PSI and Varus: Accuracy in High Varus Ankles
Published in Foot & Ankle Specialist, Ben Umbel and co-authors studied the impact of CT-derived patient specific instrumentation and the degree of ankle varus. The upshot is that final implant alignment accuracy with PSI does not appear to be impacted by worsening preoperative varus deformity.
Read between the lines
Contemporary belief is that around 20% of ankle replacements will need additional procedures at the time of index. This paper studied that number of additional procedures and correlated an increased number of procedures with more severe degree of varus. It follows that a system to guide implant placement (PSI) could be aided by an algorithm for stepwise varus correction. A market opportunity?