Evaluation of Accessory Navicular Bone Using a Bone Scan and Its Clinical Significance for the Prognosis and Treatment / 대한족부족관절학회지

ABSTRACT

PURPOSE: To evaluate the clinical significance and usefulness of a bone scan in accessory navicular bone. MATERIALS AND METHODS: Eighty-five patients with foot pain and accessory navicular bone on radiography, who underwent bone scan from 2012 to 2015, were analyzed retrospectively. The subjects was divided into a symptomatic and asymptomatic group according to the presence of navicular bone tenderness. The grade of bone scan uptake was divided into 3 grades. Age, gender, grade of bone scan and size of the accessory navicular bone were analyzed. The symptomatic group were divided into a low (grade 0, 1) and high uptake (grade 2) group to determine the appropriate treatment. The low uptake group was treated conservatively for 3 months. The high uptake group was initially treated conservatively for 3 months and surgery was performed if pain persisted. For the clinical evaluation, the visual analogue scale, American Orthopaedic Foot and Ankle Society midfoot scale were evaluated in the first examination and last follow-up date. The patient's satisfaction grade was also evaluated at the last follow-up. RESULTS: The asymptomatic group mostly showed no uptake in the bone scan. On the other hand, some patients in the asymptomatic group showed an increase in uptake. In these patients, the size of accessory navicular bone was related to the grade of bone scan uptake, showing that the bone scan uptake grade can be predicted when applying different cut off values for the bone size. The symptomatic group mostly showed uptake in the bone scan and the grade of uptake had a positive correlation with the size of the accessory navicular bone (p<0.05). Age and gender were not related to the bone scan uptake. In the clinical evaluation, conservative and surgical treatment showed a good outcome. CONCLUSION: The bone scan uptake grade alone cannot be used to completely predict the symptoms. On the other hand, the size of the accessory bone can increase the bone scan uptake. Therefore, the size of the accessory bone, and patient symptoms should be considered in patients with a high uptake when deciding treatment.