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Patellar Tendonitis

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Other Names

  • Jumpers Knee
  • Patellar Tendinitis
  • Patellar Tendinopathy
  • Patellar Tendinosis
  • Patellar tendon pain




  • Prevalence
    • 7% of 14-18 year old junior Australian basketball players had clinical signs of patellar tendinopathy[1]
    • The prevalence of patellar tendon pain was 5.8% among 760 athletes across 16 different sports[2]
    • Among Elite volleyball players, Ferretti found the incidence to be 22.8%[3]
    • Taunton found 4.8% of runners had patellar tendon pain[4]
    • Among Norwegian athletes, the overall prevalence was 14.2%, highest in volleyball (44.6%) and basketball (31.9%)[5]
    • Among non-elite athletes, the overall prevalence was 8.5% with the highest in volleyball (14.4%) (need citation)


  • See: Tendinopathies (Main)
  • General
    • Represents a common overuse injury of the knee extensor mechanism
    • Can be seen acutely or chronically
    • Sports that involve rapid changes of direction, jumping, and running such as basketball and volleyball[6]
    • Landing phase contributes more to injury than take off phase
  • Occurs due to chronic repetitive tendon overload
    • Microtrauma can lead to individual fibril degeneration due to stress across the tendon
    • May result in weakening of the tissue
    • Tension is greatest with increased knee flexion
  • Other proposed theories of pathogenesis
    • Vascular
    • Mechanical
    • Impingement–related
    • Nervous system
  • Histopathology
    • Initially thought to be inflammatory, now considered a degenerative condition (tendinosis or tendinopathy)

Associated Conditions


Risk Factors

  • Sports
    • Basketball
    • Volleyball
    • Ice skating
  • Intrinsic factors
    • Male slightly more common than females[7]
    • Weight
    • Body Mass Index
    • Waist-to-hip ratio[8]
    • Leg-length difference
    • Arch height of the foot
    • Decreased quadriceps flexibility
    • Decreased hamstring flexibility
    • Quadriceps strength
    • Vertical jump performance
    • Patella alta[9]
    • Abnormal patellar tracking[10]
  • Extrinsic
    • Single sport athletes in basketball, volleyball or soccer at 4x greater risk[11]
  • Among volleyball players
    • Volume of training[3]
    • Training surface (concrete worse than wood)
    • Greater match exposure[12]

Differential Diagnosis

Clinical Features

  • History
    • Onset of pain is typically insidious
    • Patients will complain of knee pain just below the patella
    • Initially pain is only after activity, then eventually during activity and potentially all the time
    • Movie Theatre Sign: Patient can endorse pain after prolonged periods of sitting, for example in a movie theatre
  • Physical Exam: Physical Exam Knee
    • Swelling over the tendon may or may not be present
    • Tenderness the inferior patella pole, along the tendon or at the tibial insertion
    • Pain with resisted extension of the knee or with maximal stretching of the quadriceps
  • Special Tests
    • Bassets Sign: Tenderness of inferior patellar pole in extension but not in flexion




  • Ultrasound can be used to evaluate tendon integrity
  • Findings
    • Hyppoechoic areas
    • Thickened tendon
    • Neovascularization (chronic)


  • Indications
    • Chronic cases
    • Surgical planning
  • Findings
    • Tendon thickening
    • Increased signal on T1, T2
    • Sometimes loss of posterior border of fat pad


Blazina Classification System

  • Phase I: pain after activity only
  • Phase II: pain during and after activity
  • Phase III: persistent pain with or without activities, deterioration of performance



  • General
    • Temporary discontinuation of offending sport
    • Relative rest
    • Ice Therapy
    • Avoid complete immobilization to prevent atrophy
  • Oral Medications[13]
  • Topical Nitroglycerin
    • No significant difference between topical NO and placebo + eccentric training at 24 weeks, with both groups showing improvement[15]
  • Physical Therapy
    • Avoidance of jumping activities with stretching after physical activity may help in early disease[16]
    • Individuals performing eccentric exercises improved significantly compared with those undergoing a concentric exercise program[17]
    • RCT: Progressive tendon-loading exercises (PTLE) resulted in a significantly better clinical outcome after 24 weeks than eccentric exercise therapy (EET)[18]
  • Consider Patellar Counterforce Strap
    • May decrease patellar tendon strain by altering angle between patella and patella tendon[19]
    • Overall evidence is weakly favorable[20]
    • There are no high quality level 1 studies
  • Corticosteroid Injection
    • Not generally recommended due to risk of rupture
    • Under ultrasound guidance, some benefit over placebo at 4 weeks for pressure, walking pain[21]
    • At 6 months, was inferior to eccentric training and heavy slow resistance training[22]
  • Aprotinin Injection
    • When compared to corticosteroids and placebo, aprotinin had 72% good/excellent results compared with 59% in the CSI group and 28% in the placebo group[23]
    • High risk of side effects including anaphylaxis, bovine spongiform encephalopathy
  • Sclerosing Injection
    • Polidocanol injection showed significant improvement in VISCA score at 4 months[24]
    • Polidocanol was inferior to arthroscopy for pain, satisfaction and return to sport[25]
  • Platelet Rich Plasma
  • Extracorporeal Shock Wave Therapy (ESWT)
    • No difference between ESWT and surgical tenotomy at 22-26 months[26]
    • Compared to a control arm of NSAIDS, physical therapy and patellar strap, ESWT was superior at 2- and 3-years of follow-up[27]
  • Consider Needle Tenotomy
  • Consider Orthobiologics


