2025 ISAKOS Congress in Munich, Germany

2025 ISAKOS Biennial Congress Paper


The Influence of Femoral and Tibial Derotational Osteotomy on Intraarticular Knee Rotation

Anne Thielmann, Assistenzarzt, Bamberg GERMANY
Christoph Lutter, MD, Rostock, - GERMANY
Felix Ferner, Dr., Lichtenfels GERMANY

Klinikum Lichtenfels, Lichtenfels, GERMANY

FDA Status Not Applicable

Summary

The current study showed a decrease of knee version by de-rotational osteotomy with a statistical significance in femoral osteotomies and without significance in tibial osteotomies.

Abstract

Purpose

Patients with an increased femoral or tibial torsion often present with a patellofemoral instability or anterior knee pain due to patellofemoral maltracking. The knee version (=intraarticular rotation) is a value that has gained increasing attention in the past few years as another possible risk factor contributing to a patellofemoral maltracking. Whereas a pathologically increased torsion of the tibia or femur can be corrected by a de-rotational (torsional) osteotomy, the change of knee version by torsional osteotomies around the knee remains unclear so far. We hypothesize that a pathologically increased knee version can be influenced by derotational osteotomies and that the change of knee version correlates to the extent of the correction.

Methods

The data for the retrospective study were recorded between 01/2018 and 10/2021. The patient cohort consisted of 40 patients aged between 14 and 57 years. 19 patients were treated with a tibial, and 21 patients with a femoral osteotomy. Torsional CT scan according to the Waidelich protocol was obtained preoperatively. The tibial osteotomy was performed supratuberositary with a lateral approach and the femoral osteotomy uniplanar from the medial side. A postoperative torsion CT scan was performed before discharge. The knee version was measured pre- and postoperatively and the values were compared within the whole study population and divided into a tibial and a femoral group.

Results

Measuring the knee version of the entire patient population, a significant decrease in knee version was found between pre- and postoperatively (p=0.014). Hereby the knee version decreased from 9,3° ± 6,6° to 5,7° ± 5,4°. In tibial osteotomies, the knee version decreased from 5,2° ± 5,9° to 4,2° ± 5,8° without statistically significance (p=0.678). The group with the femoral osteotomies showed a statistically significant (p=0.002) decrease from 11,5° ± 5,8° to 6,2° ± 4,4°. No strong correlation was found between the degree of torsional correction and the degree of change in knee version, neither tibially (r=0.37, p=0.139) nor femorally (r=-0.39, p=0.080).

Conclusion

The current study revealed that a pathological increased knee version in patients with a femoropatellar maltracking or instability can be reduced indirectly by derotational osteotomy. Hereby, the tibial osteotomy showed a non-statistically significant decrease and the decrease for femoral osteotomies was statistically significant. Moreover, the extent of the derotation does not strongly correlate to the change in knee version.

Key words
Osteotomy, derotational osteotomy, knee version, patellofemoral instability