What pain must one expect with a knee prosthesis
A knee prosthesis is usually only used when there is considerable pain and the person affected is exposed to a high level of suffering. The aim of the knee prosthesis operation is therefore naturally to relieve the patient of this severe pain. Today, this is achieved in over 90% of cases when physiotherapy is performed and the prosthesis is handled well.
Rarely, however, it can happen that the pain persists or worsens after the operation; in some cases it can even radiate into the ankle. If this is the case, the affected person must consult a doctor as soon as possible. It helps the doctor to find the cause of the pain more quickly if a so-called pain diary is kept beforehand, i.e. exact information about the pain is written down, for example when exactly it occurs, how long it lasts, how it feels, where it is located and so on.
The reason for a painful knee prosthesis can be an infection, which in principle can occur after any operation. Such a postoperative infection is rare due to modern surgical techniques and hygiene measures, but must be treated immediately with antibiotics. This can be ruled out with the help of X-rays and laboratory values.
If the pain does not occur immediately after the operation, but only later, this may be an indication that the knee joint prosthesis has loosened. As a result of constant irritation of the joint, this leads to a joint effusion, which then causes pain to the patient. Normally, the lifetime of a prosthesis is about 15 to 20 years, which is why one should pay special attention to pain after this time.
Such loosening can also be seen by a doctor on an X-ray, and even relatively early on, which is why it is very important to make regular visits to the doctor. Here too, action must be taken as quickly as possible, since a loose artificial joint can permanently damage the bone and cartilage structures of the joint, making it difficult to reattach or reinsert a prosthesis. Otherwise, in everyday life with a knee prosthesis, pain may occur from time to time when the joint is subjected to particular stress, such as during certain sports or when climbing stairs.
However, if the pain is limited to these special activities, the patient should avoid them as far as possible and there is not necessarily a compulsion to treat this pain. An important reason for pain after a knee prosthesis operation can be the loosening of the prosthesis. In principle, the implanted prosthesis material can always loosen, so this is not an untypical complication.
As a rule, however, the durability is 10-15 years. The loosening is then caused by natural wear and tear. Pain that occurs at an earlier stage should be clarified, as it can be an indication of a knee prosthesis loosening.
The pain can be attributed to an inflammatory process in the knee joint. This inflammation is in turn caused by the fact that there is abrasion and wear and tear on the implant and therefore small particles of material become detached from the implant. These get into the joint where they cause an inflammatory process as a defensive reaction of the body through a deposit.
Cells of the defensive reaction accumulate in the space between bone and implant and thus create a cleft space. This gap formation means more space and mobility for the implant, so that in this case one speaks of a loosening of the knee prosthesis. An X-ray or scintigraphy can be taken to determine whether the pain is actually the result of the loosening.
As already mentioned, the loosening is accompanied by severe pain. Painkillers may help conditionally and relieve the symptoms temporarily, but it is necessary to treat the pain trigger itself therapeutically. This means that the knee prosthesis must be removed and replaced.
Although the inflammation can also be reduced by medication, the gap between the bone and the implant is irreversible. The indication for a knee joint prosthesis operation (see: knee prosthesis operation) is, among other things, to reduce or eliminate the existing restriction of movement.Nevertheless, these symptoms may still be present immediately after the procedure, accompanied by pain. The restriction of movement after the operation should be prevented by a quick mobilization in the form of rehabilitation measures with movement exercises (especially stretching).
A further goal is the freedom from pain, which, for certain reasons explained above, does not occur immediately or in every case. During the rehabilitation measures, slight dislocations of the knee joint may occur in rare cases, which may subsequently restrict mobility. The risk of dislocation is also present outside of rehabilitation.
Especially at the beginning, patients should not expect too much. Regeneration of the knee joint takes time. However, despite regular physiotherapy or exercise, not all degrees of movement are fully possible at the beginning, especially not without slight pain.
Patients must be aware of this, on the one hand, so that they do not overestimate themselves and put too much strain on the knee and, on the other, so that they can classify possible pain. It is quite normal that climbing stairs after a knee prosthesis operation causes pain, as the knee joint is not yet fully mobile and capable of bearing weight. The restriction of movement including the pain can also be a consequence of certain risks.
As with any operation, there are general and specific risks. A special risk of knee prosthesis surgery is the occurrence of adhesions or sticking of structures of the knee joint, which is associated with unpleasant pain. As a rule, this complication does not occur, since special emphasis is placed on early mobilization after the operation, so that the probability of adhesions or adhesions is low.
However, if the rehabilitation measures are not followed appropriately by the patient, the knee joint may lose mobility immediately after the operation and become very painful. In the worst case, a second operation may be necessary to remove adhesions and relieve the pain. The pain caused by restricted mobility can also be secondary to a fall.
The risk of falling is extremely increased after a knee prosthesis operation. Immediately after the operation, patients are not yet as mobile and are less stable and safe when walking and standing. In addition, the knee joint is still stiff, which is why movement exercises are so important.
If a fall occurs, the knee joint is not very flexible and can hardly compensate for a fall with strong pressure and force, resulting in a compression, contusion or fracture. This, in turn, is accompanied by swelling, severe pain and the associated restrictions on movement. A final reason for pain can be limited movement due to calcification in the muscular structures of the knee joint.