  • Indications
    • Refractory cases
  • Surgery
    • Open debridement
    • Arthroscopic debridement

Rehab and Return to Play


  • Early phase
    • Pain reduction
    • Quadriceps strengthening
    • Isometric strengthening
  • Late phase
    • Begin when symptoms/ pain has resolved
    • Start eccentric strengthening

Return to Play

  • Needs to be updated

Complications and Prognosis


  • General conservative management
    • 90% of patients will have pain free return to play at 6 months (need citation)
  • Open surgical debridement
    • In 11 knees that failed conservative treatment, open debridement and drilling of the inferior pole of the patella produced 7 (64%) excellent, 3 (27%) good, and 1 (9%) poor result at an average of 2.1 years follow-up[28]
    • Other studies have produced similar results: Griffiths (86%)[29], Feetti found 70% had excellent results and 82% returned to play[30]
  • Arthroscopic surgical debridement
    • Lorbach achieved 90% good-to-excellent results among 20 patients[31]
    • Pascarella had 19/27 professional athletes return to sport[32]
    • Santander had 19/23 athletes return to play[33]


See Also


  1. Cook JL Khan KM Kiss ZS Griffiths L. Patellar tendinopathy in junior basketball players: a controlled clinical and ultrasonographic study of 268 patellar tendons in players aged 14-18 years. Scand J Med Sci Sports. 2000;10(4):216-220.
  2. Cassel M Baur H Hirschmuller A Carlsohn A Frohlich K Mayer F. Prevalence of Achilles and patellar tendinopathy and their association to intratendinous changes in adolescent athletes. Scand J Med Sci Sports. 2014.
  3. 3.0 3.1 Ferretti A. Epidemiology of jumper's knee. Sports Med. 1986;3(4):289-295.
  4. Taunton JE Ryan MB Clement DB McKenzie DC Lloyd-Smith DR Zumbo BD. A retrospective case-control analysis of 2002 running injuries. Br J Sports Med. 2002;36(2):95-101.
  5. Lian OB Engebretsen L Bahr R. Prevalence of jumper's knee among elite athletes from different sports: a cross-sectional study. Am J Sports Med. 2005;33(4):561-567.
  6. Lian OB, Engebretsen L, Bahr R. Prevalence of jumper’s knee among elite athletes from different sports: a cross-sectional study. Am J Sports Med. 2005;33:561-567.
  7. Karahan, Mustafa, and E. R. O. L. Bulent. "Muscle and tendon injuries in children and adolescents." Acta orthopaedica et traumatologica turcica 38 (2004): 37-46.
  8. Worp H, Ark M, Roerink S, Pepping GJ, Akker-Scheek I, Zwerver J. Risk factors for patellar tendinopathy: a systematic review of the literature. Br J Sports Med. 2011;45:446-452.
  9. Kujala UM Osterman K Kvist M Aalto T Friberg O. Factors predisposing to patellar chondropathy and patellar apicitis in athletes. Int Orthop. 1986;10(3):195-200.
  10. Allen GM Tauro PG Ostlere SJ. Proximal patellar tendinosis and abnormalities of patellar tracking. Skeletal Radiol. 1999;28(4):220-223.
  11. Hall R Barber Foss K Hewett TE Myer GD. Sport specialization's association with an increased risk of developing anterior knee pain in adolescent female athletes. J Sport Rehabil. 2015;24(1):31-35.
  12. Visnes H Bahr R. Training volume and body composition as risk factors for developing jumper's knee among young elite volleyball players. Scand J Med Sci Sports. 2013;23(5):607-613.
  13. Larsson, Maria EH, Ingela Käll, and Katarina Nilsson-Helander. "Treatment of patellar tendinopathy—a systematic review of randomized controlled trials." Knee surgery, sports traumatology, arthroscopy 20.8 (2012): 1632-1646.
  14. Andres BM, Murrell GA. Treatment of tendinopathy: what works, what does not, and what is on the horizon. Clin Orthop Relat Res. 2008;466:1539-1554
