Bone inflammation of the knee

Definition

Inflammation of the periosteum of the knee is understood to be inflammatory damage to the so-called periosteum. Since the knee includes the lower thigh bone, the upper tibia bone and the kneecap, all three of these bony structures also offer the possibility of being affected by an inflammation. This inflammation affects a layer that lies on the outside of all bones and is the only structure within the bone that can feel pain because small nerve fibers run only within this layer. And these fibers transmit the pain stimulus to the brain during an inflammation.

Causes

In principle, two potential causes of bone inflammation can be identified. On the one hand, periosteal inflammation due to overloading and on the other hand, infectious mediated periosteal inflammation. The first part clearly predominates.

Overloading occurs primarily in enthusiastic runners who increase their training workload massively for a short period of time or who put too much strain on the knee due to poor posture. The infectious variant can be traced back either to an injury to the knee itself or to pathogens that spread through the blood. It is difficult to predict exactly which part of the knee will be affected.

However, the tibia is the most common location for the occurrence of periosteal inflammation. The “runner’s knee” or Iliotibial Ligament Syndrome (ITBS) is primarily a differential diagnosis, but may be a precursor or cause of periostitis of the knee. The runner’s knee is a disease of the tendons and ligaments that stabilize the knee caused by overloading or, in most cases, incorrect loading.

Leg axis misalignments or legs of different lengths cause one side of the leg to be overstretched when running, while the opposite side is increasingly shortened. However, this also ensures that the ligaments and tendons on the stretched side are brought closer to the bone. Constant rubbing of bones and ligaments ultimately results in damage not only to the ligaments but also to the bony structures; in the worst case, this can lead to periosteitis if the sport is not stopped in time.

A fall on the knee usually carries the risk of an open wound, which can be the entry point for various germs. The knee is particularly predestined for this, as both the kneecap and the upper part of the tibia are only a few mm below the level of the skin. If a germ reaches the inside of the body via this route, the path to the periosteum is no longer a real obstacle. For most immunocompetent persons, however, this does not pose a problem, as their own immune system can easily fight off the pathogens. In contrast, immunocompromised patients are more susceptible to any kind of infection.