We need you! See something you could improve? Make an edit and help improve WikSM for everyone.

Patellar Tendonitis

From WikiSM
Jump to: navigation, search

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)


Basic illustration of the extensor mechanism of the knee[6]


  • 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[7]
  • 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

Anatomy of the Patellar Tendon

Risk Factors

  • Sports
    • Basketball
    • Volleyball
    • Ice skating
  • Intrinsic factors
    • Male slightly more common than females[8]
    • Weight
    • Body Mass Index
    • Waist-to-hip ratio[9]
    • Leg-length difference
    • Arch height of the foot
    • Decreased quadriceps flexibility
    • Decreased hamstring flexibility
    • Quadriceps strength
    • Vertical jump performance
    • Patella alta[10]
    • Abnormal patellar tracking[11]
  • Extrinsic
    • Single sport athletes in basketball, volleyball or soccer at 4x greater risk[12]
  • Among volleyball players
    • Volume of training[3]
    • Training surface (concrete worse than wood)
    • Greater match exposure[13]

Differential Diagnosis

Differential Diagnosis Knee Pain

Demonstration of Basset's sign

Clinical Features


  • 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

Patellar tendonitis seen in long axis at the inferior pole of the patella (right side of screen). Note the significant hypoechoic fluid collection in/ around the tendon where the patient was point tender
The fat-suppressed proton density weighted sagittal view confirms the abnormally thickened and edematous tendon (arrow). Mild adjacent edema is seen within the surrounding subcutaneous and infrapatellar fat, and small interstitial splits (arrowheads) are present within the proximal tendon.[14]




  • 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[15]
  • Topical Nitroglycerin
    • No significant difference between topical NO and placebo + eccentric training at 24 weeks, with both groups showing improvement[17]
  • Physical Therapy
    • Avoidance of jumping activities with stretching after physical activity may help in early disease[18]
    • Individuals performing eccentric exercises improved significantly compared with those undergoing a concentric exercise program[19]
    • RCT: Progressive tendon-loading exercises (PTLE) resulted in a significantly better clinical outcome after 24 weeks than eccentric exercise therapy (EET)[20]
  • Consider Patellar Counterforce Strap
    • May decrease patellar tendon strain by altering angle between patella and patella tendon[21]
    • Overall evidence is weakly favorable[22]
    • 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[23]
    • At 6 months, was inferior to eccentric training and heavy slow resistance training[24]
  • 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[25]
    • High risk of side effects including anaphylaxis, bovine spongiform encephalopathy
  • Sclerosing Injection
    • Polidocanol injection showed significant improvement in VISCA score at 4 months[26]
    • Polidocanol was inferior to arthroscopy for pain, satisfaction and return to sport[27]
  • Platelet Rich Plasma
  • Extracorporeal Shock Wave Therapy (ESWT)
    • No difference between ESWT and surgical tenotomy at 22-26 months[28]
    • Compared to a control arm of NSAIDS, physical therapy and patellar strap, ESWT was superior at 2- and 3-years of follow-up[29]
  • Consider Needle Tenotomy
  • Consider Orthobiologics


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

Demonstration of the decline eccentric squats used in rehab[30]

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[31]
    • Other studies have produced similar results: Griffiths (86%)[32], Feetti found 70% had excellent results and 82% returned to play[33]
  • Arthroscopic surgical debridement
    • Lorbach achieved 90% good-to-excellent results among 20 patients[34]
    • Pascarella had 19/27 professional athletes return to sport[35]
    • Santander had 19/23 athletes return to play[36]


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. Image courtesy of drerikhohmann.com, "Knee Extensor Mechanism"
  7. 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.
  8. 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.
  9. 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.
  10. 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.
  11. Allen GM Tauro PG Ostlere SJ. Proximal patellar tendinosis and abnormalities of patellar tracking. Skeletal Radiol. 1999;28(4):220-223.
  12. 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.
  13. 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.
  14. Image courtesy of https://radsource.us/jumpers-knee/
  15. 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.
  16. 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
  17. 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
  18. Fredberg U, Bolvig L. Jumper’s knee. Review of the literature. Scand J Med Sci Sports. 1999;9:66-73.
  19. 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.
  20. 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.
  21. 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
  22. Schwartz, Aaron, Jonathan N. Watson, and Mark R. Hutchinson. "Patellar tendinopathy." Sports Health 7.5 (2015): 415-420.
  23. 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
  24. 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.
  25. 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.
  26. 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.
  27. 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.
  28. 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.
  29. Wang CJ, Ko JY, Chan YS, Weng LH, Hsu SL. Extracorporeal shockwave for chronic patellar tendinopathy. Am J Sports Med. 2007;35:972-978.
  30. Theodorou, A., Komnos, G. & Hantes, M. Patellar tendinopathy: an overview of prevalence, risk factors, screening, diagnosis, treatment and prevention. Arch Orthop Trauma Surg 143, 6695–6705 (2023).
  31. 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.
  32. Griffiths GP, Selesnick FH. Operative treatment and arthroscopic findings in chronic patellar tendinitis. Arthroscopy. 1998;14:836-839.
  33. 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.
  34. Lorbach O, Diamantopoulos A, Paessler HH. Arthroscopic resection of the lower patellar pole in patients with chronic patellar tendinosis. Arthroscopy. 2008;24:167-173.
  35. 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
  36. 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:
21 April 2024 21:58:09