Patellar Tendinopathy

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Original Editors - Dorien De Ganck

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Search Strategy

I consulted Pubmed to search for randomized clinical trials. I also consulted Pedro but I didn’t found much useful information. At Web of knowledge there were some interesting studies. I searched in books that I lent from the VUB library and in books that I lent from a physiotherapist.

These are the words I used: - Patellar tendinitis- Patellar tendonitis- Patellar tendinopathy- Jumper’s knee- tendinitis
- tendinosis- Patellar tendinitis therapy- Anterior knee pain

Definition/Description

If the normal smooth gliding motion of the tendon is impaired, it will become inflamed and tender and movement will become painful. Pain usually centers where the kneecap meets the patellar tendon. Tendinitis is the condition that arises when the tendon and the tissues that surround it, become inflamed and irritated meaning that inflammatory cells and components are found in the blood or in the tissues surrounding the patella. Patellar tendinitis is a condition resulting from overuse of the knee.Jumper’s knee, another name for patellar tendinopathy is a syndrome with micro tears and collagen degeneration in the patellar tendon also due to overuse but non- inflammatory . When this condition exists without clinical symptoms, it’s called tendinosis . The term tendinosis should be used as a histopathological and not a symptomatic description.
- Patellar tendinitis should also be distinguished from Osgood-Schlatter’s disease which is a form of osteochondritis.
-Adolescents growing fast in a short time can be affected by the Sinding-Larsen-Johansson disease.

Clinically Relevant Anatomy

 The knee joint consists three bones, the femur, the tibia, the fibula and also the patella which is a sesamoid. The quadriceps muscles are connected to the patella with a shared tendon and there is also a tendon that connects the bottom of the patella to the tibia, called the patellar tendon. This tendon is extremely strong and allows the quadriceps muscle group to straighten the leg. The patellar tendon is made of tough string-like bands. These bands are surrounded by a vascular tissue lining providing nutrition to the tendon. The patellar tendon is also a ligament.

Epidemiology /Etiology

 These are the most common causes of patellar tendinitis:
• a rapid increase in the frequency of training,
• sudden increase in the intensity of training,
• transition from one training method to another,
• repeated training on a rigid surface,
• improper mechanics during training,
• genetic abnormalities of the knee joint, and/or
• poor base strength of the quadriceps muscles.

Tendinitis can be the result of a tendinopathy .
Some patients develop patellar tendinitis after sustaining an acute injury to the tendon, and not allowing adequate healing.

Characteristics/Clinical Presentation

Pain is the first symptom of patellar tendinitis. The pain usually is located in the section of the patellar tendon . During physical activity, it may feel sharp especially when running or jumping. After the workout it will feel like a dull ache. There is swelling and tenderness in and around the patellar tendon. The knee will often feel ‘tight’ when moved towards flexion.

Differential Diagnosis

Knee pain is a common presenting complaint with many possible causes. Therefore it is important to identify the different disorders. Each have a different patterns that can help to identify the underlying cause more efficiently.

Anterior knee pain:
• Patellar subluxation or dislocation
• Tibial apophysitis (Osgood shlatter)
• Jumpers knee (patellar tendonitis)
• Patellofemoral pain syndrome (chondromalacia patellae)
Medial knee pain:
• Medial collateral ligament strain
• Medial meniscal tear
• Pes anserine bursitis
• Medial plica syndrome
Lateral knee pain:
• Lateral collateral ligament sprain
• Lateral meniscal tear
• Iliotibial band tendonitis
Posterior knee pain:
• Popliteal cyst (Baker’s cyst)
• Posterior cruciate ligament injury

Diagnostic Procedures

The signs and symptoms of patellar tendinitis are fairly easy to detect. The athlete will complain of:

• pain in the area of the tendon,
• the knee will often feel "tight,"
• pain will be experienced early in the workout and after the workout is completed,
• there may be some subtle swelling of the tendon, and
• the athlete may feel that the tendon is "squeaking."

