Trevor’s disease is a rare hereditary disorder that manifests itself in disorders of the ossification processes. Affected individuals suffer from overgrowth of cartilage systems affecting one or more bones, usually in the lower extremities.
What is Trevor’s disease?
Bone tissue forms during the process of ossification. Ossification occurs both for bone growth and for bone repair. In desmal ossification, bone forms through the intermediate step of connective tissue. Bone formation from cartilage tissue corresponds to chondral ossification. If the bone grows by accumulation of bone tissue, appositional ossification takes place. Ossification processes can take on pathological forms. Such pathological ossification is referred to by physicians as heterotopic ossification. Bone formation is affected by disorders in the context of various diseases. One such disorder is Trevor’s disease (dysplasia epiphysealis hemimelica). The characteristic feature is congenital malformations of the extremities as a result of disturbed ossification processes. Trevor’s disease (Trevor’s disease, Fairbank’s disease) manifests itself in the form of a circumscribed overgrowth of cartilage in one or more bones. David Trevor gave his name to the disease. The first description of this rare phenomenon was provided by A. Mouchet and J. Bélot in 1926. Medical science now distinguishes between classic, localized, and generalized forms.
Causes
As of 2011, the world clinical literature documented approximately 200 cases of Trevor’s disease. The prevalence is reported to be about one case per million people. Because of its rarity, the causes of the disease have not yet been conclusively determined. The cases documented to date manifest much more frequently in boys than girls. In addition, scientists have documented familial clustering in their case reports, suggesting a hereditary basis. Trevor’s disease is therefore now associated with chromosomal abnormalities. These are changes in the number or structure of chromosomes that characterize mutations. Hereditary chromosomal abnormalities are genetically inherited, but usually take shape only in the context of external damaging influences. In addition, chromosomal abnormalities can occur in the form of new mutations and in this case have no genetic component. The type of chromosomal abnormality involved in Trevor’s disease remains a matter of speculation. Also, the causative chromosomes could not be defined in detail so far. Scientists at least agree on the type of inheritance: the disease is said to be based on autosomal-dominant inheritance.
Symptoms, complaints, and signs
Patients with Trevor’s disease suffer from bone deformities, which in most cases are associated with malalignment and joint deformities. Often, the deformities occur unilaterally on the lower extremity, where they primarily affect the distal femur or distal tibia. The epiphyses of the long tubular bones show the most severe symptoms. Overgrowth can be seen on the bones at the distal-medial ends. Joint symptoms consist of deformity leading to malalignment with local swelling. As a general symptom, muscle atrophy occurs in the affected areas. Trevor’s disease rarely causes pain. If joint symptoms develop, however, movement-related wear and tear can promote joint pain symptoms. Joint symptomatology does not usually exist from birth, but develops during the growth process. Associations have been described with enchondromatosis. Three size extensions of Trevor’s disease are distinguished by medicine. The local form remains confined to a single bone. The classic Trevor’s disease shows large-volume extension and accounts for about two-thirds of all cases. In the generalized form, all bones are affected.
Diagnosis and disease course
The physician makes the diagnosis of Trevor’s disease on the basis of the X-ray image. In addition to the typical localization, the irregular overgrowth is decisive for this. In addition, several unconnected bone nuclei usually appear as accumulations on the epiphyses. Precise imaging by MRI serves to confirm the diagnosis.In the histology of the tissue, the changes can hardly be differentiated from osteochondroma, which, however, always occurs in the area of the metaphysis. A possible differential diagnosis is with synovial chondromatosis or trauma-related splintering. The prognosis for patients with Trevor’s disease depends on the extent of the changes in each individual case.
Complications
As a result of Trevor’s disease, affected individuals suffer from various deformities to the bones. In this case, these deformities usually lead to restricted movement and malalignment of the feet or other joints. In most cases, swelling occurs and the affected person suffers from muscle atrophy and thus a reduced ability to bear weight. It is not uncommon for the pain to spread from the affected areas to other parts of the body, where it can also cause discomfort. Pain at night can cause sleep problems and depression. As a rule, Trevor’s disease can be diagnosed relatively easily and quickly, so that early treatment of this disease is also possible. There are usually no particular complications, as the symptoms can only be treated symptomatically. Especially in children, treatment must take place to avoid complications or other complaints as they grow. In most cases, the limitations can be treated relatively well with physiotherapy. Trevor’s disease also does not cause further limitations or complications in life expectancy.
When should you see a doctor?
