Perthes disease is a partial aseptic necrosis of the femoral head. The disease occurs in adolescence or childhood. The beginning is gradual. There are minor pains in the joint, perhaps a slight limping or “dragging” of the leg. Subsequently, the pain becomes intense, pronounced lameness, swelling and weakness of the limb muscles appear, contractures form. In the absence of treatment, the likely outcome is the deformation of the head and the development of coxarthrosis. The diagnosis is made based on the symptoms and the X-ray picture. Treatment is long-term, conservative, includes immobilization, physical therapy, massage, physiotherapy. In severe cases, reconstructive and reconstructive operations are performed.
M91.1 Juvenile osteochondrosis of the femoral head [Legg-Calve-Perthes disease]
Perthes disease (Legg-Calve-Perthes disease) is a pathological process characterized by impaired blood supply and subsequent necrosis of the femoral head. It is a fairly common disease and accounts for about 17% of the total number of osteochondropathies. Children aged 3 to 14 years suffer. Boys get sick 5-6 times more often than girls, but girls tend to have a more severe course. Both unilateral and bilateral lesions are possible, while the second joint usually suffers less and recovers better.
Currently, no single cause of Perthes disease has been identified. It is believed that this is a polyethological disease, in the development of which both the initial predisposition and metabolic disorders, as well as environmental influences, play a certain role. According to the most common theory, Perthes disease is observed in children with myelodysplasia – congenital underdevelopment of the lumbar spinal cord, a common pathology that may not manifest itself in any way or cause various orthopedic disorders. It is assumed that the starting points in the occurrence of Perthes disease may be the following factors:
- Minor mechanical injury (for example, bruising or spraining of ligaments when jumping from a small height). In some cases, the injury is so small that it can go unnoticed. Sometimes an awkward movement is enough.
- Inflammation of the hip joint (transient synovitis) in microbial and viral infections (flu, sore throat, sinusitis).
- Hormonal changes in the transition age.
- Disorders of the metabolism of calcium, phosphorus and other minerals that are involved in the formation of bones.
In some cases, a hereditary predisposition to the development of Perthes disease is revealed, which may be due to a tendency to myelodysplasia and genetically determined features of the structure of the hip joint.
With myelodysplasia, the innervation of the hip joints is disrupted, and the number of vessels delivering blood to the tissues of the joint also decreases. Simplistically, it looks like this: instead of 10-12 large arteries and veins in the area of the femoral head, the patient has only 2-4 underdeveloped vessels of a smaller diameter. Because of this, the tissues constantly suffer from insufficient blood supply. A change in vascular tone due to a violation of innervation also has its negative effect.
In relatively unfavorable conditions (with partial compression of arteries and veins due to inflammation, trauma, etc.), in a child with a normal number of vessels, the blood supply to the bone worsens, but remains sufficient. In a child with myelodysplasia, in similar circumstances, blood completely stops flowing to the femoral head. Due to the lack of oxygen and nutrients, some of the tissues die off – an area of aseptic necrosis is formed, that is, necrosis that develops without microbes and signs of inflammation.
In traumatology and orthopedics , there are five stages of Perthes ‘ disease:
- Cessation of blood supply, formation of a focus of aseptic necrosis.
- Secondary depressed (impression) fracture of the femoral head in the destroyed area.
- Resorption of necrotic tissues, accompanied by shortening of the femoral neck.
- The growth of connective tissue at the site of necrosis.
- Replacement of connective tissue with a new bone, fusion of the fracture.
The outcome of Perthes disease depends on the size and location of the necrosis site. With a small hearth, a full recovery is possible. With extensive destruction, the head splits into several separate fragments and after fusion may take an irregular shape: flatten, protrude beyond the edge of the articular cavity, etc. Violation of the normal anatomical relationships between the head and the acetabulum in such cases causes further aggravation of pathological changes: formation of contractures, limitation of support and rapid development of severe coxarthrosis.
In the early stages, there are non-intense dull pains when walking. Usually, the pain is localized in the hip joint, but in some cases, pain is possible in the knee joint or throughout the leg. The child begins to limp slightly, falls on a sore leg or drags it. As a rule, during this period, clinical manifestations are so poorly expressed that parents do not even guess to consult an orthopedic doctor, and explain the symptoms of the disease by bruising, increased stress, the consequence of an infectious disease, etc.
