Platelet Rich Plasma

Reviewed by

Dr Owen Mattern
MBBS | Unaccredited Orthopaedic Registrar

Platelet-rich plasma (PRP) thought to hold potential beneficial effects in
- Bone regeneration
- Reduction in blood loss
- Rapid tissue healing
Autologous product procured from patient up to 8 hours prior to use
Contains various growth factors act as
- Chemotactic agents
- Removal of tissue debris
- Angiogenesis
- Extracellular matrix deposition
- Proliferation and differentiation
Described benefit in

Activated by calcium and thrombin to release
- Growth factors
- Chemokines
- Cytokines
Also contains other proteins
- Fibrin, fibronectin, vitronectin, thrombospondin
These growth factors and proteins activate cells involved in
- Soft tissue healing
- Bone regeneration

PDGF- platelet derived growth factor
- Angiogenesis, macrophage activation, fibroblast proliferation and chemotaxis, collagen synthesis, bone cell proliferation
TGF - transforming growth factor
- Extracellular matrix production, fibroblast proliferation, type I collagen and fibronectin synthesis, bone matrix deposition, inhibition of osteoclasts and bone resorption
IGF - vascular endothelial growth factor
- Chemotactic for fibroblasts, protein synthesis stimulation, proliferation and differentiation of osteoblasts
PDEF - platelet derived growth factor
- Wound healing through epidermal regeneration, keratinocyte and dermal fibroblast stimulation
- Growth factors in PRP
PDAF - platelet derived angiogensis factor
- Induce vascularisation, upregulated by other cytokines and growth factors
PF-4 - platelet factor 4
- Chemoattractant to neutrophils, fibroblasts, promotes coagulations by moderating heparin like molecules
EGF - epidermal growth factor
- Epithelial proliferation and differentiation
VGEF - vascular endothelial growth factor
- Vasculogenesis and angiogenesis, vasodilator and increased microvascular permeability

No agreement on concentration of platelets
- Some authors advocate 10%
- Others 1-5%
Different concentrations lead to variable effects on tissue regeneration
Affected by technique used to measure platelet count
Dependent on donor factors
- Age, sex, platelet count of patient.
Higher platelet counts have higher growth factor concentrations

Stable for 8 hours
Must be activated
- Usually with topical bovine thrombin and CaCl
- Must be used within 10 min of activation

Likely effects are synergistic
PRP shown to stimulate bone growth in rat bone marrow
- Compared to individual growth factors having no effect
Improved cell proliferation in tendons cultured in PRP
Conflicting evidence over whether platelet need to be intact

Quantity and delivery method are procedure specific
Most studies limited case series
Some evidence for increased bone consolidation in mandibular surgery
Some use in chronic ulcers and soft tissue defects
Study from Netherlands showed no benefit to PRP to NS in chronic achilles tendonitis

Minimal evidence supporting use in trauma and orthopaedic procedures
PRP in tendons
- Some evidence for use in
  - Refractory lateral epicondylitis
  - Open achilles repair
  - Rotator cuff repairs
PRP in bone
- Common to use with bone graft in mandible and cranium
- PRP administered with good result in spinal fusion and osteogenesis distraction
- PDGF and TGH-b measured in fracture haematomas of foot fractures
  - Non-union patients had no proteins found
  - PRP applied at revision operations had union at 8.5/52
- Percutaneous application in non-union and delayed union when applied at <11 months resulted in union
PRP in arthroplasty
- PRP when applied in TKR to exposed tissue and synovium and wound at closure
  - Decreased bleeding, analgesic requirement, improved ROM, decreased hospital stay
- Evidence in oral surgery that PRP and HA compared to NS and HA improved intra-bony periodontal defects
PRP in diabetic fractures
- Reduction in PDGF, TGF, IGF and VEGF demonstrated at fracture site in diabetics
  - PRP injected early, normalised cell proliferation (only partially restored when injected late)
- Improved healing and fewer complications in Charcot foot patients undergoing ankle fusion
PRP in wound healing
- Improved wound healing in skin ulcers using human platelet-derived wound healing factors
- Platelet releasate provided more effective healing than standard care in diabetic ulcers
- 78% limb salvage rate in patients who had amputation recommended

Is autologous
- Inherently safe from HIV, Hep, CJD, immunogenic reactions
Potential reactions to bovine thrombin used in activation
- Coagulopathies related factor V antibodies

Limited literature
- Some evidence in in vitro studies
- Limited evidence in clinical scenarios
- Some evidence in dental and max/fax use which may translate to orthopaedics
Allows for further research into other similar treatments if we can better classify growth factor effects
- Stem cell, tenocyte use

Webpage Last Modified: 22 May, 2010