The patient is presenting with Kohler disease or osteochondrosis of the tarsal navicular. Kohler disease is a rare idiopathic disorder that usually occurs in children between the ages of 4 and 8 years.1,2
The navicular is the last bone in the midfoot to ossify; the theory is that running activities in children cause compression forces that disrupt the blood supply to the navicular. This leads to flattening of the navicular with loss of trabecular bone pattern, which can be seen on the lateral radiograph of this patient’s foot.1
Treatment involves a walking boot or cast on the foot for 6 weeks. Physical activities such as running sports should be avoided for 2 to 3 months or until the patient does not experience pain. The natural course of the disease is gradual revascularization with bony reconstitution starting approximately 8 weeks following treatment.1,2
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants.
References
1. Image quiz: Osteochondrosis of the tarsal navicular. J Bone Joint Surg Am. 2018;6(4):e36.
2. Gillespie H. Osteochondroses and apophyseal injuries of the foot in the young athlete. Curr Sports Med Rep. 2010;9(5):265-268.
