This 1982 paper by Catterall and 12 co-authors examines the histopathology of Perthes' disease using six whole femoral heads and five core biopsies. The central question: is epiphysial infarction uniform across all cases, or does its extent vary in a way that explains radiological severity and prognosis? Sections were studied radiographically and histologically to correlate infarction extent with Catterall group.
The working assumption before this paper was that the entire femoral epiphysis infarcted uniformly at disease onset in every patient. Catterall's histological work disproved this, showing infarction extent ranges from zero (Group 1) to repeated complete destruction (Group 4) — and that this extent directly determines prognosis.
When you classify a child with Perthes' into a Catterall group, you are estimating the biological severity of infarction, not just describing an X-ray. Group 1 and 2 patients have limited infarction and generally do well with observation. Group 4 patients have sustained repeated complete infarctions, carrying a significantly worse prognosis and driving consideration of surgical containment.
The growth plate abnormalities on the unaffected contralateral hip matter in the clinic: when families ask about bilateral disease risk, this paper supports the concept of a systemic constitutional predisposition, not just a one-time local vascular accident. The 'head at risk' signs described by Catterall (calcification lateral to the epiphysis) correspond histologically to ossification islands forming in the anterolateral articular cartilage as blood supply is re-established. Connecting the radiographic warning signs to the underlying biology.
This 1982 paper by Catterall and 12 co-authors examines the histopathology of Perthes' disease using six whole femoral heads and five core biopsies. The central question: is epiphysial infarction uniform across all cases, or does its extent vary in a way that explains radiological severity and prognosis? Sections were studied radiographically and histologically to correlate infarction extent with Catterall group.
The working assumption before this paper was that the entire femoral epiphysis infarcted uniformly at disease onset in every patient. Catterall's histological work disproved this, showing infarction extent ranges from zero (Group 1) to repeated complete destruction (Group 4) — and that this extent directly determines prognosis.
When you classify a child with Perthes' into a Catterall group, you are estimating the biological severity of infarction, not just describing an X-ray. Group 1 and 2 patients have limited infarction and generally do well with observation. Group 4 patients have sustained repeated complete infarctions, carrying a significantly worse prognosis and driving consideration of surgical containment.
The growth plate abnormalities on the unaffected contralateral hip matter in the clinic: when families ask about bilateral disease risk, this paper supports the concept of a systemic constitutional predisposition, not just a one-time local vascular accident. The 'head at risk' signs described by Catterall (calcification lateral to the epiphysis) correspond histologically to ossification islands forming in the anterolateral articular cartilage as blood supply is re-established. Connecting the radiographic warning signs to the underlying biology.