Platelet-Rich Plasma in Tendinopathy: Clinical Applications in Patellar Tendinopathy and Plantar Fasciitis

Tendinopathies such as patellar tendinopathy and plantar fasciitis are among the most common overuse injuries seen in orthopaedic and sports medicine practice. These conditions are typically chronic, degenerative, and resistant to conservative interventions once well established. In recent years, platelet-rich plasma (PRP) has emerged as a regenerative therapeutic option offering biological repair rather than symptomatic relief alone. This article provides an evidence-based review of PRP application in both conditions for the informed orthopaedic clinician.

Pathophysiology and Challenges in Chronic Tendinopathy

Tendinopathies are no longer viewed as inflammatory disorders. Instead, they are recognized as degenerative, with hallmark features including:

• Collagen disorganization
• Tenocyte apoptosis
• Neovascularization
• Mucoid degeneration

These pathologic changes are common to both patellar tendinopathy and plantar fasciitis, leading to persistent pain and functional impairment. Standard treatments such as physical therapy, NSAIDs, corticosteroid injections, and shockwave therapy often fail to stimulate tendon regeneration or provide lasting relief in chronic cases.

PRP: Biological Rationale in Tendon Healing

PRP is an autologous concentration of platelets containing growth factors such as PDGF, TGF-β1, VEGF, and IGF-1. These bioactive molecules:

• Stimulate tenocyte proliferation
• Enhance collagen synthesis
• Promote angiogenesis
• Modulate inflammation

PRP’s regenerative capacity directly addresses the cellular and extracellular matrix deficits present in chronic tendinopathy. Its growing adoption in orthopaedics reflects a shift toward biologically driven repair strategies.

PRP in Patellar Tendinopathy

Clinical Presentation

Patellar tendinopathy, or jumper’s knee, primarily affects athletes involved in jumping, running, or explosive leg movements. Pain is localized at the inferior pole of the patella, worsened by activities like squatting and stair descent.

Evidence Summary

• Dragoo et al. (2014): PRP combined with eccentric rehab showed superior results to dry needling.
• Vetrano et al. (2013): PRP outperformed shockwave therapy in a randomized trial of athletes.
• Charousset et al. (2014): Sustained pain and function improvement at 2 years post PRP injection.

Clinical Protocol

• Formulation: Leukocyte-rich PRP (LR-PRP) preferred for tendinopathic tissue
• Injection technique: Ultrasound-guided; peppering or fanning technique into the degenerative region
• Dosing: 1–3 injections, spaced 1–2 weeks apart
• Post-injection rehab: Gradual loading protocol, avoiding NSAIDs for 1 week pre- and post-injection

PRP in Plantar Fasciitis

Clinical Presentation

Plantar fasciitis is characterized by heel pain at the medial calcaneal tuberosity, particularly upon first steps in the morning. Chronic cases (>6 months) often show degeneration of the plantar fascia on imaging.

Evidence Summary

• Aksahin et al. (2012): PRP provided superior pain relief vs corticosteroids at 3-month follow-up
• Ragab and Othman (2012): 77% of chronic plantar fasciitis patients had significant pain relief after a single PRP injection
• Monto (2014): PRP maintained clinical benefits up to 24 months vs corticosteroids (which declined after 6 months)

Clinical Protocol

• Formulation: LR-PRP commonly used
• Injection technique: Ultrasound-guided; direct injection into degenerated fascia origin
• Dosing: Typically a single injection; repeat only if symptoms persist beyond 8–10 weeks
• Post-injection rehab: Limit weight-bearing for 48 hours, then initiate stretching and strengthening

Comparative Insights 

Both conditions share common degenerative features and respond favorably to PRP in chronic, treatment-resistant cases. Proper diagnosis, imaging guidance, and post-procedural rehabilitation are key to success.

Safety and Limitations

PRP is autologous and carries a very low risk of complications. Minor local reactions such as pain or swelling are self-limited. Contraindications include:

• Active infection
• Bleeding disorders
• Use of anticoagulants
• Systemic autoimmune disease

Limitations of PRP use include:

• Lack of standardization in PRP preparation
• Variability in response based on chronicity and patient biology
• Out-of-pocket cost for many patients

Future research is needed to optimize dosing, explore combination therapies (e.g., PRP + shockwave), and refine patient selection criteria.

Conclusion

PRP therapy represents a promising biologic treatment for chronic patellar tendinopathy and plantar fasciitis, especially when conservative treatments have failed. With increasing clinical evidence and practical protocols now established, PRP is a valuable tool in orthopaedic regenerative medicine. Careful application of technique, appropriate candidate selection, and evidence-informed rehabilitation strategies are critical for maximizing outcomes.

References

1. 1. Dragoo JL, et al. (2014). PRP injections for patellar tendinopathy: A randomized controlled trial. Am J Sports Med, 42(3):610–618.
   2. Vetrano M, et al. (2013). Platelet-rich plasma versus shockwave therapy for jumper’s knee. Br J Sports Med, 47(2):77–82.
   3. Charousset C, et al. (2014). Two-year outcomes after PRP injection in chronic patellar tendinopathy. Am J Sports Med, 42(4):906–911.
   4. Aksahin E, et al. (2012). PRP vs corticosteroid injection for plantar fasciitis. Foot Ankle Int, 33(6): 518–523.
   5. Ragab EM, Othman AM. (2012). PRP in treatment of chronic plantar fasciitis. Clin Res Foot Ankle, 2(3): 1–5.
   6. Monto RR. (2014). Platelet-rich plasma efficacy in plantar fasciitis: Long-term results. Foot Ankle Int, 35(4):313–318.
   7. Mautner K, et al. (2015). Proposed PRP classification for orthopaedic biologics. PM&R, 7(4 Suppl):S53–S59.
   8. RegenOMedix. (2024). PRP Therapy. Available at: https://regenomedix.com/prp-therapy