Patellar tendinitis is the most common form of overuse injury that occurs at the knee joint. Tendinitis is the inflammatory response of paratenon due to overuse injury. This injury is often the result of repetitive overuse of extensor mechanisms like during repetitive jumping activities or sports. Lower extremity biomechanical dysfunctions like foot pronation, stiff hip or knee joint, tight hamstrings may expedite the tendon injury.
On examination, patients usually complain of anterior knee pain just below the inferior pole of the patella. They also exhibit swelling along the painful area. The patients are very tender on palpation at the inferior pole of patella which can be provoked by the resisted knee extension.
|Pain only after participation Phase I|
|Some pain/discomfort during practice but not sufficient enough to interfere with participation Phase II|
|Pain during and after participation, sufficient enough to interfere with performance Phase III|
|Complete disruption of tendon Phase IV|
Classification of patellar tendinitis (Blazina et al, 1973).
Above classification of patellar tendinitis provides a clinical guideline to plan a treatment program for the patient.
- Adequate warm-up before prolong or sporting activities and ice following the activities
- A patellar re-straining brace or strap
- Modalities like ultrasound, cryo and heat therapies
- Correction of biomechanical disorders
- Exercise therapy to improve flexibility and AROM of joints. Especially, stretching of hamstrings and calf muscle are important.
- Muscular strength training starting at shorter muscle length-tension.
- Eccentric muscle strength training is reported being the most effective way to gain muscle strength back following tendinitis.
- Proprioceptive training
Apophysitis is also a type of injury due to overuse of extensor mechanism of the knee. Two types of apophysitis have been reported;
- Osgood-Schlatter’s disease – a traction apophysitis seen at the tibial tuberosity characterized by an enlargement of the tibial tuberosity.
- Sinding-Larsen-Johansson syndrome – a traction apophysitis that occurs on the inferior pole of the patella.
These apophysitis injuries are most commonly seen among the adolescents during the growth spurts and in the athletes participating in the jumping sports. The patients with apophysitis are managed as per the management of patellar tendinitis.
Some other possible causes of patellofemoral pain are;
- Direct patellar trauma
- Soft tissue lesions around patella like plica, infrapatellar fat pad, medial patellofemoral ligament, bursa, and distal ITB.
- Osteochondritis dissecans of the patella