Bone necrosis can be divided into different categories:

1. Aseptic bone necrosis: Occurs without an infection, usually due to circulatory disorders, as in the case of femoral head necrosis.
2. Septic bone necrosis: Is caused by an infection, for example after injuries or surgeries.
3. Traumatic bone necrosis: Occurs as a result of bone fractures or other injuries that impair blood supply.
4. Idiopathic bone necrosis: Has no clearly identifiable cause and is often diagnosed in young adults.
5. Medication-induced bone necrosis: Is favored by the long-term use of certain medications, such as corticosteroids.

The main causes of bone necrosis can be divided into several categories:

• Circulatory disorders:
  • Vascular injuries or thromboses lead to an interruption of blood supply.
  • Chronic diseases such as diabetes or arteriosclerosis impair blood flow.
• Trauma:
  • Bone fractures or joint dislocations can damage vessels and lead to local ischemia.
• Medication intake:
  • Long-term use of corticosteroids or chemotherapy drugs increases the risk.
• Alcohol abuse:
  • Regular excessive alcohol consumption can impair microcirculation and lead to bone necrosis.
• Systemic diseases:
  • Autoimmune diseases such as lupus erythematosus or sickle cell anemia can promote circulatory disorders.

The symptoms vary depending on the affected bone region and the progression of the disease:

- **Pain:** Localized pain that initially occurs only under stress and may later persist at rest.

- **Movement restrictions:** Problems with bending, stretching, or rotating the affected joint.

- **Swelling:** Inflammation-related swelling or fluid accumulation in the joint.

- **Bone weakness:** An increased susceptibility to fractures or deformations in the area of necrosis.

- **Gait changes:** Limping or altered movement patterns with hip or knee involvement.

- **Joint instability:** Uncertainty or instability under stress, especially in advanced stages.

The diagnosis is made through a combination of medical history, clinical examination, and imaging techniques:

- Medical history:

- The doctor inquires about typical symptoms, risk factors such as medication use or alcohol abuse, and existing preconditions.

- Physical examination:

- Checking for tenderness, movement restrictions, and swelling.

- Imaging techniques:

- X-ray: Depiction of bone density loss or collapse in advanced stages.

- MRI: Early detection of circulatory disorders and necrosis areas.

- CT: Detailed imaging of bone structure to assess damage.

Conservative Therapy

In the early stages of bone necrosis, non-operative measures can help stabilize the condition and alleviate symptoms:

• Pain Therapy:
  • NSAIDs to relieve pain and inflammation.
• Physiotherapy:
  • Exercises to improve mobility and strengthen the surrounding muscles.
• Relief:
  • Use of walking aids or orthoses to reduce the load on the affected bone.
• Medication Therapy:
  • Use of bisphosphonates or other bone-strengthening medications to delay progression.

Surgical Therapy

In advanced stages of bone necrosis, surgical intervention may be necessary:

• Decompression:
  • Surgical pressure relief of the affected bone to promote blood circulation.
• Bone Reconstruction:
  • Transplantation of bone substance or stem cells to restore bone structure.
• Joint Replacement:
  • Implantation of an endoprosthesis in cases of irreparable joint damage.

To prevent bone necrosis, the following measures are recommended:

1. Avoidance of risk factors: Reduction of alcohol and nicotine consumption.
2. Early detection: Regular medical check-ups for at-risk patients, especially when taking corticosteroids.
3. Healthy lifestyle: A balanced diet and regular exercise promote blood circulation.
4. Protection from injuries: Avoidance of trauma through precautions, especially during sports activities.
5. Timely treatment: At the first signs of discomfort, a doctor should be consulted early to prevent the progression of the disease.