International Orthopaedics

, Volume 37, Issue 8, pp 1583–1589 | Cite as

Platelet-rich plasma for the treatment of patellar tendinopathy: clinical and imaging findings at medium-term follow-up

  • Giuseppe Filardo
  • Elizaveta Kon
  • Berardo Di Matteo
  • Patrizia Pelotti
  • Alessandro Di Martino
  • Maurilio Marcacci
Original Paper



The purpose of this study was to evaluate the efficacy of multiple platelet-rich plasma (PRP) injections on the healing of chronic refractory patellar tendinopathy, and report the quality and duration of the clinical improvement up to a medium-term follow-up.


Forty-three patients (mean age, 30.6 years; mean BMI, 24.7; 42 men, one woman) affected by chronic patellar proximal tendinopathy were enrolled in this trial. Eleven patients were affected by bilateral tendinopathy. They underwent three ultrasound guided intra-tendinous injections of five millilitres PRP, two weeks apart from each other. Patients were prospectively evaluated initially, then after two, six, and up to mean 48.6 ± 8.1 months of follow-up (minimum evaluation at 36 months). The following evaluation tools were used: Blanzina, VISA-P, EQ-VAS for general health, and Tegner scores. Patients’ overall satisfaction and time to return to sport were also reported.


Good and stable results were documented over time, with the VISA-P score increasing from 44.1 ± 15.6 at baseline to 61.4 ± 22.2 at two months, 76.6 ± 25.4 at six months, and 84.3 ± 21.6 at four years’ follow-up. The same trend was confirmed by the other scores used, and 80 % of the patients were satisfied and returned to previous sports activities. Significantly poorer results were obtained in patients with a longer history of symptoms, and poor results were also observed in bilateral lesions. No correlation between ultrasonographic and clinical findings could be found.


Multiple injections of PRP provided a good clinical outcome for the treatment of chronic recalcitrant patellar tendinopathy with stable results up to medium-term follow-up. Patients affected by bilateral pathology and presenting a long history of pain obtained significantly poorer results.


Platelet rich plasma Patellar tendinopathy Ultrasound guidance Intra tendon injections 



A. Montaperto, S. Bassini: Biomechanics and Technology Innovation Laboratory, Rizzoli Orthopedic Institute, Bologna, Italy.

P. M. Fornasari, A. Cenacchi, M. Vaccari: Immunohematology and Transfusion Medicine Service, Rizzoli Orthopedic Institute, Bologna, Italy.

E. Pignotti, K. Smith: Task Force, Rizzoli Orthopedic Institute, Bologna, Italy.

Conflict of interest

The authors declare that they have no conflict of interest.


