Tibial rotational realignment has no noticed negative effect on the patellar cartilage 1-year after open-wedge high tibial osteotomy

Purpose

Proximal tibial plateau/distal tibial rotational realignment, which is defined as tibial rotational realignment (TRR), is uncertain in open-wedge high tibial osteotomy (OWHTO). This study descriptively analysed TRR outliers in OWHTO, and also examined influence of TRR on the patellar cartilage at a 1-year postoperative examination.

Methods

In total, 206 consecutive cases with computer-navigated OWHTO were reviewed. Patellar cartilage aggravation was evaluated in reference to the International Cartilage Repair Society grade (ICRS) at a 1-year postoperative arthroscopic view. Also, the lateral patella tilt correction and the Iwano classification deterioration grades were examined using axial radiographic views at a 1-year postoperative follow-up visit.

Results

The TRR ranged from −12° (the distal tibia was externally rotated based on the proximal tibia) to 13° (internal rotation (IR): the distal tibia was internally rotated based on the proximal tibia) with mean 1.9° IR and standard deviation 5.4°. The inter-quantile range (IQR) was 8°, suggesting that there was no outlier in this cohort, (outliers were defined as either more than Q3+1.5IQR (upper limit: 18°), or Q1-1.5IQR (lower limit: −14°)). In univariate regression models, the TRR did not exhibit any significant influence to the patellar cartilage damage (odds ratio (OR) 1.047, 95% confidence interval (95%CI) 0.976–1.122), the patella tilt correction (OR 1.010, 95%CI 0.953–1.071), or the Iwano classification degradation scale (OR 1.041, 95%CI 0.971–1.116).

Conclusion

We found no outlier in the TRR with OWHTO, and an insignificant negative impact of the TRR with OWHTO on the patellar cartilage in the 1-year follow-up examinations.