Patella aplasia is a condition that causes restricted movement of the knee. In most cases, it is painless and shows no other symptoms. As a result, treatment is often not necessary.
What is patella aplasia?
The condition patella aplasia is associated with an impairment of the patella. This is a bone located in front of the knee joint. With patella aplasia, the affected person is often unable to fully extend the knee. The condition is a malformation that is hereditary. It is inherited autosomal-dominant to the child. The disease occurs very rarely. Patella aplasia is characterized by the fact that the patella is absent or very much diminished in the patient. Nevertheless, most patients do not present with any other symptoms. They neither suffer from additional pain nor do they need walking aids to get around. Their symptoms are often limited to the fact that the knee joint cannot be sufficiently extended. Since it is a hereditary condition, it is diagnosed no later than infancy. However, the absence of the patella can already be seen at birth, as it is a very noticeable flat bone on the knee that is missing or atrophied.
Causes
The cause of patella aplasia is a genetic predisposition. The PTLAH and FPAH genes have alterations that are responsible for the formation of the hyperplasia. In a genetic test, the alterations are localized on strand 17q21-q22. Since the disease is an autosomal dominant inheritance, the defective gene is passed on to the child as soon as one parent carries it. Due to the dominant inheritance, it is not possible to prevent the disease according to the current legal status. It is not permitted to make genetic changes in humans. Nevertheless, it is possible that the degree of expression differs between the parent and the child. Patella aplasia can range from complete absence, to a patella that is not fully expressed. For this reason, it is possible for the patella to be developed in the offspring to a sufficient degree to allow stretching of the knee joint. Other syndromes occur in Patalle’s aplasia. These are also due to a genetic cause.
Symptoms, complaints, and signs
Patella aplasia is characterized by impaired function of the affected person’s patella. The patella is the kneecap of the human knee. It is disc-shaped, flat, and a bone structure that has a triangular shape. The patella can be easily palpated in healthy people. It rests on the knee joint and protects it. It also increases the distance of the force vector and reduces sliding resistance. Patients with patella aplasia are symptom-free in most cases. They do not complain of pain, nor do they suffer from impaired locomotion. Those affected are unable to fully extend their knee. This means that they always have their legs slightly bent when standing. In some cases, those affected suffer from other syndromes, as there are often other deformities. This can mean shortening of tendons, muscles or further bone changes. These can cause pain or problems with the gait. If additional changes in the extensor apparatus occur, standing becomes difficult for the affected person or, in severe cases, problematic.
Diagnosis and course of the disease
In most cases, the diagnosis is made immediately after birth. This is especially true when the patella is completely absent. Visual contact by the physician will make the assumption, and imaging will confirm it. In some cases, the condition is posited in infancy. If the patella is well developed at first glance, it is noticed when learning to walk and stand that the knee joint cannot be pushed through. After x-ray, the diagnosis is made.
Complications
As a rule, patella aplasia itself does not lead to any particular complaints or complications. Most patients also do not complain of pain in the process, and continue to suffer no restrictions in movement or other limitations in life.The knee can also usually be used, so that the development of children is also not restricted by this complaint. However, those affected cannot fully extend their knees. The posture of the legs is also slightly bent due to patella aplasia. In most cases, however, patients suffer from other deformities in addition to patella aplasia, which can also lead to discomfort or complications. Gait disturbances or mild pain may also occur as a result, possibly having a slight negative impact on the patient’s quality of life. In severe cases, those affected are then unable to stand properly and require various walking aids. Causal treatment of patella aplasia is usually not possible. In some cases, sufferers rely on surgical intervention. Physical therapy and performing various exercises is also necessary for the affected person. However, the patient’s life expectancy is not affected by this disease.
When should one go to the doctor?
Patella aplasia is congenital and should be treated surgically in the first few weeks of life. Parents should stay in consultation with the pediatrician and the surgeon in charge. If there are any problems walking or moving the knee after surgery, the doctor must be informed. If the child shows signs of pain or discomfort, medical advice is also needed. However, patella aplasia can be treated well and usually does not cause further discomfort after surgical adjustment of the knee joint. In the first few weeks after surgery, the child may need to take mild pain medication and perform physiotherapy exercises. If the condition is not treated, osteoarthritis of the knee joints may develop. Parents who notice that 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 management and behavioral therapy are done under the guidance of a specialist and require longer-term follow-up. Parents should inform the physician if side effects occur, the medications used do not have the desired effect, or other complications arise.
Treatment and therapy
Treatment of patellar aplasia is usually not necessary. The patient does not suffer from pain or problems with locomotion. The inability to extend the knee joint remains constant throughout life. Changes are not expected under normal circumstances. Therefore, no further medical measures are usually taken. If the patient suffers from the deformity, psychotherapy is recommended to learn the background. If these can be worked on, the patella aplasia is not treated further. If the patient decides to undergo surgery, cosmetic correction can be performed. It is unclear whether the functional activity of the knee subsequently meets the desired expectations. If patella aplasia occurs in conjunction with other changes in the knee, these areas are usually treated. In severe cases, surgical intervention and placement of an artificial knee joint occurs.
Outlook and prognosis
Patella aplasia is based on a genetic defect in the affected individual. Because current legal guidelines prohibit interfering with a person’s genetics, a cure for the disease is not possible. Nevertheless, the further development is to be classified as little threatening. The health impairments are normally comparatively minor. In most cases, the affected person can successfully go about his or her life without further restrictions. Although the leg cannot be fully extended, everyday activities can be performed. Locomotion is possible to a sufficient degree despite the disease. Occupational and sporting tasks can be performed accordingly. In the event of an unfavorable course of the disease, locomotion is restricted. This occurs rarely and leads to a worsened prognosis. These patients require walking aids. In addition, physiotherapeutic support is required to improve the symptoms. During therapy, the patient learns the optimal movement sequences and loading possibilities for his or her body. Entirely according to the individual specifications, the treatment is carried out and alleviates health irregularities.Further complications are not to be expected with this disease. The quality of life is also not restricted. Nevertheless, there is an increased risk for the development of a psychological or psychosomatic secondary disease. This depends on the personality of the affected person and how he or she deals with the physical limitations.
Prevention
Because patella aplasia is inherited in an autosomal-dominant manner, no preventive measures can be taken to protect against it. The only hope is that the patella will form as much as possible in the child despite the dominant inheritance. People who know they have the disease because of a genetic test or their own condition may choose not to have offspring. Alternatively, it can be assumed that patella aplasia is inherited by one’s own child. Only the degree of expression may vary between the parent and the child.
Follow-up
Affected individuals have very few and usually very limited aftercare measures and options available to them in most cases of patella aplasia. Therefore, the affected person should ideally see a doctor at the first symptoms and signs of the disease to prevent the occurrence of further complications or other complaints. As a rule, early diagnosis always has a very positive effect on the further course of the disease. In this case, those affected are usually dependent on the measures of physiotherapy or physical therapy in order to permanently alleviate the symptoms. Many of the exercises from these therapies can also be repeated at home, which accelerates the healing process. If patella aplasia has a genetic origin, those affected should definitely have a genetic examination and counseling if they wish to have children, in order to prevent the recurrence of the condition. Some of the malformations can also be corrected by surgery. After such an operation it is recommended to take care of the body and to rest. From efforts or stressful activities is to be refrained thereby in any case.
What you can do yourself
Patella aplasia does not usually cause any noticeable symptoms or discomfort, which is why treatment is not necessarily required. In most cases, the symptoms are limited to slight movement restrictions in the area of the knee joint, which only cause problems during intensive sports activities. However, if deformities accompany patella aplasia, physiotherapy is necessary. Patients should also keep a complaints diary and note any complaints and abnormalities in it. This will allow the causes of the deformities to be identified more quickly and appropriate therapy to be started. If a surgical procedure is to be performed, the patient must comply with the physician’s instructions regarding preoperative measures. These usually concern nutrition as well as the possible intake of medication. Persons who regularly take painkillers, antidepressants or other preparations must inform the responsible physician about this in any case. Otherwise, serious complications may arise during the operation. After the operation, the affected knee must initially be rested. Physical activity may be resumed after four to six weeks at the earliest, always depending on how pronounced the patella aplasia is.
