Patellar tendinitis
Other namesquadriceps tendinopathy, patellar tendinopathy, jumper's knee, patellar tendinosis, patellar tendinitis
Location of the pain in patellar tendinitis
SpecialtyOrthopedics, sports medicine
SymptomsPain at the front of the knee[1]
ComplicationsPatellar tendon rupture[2]
Risk factorsJumping sports, being overweight[1]
Diagnostic methodBased on symptoms and examination[2]
Differential diagnosisChondromalacia patella, Osgood-Schlatter disease, patellofemoral syndrome, infrapatellar bursitis[1][2]
TreatmentRest, physical therapy[2]
PrognosisRecovery can be slow[2]
Frequency14% of athletes[1]

Patellar tendinitis, also known as jumper's knee, is an overuse injury of the tendon that straightens the knee.[1] Symptoms include pain in the front of the knee.[1] Typically the pain and tenderness is at the lower part of the kneecap, though the upper part may also be affected.[2] Generally there is no pain when the person is at rest.[2] Complications may include patellar tendon rupture.[2]

Risk factors include being involved in athletics and being overweight.[1] It is particularly common in athletes who are involved in jumping sports such as basketball and volleyball.[1][2] Other risk factors include sex, age, occupation, and physical activity level.[3] It is increasingly more likely to be developed with increasing age.[3] The underlying mechanism involves small tears in the tendon connecting the kneecap with the shinbone.[2] Diagnosis is generally based on symptoms and examination.[2] Other conditions that can appear similar include infrapatellar bursitis, chondromalacia patella and patellofemoral syndrome.[1][2]

Treatment often involves resting the knee and physical therapy.[2] Evidence for treatments, including rest, however is poor.[4][5] Recovery can take months and persist over years.[6][7][8][2] It is relatively common with about 14% of athletes currently affected; however research reflects that more than half of athletes with this injury end their careers as a result.[9][8][1] Males are more commonly affected than females.[2] The term "jumper's knee" was coined in 1973.[2]

Signs and symptoms

People report anterior knee pain, often with an aching quality. The symptom onset is insidious. Rarely is a discrete injury described. Usually, the problem is below the kneecap but it may also be above. Jumper's knee can be classified into 1 of 4 stages, as follows:[2]

Stage 1: Pain only after activity, without functional impairment

Stage 2: Pain during and after activity, although the person is still able to perform satisfactorily in his or her sport

Stage 3: Prolonged pain during and after activity, with increasing difficulty in performing at a satisfactory level

Stage 4: Complete tendon tear requiring surgical repair

It begins as inflammation in the patellar tendon where it attaches to the patella and may progress by tearing or degenerating the tendon. People present with an ache over the patella tendon. Magnetic resonance imaging can reveal edema (increased T2 signal intensity) in the proximal aspect of the patellar tendon.[citation needed]

Causes

It is an overuse injury from repetitive overloading of the extensor mechanism of the knee. The microtears exceed the body's healing mechanism unless the activity is stopped.[citation needed]

Among the risk factors for patellar tendonitis are low ankle dorsiflexion, weak gluteal muscles, and muscle tightness, particularly in the calves, quadriceps muscle, and hamstrings.[10]

It may be associated with stiff ankle movement and ankle sprains.[11][12]

Diagnosis

Diagnosis is generally based on symptoms and a physical examination.[2] Ultrasound or magnetic resonance imaging may help clarify how severe the problem is.[2]

Having a clinical diagnosis is the preferred way to diagnose patellar tendonitis, due to ultrasonographic abnormality. [3]

Treatment

Evidence for treatment is poor.[4] In the early stages rest, ice, compression, and elevation may be tried. Tentative evidence supports exercises involving eccentric muscle contractions of the quadriceps on a decline board.[13] Specific exercises and stretches to strengthen the muscles and tendons may be recommended, e.g. cycling or swimming. Use of a strap for jumper's knee and suspension inlays for shoes may also reduce the problems. Corticosteroid injections and NSAIDs are generally recommended.[2][dubious – discuss]

Procedures

Dry needling, sclerosing injections, platelet-rich plasma, extracorporeal shock wave treatment (ESWT), and heat therapy have been tried.[2]

According to a study comparing ESWT to conservative treatment, it was found with low certainty that ESWT has a large treatment effect to reduce short term pain. [3]

