Background: Fixation of intra-articular calcaneal fractures has traditionally been guided by intraoperative fluoroscopy. Recent reports indicate that there is a role for subtalar arthroscopy in surgical fixation of these fractures. The earliest reports described the use of subtalar arthroscopy for joint assessment during late hardware removal. It then served as an adjunct for joint inspection in open reduction and internal fixation. In its final permutation, percutaneous arthroscopy was performed with minimally invasive reduction and fixation, minimizing soft tissue complications commonly associated with the open approach. In practiced hands, this technique yields good results with minimal morbidity. Methods: We performed a prospective analysis of 22 consecutive patients with Sanders II, AO-OTA 83-C2 intra-articular calcaneal fractures who underwent dual-modality imaging (subtalar arthroscopic- and intraoperative fluoroscopic-) guided percutaneous fracture fixation with a minimum follow-up of 2 years. Maximum accepted postreduction step-off was 1 mm. Fractures were fixed definitively with four to eight percutaneous cancellous screws. Results: There was significant correction of Bohler's tuberosity-joint angle from 4.2 degrees +/- 11.1 degrees preoperatively to 21.3 degrees +/- 8.8 degrees on immediate postoperative radiographs, with minimal subsidence to 20.1 degrees +/- 8.2 degrees at 2 years. Bohler's angle correction and joint surface restoration could not be achieved percutaneously in one patient with an impacted, depressed joint fragment. Compared with preoperative values, there was significant improvement in mean Visual Analog Scale, American Orthopedic Foot and Ankle Society Ankle-Hindfoot Score, and Short Form-36 (Physical Function) scores at 3 months, with further improvement up to 2-years. Conclusions: Subtalar arthroscopy augments intraoperative fluoroscopy in anatomic reduction of the posterior calcaneal facet of the subtalar joint and is most useful for Sanders type II, AO-OTA 83-C2 fractures. The percutaneous approach further avoids soft tissue complications associated with open reduction. However, this procedure has a steep learning curve, and conversion to open reduction must be considered when percutaneous reduction fails.
