When a child is diagnosed with Legg-Calvé-Perthes disease, the first weeks are often defined by confusion. The diagnosis — avascular necrosis of the femoral head — sounds severe, the imaging is alarming, and the treatment path is rarely straightforward.

Periarticular heterotopic ossification — bone forming in the soft tissue around a joint — is one of those conditions that tends to arrive without much warning. You might notice stiffness after a hip replacement, limited range of motion months after a spinal cord injury, or a strange firmness in tissue that was previously pliable.

If you or your child has been told the joints are "just inflamed" or that the finger contractures are "probably juvenile arthritis," but the treatments never quite fit, you are not imagining the mismatch.

Coxa valga is not something most people go looking for. Usually a doctor mentions it after an X-ray taken for something else — a limp that would not resolve, a hip that felt loose, a routine scan in a child with cerebral palsy or a connective tissue condition.