Surgery

Surgery may be tried if other measures fail.[2] This may involve removal of myxoid degeneration in the tendon. This is reserved for people with severe pain for 6–12 months despite conservative measures. Novel treatment modalities targeting the abnormal blood vessel growth which occurs in the condition are currently being investigated.[citation needed] Knee operations in most cases have no better effects than exercise programs.[citation needed]

Epidemiology

It is relatively common with about 14% of athletes currently affected.[1] Males are more commonly affected than females.[2]

References

  1. ^ a b c d e f g h i j k King D, Yakubek G, Chughtai M, Khlopas A, Saluan P, Mont MA, Genin J (February 2019). "Quadriceps tendinopathy: a review-part 1: epidemiology and diagnosis". Annals of Translational Medicine. 7 (4): 71. doi:10.21037/atm.2019.01.58. PMC 6409230. PMID 30963066.
  2. ^ a b c d e f g h i j k l m n o p q r s t u v w Santana JA, Sherman A (January 2019). Jumpers Knee. Treasure Island, FL: StatPearls Publishing. PMID 30422564.
  3. ^ a b c d Charles R, Fang L, Zhu R, Wang J (2023). "The effectiveness of shockwave therapy on patellar tendinopathy, Achilles tendinopathy, and plantar fasciitis: a systematic review and meta-analysis". Frontiers in Immunology. 14: 1193835. doi:10.3389/fimmu.2023.1193835. ISSN 1664-3224. PMC 10468604. PMID 37662911.
  4. ^ a b Mendonça LM, Leite HR, Zwerver J, Henschke N, Branco G, Oliveira VC (6 June 2019). "How strong is the evidence that conservative treatment reduces pain and improves function in individuals with patellar tendinopathy? A systematic review of randomised controlled trials including GRADE recommendations". British Journal of Sports Medicine. 54 (2): bjsports–2018–099747. doi:10.1136/bjsports-2018-099747. PMID 31171514. S2CID 174810797.
  5. ^ Saithna A, Gogna R, Baraza N, Modi C, Spencer S (30 November 2012). "Eccentric Exercise Protocols for Patella Tendinopathy: Should we Really be Withdrawing Athletes from Sport? A Systematic Review". The Open Orthopaedics Journal. 6 (1): 553–557. doi:10.2174/1874325001206010553. ISSN 1874-3250. PMC 3522085. PMID 23248727.
  6. ^ Nuhmani S, Muaidi QI: Patellar tendinopathy: a review of literature. J Clin Diagn Res 2018;12. doi:10.7860/JCDR/2018/35797.11605.
  7. ^ Cummings K, Skinner L, Cushman DM: "Patellar tendinopathy in athletes". Curr Phys Med Rehabil Rep 2019;7:227–36
  8. ^ a b Plinsinga M.L., Meeus M., Brink M., Heugen N., Van Wilgen P. "Evidence of Widespread Mechanical Hyperalgesia but Not Exercise-Induced Analgesia in Athletes with Mild Patellar Tendinopathy Compared with Pain-Free Matched Controls: A Blinded Exploratory Study". Am. J. Phys. Med. Rehabil. 2021;100(10):946-951. doi:10.1097/PHM.0000000000001673
  9. ^ Kettunen JA, Kvist M, Alanen E, et al: Long-term prognosis for Jumper's knee in male athletes: a prospective follow-up study. Am J Sports Med 2002;30:689–92
  10. ^ Koban M (2013). Beating Patellar Tendonitis. CreateSpace Independent Publishing Platform. pp. 20–25. ISBN 978-1-4910-4973-0.
  11. ^ Marcus A (7 October 2011). "Stiff ankles tied to young athletes' painful knees". Reuters.
  12. ^ Backman LJ, Danielson P (December 2011). "Low range of ankle dorsiflexion predisposes for patellar tendinopathy in junior elite basketball players: a 1-year prospective study". The American Journal of Sports Medicine. 39 (12): 2626–33. doi:10.1177/0363546511420552. PMID 21917610. S2CID 39755525.
  13. ^ Visnes H, Bahr R (April 2007). "The evolution of eccentric training as treatment for patellar tendinopathy (jumper's knee): a critical review of exercise programmes". British Journal of Sports Medicine. 41 (4): 217–23. doi:10.1136/bjsm.2006.032417. PMC 2658948. PMID 17261559.
Categories