Fusion versus excision of the symptomatic Type II accessory navicular: a prospective study

Patients with symptomatic Type II accessory naviculars that fail nonoperative measures may be treated with excision, percutaneous drilling, a modified Kidner procedure, or a fourth option, arthrodesis of the accessory ossicle to the navicular body. There is little information in the literature on the relative merits of arthrodesis.

A prospective evaluation of 20 patients undergoing surgical intervention for symptomatic Type II accessory naviculars was performed. The decision to perform either an arthrodesis (10 feet) or a modified Kidner (10 feet) was made intraoperatively based on the size of the accessory ossicle. Outcomes were measured using pre- and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot scores, plain radiographs, and chart reviews.

At an average followup of 35 months, the mean AOFAS score for the arthrodesis group improved from 50 to 93 points. There were two non-unions (20%) and one patient complained of painful hardware. At an average followup of 48 months, the mean AOFAS score for the modified Kidner group improved from 52 to 80 points. However, in this group, three of ten patients (30%) had persistent midfoot pain and radiographic evidence of progressive loss of the longitudinal arch.

Although the methods do not represent a randomized comparison of treatments for the same condition, the results suggest that arthrodesis may be a reasonable treatment option in selected cases of patients with symptomatic recalcitrant Type II accessory naviculars that are large enough to accept small fragment screws.