Patella Aplasia

Patellar aplasia is a condition that causes restricted movement of the knee. Mostly is painless and shows no further complaints. As a result, no treatment is often necessary.

Patella Aplasia

What is Patella Aplasia?

The disease patellar aplasia is associated with an impairment of the patella. This is a bone located in front of the knee joint. In the case of patellar aplasia, the affected person is often unable to fully straighten the knee. The disease is a malformation that is hereditary. It is passed on to the child in an autosomal dominant manner.

The disease occurs very rarely. Patellar aplasia is characterized by the fact that the patient’s patella is missing or very much reduced. However, most patients do not have any other symptoms. They do not suffer from additional pain, nor do they need crutches to move around. See foodanddrinkjournal for Diabetes Mellitus Dictionary Definitions.

Your symptoms are often limited to the fact that the knee joint cannot be stretched sufficiently. Since it is a hereditary disease, it is diagnosed in infancy at the latest. However, the absence of the kneecap can already be seen at birth, as it is a very noticeable flat bone on the knee that is missing or atrophied.


The cause of patellar aplasia is a genetic disposition. The genes PTLAH and FPAH show changes that are responsible for the development of hyperplasia. In a genetic test, the changes are located on strand 17q21-q22. Since the condition is an autosomal dominant inheritance, the faulty gene is passed on to the child once one of the parents carries it.

Due to the dominant inheritance, it is not possible to prevent the disease according to the current legal status. Genetic modifications to humans are not permitted. Nevertheless, it is possible that the degree of expression between the parent and the child is different. Patellar aplasia can range from a complete absence to a not fully developed patella.

For this reason, it is possible for the offspring to develop the patella to a sufficient extent to allow extension of the knee joint. Other syndromes occur in Patalle’s aplasia. These are also due to a genetic cause.

Symptoms, Ailments & Signs

Patellar aplasia is characterized by impaired function of the sufferer’s patella. The patella is the human kneecap. It is disk-shaped, flat, and has a bone structure that is triangular in shape. The kneecap can be felt without any problems in healthy people.

It rests on the knee joint and protects it. In addition, it increases the distance of the force vector and reduces the sliding resistance. Patients with patellar aplasia are symptom-free in most cases. They do not complain of pain, nor do they suffer from impairments in locomotion. Sufferers are unable to fully straighten their knee.

This means that they always have slightly bent legs when standing. In some cases, those affected suffer from other syndromes, since other malformations often occur. This can mean shortening of the tendons, muscles or other bone changes.

These can cause pain or gait problems. If there are additional changes in the extensor apparatus, standing becomes more difficult for the person concerned or, in severe cases, problematic.

Diagnosis & course of disease

In most cases, the diagnosis is made immediately after birth. This is especially true when the patella is completely absent. The suspicion is expressed by visual contact with the doctor and confirmed by an imaging procedure.

In some cases, the disease is diagnosed in childhood. If the patella is well developed at first glance, when you learn to walk and stand you will notice that the knee joint cannot be straightened. The diagnosis is made after the X-ray.


As a rule, patellar aplasia itself does not lead to any special discomfort or complications. Most patients do not complain about pain and do not suffer from restricted mobility or other limitations in life. The knee can also usually be used, so that the development of children is not restricted by this complaint.

However, those affected cannot fully straighten their knees. The posture of the legs is also slightly bent due to the patella aplasia. In most cases, however, the patients also suffer from other malformations in addition to the patellar aplasia, which can also lead to symptoms or complications. Gait disturbances or slight pain can also occur as a result and possibly have a slightly negative effect on the patient’s quality of life.

In severe cases, those affected can no longer stand properly and need different walking aids. A causal treatment of patellar aplasia is usually not possible. In some cases, those affected require surgical intervention. Physiotherapy and the execution of various exercises are also necessary for those affected. However, the life expectancy of the patient is not affected by this disease.

When should you go to the doctor?

Patellar aplasia is congenital and should be treated surgically in the first few weeks of life. Parents should remain in consultation with the pediatrician and the attending surgeon. If there are problems walking or moving the knee after the operation, the doctor must be informed. If the child shows signs of pain or discomfort, medical advice is also required. However, patella aplasia can be treated well and usually does not cause any further symptoms after the surgical adjustment of the knee joint. For the first few weeks after the procedure, the child may need to take mild painkillers and do physical therapy.

