Patellar tendonitis/tendinosis (Runners Knee or Jumpers Knee)

Patellar tendonitis is caused by overuse of the patellar tendon and happens usually at the middle of the tendon on the deep side of the tendon where it attaches to the patella (kneecap) or less often at the tibia (shin bone).

Relative overuse will lead to small (micro) tears in the tendon that in the repair process will lead to scar tissue that will become painful when the affected area is large enough to threaten the structure of the tendon (danger of it tearing). This condition is often asymptomatic and at the stage that the patients become aware of it, he or she faces a long recovery process.

Patellar tendinitis is an overuse injury seen in athletes in all high impact sports like athletics, tennis, basket, vaulting, gymnastics, cross fit etc. This injury is the most common lower limb overuse injury in high performance tennis players and has curtailed or even ended many promising tennis careers.

Initially the knee will only hurt after sport and then later at the start of play and gets better as the knee warms up. Once a swelling develops just below the kneecap at the attachment of the patellar tendon, it usually means significant part of the tendon involved, Grade 4 per definition.


Research on the effect of different shoes and court surfaces on patellar tendon tensile forces have not yielded much. Changing from a long, heal strike, stride in running to a shorter, midfoot strike, stride seems to promise lower tensile forces on the patella. In tennis focussing on midfoot or fore foot strike running, should lower the incidence of patellar tendinitis. Adjusting of running patterns should be done very early in any athlete’s career.

Inadequate recovery is most probably the biggest cause for patellar tendinosis. It is important that athletes follow an injury prevention program, focussing on eccentric training of quadriceps and hamstring exercises, core muscle strengthening and adequate recovery.


On clinical evaluation, diagnostic high resolution ultrasound and MRI scan are the best ways to make the diagnosis.


Aim in treatment

The aim in treatment is to stop the overload on the tendon and allow the tendon to heal itself.


Prevention is better than cure in these injuries that can take 2 years to heal, in the severe cases. Adequate recovery in a high performance athlete’s training program is most probably one of the most difficult challenges that any aspiring athlete or coach face. It is even more important in the growing athlete. Measurements of sleep patterns, jump tests or beep tests are all guidelines to determine adequate recovery in individual athletes.


Rest does not mean total immobilization, but adjustment of activities and no competitive sport or jumping exercises. Eccentric and low impacted exercises with attention to detail under supervision of an experienced biokineticist or trainer will yield the best results.

PRP infiltrations or needling

Platelet rich plasma needling seems to have saved some high profile athlete’s careers and is an option that is used in many cases, successfully. The amount of different infiltrations is still unclear.

Surgical excision of scar tissue

If everything fails, in the resistant grade 4 cases, surgery removal of scar tissue and . In all cases the recovery is at least 6 months.

None of these treatment methods give good results without also adjustment of the load and sufficient recovery period.