Coxa plana, unspecified hip

This code represents Legg-Calvé-Perthes disease (LCPD), an idiopathic avascular necrosis of the femoral head, without specifying which hip is affected. It describes the collapse and subsequent regeneration of the femoral head due to a temporary loss of blood supply, leading to deformity and potential long-term hip dysfunction.

Use this code when the medical record clearly documents a diagnosis of Legg-Calvé-Perthes disease but does not specify laterality (left or right hip). This is appropriate for initial diagnoses where laterality is not yet determined or when the documentation explicitly states "unspecified hip."

• Avoid using this code if the medical record specifies the affected hip; instead, use the more specific codes for left (M91.22) or right (M91.21) coxa plana.
• Ensure documentation supports the diagnosis of coxa plana (LCPD) and not other forms of avascular necrosis or hip deformities.
• Consider sequencing this code as the primary diagnosis when it is the reason for the encounter, especially for diagnostic workups or initial treatment planning.