Patellar tendinitis
Overuse injury of the patellar tendon causing anterior knee pain.
Patellar tendinitis, commonly called jumper's knee, is an overuse injury affecting the tendon responsible for straightening the knee. It causes pain in the front of the knee, usually at the lower edge of the kneecap, though the upper area can also be involved. The pain is generally absent when at rest. A possible complication is a complete tear of the patellar tendon.
The condition is most frequent in athletes who play jumping sports like basketball and volleyball. Other risk factors include being overweight, sex, age, occupation, and overall physical activity level. The likelihood of developing it increases with age. The underlying problem involves small tears in the tendon that connects the kneecap to the shinbone. Diagnosis is usually made based on symptoms and a physical exam, though ultrasound or MRI can help assess severity. Conditions that may appear similar include infrapatellar bursitis, chondromalacia patella, and patellofemoral syndrome.
Treatment often involves resting the knee and physical therapy, but evidence supporting these measures is weak. Recovery can take months and may persist for years. The condition is fairly common, affecting about 14% of athletes at any given time. Males are affected more often than females. The term "jumper's knee" was first used in 1973.
**Signs and symptoms** People typically feel an aching pain in the front of the knee that develops gradually. A specific injury is rarely reported. The pain is usually below the kneecap but can also be above. Jumper's knee is classified into four stages: - Stage 1: Pain only after activity, with no loss of function. - Stage 2: Pain during and after activity, but the person can still perform well in their sport. - Stage 3: Prolonged pain during and after activity, with increasing difficulty performing at a satisfactory level. - Stage 4: Complete tendon tear requiring surgery.
The condition starts as inflammation where the patellar tendon attaches to the kneecap and may progress to tearing or degeneration of the tendon. MRI can show swelling (increased T2 signal) in the upper part of the tendon.
**Causes** Patellar tendinitis is an overuse injury from repetitive stress on the patellar tendon, leading to microtears and inflammation that don't heal between uses. It is common in athletes who do a l
- also_known_as
- Jumper's knee
- common_in
- Athletes, especially in jumping sports
- affected_population
- About 14% of athletes currently affected
- sex_prevalence
- Males more commonly affected than females
- risk_factors
- Athletics, overweight, low ankle dorsiflexion, weak gluteal muscles, muscle tightness
- stages
- 4 stages, from pain only after activity to complete tendon tear
- term_coined
- 1973
Lore & Background
Patellar tendinitis is an overuse injury resulting from repetitive overloading or repetitive stress of the patellar tendon, leading to microtears and inflammation that do not have time to heal. The underlying mechanism involves small tears in the tendon connecting the kneecap with the shinbone. Symptoms include anterior knee pain with an aching quality, and onset is insidious; rarely is a discrete injury described. The condition can be classified into four stages, from pain only after activity to complete tendon tear requiring surgical repair.
Reader's Guide
Patellar tendinitis is a significant condition in sports medicine, affecting about 14% of athletes, with more than half of those affected ending their careers as a result. The term 'jumper's knee' was coined in 1973, reflecting its prevalence in jumping sports. The condition's classification into four stages helps guide treatment, though evidence for most treatments is poor. Recovery can take months and persist over years. The condition highlights the challenges of managing overuse injuries in athletes, where rest and rehabilitation are critical but often insufficient. Novel treatment modalities targeting abnormal blood vessel growth are under investigation, but current surgical options show no better effects than exercise programs. The condition's epidemiology underscores its impact on athletic populations, particularly males.
Did You Know?
- The term 'jumper's knee' was coined in 1973.
- More than half of athletes with patellar tendinitis end their careers as a result.
- Males are more commonly affected than females.
- Evidence for treatments, including rest, is poor.
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