Efficacy of a target platelet concentration in platelet-rich plasma for arthroscopic rotator cuff repair
| ISRCTN | ISRCTN10265778 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN10265778 |
| Sponsor | Hospital de São João |
| Funder | Investigator initiated and funded |
- Submission date
- 24/09/2026
- Registration date
- 25/09/2026
- Last edited
- 25/09/2026
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Surgery
Plain English summary of protocol
Background and study aims
The rotator cuff is a group of muscles and tendons that help to move and support the shoulder. A tear in one of these tendons, called the supraspinatus tendon, can cause pain and problems with shoulder function. If other treatments do not help, the tendon may be repaired using keyhole surgery.
Platelet-rich plasma (PRP) is made from a person’s own blood and contains a high concentration of platelets. It is sometimes used to support healing after surgery. This study looked at whether using PRP with a specific concentration of platelets during rotator cuff surgery could help the repaired tendon to heal. It also looked at shoulder function, pain and complications after surgery.
Who can participate?
Patients aged over 18 years who needed keyhole surgery to repair a supraspinatus tendon tear that had not improved with non-surgical treatment could take part. Participants needed to be able to follow a standard rehabilitation programme after surgery and provide written consent to take part and receive PRP.
People could not take part if they had previously had surgery on the same shoulder or had certain other conditions affecting the shoulder or arm, such as a previous fracture, tumour, infection or arthritis. People with traumatic rotator cuff tears and some other types or severities of shoulder damage could also not take part.
What does the study involve?
All participants had keyhole surgery to repair the torn supraspinatus tendon. During the procedure, they also received an injection of PRP prepared from their own blood.
A small amount of blood was taken, similar to a routine blood test. The blood was then processed in a machine to separate the part containing a high concentration of platelets. The PRP was prepared to achieve a target concentration before being used during the operation. A small sample was kept to measure the concentrations of different blood cells and was then disposed of according to standard procedures.
Participants were followed for 6 months. The researchers assessed whether the repaired tendon had healed at 6 months. They also measured shoulder function and pain. Pain was assessed at 1 month and 6 months after surgery, and shoulder function was assessed at 6 months. Taking part did not require any extra hospital visits or tests beyond those normally carried out for this type of surgery.
What are the possible benefits and risks of participating?
The PRP treatment may help the repaired tendon to heal, although this cannot be guaranteed. The information collected may also help researchers understand whether PRP prepared to a specific platelet concentration is useful in rotator cuff repair.
PRP was made from each participant’s own blood. The main additional discomfort expected from taking part was having blood taken once to prepare the PRP. This was usually done shortly before anaesthesia. The study did not require additional visits or tests beyond usual care.
Where is the study run from?
The study was run at Centro Hospitalar Universitário S. João in Porto, Portugal.
When is the study starting and how long is it expected to run for?
May 2024 to 20 February 2026.
Who is funding the study?
The study was initiated and funded by the investigators.
Who is the main contact?
Dr Bernardo Nunes at Hospital de São João in Porto, Portugal.
joao.nunes@ulssjoao.min-saude.pt
Contact information
Principal investigator, Scientific, Public
Alameda Prof. Hernani Monteiro
Porto
4200
Portugal
 ORCID ID |
0000-0003-0706-8174 |
|---|---|
| Phone | +351 912950789 |
| joao.nunes@ulssjoao.min-saude.pt |
Study information
| Primary study design | Interventional |
|---|---|
| Allocation | N/A: single arm study |
| Masking | Blinded (masking used) |
| Control | Uncontrolled |
| Assignment | Sequential |
| Purpose | Treatment |
| Participant information sheet | 50350 Consent form (Portuguese).pdf |
| Scientific title | Efficacy of a target platelet concentration in platelet-rich plasma for arthroscopic rotator cuff repair: a single-arm phase II clinical trial |
| Study objectives | The aim of this study was to evaluate the efficacy of a target platelet concentration for PRP in aRCR, with tendon healing as the primary outcome. Secondary outcomes were also considered, including overall function—assessed via the Subjective Shoulder Value (SSV) and the Constant-Murley Score (CMS)—pain (Visual Analogue Scale (VAS)), and post-operative complications. |
| Ethics approval(s) |
Approved 09/11/2023, S. João University Hospital Ethics Committee (Alameda Prof. Hernani Monteiro, Porto, 4200, Portugal; +351 225512100; comissao.etica@ulssjoao.min-saude.pt), ref: Ref 279/2023 |
| Health condition(s) or problem(s) studied | Arthroscopic repair of supraspinatus tears |
| Intervention | Arthroscopic repair of the supraspinatus using a double-row technique and injection of a commercial preparation of PRP (Angel System, Arthrex, Naples, FL, USA), using a standardized protocol to reach a target dose of approximately 1160.27 × 10³/µL and a white blood cell (WBC) macrophage-depleted concentration of 11.69 × 10³/µL, including a neutrophil (NE) concentration of 2.84 × 10³/µL. Patients were followed up for 6 months. |
| Intervention type | Biological/Vaccine |
| Phase | Phase II |
| Drug / device / biological / vaccine name(s) | Platelet Rich Plasma - Angel System Arthrex |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) |
|
| Completion date | 20/02/2026 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 99 Years |
| Sex | All |
| Target sample size at registration | 40 |
| Total final enrolment | 37 |
| Key inclusion criteria | 1. Aged over 18 years 2. An indication for supraspinatus arthroscopic rotator cuff repair (aRCR) due to tears refractory to conservative management 3. Able to comply with a standardised postoperative rehabilitation protocol 4. Provided written informed consent for study participation and platelet-rich plasma (PRP) administration |
| Key exclusion criteria | 1. Prior surgery on the ipsilateral shoulder 2. A history of fracture, tumour, or infection in the ipsilateral upper limb 3. Fatty infiltration of Goutallier grade IV of the supraspinatus or infraspinatus 4. Glenohumeral arthritis 5. Rotator cuff arthropathy greater than Hamada grade II 6. Concomitant subscapularis tears ≥ Lafosse grade III 7. Traumatic rotator cuff tears (RCTs) |
| Date of first enrolment | 13/05/2024 |
| Date of final enrolment | 19/08/2025 |
Locations
Countries of recruitment
- Portugal
Study participating centre
Porto
4200
Portugal
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | in Portuguese | 25/09/2026 | No | Yes | |
| Protocol file | 25/09/2026 | No | No | ||
| Statistical Analysis Plan | 25/09/2026 | No | No |
Additional files
- 50350 Study Protocol english.pdf
- Protocol file
- 50350 Statistical analysis plan.pdf
- Statistical Analysis Plan
- 50350 Consent form (Portuguese).pdf
- in Portuguese
Editorial Notes
25/09/2026: Trial's existence confirmed by S. João University Hospital Ethics Committee.
