Fusion vs. Excision of the Symptomatic Type II Accessory Navicular: A Prospective Study

SLR - August 2009 - Japheth Ogamba Mongare

Reference:
Scott, A.T., Sabesan, V.J., Saluta, J.R., Wilson, M.A.; Easley, M.E. (2009). Fusion vs. excision of the symptomatic type II accessory Navicular: A prospective study. Foot and Ankle International, 30(1), 10-15.


Scientific Literature Review


Reviewed by: Japheth Ogamba Mongare, DPM
Residency Program: OCPM-UHHS Richmond Medical Center


Podiatric Relevance:
This study compares two treatment options for patients with a symptomatic type II accessory navicular that fails to improve with conservative treatment: one a modified kidner procedure, and the second arthrodesis of the accessory ossicle to the navicular body.

Methods:
This was a prospective study of twenty patients who underwent operative treatment for a symptomatic Type II accessory navicular. There were 11 males and 9 females. Average patient age was 25 years. All patients were diagnosed with a Type II accessory navicular, displayed symptoms attributable to the accessory navicular, and had failed a conservative treatment regimen which included antiinflammatory medications, orthotics, and a period of immobilization. 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 post-operative American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot scores, plain radiographs, and chart reviews.

Results:
Average postoperative follow-up for the arthrodesis group was 35 months, and for the modified Kidner group was 48 months. No patients were lost to follow-up. In the 10 patients who underwent arthrodesis, the average preoperative AOFAS Midfoot score was 50 points. Postoperatively, this mean score improved to 93 points. Radiographic analysis revealed two non-unions (20%), only one of which was symptomatic at final follow-up. One patient complained of painful hardware and subsequently returned to the operating table for screw removal. In the arthodesis group, there were no nerve injuries, no superficial or deep wound infections, and no clinical or radiographic signs of medial longitudinal arch collapse.
For the 10 patients who underwent the modified Kidner procedure, the preoperative AOFAS Midfoot score averaged 52 points. Postoperatively, this score improved to 80 points. 3 of the 10 feet in this group (30%) displayed radiographic signs of progressive loss of the medial longitudinal arch and persistent midfoot pain. Three patients had AOFAS score of 70,75,and 77 points. Those patients who underwent arthodesis saw a significantly greater increase in AOFAS scores when compared with those in the modified Kidner group (p= 0.008). However ,the final AOFAS scores were not significantly different between the two groups (p>0.05).

Conclusions:
This results indicate that arthrodesis perfomed as well as the modified Kidner procedure for the treatment of the symptomatic Type II accessory navicular at intermediate follow-up. These results are comparable to previous reports of surgically managed accessory naviculars. Although this reports do not represent a randomized comparison of treatments for the same condition, the results suggest that arthodesis may be a reasonable treatment option in selected cases. Further studies with a larger patient pools are needed to determine the potential benefits of arthrodesis as compared to the kidner procedure.