With further destruction of the head and the occurrence of an impression fracture, the pain increases sharply, the lameness becomes pronounced. Soft tissues in the joint area swell. The limitation of movements is revealed: the patient cannot turn the leg outwards, rotation, flexion and extension in the hip joint are limited. Walking is difficult. Vegetative disorders are noted in the distal parts of the diseased limb – the foot is cold, pale, its sweating is increased. It is possible to increase body temperature to subfebrile figures. Subsequently, the pain becomes less intense, the support on the leg is restored, but lameness and restriction of movements may persist. In some cases, a shortening of the limb is detected. Over time, there is a clinic of progressive arthrosis.
The most important study that is crucial in the diagnosis of Perthes disease is the radiography of the hip joint. If this disease is suspected, not only pictures in standard projections are performed, but also an X-ray in the Lauenstein projection. The X-ray picture depends on the stage and severity of the disease. There are various radiological classifications, the most popular of which are the Catterol and Salter-Thomson classifications.
Classification of Catterol:
- Group 1. Radiological signs of Perthes disease are poorly expressed. A small defect is detected in the central or subchondral zone. The femoral head has a normal configuration. There are no changes in the metaphysics, the fracture line is not defined.
- Group 2. The contours of the head are not broken, destructive and sclerotic changes are visible on the X-ray. There are signs of fragmentation of the head, the emerging sequester is determined.
- Group 3. The head is affected almost completely, deformed. The fracture line is revealed.
- Group 4. The head is completely affected. The fracture line and changes in the acetabulum are revealed.
- Group 1. A subchondral fracture is determined only on an X-ray in the Lauenstein projection.
- Group 2. The subchondral fracture is visible in all the images, the outer border of the head is not changed.
- Group 3. A subchondral fracture “captures” the outer part of the epiphysis.
- Group 4. The subchondral fracture extends to the entire epiphysis.
In doubtful cases, at the first stage of the disease, an MRI of the hip joint is sometimes prescribed for a more accurate assessment of the condition of the bone and soft tissues.
Children aged 2-6 years with mild symptoms and the presence of minimal changes on radiographs should be observed by a pediatric orthopedist; special therapy is not required. In other cases, patients are referred for treatment to the orthopedic department, followed by outpatient follow-up. Conservative therapy is long-term, lasting at least a year (on average 2.5 years, in severe cases up to 4 years). Treatment includes:
- Complete unloading of the limb.
- The application of skeletal traction, the use of plaster castings, orthopedic structures and functional beds to prevent deformation of the femoral head.
- Improvement of blood supply to the joint using medicinal and non-medicinal methods.
- Stimulation of the processes of resorption of destroyed tissues and bone restoration.
- Maintaining muscle tone.
Children with Perthes disease remain sedentary for a long time, which often provokes the appearance of excess weight and a subsequent increase in the load on the joint. Therefore, all patients are prescribed a special diet to prevent obesity. At the same time, the diet should be full-fledged, rich in proteins, fat-soluble vitamins and calcium. During the entire period of treatment, massage and special exercise therapy complexes are used. When using skeletal traction and plaster dressings, excluding the possibility of active movements, electrical stimulation of muscles is performed.
Children are prescribed angioprotectors and chondroprotectors in the form of oral and intramuscular injections. Starting from the second stage, patients are referred for UHF, diathermy, electrophoresis with phosphorus and calcium, mud treatment and ozokeritis. The load on the leg is permissible only after radiologically confirmed fusion of the fracture. At the fourth stage, patients are allowed to perform active exercises, at the fifth, a complex of physical therapy is used to restore muscles and the volume of movements in the joint.
Surgical interventions in Perthes disease are indicated in severe cases (the occurrence of pronounced deformity, hip subluxation) and only in children older than 6 years. Usually, a rotational transposition of the acetabulum by Salter or a corrective medializing osteotomy of the hip is performed. In the postoperative period, physiotherapy, physical therapy, massage, chondroprotectors and angioprotectors are prescribed.
Prognosis and prevention
With early detection and adequate treatment of pathology, the prognosis of Perthes disease is usually quite favorable, full recovery is possible. In severe cases, deforming arthrosis is found in the outcome. People who have suffered from this disease, regardless of the severity of the disease, are recommended to exclude excessive loads on the hip joint throughout their lives. Jumping, running and lifting weights are contraindicated. Swimming and cycling are allowed. It is necessary to regularly engage in therapeutic gymnastics. You should not choose a job associated with heavy physical exertion or prolonged stay on your feet. It is necessary to undergo periodic restorative treatment in polyclinic conditions and sanatoriums.
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