The key physical finding in patellar tendinopathy is tenderness at the inferior pole of the
patella or in the main body of the tendon when the knee is fully extended and the quadriceps relaxed. When the knee is flexed to 90 degrees, thus putting the tendon under tension, tenderness significantly decreases and often disappears altogether.

Outcome Measures

A visual analog pain scale can be used to describe the level of pain provoked as the tendon is palpated.

(also see Outcome Measures Database)

Examination

Two clinical signs can be performed to assess patellar tendinitis .

In the “passive extension – flexion sign” the patient lies supine on the examination table. The anterior aspect of the extended knee is palpated to define the point of maximal tenderness.
In the case of patellar tendinitis, tenderness to palpation of the tendon is most often located at the origin of the tendon at the inferior pole of the patella.
Once the point of maximal tenderness is identified, the knee is flexed to 90° and pressure is again applied to the tendon.

For the “standing active quadriceps sign”, the patellar tendon is palpated along its course while the patient stands. The point of maximal tenderness identified. The patient is then asked to stand only on the involved extremity with 30° of knee flexion and the tendon was re-palpated.

In both these tests, the patient should note a marked reduction of tenderness to palpation when the knee is flexed or the quadriceps contract, in order to confirm the diagnosis of patellar tendinitis.

Medical Management

There are different types of treatment used in the medical management of tendon disorders.
Unfortunately, few have a strong evidence base.

1. Non-steroidal anti-inflammatory drugs
The use of non-steroidal anti-inflammatory drugs (NSAID’s) in the treatment of tendinopathy remains controversial both in the acute stage and in the chronic stage. NSAID’s do, however, have an analgesic effect possibly independent of the anti-inflammatory action.

2. Corticosteroid injections
Corticosteroid injections are a commonly administered treatment for tendon disorders. All the usual side-effects of corticosteroids are possible (such as skin atrophy, skin hypopigmentation, postinjection flare of symptoms, infection and possible effects from systemic absorption particularly after multiple injections). There is also the possible effect on the mechanical integrity of the
tendons themselves.

3. Surgical treatment
Very good results were achieved. In the chronic stage the lesions are irreversible and constitute permanent intratendinous lesions. It thus seems logical to excise these lesions from their origin at the apex of the patella and entry into the adjacent tendon.

Physical Therapy Management

Physical therapy for about four to six weeks (3 times a week) is usually recommendet. The first step before treatment is rest. It’s important that the patient avoids activities that aggravate the problem. He can take non steroidal anti- inflammatory medications. These will decrease pain and swelling.
The physiotherapist can use ice massage(cryotherapy), electrotherapy, Iontophoresis , and ultrasound to limit pain and to control swelling.
Typical for a tendinitis therapy is to perform deep transverse frictions.
After a five-minute warm up period, an important thing to perform are stretching exercises for the quadriceps. Inflexible muscles, especially inflexible thigh muscles (quadriceps), contribute to the strain on the patellar tendon and to correct any muscle imbalances.
In the second week the physiotherapist will try ‘shock wave therapy’. It helps to regenerate the tendon and stimulates circulation.
After a while as the symptoms allow, strengthening exercises can start. They are very useful for the knee joint and quadriceps. A few examples are:
- Straight Leg Raises
- knee flexion and extension, as well as hip flexion
- squats, calf raises, step-ups

Researchers have discovered that patellar tendinitis responds to a concentric-eccentric program of closed chain exercises for the anterior tibialis muscle. That is the muscle in the lower leg that helps dorsiflex the ankle. For example toe stand and heel position.
Eccentric closed chain exercises are also good for strengthening the quadriceps
After a while the patient can start with proprioceptive exercises: cycling, aerofit, etc…
Next in line are flexibility exercises, those are useful to restart especially running or jumping sports. For less pain and more stability a brace or tape for the patella can be useful. Most braces for patellofemoral problems are made of soft fabric, such as cloth or neoprene. Patella taping may be used to provide support for the patella and knee and to reduce abnormal patella positioning or tracking. One of those techniques is the McConnell taping technique.
After the exercising program it’s good to cool down, stretch and use cryotherapy.
Therapists also design special shoe inserts, called orthotics, to improve knee alignment and function of the patella.
Don’t overdo the own limits in the exercise program.
For people who do high-level sports: coaches, trainers, and therapists can work together to design a training program that allows to continue training without irritating the tendon and surrounding tissues.
If nonsurgical treatment fails to improve the condition, then surgery may be suggested. Surgery is designed to stimulate healing through revascularization .

