P0189 - Surgical Outcomes for Accessory Navicular in Adolescent Athletes

Introduction: An accessory navicular is a plantar medial enlargement of the navicular bone of the foot. The accessory navicular is incorporated with the posterior tibial tendon which inserts into the navicular tuberosity. Patients with an accessory navicular present with a foot bump. This condition occurs in up to 12% of the population. Only some patients are symptomatic. The purpose of this study is to report the surgical outcomes in a consecutive series of adolescent athletes with symptomatic accessory navicular.

Methods: The study was approved by the College of Medicine IRB. 15 athletes who underwent surgical treatment were evaluated. Patient gender, age, complaints, family history, sports played, conservative treatments attempted, duration of symptoms, surgical technique, post-operative care, complications, outcomes, average follow up, time to return to normal activity, # that returned to sports, and the time to return to sports were recorded. Radiographs were used to identify the type of accessory navicular, skeletal maturity, and presence of concurrent pes planus.

Results: 15 patients and 17 feet were studied. 5 right feet, 8 left feet and 2 bilateral cases were treated. 16 were female (94%) and 1 was male (6%). The average age at surgery was 13 years (range 10 to 17 years). 0 patients had a family history of accessory navicular. The most common pre-operative complaint was foot pain. 15 patients and 17 feet played sports including 2 basketball, 2 cheer, 4 gymnastics, 3 soccer, 1 volleyball, 1 dance, 1 softball, 3 others. The average duration of symptoms was 20 months (range 1 to 36 months). Conservative care methods attempted included: shoe inserts, activity modification, anti-inflammatory medications, icing, crutches, and changes in footwear. Pre-op radiographs demonstrated 8 Type 1, 3 Type 2, and 6 Type 3 accessory naviculars. Pre-op radiographs demonstrated 5 patients (29.4%) had flat foot. 9 feet (53%) had fused the calcaneal growth plate and 8 feet (47%) had an open calcaneal growth plate. 3 patients (17.6%) had a simple excision of the accessory navicular and 14 patients (82.4%) had a reefing of the posterior tibial tendon. The average time to return to normal activities was 13 weeks (range 8 to 16 weeks). All patients were able to return to their pre surgery sports. The average follow-up time was 8.4 months. At final follow up, 16 cases (94%) reported no pain and 1 (6%) with minimal pain. No complications were reported.

Conclusion: Surgery is indicated for recalcitrant cases that have failed conservative management. Female athletes are more commonly afflicted with a symptomatic accessory navicular. Excision and reefing of the posterior tibial tendon resulted in improved pain relief compared to simple excision. 100% of the patients who underwent surgical treatment were able to return to their sports activities.