  15. Steunebrink M, Zwerver J, Brandsema R, Groenenboom P, Akker-Scheek I, Weir A. Topical glyceryl trinitrate treatment of chronic patellar tendinopathy: a randomised, double-blind, placebo-controlled clinical trial. Br J Sports Med. 2013;47:34-39
  16. Fredberg U, Bolvig L. Jumper’s knee. Review of the literature. Scand J Med Sci Sports. 1999;9:66-73.
  17. Jonsson P, Alfredson H. Superior results with eccentric compared to concentric quadriceps training in patients with jumper’s knee: a prospective randomised study. Br J Sports Med. 2005;39:847-850.
  18. Breda, Stephan J., et al. "Effectiveness of progressive tendon-loading exercise therapy in patients with patellar tendinopathy: a randomised clinical trial." British journal of sports medicine 55.9 (2021): 501-509.
  19. Lavagnino M, Arnoczky SP, Dodds J, Elvin N. Infrapatellar straps decrease patellar tendon strain at the site of the jumper’s knee lesion: a computational analysis based on radiographic measurements. Sports Health. 2011;3:296-302
  20. Schwartz, Aaron, Jonathan N. Watson, and Mark R. Hutchinson. "Patellar tendinopathy." Sports Health 7.5 (2015): 415-420.
  21. Fredberg U, Bolvig L, Pfeiffer-Jensen M. Ultrasonography as a tool for diagnosis, guidance of local steroid injection and, together with pressure algometry, monitoring of the treatment of athletes with chronic jumper’s knee and Achilles tendinitis: a randomized, double-blind, placebo-controlled study. Scand J Rheumatol. 2004;33:94-101
  22. Kongsgaard M, Kovanen V, Aagaard P. Corticosteroid injections, eccentric decline squat training and heavy slow resistance training in patellar tendinopathy. Scand J Med Sci Sports. 2009;19:790-802.
  23. Capasso G, Testa V, Maffulli N, Bifulco G. Aprotinin, corticosteroids and normosaline in the management of patellar tendinopathy in athletes: a prospective randomized study. Sports Exerc Inj. 1997;3:111-115.
  24. Hoksrud A, Ohberg L, Alfredson H, Bahr R. Ultrasound-guided sclerosis of neovessels in painful chronic patellar tendinopathy: a randomized controlled trial. Am J Sports Med. 2006;34:1738-1746.
  25. Willberg L, Sunding K, Forssblad M, Fahlstrom M, Alfredson H. Sclerosing polidocanol injections or arthroscopic shaving to treat patellar tendinopathy/jumper’s knee? A randomised controlled study. Br J Sports Med. 2011;45:411-415.
  26. Peers KH, Lysens RJ, Brys P, Bellemans J. Cross-sectional outcome analysis of athletes with chronic patellar tendinopathy treated surgically and by extracorporeal shock wave therapy. Clin J Sport Med. 2003;13:79-83.
  27. Wang CJ, Ko JY, Chan YS, Weng LH, Hsu SL. Extracorporeal shockwave for chronic patellar tendinopathy. Am J Sports Med. 2007;35:972-978.
  28. Pascarella A, Alam M, Pascarella F, Latte C, Di Salvatore MG, Maffulli N. Arthroscopic management of chronic patellar tendinopathy. Am J Sports Med. 2011;39:1975-1983.
  29. Griffiths GP, Selesnick FH. Operative treatment and arthroscopic findings in chronic patellar tendinitis. Arthroscopy. 1998;14:836-839.
  30. Ferretti A, Conteduca F, Camerucci E, Morelli F. Patellar tendinosis: a follow-up study of surgical treatment. J Bone Joint Surg Am. 2002;84:2179-2185.
  31. Lorbach O, Diamantopoulos A, Paessler HH. Arthroscopic resection of the lower patellar pole in patients with chronic patellar tendinosis. Arthroscopy. 2008;24:167-173.
  32. Pascarella A, Alam M, Pascarella F, Latte C, Di Salvatore MG, Maffulli N. Arthroscopic management of chronic patellar tendinopathy. Am J Sports Med. 2011;39:1975-1983
  33. Santander J, Zarba E, Iraporda H, Puleo S. Can arthroscopically assisted treatment of chronic patellar tendinopathy reduce pain and restore function? Clin Orthop Relat Res. 2012;470:993-997.
Created by:
John Kiel on 5 June 2019 04:06:51
Last edited:
4 October 2022 15:46:44