Key Research 

- Patellar tendinitis
- Patellar tendonitis
- Patellar tendinopathy
- Jumper’s knee
- Tendinitis
- Tendinosis
- Patellar tendinitis therapy
- Anterior knee pain

Resources 

Primary
1. Blazina ME, Kerlan RK, Jobe FW, Carter VS, Carlson GJ. Jumper’s knee. Orthop Clin North Am. 1973;4:665–78. [PubMed]
2. Romeo AA, Larson RV. Arthroscopic treatment of infrapatellar tendonitis. Arthroscopy. 1999;15:341–5. [PubMed]
3. Jonsson P, Alfredson H. Superior results with eccentric compared to concentric quadriceps training in patients with jumper’s knee. Br J Sports Med 2005;39:847-850
4. Duri ZA, Aichroth PM, Wilkins R, Jones J. Patellar tendonitis and anterior knee pain. Am J Knee Surg. 1999 Spring;12(2):99-108.
5. Aronen JG, Garrick JG. Sports-induced inflammation in the lower extremities. Hosp Pract . 1999;34:51.
6. O'Connor FG, Howard TM, Fieseler CM, Nirschl RP. Managing overuse injuries: a systematic approach. Phys Sportsmed . 1997 May;25(5).
7. De Bruin ED, Mangold S, Menzi C. Evidence based evaluation of conservative treatment options for patellar tendinitis syndromes. 2003 Dec;17(4):165-70 [pubmed]

8. Khan K, Cook J. The painful nonruptured tendon: clinical aspects. Clin Sports Med 2003;22:711-25.
9. Almekinders LC, Temple JD. Etiology, diagnosis, and treatment of tendonitis: an analysis of the literature. Med Sci Sports Exerc 1998;30:1183-90.
10. Torstensen, Eric T.; Bray, Robert C.; Wiley, J. Preston. Patellar Tendinitis: A Review of Current Concepts and Treatment. Clinical Journal of Sport Medicine. 1994 4(2):77-82, April.
11. Vargas B, Lutz N, Dutoit M, Zambelli PY. Osgood-Schlatter disease. Rev Med Suisse. 2008 Sep
24;4(172):2060-3.
12. Alfredson H., Pietila T., Johnston P., Lorentzon R. Heavy-load eccentric muscle training for the
treatment of chronic Achilles tendinosis.Am J Sports Med 1998; 26 (3);360-366
13. Stalder H. What is your diagnosis? Sinding-Larsen-Johansson syndrome. Praxis (Bern 1994).
1995 Mar 1;84(9):241-3.

14. CALMBACH. W., Evaluation of Patients Presenting with Knee Pain: Part II. Differential Diagnosis,  AMERICAN FAMILY PHYSICIAN, SEPTEMBER 1, 2003

== References ==

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References

1. International Orthopedics Volume 34, Number 6, 909-915, DOI: 10.1007/s00264-009-0845-7
2. http://www.shakadula.com/p90x/?p=1160
3. Physical Therapy March 1989 vol. 69 no. 3 211-216
4. http://www.medical-library.org/journals5a/patellar_tendonitis.htm
5. Patrick Milroy .Bodyworks: Patellar Tendinitis. Runners world 2000, 5 june
6. Medicine & Science in Sports & Exercise:August 1998 - Volume 30 - Issue 8 - pp 1183-1190
7. http://www.eorthopod.com/content/patellar-tendonitis
8. E.Witvrouw,M.Lorent. Oefentherapie bij knieaandoeningen.1e druk 2005