Avascular necrosis

AVN is a disease where there is necrosis of bone components due to temporary or permanent interruption of the blood supply. Without blood, the bone tissue dies and the bone collapses. It most often affects the extremities of the long bones, such as the femur and tibia, leading to destruction of articular surfaces and resulting in hip, knee, and ankle problems.

Factors that predispose paediatric oncology patients to AVN are:

Radiotherapy (especially to weight-bearing bones)
Bone marrow transplant
Suboptimal nutrition
Growth hormone deficiency (resulting from treatment)
Inactivity/immobilisation
Medications
- Steroids
- Cyclosporin

Clinical signs and symptoms

Pain that is ongoing without easing
Loss of range of movement (ROM)
Altered gait pattern
Swelling around joints

For early detection and staging, MRI is the most reliable method and is recommended when symptoms arise (Vladutu et al., 2025).

Treatment

Analgesia
Reduced weight bearing, rest and use of mobility aids such as crutches or walking frames
Physiotherapy
Surgical
Drugs: Bisphosphonates

If you are concerned that a patient you are treating may have AVN, they need to be reviewed by orthopaedics for combined management with the cancer team. Liaise with the patient’s consultant or Paediatric Oncology Outreach Nurse Specialist (POONS) to arrange this.

Late effects: bone issues publication

Clinical signs and symptoms

Treatment

Further reading