What causes damage to the knee joint?

Friction and pain-free movement of the knee joint requires the joint cartilage on the femoral condyle and tibial plateau to be intact. A variety of factors can cause wear or damage to the protective cartilage layer, known as knee arthrosis (gonarthrosis):

  • wear of the joint cartilage for unexplained reasons (idiopathic arthrosis)
  • inflammation of the joint (chronic arthritis, rheumatism)
  • hereditary knee joint dysplasia (knock knee or bow leg)
  • incorrect loading or overloading of the knee joint during work or sporting activities; accidents with knee involvement
  • excess weight is regarded as an adverse factor in the development and progression of gonarthrosis

Progression of gonarthrosis

Damage knee joint: Lateral view of knee with gonarthrosis

In healthy knee joints the joint cartilage forms a smooth surface and the menisci also protect the joint surfaces against friction.

In the case of gonarthrosis damage is often first caused to the cartilaginous menisci, which then can no longer sufficiently protect the joint surfaces against pressure exerted by the weight of the body. In the course of time the joint surfaces of the femoral condyle and tibial plateau also suffer: the protective coating of cartilage becomes roughened at the point where the load is highest and eventually becomes completely worn.

Pain and restricted movement

If the joint surfaces rub against each other without the protective layer of cartilage, this will result in pain. Initially the sufferer only notices the pain when the joint is loaded, yet over the course of time, pain is increasingly experienced when the joint is not loaded, particularly at night. Most pain is experienced in the region of the knee affected but it can also radiate to the thigh or buttocks.

In addition, the knee joint increasingly loses its mobility, until it stiffens completely. As a result of this, sufferers adopt a relieving posture, which in turn causes muscle tension and pain in other regions of the body such as the hip or back.

Since the knee joint plays a key role in day-to-day activities, sufferers are increasingly affected in their everyday lives and experience diminished quality of life. Even getting out of bed or a chair, climbing stairs or getting in and out of a car can become a challenge.

Pain relief options

Depending on the nature of the pain experienced, the attending doctor will firstly try conservative methods to ease the pain. These include pain relief and anti-inflammatory medication, physiotherapy, baths and packs. These help to reduce the pain and improve joint mobility. Knee arthroscopy with irrigation of the articular cavity can also bring temporary relief.

However, there is currently no sure way of recreating an intact cartilage layer in the joint and healing arthrosis. Thus, if all the measures fail to ease the pain, sufferers can be helped with a replacement of the diseased joint using a knee endoprosthesis.