Patella Tendonopathy

The patellar tendon is the structure lying below the kneecap (patella) attaching the quadriceps muscle to the tibia. Through the patellar tendon the quadriceps contraction allows the knee to extend or straighten. It is thought that the patella is a bone thickening (sesamoid bone) in the quadriceps tendon. Occasionally the patella itself can be two, three or even four discrete sesamoids, which can be associated with problems behind the patella.

Patellar tendon pain can occur in a number of different sports, most commonly in those that load the area (eg, weightlifting) but also in jumping sports and those that produce significant deceleration forces through the tendon, eg, basketball, squash, fencing, jumpers and field sports with high traction forces (such as hockey played on Astroturf). All patellar tendon pain was once referred to as ‘jumper’s knee’.

In the early stages of patellar tendinitis the most common symptom is tenderness over the bottom (the ‘lower pole’) of the patella. This tenderness is more usually felt after exercise and the athlete often finds it uncomfortable to squat or kneel. In my experience it is more common in the dominant leg and generally more common in men. As the problem evolves the athlete develops pain during exercise. The pain can become continuous both at rest and during training; unfortunately it is only at this later stage that athletes tend to seek medical advice.

It is thought that the first symptoms of patellar pain correlate with fluid or oedema in the patellar tendon, often close to the lower pole of the patella. Very little inflammation if any occurs and studies show degenerative changes in the tendon rather than any clear inflammatory process. This syndrome of degenerative change in the patellar tendon is called ‘patellar tendinosis’. Problems in the mid-third of the tendon are rarer but they can occur at the tendon insertion.

There are separate problems in adolescents both at the top (Sinding- Larsen-Johansson syndrome)...