What is exostosis and where does it appear?
Osteochondroma is formed from the tissue of the growth zone, which for some reason shifted outward and continued to build bone to the side. The growth is covered with a cartilaginous cap and is connected from the inside to the spongy bone of the main mass. Favorite places are the metaphyses of long tubular bones: the lower third of the femur, the upper third of the tibia, the proximal humerus. Less common are exostoses of the scapula, ribs, pelvis and vertebrae. Separately, subungual exostosis of the big toe is distinguished, which is often mistaken for a wart or ingrown nail.
- Single osteochondroma is the most common variant
- Multiple exostotic chondrodysplasia is a hereditary disease
- Subungual exostosis of the toe
- Exostoses after radiation therapy in childhood
- Bone growths of the ear canal in swimmers
Causes and heredity
A single exostosis occurs randomly, without connection with lifestyle, nutrition or injury - although injury often becomes a reason to notice a long-existing growth. The multiple form is inherited and is associated with mutations in genes responsible for the development of cartilage. With it there are many growths, they are located symmetrically, sometimes causing shortening and curvature of the bones of the forearm and lower leg. If the parents had similar formations, the child should be shown to an orthopedist, even if there are no complaints.
- Impaired development of the bone growth plate
- Hereditary transmission in multiple forms
- Irradiation of the skeletal area in childhood
- Growth age - from 5 to 20 years
- No association with injury or stress has been proven
Symptoms: when exostosis interferes
Most often, the formation is discovered by chance - on an image for another reason or by feeling a hard lump under the skin. Complaints appear if the growth is poorly located. It can rub against shoes, inflame a tendon bursa, limit joint flexion, or put pressure on a nerve, causing numbness and weakness. A large exostosis in the popliteal region can compress the vessel. In children, pain sometimes occurs when the stem of the growth is fractured after a blow.
- Dense, immovable lump fused to bone
- Discomfort and pain when exerting weight or pressure from shoes
- Limitation of movement in an adjacent joint
- Numbness, tingling due to nerve compression
- Crunching and clicking sounds when the tendon moves through the growth
- Cosmetic defect
Diagnostics
The basis of the diagnosis is radiography: osteochondroma has a typical appearance of an outgrowth, the medullary canal of which continues into the canal of the maternal bone. This sign almost excludes a malignant tumor. CT clarifies the shape and relationship to the vessels before surgery and clearly shows exostoses of the pelvis and scapula. MRI is used to measure the thickness of the cartilage cap: its pronounced thickening in an adult is a reason for caution. With a typical picture, a biopsy is not needed, and the removed growth must be sent for histological examination.
- X-ray of bone in two projections
- CT for surgery planning
- MRI for deep placement and for evaluation of the cartilage cap
- Ultrasound of soft tissues and vessels near the growth
- Histological examination of distant formation
- In case of multiple form - examination of other skeletal segments
Treatment and observation
Asymptomatic exostosis in a child is usually not touched: it is observed while the skeleton continues to grow, with control images as prescribed by the doctor. Surgery is planned if the growth hurts, limits movement, is injured, or grows rapidly. The growth is removed along with the cartilaginous cap and periosteum - this reduces the likelihood of re-growth. They try to carry out intervention in children after the main growth has been completed, so as not to damage the growth zone. Physiotherapy, ointments and massage do not reduce the growth, and heating if the formation is unclear is unacceptable.
- Observation and control images in the absence of complaints
- Surgical removal of a growth with a cartilaginous cap
- Freeing a compressed nerve or vessel
- Selection of shoes and unloading for subungual exostosis
- Histological examination of the removed tissue
- Annual examination by an orthopedist for hereditary multiple forms
