What are the complications of a joint injection with Platelet Rich Plasma (PRP) therapy?

Complications of Joint Injection with PRP Therapy

While PRP therapy is generally considered safe as it uses the patient's own blood products, several potential complications can occur following joint injections, including infection, pain flares, and inflammatory reactions.

Common Complications

Immediate Complications

• Pain and discomfort at injection site - Most common adverse effect
• Local swelling and redness - Typically self-limiting and resolves within 24-48 hours
• Post-injection flare - Temporary increase in pain following the procedure

Serious Complications

• Infection risk - While rare, septic arthritis remains a potential complication of any joint injection
  • Risk estimated at 0.035% (approximately 3 per 7,900 procedures) 1
  • Requires strict aseptic technique to minimize risk

Specific PRP-Related Complications

Pseudoseptic Reaction

• Mimics true septic arthritis with acute post-injection pain and joint effusion
• Characterized by significantly elevated white blood cell counts in synovial fluid
• Clinically important as it must be differentiated from true infection 2

Exuberant Inflammatory Reaction

• More severe in patients with certain comorbidities (e.g., type 1 diabetes)
• Presents with excessive inflammation beyond typical post-injection response 3

Risk Factors and Special Populations

Diabetic Patients

• Higher risk of inflammatory reactions
• PRP injections should be used with caution in patients with insulin-dependent diabetes 3
• Similar to glucocorticoid injections, blood glucose monitoring may be prudent following injection

Prosthetic Joints

• Limited data on safety of PRP in prosthetic joints
• By extrapolation from glucocorticoid injection data, there may be increased infection risk
• Should be considered only after consultation with the orthopedic surgical team 1

Prevention Strategies

Procedural Considerations

1. Strict aseptic technique:

   • Use of surgical gloves
   • Skin preparation with alcohol, iodine disinfectant, or chlorhexidine
   • Changing needles between drawing the product and injecting it into the joint 1

2. Post-procedure care:

   • Avoid overuse of injected joints for 24 hours following injection
   • Complete immobilization is not recommended 1

Management of Complications

Pain Flares

• Usually self-limiting
• Managed with rest, ice, and over-the-counter analgesics

Suspected Infection

• Prompt joint aspiration for cell count, culture
• Immediate referral for possible surgical intervention if infection confirmed
• Early antibiotic therapy

Pseudoseptic Reaction

• Differentiate from true infection through aspiration and culture
• Typically resolves with supportive care

Efficacy Considerations

While not directly related to complications, it's worth noting that current guidelines express concerns about PRP therapy:

• The American College of Rheumatology/Arthritis Foundation strongly recommends against PRP treatment for knee and hip OA due to inconsistent evidence 4
• Major concerns include heterogeneity in PRP preparations and variable techniques used for injection 4

Conclusion

PRP joint injections have a generally favorable safety profile compared to other injectables, with most complications being minor and self-limiting. However, clinicians should be aware of the potential for pseudoseptic reactions and exuberant inflammatory responses, particularly in patients with certain comorbidities. Strict adherence to aseptic technique remains essential to minimize the risk of infection.