PATH-2: Platelet Rich Plasma in Achilles Tendon Healing
Research type
Research Study
Full title
A pragmatic multi-centre, blinded, randomised placebo-controlled trial comparing Platelet Rich Plasma injection (PRP) to placebo (imitation) injection in adults with Achilles tendon rupture. Two sub-studies are embedded within the main study to contribute to the understanding of the PRP mechanism in tendon healing.
IRAS ID
146684
Contact name
Heather House
Contact email
Sponsor organisation
Oxford University Hospitals NHS Foundation Trust
Duration of Study in the UK
2 years, 9 months, 31 days
Research summary
Research Summary
Platelet Rich Plasma in Achilles Tendon Healing
Does using a Platelet Rich Plasma (PRP) injection immediately before standard casting benefit patients between the ages 18-70 years who are suitable for non-surgical treatment of the Achilles tendon rupture (ATR). This is a multicentre, blinded, randomised, placebo-controlled trial with two sub-studies: (1) blood sample analysis and (2) needle biopsy in 16 participants.ATR is the most common tendon injury and lead to months of incapacity. With an average work absence of 63-108 days there are significant societal and NHS costs. PRP potential benefit is to improve recovery and return to normal activities earlier, and reduce the NHS and societal impact. We will investigate the efficacy of PRP using disease-specific and patient-important outcomes to improve the evidence for this treatment of ATR.
A minimum of 15 UK NHS hospitals will be included to recruit 214 participants. Patients will be identified in the orthopaedic outpatient clinic, usually following an emergency hospital attendance for ATR. After checking eligibility and the informed consent process, baseline data is collected and participants randomised to either ‘PRP injection’ or ‘Imitation (placebo) injection’. Participants’ own blood sample is taken and prepared according to allocation. The injection is delivered by a trained surgeon in clinic who will be aware of allocation, the participant remains blind. Participants complete a pain diary and have four study assessments at 4,7,13 and 24 weeks, carried out by a member of the research team blind to allocation. Assessments take place over the telephone or during a hospital outpatient visit. The 24-week hospital visit includes an exercise test of ankle function. All assessments include collection of patient-reported responses to pre-set questions.
The results may be applicable to the many other tendon and ligaments injuries. The NIHR/MRC Efficacy and Mechanism Evaluation Programme provide funding and University of Oxford is Sponsor.
Summary of Results
Achilles tendon rupture (ATR) is a common injury and leads to months of difficulty walking. The tendon attaches calf muscle to the heel. Most ATRs in the UK are treated by immobilising the lower leg in a plaster cast or boot, followed by months of exercises to restore calf muscle strength. Absence from work is often for 2-3 months.
Platelets are the smallest blood cells and contain proteins that promote healing. Platelet rich plasma (PRP) is a concentrate of a patient’s own blood. Laboratory experiments suggest it could improve tendon healing. We investigated the effects of PRP on ATR healing in adults and measured recovery using patient-reported measures.
Using a computer, we randomly allocated 230 patients from 19 hospitals to either PRP injection or an imitation injection (placebo). We did not include patients having surgical repair of the tendon. We assessed participants before and at 4, 7, 13 and 24 weeks after treatment. We collected information on calf muscle strength, quality of life, pain, and whether participants recovered the ability to do activities important to them. We also monitored any problems with their recovery. We tested participants’ blood for proteins known to help healing. In 16 participants we took tiny samples of tendon tissue to assess the healing.
There were no differences between participants injected with PRP and placebo in calf muscle strength, or in the patient-reported measurements. This meant that PRP did not improve tendon healing during the 24 weeks. Complications were similar with 1 in 20 in each group having a further tear of the tendon. The number of platelets in PRP did not influence the outcome. The biopsy showed similar healing between PRP and placebo groups.
We conclude that PRP does not improve recovery from ATR over 24 weeks. We will reassess participants at 2 years. PRP is used widely in other musculoskeletal problems and should be tested just as rigorously there.REC name
South Central - Oxford A Research Ethics Committee
REC reference
14/SC/1333
Date of REC Opinion
11 Nov 2014
REC opinion
Favourable Opinion