Short-Term Outcomes After Derotational Femoral Osteotomy to Correct Abnormal Tibiofemoral Rotation in Patients With Recurrent Patellar Dislocations and Severe Rotational Malalignment

Abstract

Background:

Tibiofemoral rotation is often increased in patients with recurrent patellar dislocations (RPDs), and excessive tibiofemoral rotation may contribute to a higher failure rate of medial patellofemoral ligament (MPFL) reconstruction. However, there is currently limited research on the optimal treatment strategy for RPDs with excessive tibiofemoral rotation.

Purpose:

To report the clinical outcomes of derotational femoral osteotomy (DFO) combined with MPFL reconstruction for managing RPDs with excessive tibiofemoral rotation and to compare them with those of nonderotational surgical techniques.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This retrospective study analyzed data from patients with RPDs and excessive tibiofemoral rotation treated between 2014 and 2021. According to the surgical procedure performed, a total of 49 patients who underwent DFO combined with MPFL reconstruction were included in the derotational group, while 31 patients who underwent MPFL reconstruction with or without tibial tubercle osteotomy were included in the control group. Radiological and clinical outcomes were compared between the derotational group and the control group, and changes in tibiofemoral rotation from preoperatively to postoperatively were analyzed for both groups. Additionally, subgroup analysis was conducted to explore the effect of femoral anteversion (≤30° vs >30°) on the aforementioned results.

Results:

A total of 80 patients with a median follow-up of 4.0 years were included. All included patients (n = 80) demonstrated excessive tibiofemoral rotation (derotational group: 17° ± 4° vs control group: 16° ± 5°; P = .330). No significant differences in preoperative functional scores or anatomic parameters were found between groups. At the final follow-up, the derotational group had a significantly higher Kujala score (84 ± 10 vs 78 ± 11, respectively; P = .033) and no redislocations (0% vs 19%, respectively; P < .001) compared with the control group. In the derotational group, tibiofemoral rotation showed significant improvement from preoperatively to postoperatively (from 17° ± 4° to 12° ± 6°; P < .001), whereas no significant change was observed in the control group from preoperatively to postoperatively (from 16° ± 5° to 17° ± 5°; P = .515). Subgroup analysis based on preoperative femoral anteversion revealed that the clinical outcomes in the derotational group were superior to those in the control group, regardless of whether the preoperative femoral anteversion was >30° or ≤30°.

Conclusion:

This study established that combined DFO and MPFL reconstruction yielded superior clinical outcomes relative to MPFL reconstruction performed with or without tibial tubercle osteotomy in patients with RPDs and excessive tibiofemoral rotation (>12°). Importantly, this therapeutic advantage was maintained even in patients exhibiting femoral anteversion ≤30°. Furthermore, DFO resulted in a mean reduction of 5° in tibiofemoral rotation at the final follow-up, in contrast to the control group, which showed no significant change.