The Process of Platelet Rich Plasma Injection

Courtesy:
Dr Vijay Shetty, Consultant Orthopaedic Surgeon, Specialist in Hip Arthroscopy and Joint Reconstruction, Hiranandani Hospital, Powai, Mumbai, India

 

Introduction

• PRP injections are commonly performed in an outpatient setting.
• Proper documentation of indication and patient details is important because:
  • PRP indications are still evolving.
  • Data collection supports future research.

PRP Preparation System

• The procedure described uses a commercial PRP preparation kit.
• Example: Harvest Technologies PRP kit.

Components of the Kit

The kit contains two main chambers:

• Processing chamber
  • Used for centrifugation and blood separation.
• PRP collection chamber
  • Used for collecting the final platelet-rich plasma concentrate.

Anticoagulation

• Anticoagulant Citrate Dextrose (ACD-A) is used.
• Purpose:
  • Prevents clot formation during blood processing.
  • Preserves platelet integrity.

Blood Collection

• Blood is drawn from a suitable peripheral vein in the patient’s arm.
• The blood is collected in a pre-filled syringe containing ACD-A.

Typical Blood Volumes

Depending on the PRP kit used:

• 20 mL system
• 60 mL system

After collection:

• The blood sample may be analyzed if required for baseline parameters.

Transfer to Processing Chamber

• The collected blood is slowly dispensed into the processing chamber.
• The disposable processing unit is then placed into a centrifuge machine.
• The centrifuge must be properly balanced before spinning.

Centrifugation Process

The centrifugation typically involves two phases:

1. Soft Spin

• Initial spin separates blood into layers.

2. Hard Spin

• Further concentrates platelets.

Total centrifugation time:

• Approximately 15 minutes.

Blood Layer Separation

After centrifugation, three layers can be visualized:

Top Layer

• Platelet-Poor Plasma (PPP)
• Yellow in color.

Middle Layer

• Platelet-Rich Plasma (PRP).

Bottom Layer

• Red Blood Cells (RBCs).

Isolation of PRP

• The platelet-poor plasma (PPP) from the top layer is carefully removed using a syringe.
• A small amount of PPP is intentionally left behind.

Purpose:

• Allows resuspension of the platelet pellet.

Resuspension of Platelets

• The platelet concentrate is resuspended by gentle mixing.
• This step is repeated 3–4 times.

Purpose:

• Ensures platelets do not remain adhered to the chamber walls.
• Produces a uniform platelet suspension.

Platelet Concentration

The final PRP preparation contains:

• Platelet concentrations approximately 5–6 times baseline levels.

This concentrate contains:

• Platelets
• Growth factors
• Cytokines involved in tissue healing.

Laboratory Analysis

• A small sample of PRP is sometimes sent to the laboratory for:
  • Platelet count
  • Quality verification.

Injection Procedure

Local Anaesthesia

• A small amount of local anesthetic may be injected before the procedure.

Reasons:

• PRP injections often require large-bore needles.
• Helps reduce procedural discomfort.

PRP Administration

• The prepared PRP concentrate is injected into the affected area.
• The injection site depends on the clinical condition being treated.

Common targets include:

• Tendons
• Ligaments
• Joints
• Muscle injuries.

Post-Injection Care

After injection:

• An occlusive dressing is applied.
• Patients are discharged with:
  • Analgesics for 1–2 days
  • Advice regarding expected pain.

Patient Counseling

Patients should be informed about:

• Temporary pain at the injection site
• Mild swelling or discomfort for a short duration after injection.

These symptoms are typically self-limiting.