This tendon is called the patellar tendon. It is an overuse injury which happens when repeated movements cause damage to the tissues to a certain part of the body. Constant jumping, landing and changing direction can cause such damage to the patella tendon. Jumpers knee is therefore often seen in people who play professional or recreational sports . The condition has a huge impact on whether the sufferer can play their sport or indeed their usual daily activities. Treatment usually involves eccentric training, a number of exercises that are designed to strengthen the knee, but the results of this treatment is not satisfactory for a significant number of jumper knee patients. Other treatments for the condition include rest, anti-inflammatory medication, extracorporeal shockwave therapy and surgery. However, no single treatment has proven to result in a consistent, near complete recovery in all patients. In recent years, many studies have been published on the effects of ‘dry needling’ (a form of acupuncture), autologous blood injection and platelet-rich plasma (PRP) injections. All of these treatments have had positive results. The latter two treatments work by releasing growth factors and other substances into the knee that boost the healing process in chronic injury. However, autologous blood injections involve injecting a patient’s own blood from another part of the body into the joint while PRP injections works by injecting just the plasma component of the blood. We want to compare how successful the PRP injection is at treating jumpers knee compared to the autologous blood injection and a saline injection.

Who can participate?
Participants diagnosed as having a jumper’s knee, aged between 18-55 years old and have already been treated with eccentric training for 6 weeks.

What does the study involve?
Participants are randomly allocated into one of three groups. Those in group 1 are treated with a PRP injection. Those in group 2 are treated with a autologous blood injection . Those in group 3 are treated with a saline injection. All participants are asked to fill in a questionnaire about how well their knee works and how painful it is before treatment starts and then at 6, 12, 26 and 52 weeks after treatment.

What are the possible benefits and risks of participating?
Based on previous studies, a reduction of pain and improvement in function can be expected from any of the three injection treatments. A slight increase in pain is possible the first few days after injection. As with any injection, a very small risk of inflammation exists.

Where is the study run from?
Participants are recruited at two medical centers in The Netherlands. Meander Medical Center in Baarn and University Medical Center in Groningen.

When is study starting and how long is it expected to run for?
March 2009 to December 2015.

Who is funding the study?
Meander Medical Center, Baarn (Netherlands)
University Medical Center, Groningen (Netherlands)
Biomet Europe B.V. (Netherlands)

Who is the main contact?
Mathijs van Ark

Trial website

Contact information



Primary contact

Mr Mathijs van Ark


Contact details

P.O. Box 30.001
9700 RB

Additional identifiers

EudraCT number number

Protocol/serial number

ABR nr: NL23993.100.08

Study information

Scientific title

The value of platelet-rich plasma injections in the treatment of the jumper’s knee: a double blind randomized trial


Study hypothesis

Platelet-rich plasma injection treatment results in more improvement in pain and function of a jumper’s knee patient than an autologous blood or saline injection.

Ethics approval

Committee Examination Scientific Research of Meander Medical Center, The Netherland (The Commissie Toetsing Wetenschappelijk Onderzoek [CTWO]), 06/03/2009 ref.:(v.09.028/R.08.30).
Medical Ethics Committee of University Medical Center Groningen, 24/01/2011, ref.: (METc nr 2010.193) - Approval for multi center recruitment for this study

Study design

Double-Blind Randomized Controlled Trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Patellar tendinopathy (jumper's knee)


PRP, autologous blood or saline injection

Blood (54cc) will be extracted from the elbow vein in every patient, because this is necessary to obtain 6cc PRP. The liquid to be injected will be placed in a 10ml blinded syringe by someone else than the treating physician and radiologist. The location of penetration will be anesthetized with Lidocaine. Subsequently, the tendon will be dry-
needled five times under ultrasound guidance. Depending on the injection treatment, the correct liquid will be injected under ultrasound guidance (injections described below). This will occur double-blind, the syringe will be blinded to the treating physician and radiologist.

The researcher who will analyse the data will be blinded as well. The first two weeks after injection the patient should not take part in any (sport) activities with higher load than normal daily life activities. After two weeks, the load will be increased during a standardized supervised physiotherapy protocol. This protocol will take approximately 12 weeks. The first month after injection, patients are not allowed to use NSAIDs. Final follow-up will be one year after injection treatment.

Platelet-Rich Plasma injection (PRP)
The mini GPS II kit from the company Biomet B.V. will be used to prepare 6ml of PRP and placed in a blinded syringe for injection.

Autologous blood
A part (6ml) of the extracted blood will be placed in a blinded syringe for injection.

NaCl (6ml) will be placed in a blinded syringe for injection.

Intervention type



Not Applicable

Drug names

Primary outcome measure

VISA-P – a validated questionnaire for patellar tendinopathy which assesses pain and function of the knee (100 = maximal score, indicating a normal functional knee, 0 = minimal score).
This will be assessed at baseline, 6, 12, 26 and 52 weeks after injection treatment.

Secondary outcome measures

1. Ultrasound abnormalities (tendinosis zone, thickness of tendon and degree of neovascularisation) at baseline and 12 weeks after injection
2. Pain, measured using Visual Analogue Scale (VAS) score (0 = no pain, 10 = unbearable pain)
3. Costs of the treatments
4. Return to sport (level and duration)

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Jumper’s knee patients aged 18-55
2. Pain at the inferior pole of the patella for more than 3 months
3. Tendinosis or thickening compared to the contralateral side of > 3mm, detected with ultrasonography or MRI
4. Already undergone eccentric training for 6 weeks following a standardized protocol

Participant type


Age group




Target number of participants

90 – Divided over 3 groups

Participant exclusion criteria

1. Pregnancy
2. Injection in the patellar tendon in the last 3 months, irrespective of the applied substance
3. Operation on the patellar tendon in the past
4. At examination indications for intra articular pathology or patellofemoral pain syndrome
5. Chronic NSAID use in the last 3 months

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

P.O. Box 30.001
9700 RB

Sponsor information


Biomet Europe B.V. (Netherlands)

Sponsor details

Toermalijnring 600
3316 LC

Sponsor type




Funder type

Hospital/treatment centre

Funder name

Biomet Europe B.V. - Supplied the PRP preparation kits free of cost and funding for 0.1 FTE junior researcher for 1 year (euro 5000) (Netherlands)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

Meander Medical Center, Baarn (Netherlands)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

University Medical Center, Groningen (Netherlands)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes