Pyle syndrome

The Pyle syndrome is a skeletal dysplasia that particularly affects the metaphyses of the long tubular bones. The cause has not yet been clarified, but probably corresponds to an autosomal recessive mutation. Many of the patients are lifelong asymptomatic and in this case do not need any further treatment.

What is Pyle Syndrome?

Skeletal dysplasia is a congenital disorder of the bone and cartilage tissue. The metaphyseal dysplasias form a group of skeletal dysplasias. These are congenital disorders that particularly affect the tissue of the metaphysis, i.e. the section of the long bones between the shaft and the epiphysis. The Pyle syndrome is a metaphyseal skeletal dysplasia in which the metaphyses of the long tubular bones show swellings.

The rare hereditary disease was first described in 1931. The American orthopedist Edwin Pyle is considered to be the first to describe metaphyseal dysplasia. The frequency of the disease is stated to be significantly less than one case in 1,000,000 people. Only about 30 cases have been documented since the first description by Pyle.

For this reason, the Pyle syndrome has not yet been conclusively researched. Since many patients show no symptoms whatsoever, the diagnoses are often incidental. The number of unreported cases of the disease is presumably much higher than the stated frequency of spread because of the asymptomatic symptoms.

causes

Pyle syndrome is associated with familial clusters. Daniel in particular presented a case study in 1960 that suggests a genetic basis for the syndrome and seems to support the hereditary nature of skeletal dysplasia. Bakwin and Krida documented a case of affected siblings as early as 1937.

Hermel described a similar case in 1953 and Feld in 1955. In 1954, Komins documented a particularly significant family case of Pyle's syndrome, which affected the mother and the maternal uncle in addition to mixed-sex siblings. In 1987, Beighton reported 20 cases in which the parents did not show any abnormalities seven times.

On the basis of these case reports, scientists have now agreed on an autosomal recessive inheritance for Pyle syndrome. The anomalies are probably caused by a mutation. So far, however, the causative gene has not been determined.

Symptoms, ailments & signs

Patients with Pyle syndrome often suffer from an axis deviation between the upper and lower legs, which equates to a misalignment of the knees. In most cases, the patient's head is not affected by skeletal malformations. Only in isolated cases is there a slight hyperstosis of the skull in the sense of a thickening of the skull bones.

In many cases, there are inhibited extensions in the elbow area. In the area of ​​the collarbones and ribs, there are characteristic swellings. The metaphyses of those affected are often widened. The anomalies of the bones favor abnormally frequent fractures in individual cases.

In all cases documented so far, without exception, the patients were in excellent health, apart from the skeletal dysplasias. Narrowing of the foramina in the area of ​​the skull was not observed in any single case. The patients are typically asymptomatic, so that the diagnosis is usually made on the basis of an incidental finding.

Diagnosis & course of disease

The diagnosis of Pyle syndrome is made through imaging tests. The x-ray shows groundbreaking changes such as an Erlenmeyer flask-like swelling, which corresponds to a widening of the metaphyses without a cup. The abnormalities mainly affect the long tubular bones and extend into the diaphysis on these bones.

The changes are less clear in the short tubular bones. Apart from these criteria, platyspondyly in the sense of a knee misalignment can speak in favor of Pyle syndrome. The syndrome has to be differentiated from other diseases in the context of which an Erlenmeyer deformity can occur, for example from the autosomal dominant inherited type Braun-Tinschert of metaphyseal dysplasia. The form of inheritance is a differentiation criterion here.

Complications

In most cases, Pyle syndrome results in a misalignment of the knees. This misalignment also leads to restricted mobility and thus to difficulties and complications in the everyday life of the person concerned. In some cases, the patients are therefore also dependent on the help of other people in everyday life. The bones of the skull can also thicken.

In many cases, those affected can no longer straighten their knees properly. However, the symptoms usually appear in a very mild form, so that the everyday life of most patients is not restricted by the disease. For this reason, treatment of Pyle's syndrome is not always necessary. As a rule, however, osteoarthritis must be prevented so that there are no further symptoms.

Complication-free development must be guaranteed, especially in children. In serious cases, those affected depend on the use of prostheses. There are no particular complications and the disease usually progresses positively. The life expectancy of those affected is also not influenced by Pyle syndrome.

When should you go to the doctor?

Since the Pyle syndrome does not heal itself and the symptoms usually make everyday life much more difficult, a doctor should be consulted immediately at the first signs of the syndrome. Since this is a genetic disease, it cannot be treated completely or causally. The person affected is therefore only offered a purely symptomatic treatment.

In the case of Pyle syndrome, the doctor should be consulted if the person concerned suffers from restricted mobility or from stretching inhibitions, which can make everyday life much more difficult. The bones show clear abnormalities, so that normal movement of the patient is usually not possible. In most cases, however, Pyle's syndrome is only diagnosed through a routine examination, so that an early examination usually does not take place. Treatment of the syndrome is then carried out with the help of various operations and without complications.

Treatment & Therapy

In most cases, patients with Pyle syndrome no longer suffer from their abnormalities. As long as the changes in the metaphyses do not cause any symptoms, further therapy is not necessary. Therapeutic intervention is only indicated when the first impairments appear. Since the misalignment of the knees can promote osteoarthritis in the course of the disease, epiphysodesis should ideally take place before the end of growth if there is a significant misalignment.

In this procedure, the growth plates of the bones are closed on one side so that the residual growth on the other side can compensate for the misalignment. After the growth is complete, the malalignment can be corrected by means of osteotomies over the articular cartilage on the thigh bone and then corresponds to the surgical procedure of a supracondylar femoral osteotomy.

Another approach is the intervention below the tibial plateau, which corresponds to a high tibial head osteotomy. If the misalignment has already led to osteoarthritis, no correction is made, but a knee joint prosthesis is used.

Orthopedic correction may also be necessary on the elbows if the patient's everyday life is severely impaired by an inhibition of extension. However, since those affected often remain without symptoms their entire life, interventions are actually only required in individual cases.

prevention

So far, one can only speculate about the causes of Pyle syndrome. Therefore, no measures are currently available to prevent the disease. Since the syndrome has a hereditary basis, those affected can at most avoid passing it on by deciding against having their own children. However, since the syndrome is not a disease with severe impairments, such a radical decision is not absolutely necessary.

The subject of aftercare for Pyle syndrome is the continuation of therapeutic treatments and measures. The aftercare treatments are therefore usually aimed at maintaining the mobility of the affected person's musculoskeletal system. In the majority of diseases, those affected can no longer properly straighten their knees. In these mild cases of illness, further medical examinations are often no longer necessary. Because neither complications nor difficulties are to be expected in the everyday life of the person concerned. Basically, however, measures should be taken to prevent osteoarthritis in the knee (gradual wear and tear of the cartilage in the knee joint). A balanced diet that is low in fat and gentle on the joints can help here. Obesity should also be avoided. In children affected by Pyle's syndrome, follow-up care must guarantee the complication-free development of the musculoskeletal system. In order to be able to treat an aggravation of the misalignment of the knee in good time, regular (at least every six months) clinical or outpatient x-rays must be taken and evaluated accordingly by specialists. Despite medical supervision, Pyle syndrome can still lead to severe restrictions on movement. In individual cases, prostheses may also have to be used to maintain mobility. The aftercare then focuses on dealing with the disease and the prostheses in everyday life. Basically, however, the Pyle syndrome does not reduce the life expectancy of those affected.

The subject of aftercare for Pyle syndrome is the continuation of therapeutic treatments and measures. The aftercare treatments are therefore usually aimed at maintaining the mobility of the affected person's musculoskeletal system. In the majority of diseases, those affected can no longer properly straighten their knees. In these mild cases of illness, further medical examinations are often no longer necessary. Because neither complications nor difficulties are to be expected in the everyday life of the person concerned. Basically, however, measures should be taken to prevent osteoarthritis in the knee (gradual wear and tear of the cartilage in the knee joint). A balanced diet that is low in fat and gentle on the joints can help here. Obesity should also be avoided.

In children affected by Pyle's syndrome, follow-up care must ensure that the musculoskeletal system develops without any complications. In order to be able to treat an aggravation of the misalignment of the knee in good time, regular (at least every six months) clinical or outpatient x-rays must be taken and evaluated accordingly by specialists. Despite medical supervision, Pyle syndrome can still lead to severe restrictions on movement. In individual cases, prostheses may also have to be used to maintain mobility. The aftercare then focuses on dealing with the disease and the prostheses in everyday life. Basically, however, the Pyle syndrome does not reduce the life expectancy of those affected.

Aftercare

The subject of aftercare for Pyle syndrome is the continuation of therapeutic treatments and measures. The aftercare treatments are usually aimed at maintaining the mobility of the affected person's musculoskeletal system. In the majority of diseases, those affected can no longer properly straighten their knees.

In these mild cases of illness, further medical examinations are often no longer necessary. Because neither complications nor difficulties are to be expected in the everyday life of the person concerned. Basically, however, measures should be taken to prevent osteoarthritis in the knee (gradual wear and tear of the cartilage in the knee joint). A balanced diet that is low in fat and gentle on the joints can help here. Obesity should also be avoided.

In children affected by Pyle's syndrome, follow-up care must ensure that the musculoskeletal system develops without any complications. In order to be able to treat an aggravation of the misalignment of the knee in good time, regular (at least every six months) clinical or outpatient x-rays must be taken and evaluated accordingly by specialists.

Despite medical supervision, Pyle syndrome can still lead to severe restrictions on movement. In individual cases, prostheses must also be used to maintain mobility. The aftercare then focuses on dealing with the disease and the prostheses in everyday life. Basically, however, the Pyle syndrome does not reduce the life expectancy of those affected.