Apexitis patellae / tendinosis of the patellar tendon
Jumper's knee gets its name from the fact that the condition is very common with people who play sports that involve a lot of jumping. The symptoms are located around the patellar tendon on the front of the knee.
Jumper's knee is common in sports where (explosive) jumping plays an important part. Volleyball and basketball are good examples of this.
Description of the condition
The patellar tendon runs from the base of the knee cap (patella) to the front of the upper part of the shin bone (the tuberositas tibiae). In the case of jumper's knee, the tendon is affected at the point where it attaches to the patella. The tendon can be inflamed (tendinitis), or the quality and structure can deteriorate (tendinosis).
Cause and origin
The symptoms develop gradually and are not preceded by any trauma.
Signs & symptoms
The pain is located primarily below the point of attachment of the patellar tendon to the patella. Movements in which the legs are extended explosively (as with jumping) can provoke the symptoms. The symptoms can occur during and after exercise. In severe cases, the pain can even be felt during normal daily activities. For example, when walking on stairs or driving a car.
Pressing on the point of attachment of the patellar tendon is painful and sometimes localised swelling is visible. The inflammation is limited to the patellar tendon and is not seen in the rest of the knee joint - unless another injury of the knee is involved.
The diagnosis can usually be made by the physiotherapist with reasonable certainty. The patellar tendon can be imaged quite accurately using ultrasound or an MRI scan.
Good results have been obtained with controlled eccentric strength training of the quadriceps muscle (the muscle that extends the knee). Eccentric strength training has a favourable effect on the quality and tractive force of the tendon.
Nugteren, K. van & Winkel, D. (2006). Onderzoek en behandeling van peesaandoeningen - tendinose. Houten: Bohn Stafleu van Loghum.
Verhaar, J.A.N. & Linden, A.J. van der (2003). Orthopedie. Houten: Bohn Stafleu van Loghum.