  1. 1.
    Cook JL, Khan KM, Harcourt PR, Grant M, Young DA, Bonar SF (1997) A cross sectional study of 100 athletes with jumper's knee managed conservatively and surgically. The Victorian Institute of Sport Tendon Study Group Br J Sports Med 31(4):332–336CrossRefGoogle Scholar
  2. 2.
    Lian OB, Engebretsen L, Bahr R (2005) Prevalence of jumper’s knee among elite athletes from different sports: a cross-sectional study. Am J Sport Med 33:561–567CrossRefGoogle Scholar
  3. 3.
    Riley G (2004) The pathogenesis of tendinopathy. A molecular perspective. Rheumatology (Oxford) 43(2):131–142CrossRefGoogle Scholar
  4. 4.
    Samiric T, Parkinson J, Ilic MZ, Cook J, Feller JA, Handley CJ (2009) Changes in the composition of the extracellular matrix in patellar tendinopathy. Matrix Biol 28(4):230–236PubMedCrossRefGoogle Scholar
  5. 5.
    Kettunen JA, Kvist M, Alanen E et al (2002) Long term prognosis for jumper’s knee in male athletes. A prospective follow-up study. Am J Sport Med 30(5):689–692Google Scholar
  6. 6.
    Peers KH, Lysens RJ (2005) Patellar tendinopathy in athletes: current diagnostic and therapeutic recommendations. Sports Med 35:71–87PubMedCrossRefGoogle Scholar
  7. 7.
    Young MA, Cook JL, Purdam CR et al (2005) Eccentric decline squat protocol offers superior results at 12 months compared with traditional eccentric protocol for patellar tendinopathy in volleyball players. Br J Sports Med 39(2):102–105PubMedCrossRefGoogle Scholar
  8. 8.
    Peers KH, Lysens RJ, Brys P, Bellemans J (2003) Cross-sectional outcome analysis of athletes with chronic patellar tendinopathy treated surgically and by extracorporeal shock wave therapy. Clin J Sport Med 13(2):79–83PubMedCrossRefGoogle Scholar
  9. 9.
    Alfredson H, Ohberg L (2005) Neovascularisation in chronic painful patellar tendinosis. Promising results after sclerosing neovessels outside the tendon challenge the need for surgery. Knee Surg Sports Traumatol Arthrosc 13(2):74–80PubMedCrossRefGoogle Scholar
  10. 10.
    Molloy T, Wang Y, Murrell G (2003) The roles of growth factors in tendon and ligament healing. Sports Med 33(5):381–394PubMedCrossRefGoogle Scholar
  11. 11.
    Cole BJ, Seroyer ST, Filardo G, Bajaj S, Fortier LA (2010) Platelet-rich plasma: where are we now and where are we going? Sports Health 2(3):203–10PubMedCrossRefGoogle Scholar
  12. 12.
    Kon E, Filardo G, Di Martino A, Marcacci M (2011) Platelet-rich plasma (PRP) to treat sports injuries: evidence to support its use. Knee Surg Sports Traumatol Arthrosc 19(4):516–527PubMedCrossRefGoogle Scholar
  13. 13.
    Tschon M, Fini M, Giardino R, Filardo G, Dallari D, Torricelli P, Martini L, Giavaresi G, Kon E, Maltarello MC, Nicolini A, Carpi A (2011) Lights and shadows concerning platelet products for musculoskeletal regeneration. Front Biosci (Elite Ed) 1(3):96–107CrossRefGoogle Scholar
  14. 14.
    Filardo G, Kon E (2012) PRP: more words than facts. Knee Surg Sports Traumatol Arthrosc 20(9):1655–1656PubMedCrossRefGoogle Scholar
  15. 15.
    Lian O, Holen KJ, Engebretsen L et al (1996) Relationship between symptoms of jumper’s knee and the ultrasound characteristics of the patella tendon among high level male volleyball players. Scand J Med Sci Sports 6:291–296PubMedCrossRefGoogle Scholar
  16. 16.
    Cook JL, Ptazsnik R, Kiss ZS, Malliaras P, Morris ME, De Luca J (2005) High reproducibility of patellar tendon vascularity assessed by colour Doppler ultrasonography: a reliable measurement tool for quantifying tendon pathology. Br J Sports Med 39:700–703PubMedCrossRefGoogle Scholar
  17. 17.
    Kajikawa Y, Morihara T, Sakamoto H et al (2008) Platelet-rich plasma enhances the initial mobilization of circulation-derived cells for tendon healing. J Cell Physiol 215(3):837–845PubMedCrossRefGoogle Scholar
  18. 18.
    De Mos M, Van der Windt AE, Jahr H et al (2008) Can platelet-rich plasma enhance tendon repair? A cell culture study. Am J Sports Med 36(6):1171–1178PubMedCrossRefGoogle Scholar
  19. 19.
    Virchenko O, Aspenberg P (2006) How can one platelet injection after tendon injury lead to a stronger tendon after 4 weeks? Interplay between early regeneration and mechanical stimulation. Acta Orthop 77(5):806–812PubMedCrossRefGoogle Scholar
  20. 20.
    Aspenberg P, Virchenko O (2004) Platelet concentrate injection improves Achilles tendon repair in rats. Acta Orthop Scand 75:93–99PubMedCrossRefGoogle Scholar
  21. 21.
    Bosch G, van Schie HT, de Groot MW, Cadby JA, van de Lest CH, Barneveld A, van Weeren PR (2010) Effects of platelet-rich plasma on the quality of repair of mechanically induced core lesions in equine superficial digital flexor tendons: A placebo-controlled experimental study. J Orthop Res 28(2):211–217PubMedGoogle Scholar
  22. 22.
    Lyras DN, Kazakos K, Verettas D, Botaitis S, Agrogiannis G, Kokka A, Pitiakoudis M, Kotzakaris A (2009) The effect of platelet-rich plasma gel in the early phase of patellar tendon healing. Arch Orthop Trauma Surg 129(11):1577–1582PubMedCrossRefGoogle Scholar
  23. 23.
