The Usefullness of Subtalar Arthroscopy in Surgical Treatment of Sanders Type 2 Calcaneal Fractures Using a Sinus Tarsi Approach

Abstract

Category: Ankle, Trauma Introduction/Purpose: The sinus tarsi approach was designed to provide a direct view of the posterior facet and reduce soft tissue and neurovascular injuries. However, it is difficult to expose posterior facet using sinus tarsi approach because of limited surgical view. Confirmation of reduction status in intra-articular calcaneal fractures has traditionally been performed by intraoperative fluoroscopy such as Brodens view. Recently some reports indicate that there is a role for subtalar arthroscopy in these fractures. We thought that combination of intraoperative fluoroscopy and subtalar arthroscopy could more accurately restore joint congruity and provide better clinical outcomes. The purpose of this study was to clarify whether this combined checking has better clinical and radiological results comparing with intraoperative fluoroscopy only. Methods: Forty-five displaced calcaneal fractures involving the posterior facet were consecutively treated using a sinus tarsi approach by a single surgeon. Among them, 25 fractures were confirmed reduction of posterior facet by fluoroscopy (Fluoroscopy group) and 20 fractures were confirmed by combined fluoroscopy and subtalar arthroscopy (Arthroscopy group). Clinical evaluations were performed using the visual analogue scale (VAS) and the Ankle-Hindfoot Scale developed by the American Orthopaedic Foot and Ankle Society (AOFAS), and short form (SF)-36 v2 questionnaires. Radiographic evaluations were performed using calcaneal lateral radiographs and CT. Changes in Böhler’s angle were evaluated from the preoperative and last follow-up lateral radiograph of calcaneus. Reduction of the posterior facet was graded according to articular step, defect, and angulation of the posterior facet in CT. Results: There were no significant differences in terms of VAS, AOFAS score, and SF-36 v2 between Fluoroscopy and Arthroscopy groups at the last follow-up. No significant difference was observed in change of Böhler’s angles between the groups. Reduction of the posterior facet was graded excellent in 5 feet (20%), good in 12 (48%), and fair in 8 (32%) in Fluoroscopy group and excellent in 7 feet (35%), good in 11 (55%), and fair in 2 (10%) in Arthroscopy on postoperative CT. Screw penetration of posterior facet were observed in 4 feet of Fluoroscopy group and 1 foot of Arthroscopy group on postoperative CT. Conclusion: Subtalar arthroscopy appears to be useful in detecting joint incongrucencies in sinus tarsi approach of intra-articular calcaneal fractures.