Editorial Commentary: Patient-Specific Instrumentation for High Tibial Osteotomy in Varus Knees Does Not Prevent...

A recent survey of practice patterns identified that knee osteotomy is being performed with increasing frequency and that the interest in patient-specific instrumentation (PSI) is high. This is likely due to the potential advantages of PSI including the possibility of better accuracy of correction, quicker surgery with less intraoperative fluoroscopy, and increased safety. Although PSI can reduce outliers and low-accuracy corrections, it does not prevent them entirely. The occurrence of low-accuracy corrections after PSI osteotomy is multifactorial and includes the reliance on supine imaging which therefore does not account for the effect of load bearing on alignment, technical errors in guide positioning, stability of cutting guides once applied, and changes in alignment postoperatively, prior to postoperative imaging. Despite these pitfalls, high tibial osteotomy is associated with significant improvements in clinical and radiological outcomes including improvements in the ICRS grade at second look arthroscopy. However, cartilage regeneration occurs variably and has not been shown to clearly confer any clinical benefit with respect to patient-reported outcome measures or osteotomy survivorship at 10-year follow-up.