If the condition is not treated, arthrosis of the knee joints can develop. Parents who find their child is having difficulty cycling or walking should seek medical advice. The older the child, the less likely a full recovery is. Measures such as surgical treatment, pain therapy and behavioral therapy are carried out under the supervision of a specialist doctor and require long-term follow-up care. Parents should inform the doctor if side effects occur, the medication used does not have the desired effect, or other complications occur.

Treatment & Therapy

Treatment of patellar aplasia is usually not necessary. The patient does not experience any pain or problems with locomotion. The inability to straighten the knee joint remains constant throughout life. Changes are not to be expected under normal circumstances. Therefore, no further medical measures are usually taken.

If the patient suffers from the malformation, psychotherapy is recommended to find out the background. If work can be done on these, the patellar aplasia will not be treated further. If the patient decides to have an operation, a cosmetic correction can be made.

It is unclear whether the functional activity of the knee then corresponds to the desired ideas. If the patellar aplasia occurs in connection with other changes in the knee, these areas are usually treated. In severe cases, surgical intervention and the insertion of an artificial knee joint are required.

Outlook & Forecast

Patellar aplasia is based on a genetic defect in the affected person. Since, according to the current status, legal requirements prohibit an intervention in human genetics, it is not possible to cure the disease. Nevertheless, the further development can be classified as little threatening. The health impairments are normally comparatively minor. In most cases, the affected person can successfully complete their lifestyle without further restrictions. Although the leg cannot be fully straightened, everyday commitments can be fulfilled. Adequate movement is possible despite the illness. Professional and sporting tasks can be managed accordingly.

If the disease progresses unfavorably, mobility is restricted. This occurs rarely and leads to a worse prognosis. These patients require walking aids. In addition, physiotherapeutic support is required to improve the symptoms. In therapy, the patient learns the optimal movement sequences and load options for his body. The treatment is carried out according to individual specifications and alleviates health irregularities.

No further complications are to be expected with this disease. The quality of life is also not restricted. Nevertheless, there is an increased risk of developing a psychological or psychosomatic secondary disease. This depends on the personality of the person concerned and how they deal with their physical limitations.


Since patellar aplasia is inherited in an autosomal dominant manner, no preventive measures can be taken to protect it. There is only hope that the patella will develop as far as possible in the child despite the dominant inheritance. People who know they have the disease from a genetic test or from their own condition can choose not to have offspring. Alternatively, it can be assumed that the patellar aplasia is inherited by one’s own child. Only the degree of expression can vary between the parent and the child.


In most cases, those affected with patellar aplasia have only very few and usually only very limited measures and options for aftercare. Ideally, the person affected should consult a doctor as soon as the first symptoms and signs of the disease appear in order to prevent the occurrence of further complications or other complaints.

An early diagnosis usually has a very positive effect on the further course of the disease. Those affected are usually dependent on the measures of physiotherapy or physiotherapy in order to relieve the symptoms permanently. Many of the exercises from these therapies can also be repeated at home, which speeds up healing.

If the patellar aplasia has a genetic origin, those affected should definitely have a genetic examination and counseling carried out if they wish to have children in order to prevent the disease from recurring. Some of the malformations can also be corrected by surgery. After such an operation, it is recommended to take care of the body and rest. You should definitely refrain from exertion or stressful activities.

You can do that yourself

A patellar aplasia does not usually cause any noticeable symptoms or complaints, which is why treatment is not absolutely necessary. The symptoms are usually limited to slight movement restrictions in the area of ​​the knee joint, which only cause problems during intensive physical activity.

However, if malformations occur alongside the patellar aplasia, physiotherapy is necessary. Patients should also keep a complaints diary and note any complaints and abnormalities in it. This means that the causes of the malformations can be determined more quickly and suitable therapy can be started. If a surgical procedure is to be performed, the patient must follow the doctor’s instructions regarding the preoperative measures. These mostly relate to dietand any medications taken. People who regularly take painkillers, antidepressants or other preparations must inform the doctor responsible in each case. Otherwise, serious complications may arise during the procedure.

After the operation, the affected knee must first be rested. Physical activity may be resumed after four to six weeks at the earliest, always depending on how severe the patellar aplasia is.