What happens in the bone
The head of the femur is supplied with blood by a limited number of arteries, and it has almost no backup routes. If a vessel becomes clogged, compressed or damaged, the area of bone is left without nutrition and dies. The shape of the head is maintained for some time because the dead bone is just as strong at first. Then the body begins to reabsorb the dead tissue, and during this period the strength drops sharply: under load, the bone beams break, the surface of the head sags, and the cartilage above it collapses. From this moment on, the changes become irreversible and severe arthrosis develops.
- Poor blood supply to the head area
- Death of bone beams without infection
- Stage before head subsidence
- Subchondral fracture and collapse
- Secondary arthrosis of the hip joint
- Bilateral lesions are common
Causes and risk factors
All causes are divided into traumatic and non-traumatic. Trauma—a hip fracture or dislocation—directly damages the blood vessels. Among non-traumatic factors, the leading ones are long-term use of glucocorticoids in high doses and alcohol abuse: both disrupt fat metabolism and microcirculation in the bone. Sickle cell anemia, systemic lupus erythematosus, previous radiation and chemotherapy, decompression sickness in divers, chronic kidney disease and organ transplantation are also significant. In some patients, no obvious cause can be found.
- Hip fracture and joint dislocation
- Long-term use of glucocorticoids
- Alcohol abuse
- Sickle cell anemia
- Systemic lupus erythematosus and other rheumatic diseases
- Radiation and chemotherapy
- Caisson disease
- Smoking and lipid metabolism disorders
Symptoms
The main symptom is pain in the groin, which can radiate to the buttock, along the front of the thigh and to the knee. Sometimes knee pain becomes the first complaint, and the wrong joint is examined. At first, the pain appears only with exercise and walking, then it occurs at rest and at night. Movements are gradually limited, especially turning the leg inward and abducting: it becomes difficult to put on a sock, get into a car, or spread your knees. Lameness appears, the person spares his leg, and the thigh muscles lose weight. Often, after some time, the second leg begins to hurt.
- Pain in the groin when walking and exercising
- Referring pain to the hip and knee
- Night pain at rest
- Limiting inward rotation of the leg
- Lameness, shortened stride
- Thigh muscle atrophy
- Damage to the second joint
Diagnostics
Early on, x-rays appear normal, and this is a major pitfall. Therefore, for persistent pain in the groin, especially in a person at risk, an MRI of the hip joints is prescribed - it detects changes long before the appearance of X-ray signs and necessarily involves both joints, since the lesion is often bilateral. X-ray is needed to assess the shape of the head and stage, computed tomography is needed for a detailed assessment of the bone structure and planning the operation. Additionally, the doctor clarifies risk factors and excludes other causes of groin pain.
- MRI of both hip joints is the main method
- X-ray of hip joints
- Computed tomography for surgery planning
- Ultrasound to evaluate joint effusion
- Blood tests to rule out inflammation
- Clarification of hormone intake and other risk factors
Treatment
In the early stages, while the head retains its shape, the task is to relieve the load and preserve the joint. They recommend walking with a cane or crutches, avoiding running and jumping, physical therapy without axial load, giving up alcohol and smoking, and reviewing the dosage of hormones with your doctor. Organ-preserving operations are used, primarily decompression - the creation of a canal in the head to reduce intraosseous pressure and the growth of new vessels, sometimes with bone grafting. After the head subsides and arthrosis develops, joint replacement becomes the most reliable method.
- Unloading the joint, walking with support
- Avoid running, jumping and heavy lifting
- Therapeutic exercise without axial load
- Quitting alcohol and smoking
- Review glucocorticoid therapy with your healthcare provider
- Femoral head decompression
- Bone grafting and corrective surgery
- Endoprosthetics for head collapse