Picture 1: A 10-year old girl with pain and swelling over her 2nd, 3rd and 4th MTP-joints.
A 10-years old boy presented with pain and swelling over his right foot for two weeks. Physical examination revealed pain, swelling and tenderness over the 2nd, 3rd and 4th MTP-joints. There was a history of minor trauma in the past.
Radiograph showed a cone-shaped epiphysis of the 2nd, 3rd and 4th phalanges.
Picture 2: Cone-shaped epiphysis are marked red, the normal epiphysis of the 5th phalanx is marked green. White arrows point at dense metaphyseal lines.
Cone-shaped epiphyses can be seen in normal children and are not necessarily expressions of generalized or local disease. They can be seen in other disorders, including sickle cell anemia, osteomyelitis, congenital diseases, infection, trauma, and radiation injury, Achondroplasia, Acrodysostosis, Beckwith Wiedemann syndrome, Chondroplasia punctata, Cockayne syndrome, Cleidocranial dysplasia, Multiple epiphyseal dysplasia.
Coned epiphyses can be result of premature closure of the central portion of the physis, following which the peripheral portion of the physis continue to grow. As result, the metaphysis lengthens around the tethered portion of the epiphysis, and the epiphysis develops into a cone shape. The situation may also be called a cupped metaphysic. This imparement to longitudinal growth also leads to a relative shortening of the affected bone. Because the growth imparement is central, there is no angular deformity. Coned epiphyses may result from vascular infarcts caused by embolic disease.
Dense metaphyseal lines (growth arrest/recovery lines) perpendicular to the longitudinal axis of the bone, are seen in children, however, can persist into adulthood. They develop when normal bone growth resumes after it has been slowed down for some reason. The metaphyseal lines can be caused by a wide variety of pathologies: infection or trauma, or systemic disorders like aneamia, renal osteodystrophia, radiation injury, heavy metal or chemical poisoning, high dosage of drug or hormone therapy etc.
The fact that the dense lines are only visible in the 2nd, 3rd and 4th phalanges and not in the unaffected 5th phalanx (figure), in combination with the absence of systematic disease and signs of infection, make that the the cone-shaped epiphysises are most likely caused by a trauma in the past.