| disease | Navicular Bone Osteochondrosis |
| alias | Avascular Necrosis of the Navicular Bone |
Tarsal navicular osteochondrosis, also known as aseptic necrosis of the tarsal navicular, refers to the sclerosis, flattening, and fragmentation of the tarsal navicular bone during growth and development. It commonly affects children aged 4 to 8 years, with boys being more frequently affected than girls.
bubble_chart Etiology
The navicular bone is the keystone of the longitudinal arch of the foot, subjected to significant stress and prone to ischemic necrosis. However, Caffey found that 30% of boys and 20% of girls have irregular ossification centers in the navicular bone. In an unselected series of 100 foot X-rays, 37% of the navicular bones developed from multiple ossification centers. Indeed, some children may show irregular fragmentation of the navicular bone on X-rays taken for other reasons; moreover, the asymptomatic contralateral foot of a child may exhibit similar radiographic findings to the symptomatic side. Clinically, the onset of symptoms is acute, with a history typically lasting only 1 to 2 days, but the radiographic manifestations cannot form in such a short period. It is difficult to imagine that bone necrosis could persist for a long time without symptoms. Therefore, many scholars now believe that this condition is a normal growth variation.
bubble_chart Clinical Manifestations
The child complains of pain on the dorsum of the foot, which worsens after bearing weight and also occurs at night. A limp has gradually developed. There is grade I swelling and tenderness above the navicular bone. Pain is also present when pressure is applied to the longitudinal arch of the foot. The child often walks on the lateral edge of the foot.
bubble_chart Auxiliary ExaminationX-ray findings: The scaphoid appears denser and flattened, possibly only 1/2 to 1/4 the thickness of a normal scaphoid. Later, it may become fragmented with widened joint spaces in the adjacent areas. After healing, the scaphoid returns to normal in most patients.
bubble_chart Treatment Measures
In the acute phase, a short leg cast can be used for approximately 6 weeks, followed by the use of shoe inserts. Occasionally, if osteoarthritis occurs due to navicular bone deformation, arthrodesis may be performed.
The prognosis of this disease is favorable. A long-term follow-up of 20 patients revealed that all were asymptomatic, and the shape of the scaphoid bone had also returned to normal.
