A retrospective study on factors predictive of operative intervention in symptomatic accessory navicular.

PURPOSE: The variables causing symptomatic accessory navicular are largely unknown and may inform management of symptomatic patients. The purpose of this study was to examine patient specific factors associated with the development of accessory navicular symptoms.

METHODS: A total of 71 patients with clinical and radiographic evidence of accessory navicular syndrome were evaluated. Patient gender, race, date of birth, date of earliest foot complaint and laterality were recorded. Treatment was defined as conservative versus surgical. Skeletal maturity was assessed based on calcaneal ossification, accessory navicular subtype and the presence of pes planus based on talo-first metatarsal angle were assessed.

RESULTS: Female patients comprised 72% of the subjects and trended towards symptoms at younger ages than male patients (p = 0.06), while no significant difference in presentation age was appreciated between male and female patients. Skeletal maturity was significantly associated with earlier complaints and age at presentation but was not associated with increased need for surgical management. Patients with pes planus were significantly more likely to undergo operative management. Accessory navicular subtype was significantly correlated with skeletal maturity.

CONCLUSION: Female patients were more likely to report symptoms and present with symptomatic accessory navicular. The stage of skeletal maturity is not a predictor of future surgical management but patients with a higher first-metatarsal angle were more likely to require surgery. The correlation between accessory navicular subtype and skeletal maturity suggests that Type II ossicles are likely to develop into Type III over time. Radiographic evaluation of the accessory navicular may lend prognostic data on the necessity of future surgical intervention.

LEVEL OF EVIDENCE: IV, Case Series.