Pathology

The structural damage in a jumper knee affects the tendon-bone transition of the patellar tendon (patella) at the tip of the patella. Microscopic examinations have revealed significant degenerative (wear-related) changes in the tendon tissue, whereas inflammatory cells were missing. This is therefore a degenerative (wear-related), not an inflammatory disease. This topic might also be of interest to you: Chronic knee pain

Symptoms

Patients with patellar tip syndrome report load-dependent pain in the patellar tip area. Depending on the stage of the disease, the pain may be present at the beginning of the load and disappear again after the warm-up phase, while it reoccurs in the phase following the load. In the advanced stage, the pain remains throughout the entire load.

In very advanced cases, the patella insertion hurts not only during sporting activities but also permanently in everyday life, for example when climbing stairs. Some patients describe a stab-like pain at certain angular conditions of the knee joint under load. The persistent character of the pain is typical.

It is often a chronic clinical picture that lasts for many months or years, with phases of low pain but recurring symptoms after peak loads. In 20-30 percent of cases, a patellar tendon syndrome occurs on both sides of the knee.The medical history (anamnesis) of patients with jumping sports as hobbies is trend-setting. Frequent jogging on hard ground or boddybuilding are also mentioned more frequently.

During the physical examination, a pressure pain above the tip of the patella is usually noticeable. A painful stretching movement of the lower leg against resistance is also typical. Visible redness or swelling are less common signs.

Sometimes the knee joint is completely unremarkable, in which case a suspected diagnosis can only be made on the basis of the patient’s medical history. Some patients also complain of a feeling of stiffness and pain after sitting for long periods, e.g. after long car journeys. Sonography (ultrasound) is an easily available and suitable procedure for the diagnosis of a Springer knee.

In order to be able to correctly assess any changes, the healthy opposite side should always be examined as well. Typical sonographic changes in a jumper’s knee are tendon thickening, irregularly limited tendon gliding tissue and an irregular tendon structure. The MRI examination of the knee is not part of the routine diagnosis of a patellar tendon jumper’s knee, even though it is a suitable procedure.

MRI is important for the localization of the degeneration area when surgical removal of the altered tendon tissue is pending. In addition, MRI of the knee allows a better assessment of the quality of the patellar tendon than sonography. The x-ray does not help with the patellar tendon syndromeSpringerkneeJumpers knee and is used to exclude other diseases.

Imaging procedures play an important role in a reliable diagnosis of patellar tendon syndrome. The main focus is on x-rays and sonography, through which changes in the bone and patellar tendon become clearly visible. In contrast to them, magnetic resonance imaging (MRI) is not part of the routine examinations of the jumper’s knee and is therefore rarely used in this procedure. The greatest advantage of this imaging technique is that it allows a very precise localization of the degenerated area, which is why it is used especially in the context of surgical removal of the affected tissue. In addition, the MRI allows the exclusion of differential diagnoses, such as degenerative changes in the cartilage, for example knee arthrosis.