Kohler\'s disease in a 6-year-old girl

Clinical History

A 6-year-old girl was referred to our hospital with persistent localised midfoot pain and limp a few weeks ago. No history of trauma was reported. No ecchymosis, bruising or bleeding was observed. Plain radiography was assisted to exclude coalition of tarsal bones. MRI was suggested due to plain radiography findings.

Imaging Findings

Anteroposterior and lateral plain radiography (Fig. 1) of foot and ankle were obtained. A sclerotic, collapsed and fragmented tarsal navicular bone was depicted. Kohler’s disease was the most probable diagnosis. The MR imaging examination was performed with a 1.5 Tesla scanner using standard sequences. The fat suppressed axial PD-w MR image shows diffuse high signal intensity in keeping with bone marrow oedema as well as cystic appearance at the lateral fragmented side (Fig. 2). The fat suppressed contrast enhanced sagittal T1-w MR image shows moderate and homogenous enhancement of the talar navicular indicating viability of the bone marrow (Fig. 3).

Discussion

Kohler’s disease is an uncommon idiopathic transient avascular necrosis of the talar navicular bone. The disease is affecting usually children around 4-6 years old. It is commonly unilateral, 2 to 3 times more frequent in boys than in girls in whom it could appear at a younger age. Kohler’s disease occurs when arterial supply is disrupted. Talar navicular bone avascular necrosis is thought to be associated with the fact that is the last bone to be ossified in the tarsus. This normal delay in ossification may result in the vulnerability of the navicular bone to withstand regular loads [1, 2].

Children present clinically with limp and moderate midfoot pain. Laboratory examinations are normal and usually there is no history of trauma. Imaging can diagnose the presence of Kohler’s disease and exclude other entities such as various types of coalition [2].

In plain radiographs, flattening, fragmentation and osteosclerotic navicular combined with the young age indicate the proper diagnosis [1, 2]. In addition, MR imaging can depict bone marrow oedema in keeping with the pain as well as the viability of the bone in case that enhancement is observed after intravenous contrast administration. The final diagnosis is based on the age of the patient, the clinical history and the imaging findings.
The treatment is symptomatic. Our patient was treated with below-the-knee-walking cast for 4 weeks and after removing there was slow and progressive return to prior activities. The overall outcome was excellent. Imaging in the case presented herein was useful in terms of excluding other pathology such as bone coalition, which would require surgical treatment [2, 3].

In young children with midfoot pain and no history of trauma, Kohler’s disease should be added to the differential diagnostic list because it is self-limited with an excellent prognosis.

Differential Diagnosis List

Final Diagnosis

Kohler’s disease

URL:	https://www.eurorad.org/case/10101
DOI:	10.1594/EURORAD/CASE.10101
ISSN:	1563-4086