    Lyras D, Kazakos K, Verettas D, Polychronidis A, Simopoulos C, Botaitis S, Agrogiannis G, Kokka A, Patsouris E (2010) Immunohistochemical study of angiogenesis after local administration of platelet-rich plasma in a patellar tendon defect. Int Orthop 34(1):143–148PubMedCrossRefGoogle Scholar
  24. 24.
    Lyras DN, Kazakos K, Verettas D, Polychronidis A, Tryfonidis M, Botaitis S, Agrogiannis G, Simopoulos C, Kokka A, Patsouris E (2009) The influence of platelet-rich plasma on angiogenesis during the early phase of tendon healing. Foot Ankle Int 30(11):1101–1106PubMedCrossRefGoogle Scholar
  25. 25.
    De Vos RJ, Weir A, van Schie HT, Bierma-Zeinstra SM, Verhaar JA, Weinans H, Tol JL (2010) Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial. JAMA 303(2):144–149PubMedCrossRefGoogle Scholar
  26. 26.
    de Jonge S, de Vos RJ, Weir A, van Schie HT, Bierma-Zeinstra SM, Verhaar JA, Weinans H, Tol JL (2011) One-year follow-up of platelet-rich plasma treatment in chronic Achilles tendinopathy: a double-blind randomized placebo-controlled trial. Am J Sports Med 39(8):1623–1629PubMedCrossRefGoogle Scholar
  27. 27.
    Torricelli P, Fini M, Filardo G, Tschon M, Pischedda M, Pacorini A, Kon E, Giardino R (2011) Regenerative medicine for the treatment of musculoskeletal overuse injuries in competition horses. Int Orthop 35(10):1569–1576PubMedCrossRefGoogle Scholar
  28. 28.
    Batten ML, Hansen JC, Dahners LE (1996) Influence of dosage and timing of application of platelet-derived growth factor on early healing of the rat medial collateral ligament. J Orthop Res 14(5):736–741PubMedCrossRefGoogle Scholar
  29. 29.
    Borzini P, Mazzucco L (2005) Tissue regeneration and in loco administration of platelet derivatives: clinical outcome, heterogeneous products, and heterogeneity of the effector mechanisms. Transfusion 45(11):1759–1767PubMedCrossRefGoogle Scholar
  30. 30.
    Kon E, Filardo G, Delcogliano M, Fini M, Salamanna F, Giavaresi G, Martin I, Marcacci M (2010) Platelet autologous growth factors decrease the osteochondral regeneration capability of a collagen-hydroxyapatite scaffold in a sheep model. BMC Musculoskelet Disord 27(11):220CrossRefGoogle Scholar
  31. 31.
    De Moes M, Koevoet JLM, Jahr H, Verstegen MMA, Heijboer MP, Kops N, van Leeuwen JPMT, Weinans H, Verhaar JAN, van Osch GJVM (2007) Intrinsic differentiation potential of adolescent human tendon tissue: an in vitro cell differentiation study. BMC Musculoskelet Disord 8:16–27CrossRefGoogle Scholar
  32. 32.
    van Ark M, van den Akker-Scheek I, Meijer LT, Zwerver J (2013) An exercise-based physical therapy program for patients with patellar tendinopathy after platelet-rich plasma injection. Phys Ther Sport 14(2):124–130. doi: 10.1016/j.ptsp.2012.05.002
  33. 33.
    Gosens T, Den Oudsten BL, Fievez E, van't Spijker P, Fievez A (2012) Pain and activity levels before and after platelet-rich plasma injection treatment of patellar tendinopathy: a prospective cohort study and the influence of previous treatments. Int Orthop 36(9):1941–1946PubMedCrossRefGoogle Scholar
  34. 34.
    Mautner K, Colberg RE, Malanga G, Borg-Stein JP, Harmon KG, Dharamsi AS, Chu S, Homer P (2013) Outcomes after ultrasound-guided platelet-rich plasma injections for chronic tendinopathy: a multicenter, retrospective review. PM R 5(3):169–175 doi: 10.1016/j.pmrj.2012.12.010 Google Scholar
  35. 35.
    Vetrano M, Castorina A, Vulpiani MC, Baldini R, Pavan A, Ferretti A (2013) Platelet-rich plasma versus focused shock waves in the treatment of jumper's knee in athletes. Am J Sports Med 41(4):795–803. doi:  10.1177/0363546513475345.Google Scholar
  36. 36.
    Kon E, Filardo G, Delcogliano M, Presti ML, Russo A, Bondi A, Di Martino A, Cenacchi A, Fornasari PM, Marcacci M (2009) Platelet-rich plasma: new clinical application: a pilot study for treatment of jumper's knee. Injury 40(6):598–603PubMedCrossRefGoogle Scholar
  37. 37.
    Filardo G, Kon E, Della Villa S, Vincentelli F, Fornasari PM, Marcacci M (2010) Use of platelet-rich plasma for the treatment of refractory jumper's knee. Int Orthop 34(6):909–915PubMedCrossRefGoogle Scholar
  38. 38.
    Gaida JE, Cook JL, Bass SL, Austen S, Kiss ZS (2004) Are unilateral and bilateral patellar tendinopathy distinguished by differences in anthropometry, body composition, or muscle strength in elite female basketball players? Br J Sports Med 38(5):581–585PubMedCrossRefGoogle Scholar
  39. 39.
    Tol JL, Spiezia F, Maffulli N (2012) Neovascularization in Achilles tendinopathy: have we been chasing a red herring? Knee Surg Sports Traumatol Arthrosc 20(10):1891–1894PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Giuseppe Filardo
    • 1
  • Elizaveta Kon
    • 2
  • Berardo Di Matteo
    • 1
  • Patrizia Pelotti
    • 3
  • Alessandro Di Martino
    • 1
  • Maurilio Marcacci
    • 1
  1. 1.II Orthopaedic and Traumatology Clinic – Biomechanics and Technology Innovation LaboratoryRizzoli Orthopaedic InstituteBolognaItaly
  2. 2.Nano-Biotechnology LaboratoryRizzoli Orthopaedic InstituteBolognaItaly
  3. 3.Radiology and Diagnostic Imaging DepartmentRizzoli Orthopaedic InstituteBolognaItaly

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