Histopathologic findings of spontaneous osteonecrosis of the knee at an early stage: a case report

Hiroyuki Hatanaka, Takuaki Yamamoto, Goro Motomura, Kazuhiko Sonoda, Yukihide Iwamoto

Research output: Contribution to journalArticle

4 Citations (Scopus)


We histopathologically examined a surgically resected full specimen obtained from an early-stage spontaneous osteonecrosis of the knee (SPONK). On a mid-coronal cut section of the resected medial femoral condyle, a linear fracture line paralleling the subchondral bone endplate was found. Histopathologically, prominent callus formation was seen comprising of reactive woven bone and granulation tissue on both sides of the fracture. Fracture-related bone debris was focally observed at the osteochondral side of the fracture. Definitive features of antecedent bone infarction such as creeping substitution and bone marrow necrosis were not detected. These findings suggested that SPONK was the result of a subchondral fracture rather than primary osteonecrosis.

Original languageEnglish
Pages (from-to)713-716
Number of pages4
JournalSkeletal Radiology
Issue number5
Publication statusPublished - May 1 2016


All Science Journal Classification (ASJC) codes

  • Radiology Nuclear Medicine and imaging

Cite this