Clinical Outcomes in Soft Tissue Repair Surgery With and Without Femoral Derotation Osteotomy for Patellar Dislocation: A Retrospective Study

Background: The purpose of our study was to report the clinical outcomes of isolated soft tissue repair or combined femoral derotation osteotomy (DFO) in patients with patellar dislocation with increased femoral anteversion angle (FAA).Methods: A total of 63 patients with patellar dislocation were retrospectively reviewed in this study. 33 patients received isolated soft tissue repair (group 1) and 30 patients were a combination with a femoral deroration osteotomy (group 2). CT were used to assess the correction of the femoral anteversion angle, the tibia tuberosity-trochlear groove (TT-TG) distance, patellar tilt (PTA), and the congruence angle (CA) following the two surgical programs. Subjective scores, such as Kujala, International Knee Documentation Committee (IKDC), Lysholm ,Tegner, and visual analogue scale (VAS) scores, were used to evaluate knee function.Results: In group 2, the mean of the FAA was corrected to15.76 ±2.02° postoperatively compared with 29.16± 2.87° preoperatively (P < 0.001). The TT-TG distance was decreased from 19.03 ±2.52 mm before surgery to 17.80 ±2.24 mm after surgery (< 0.001). Besides, Postoperative PTA and CA were corrected in both groups (P < 0.001). Kujala, IKDC, Lysholm and VAS scores of between groups were significantly improved after operation (P < 0.001). Furthermore, Compared with the isolated soft tissue repair surgery, the combined surgery achieve better postoperative outcomes in Kujala, (IKDC), Lysholm and VAS scores (P < 0.001). Conclusion: Although DFO can be used in combination with DFO to achieve better results, it should also be tailored to the individual and reduce patient suffering.