Posterior Talar Shifting in Mobile-Bearing Total Ankle Replacement.

BACKGROUND

End-stage ankle osteoarthritis frequently involves multiplanar malalignment in both the coronal and the sagittal planes. Sagittal malalignment often includes anterior translation of the talus relative to the tibia. Restoration of the correct tibial and talar alignment is essential for the long-term survival of total ankle replacement.

METHODS

This study includes 66 consecutive patients who underwent total ankle arthroplasty with the Hintegra prosthesis from May 2011 to April 2014. There were 28 females (42.4%) and 38 males (57.6%) with a mean age of about 57 years (25-82 years). Patients were clinically and radiologically assessed preoperatively and at 2, 6, and 12 months postoperatively.

RESULTS

At 12 months postoperatively, there was a statistically significant increase in American Orthopaedic Foot & Ankle Society scores from 31.9 to 72.3. Range of motion significantly increased from 9.5 to 25.4 degrees. In addition, there was a statistically significant decrease in visual analog scale (VAS) pain score from 8.9 to 2.2. Furthermore, there was a significant increase in the Tibio-Talar ratio from 2 to 6 months postoperatively (34.6%-37.2%).

CONCLUSIONS

This study demonstrated significant improvements in clinical and radiologic outcomes after Hintegra total ankle arthroplasty. Significant movement of the talus occurs within the first 6 months postoperatively. This may be the result of rebalancing of muscle and ligament forces after surgery.

LEVEL OF EVIDENCE: Level IV, case series.