Irregularities in the range of motion, malpositions of the body, or a crooked posture should be presented to and examined by a physician. If there are limitations in general mobility, changes in joint activity, or a decrease in physical strength, a doctor is needed. If sporting activities or habitual movements cannot be performed or can only be performed to a limited extent, the affected person requires medical care. In case of pain, swelling or deformation of the bones as well as joints, there is an acute need for action. A visit to the doctor is necessary for a diagnosis. Pain medication should only be taken in consultation with a doctor due to possible side effects. If existing irregularities spread further or if there is an overgrowth in different parts of the skeletal system, a visit to the doctor is advisable. A visual blemish of the physique indicates an existing disease that needs to be treated. Sleep disorders or irregularities of the vegetative system should be discussed with a doctor. If, in addition to the physical complaints, there are also emotional or mental abnormalities, a visit to the doctor is also necessary. Behavioral conspicuities, a withdrawal from social life, as well as a depressive appearance must be discussed with a physician. A persistent reduction in well-being as well as persistent strong mood swings can lead to further illnesses, which must be prevented in time.
Treatment and therapy
A causal therapy does not yet exist for patients with Trevor’s disease. Thus, the disease is considered incurable and can only be treated symptomatically to date. Accordingly, the exact therapy depends on the symptoms in each individual case. Depending on the extent of the overgrowth, surgery can be performed to remove the excess tissue. However, such surgeries do not achieve permanent effects before bone maturation is complete. In the course of the growth process, patients develop recurrences. For this reason, the treating physician must weigh the benefits of surgery against the risks of surgery before bone growth is complete. If the patient suffers from secondary symptoms such as chronic tendonitis or severe joint deformities with corresponding signs of wear and tear, surgical intervention to relieve the tendons and joints in the short term may well be appropriate. If, on the other hand, the overgrowth remains within limits and there are neither pain nor joint or tendon changes, surgery before bone maturity is usually not worthwhile. In cases of malalignment, patients usually receive physiotherapy, which prevents movement restrictions and has shown positive effects on the general course of the disease in the past.
Outlook and prognosis
Trevor’s disease offers a relatively poor prognosis.The disease can only be treated symptomatically. This can reduce the symptoms and minimize the restrictions in everyday life. However, until the skeletal maturation is completed, new symptoms can always occur, which cause further complaints and must be treated accordingly. This makes early diagnosis and treatment of Trevor’s disease all the more important. The various pain syndromes that can occur in the course of the disease are particularly problematic. With the progression of the disease, various mental ailments can develop. Any anxiety disorders or depression worsen the prospect of a symptom-free life, as they additionally restrict the patient. Medication ensures that the affected joints can be moved normally despite pain. Otherwise, further deformities and bone damage may occur, which also worsen the prognosis. Patients should talk to their specialist regarding the prognosis. The physician gives the prognosis based on the symptom picture and other factors such as the course of the disease. Life expectancy is not limited in Trevor’s disease. However, the final prognosis must be made by the responsible physician.
Prevention
Trevor’s disease cannot be prevented to date. Because the disease is genetic, the most that affected individuals can do to prevent further cases is to seek genetic counseling during the family planning phase.
Follow-up
In most cases, the person affected by Trevor’s disease has only very limited and also very few measures and options for direct aftercare. First and foremost, the affected person should see a doctor at a very early stage in order to prevent the occurrence of further complications and complaints, since Trevor’s disease cannot heal on its own. Due to the hereditary nature of the disease, those affected should also undergo genetic testing and counseling if they wish to have children, in order to prevent the recurrence of the disease in their offspring. In many cases, Trevor’s disease requires physical therapy or physiotherapy. The affected person should also repeat the exercises at home in order to increase the mobility of the body. Many patients are also dependent on the help and support of their own family in their daily lives. Loving and intensive conversations are also very important, as this can also prevent depression and other psychological upsets. Likewise, overweight should be avoided, although in general a healthy lifestyle with a healthy diet can have a positive effect on the further course of this disease. As a rule, Trevor’s disease does not reduce the patient’s life expectancy.
Here’s what you can do yourself
Children suffering from Trevor’s disease primarily need the support of relatives and friends. The actual healing process can be supported at home by yoga, Pilates or exercises from physiotherapy. It is advisable to keep a complaints diary. Especially during the growth phase, new bone structures are constantly developing, which can cause varying degrees of pain depending on their localization. The weather conditions and other factors also have an influence on how strongly the bone changes become noticeable. The sooner the changes are detected, the more effectively they can be counteracted with surgical measures. Trevor’s disease progresses until the end of the child’s physical growth, which is why careful attention must usually be paid to unusual symptoms and complaints beyond puberty. If there is discomfort at the knee joint, ankle joint, or foot bones, the child will need a walker or wheelchair. If mobility is severely limited, home modifications may also be needed. After a surgical intervention, the surgical wound should be carefully cared for. In the first few days, no sports should be practiced that could put a lot of strain on the affected limb. Thus, in the case of bone changes in the area of the tibia, running and cycling should initially be avoided, while gymnastic exercises may be performed without involving the feet.
