Evaluation of Accuracy of Preoperative Planning of the Femurofibular Angle in Open-Wedge High Tibial Osteotomy for Mild Medial Knee Osteoarthritis

Intraoperative femurofibular angle combined with tibiofibular angle measurement has fewer correction errors in open-wedge high tibial osteotomy

AIM

This study aimed to verify the accuracy of intraoperative femurofibular angle combined with tibiofibular angle (FFA-TFA) measurement and compare it with traditional alignment line methods in open-wedge high tibial osteotomy (OWHTO).

METHODS

A total of 174 knees of 122 patients undergoing OWHTO and using an alignment line or FFA-TFA measurement as an index of optimal correction were included in this retrospective study. The intraoperative alignment line passed through the targeted weight-bearing line (WBL) of the tibial plateau in the alignment line group. The intraoperative FFA-TFA aligned to the preplanned FFA-TFA angle in the FFA-TFA group. WBL, FFA, TFA, and knee joint-line convergence angle of the femur and tibia were assessed as radiological results preoperatively and one year after surgery. The Knee Society Score and the Western Ontario and McMaster Universities were assessed as objective clinical results.

RESULTS

Postoperative WBL in the FFA-TFA group was closer to the target WBL than in the alignment line group (FFA-TFA vs alignment line group: 1.43 ± 1.20% vs 3.82 ± 3.29%; P < 0.001). The FFA-TFA group had fewer over-correction and under-correction rates than the alignment line group (28.7% and 12.6% vs 11.5% and 3.40%; P < 0.001). No significant differences were observed in the clinical results between the two groups one year after surgery (P > 0.05).

CONCLUSIONS

The intraoperative measurement of FFA-TFA had fewer complications in terms of under-correction and over-correction compared with the alignment line measurement. No significant differences between the two methods were observed in clinical results one year after surgery.