Avascular necrosis, also abbreviated AVN and called avascular necrosis of bone, is defined in the packet as necrotic changes in bone tissue due to interruption of blood supply. The definition states that it most often affects the epiphysis of the long bones, and that the necrotic changes result in collapse and destruction of the bone structure. The packet lists primary avascular necrosis, secondary avascular necrosis, and dysbaric osteonecrosis as subtypes. No gene, onset category, or prevalence value is supplied in this packet.

No phenotype annotations are supplied in this packet, so symptoms are unknown here rather than absent. The only clinical description available is the definition, which refers to necrotic changes in bone tissue, most often at the epiphysis of long bones, with collapse and destruction of bone structure.

According to the packet definition, the necrotic changes arise from interruption of blood supply to bone. The packet lists primary and secondary forms as subtypes without further explanation of what distinguishes them. No genes or inheritance patterns are supplied, so the genetic basis is not described in this packet.

The packet supplies no diagnostic criteria, imaging findings, or testing information for avascular necrosis. Diagnostic approaches are therefore not described here.

The packet supplies no approved treatments, foundational therapies, or expert management guidance for avascular necrosis, so treatment information is not certified in this packet. Interventions named in clinical trial titles, such as device and surgical procedure studies, are not established treatments for the condition on that basis alone.

Prognosis is not certified in this packet; no natural history or outcome information is supplied.

ClinicalTrials.gov records in the packet include numerous active studies matched to avascular necrosis. Listed records include a recruiting study of autologous bone marrow aspirate treatment for early-stage osteonecrosis sponsored by Johns Hopkins University (NCT06123481), and a not yet recruiting study titled Emerging Indications for Hyperbaric Oxygen Treatment (NCT07240649, phase 4). Many other listed records are orthopedic device and joint replacement studies from industry sponsors. Trial titles alone do not establish efficacy or approval of any intervention.