Synonyms
Patella fracture, patella fracture, patella tendon, patella tendon, patella tendon, chondropathia patellae, retropatellar arthrosis, patella luxation, patella luxation Medical: Patella
Introduction
This topic is a continuation of the kneecap topic. More information on the topic Patella jumped out can be found under Patella luxationThe patella is a V-shaped bone in front of the knee joint. It is embedded in the tendon of the thigh muscles that are capable of stretching, which runs from the thigh via the knee to the lower leg.
Towards the knee side, it is located in a so-called slide bearing of the thigh bone, which is ideally adapted to the shape of the kneecap. Due to its special shape, the kneecap (patella) serves to transfer the pull of the thigh muscles to the lower leg while protecting the knee joint, thus enabling maximum extension of the knee. The condition of a chipped patella is called patella dislocation or patella dislocation.
Such a patella dislocation is found relatively frequently, whereby one must distinguish between two basic mechanisms how it can occur. On the one hand, there are the traumatic, accident-related patellar dislocations (which are mainly found in adolescents), on the other hand, there is the type that is caused by disposition and occurs without a specific preceding event (habitual). On average, women are affected slightly more frequently by this second form, men slightly more frequently by the first.
Factors that are believed to be conducive to the development of a habitual patella dislocation include the following: If one of these factors, or even a combination of several of the above, is present, the patella can quickly pop out, even if it is not subjected to any pronounced stress or involved in an accident. In contrast, in the case of traumatic patellar dislocation, there must have been an accident with a significant amount of force involved in the initial stages. This occurs particularly frequently in the context of sports activities, when the athlete is kicked against the knee with the leg stretched, when the thigh muscles are not or only slightly tense.
It occurs, for example, very often with footballers. In general, the kneecap almost always slips outwards through its slide rail and the ligaments on the inside of the knee tear. As a result, the kneecap is then located too far outside the knee and the joint looks deformed in a very typical way.
Regardless of the cause, however, the symptoms and treatment options for the kneecap that has popped out are almost identical.
- A little pronounced knee bearing,
- Incorrect positioning of the kneecap itself (patella dysplasia),
- A patella elevation (usually caused by an accident),
- A kneecap that is too straight,
- A general weakness of the connective tissue,
- X-legs (Genu valgum),
- If the thigh muscle tendon is too far out on the lower leg,
- A faulty contact of the gliding groove of the patella (trochleadysplasia)
- A shift of the patella to the opposite side.
First of all, it has a tendency to spontaneously jump back into its original position as soon as the affected person stretches the leg. The injury is extremely painful.
This pain is usually strongest below the knee and on the inside of the kneecap, as this is where the ligaments have been damaged. Often, shortly after the event, a massive swelling of the knee joint forms due to a joint effusion, which is caused by the fact that the injury to the ligaments causes bleeding. The pain and swelling also limit the movement of the knee joint.
Injured people tend to keep the leg in a slightly bent position, as this is the least painful. In some cases, in addition to the dislocation of the patella, small fragments of cartilage or bone may break off, which can get stuck somewhere in the joint and increase the pain. These can later lead to further cartilage damage and/or arthrosis of the knee joint.
In order to diagnose a patella dislocation, it is very important to take an x-ray in addition to a detailed medical history and physical examination.Here one can see the dislocation well and in addition, possibly already existing risk factors can be found. In addition, arthroscopy is a very popular procedure, as it not only provides a more detailed view of the situation in the joint, but also allows parts of the problem to be corrected directly by performing a joint lavage and removing small pieces of cartilage or bone. An even more precise assessment is offered by magnetic resonance imaging (MRI, magnetic resonance imaging), which is not a standard procedure in primary diagnostics, however, due to the great time and cost involved.
A successful treatment of patellar dislocation is of utmost importance. If it does not return to its correct position on its own (self-reposition), which fortunately it usually does, a doctor or experienced sports trainer must do this. Therapy must then take place, depending on the cause of the dislocation, the extent of the injury and the individual circumstances of the person affected (such as the risk profile, age, sporting activities and personal wishes).
In some cases, it can be done purely conservatively with the help of splints, bandages and physiotherapy, while in other cases one of various available surgical procedures must be used. The successful treatment is of such immense importance, because otherwise long-term complications can occur and the kneecap often tends to pop out again and again due to persistent instability. While about 80% of patients can be restored to a state of complete health with early treatment, only about 20% will be able to do so after multiple dislocations have already occurred. The urgency of treatment is therefore more than clear.
