Comparative analysis of intraoperative fluoroscopic vs. Anatomical landmark positioning methods in MPFL reconstruction for recurrent patellar dislocation.

Abstract

Objective: A retrospective analysis was conducted to evaluate the application of the intraoperative fluoroscopic positioning and anatomical landmark positioning methods in medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar dislocation. The aim was to summarize the positioning accuracy and clinical efficacy of each method, to serve as a reference for femoral positioning.

Method: We conducted a retrospective analysis of a cohort comprising 75 patients who underwent treatment for recurrent patellar dislocation at our institution between January 2014 and September 2020.Based on the different positioning methodologies utilized for identifying the MPFL femoral footprint, the included patients were systematically allocated to either the fluoroscopy group or the palpation group.Preoperative evaluations and assessments at the latest follow-up encompassed the International Knee Documentation Committee (IKDC) score, Lysholm score, and Kujala score for both groups.We utilized immediate postoperative CT scans for our evaluations. A total of 48 knee 3D-CT scans were acquired using Mimics Medical 21.0 for both groups. From these scans, we constructed a standard lateral Schottle point on a 3D-CT image. To assess the relative positions between the actual and standard location points in both groups, we established a coordinate system based on a simplified, constructed standard point baseline (as illustrated in Chart e). Subsequently, the relative positions of the actual points were evaluated.

Result: All 75 patients were followed up for a period ranging from 36 to 96 months( mean: 62.27 ± 21.36 months). Significant improvements were observed in the IKDC score, Lysholm score, and Kujala score from preoperative to the latest follow-up (p < 0.05) (Table 2), indicating statistical significance.Furthermore, the latest follow-up revealed no significant differences in knee function scores between the two groups (P > 0.05) (Table 3). Similarly, the latest evaluation showed no significant differences in knee function scores between patients undergoing MPFLR and MPFLR + TTO In their respective groups (P > 0.05) (Table 4).CT-3D reconstruction was conducted on 48 postoperative patients (24 in the fluoroscopy group and 24 in the palpation group). Evaluation of the positioning revealed that most cases in the palpation group were located in quadrants 1 and 3, whereas those in the fluoroscopy group were primarily distributed across quadrants 1, 3, and 4 (p < 0.05), indicating statistical significance.In the palpation group, the isometric distance was 3.90 ± 2.17 mm, with an isometric rate of 75%. In the fluoroscopy group, the isometric distance was 7.55 ± 3.94 mm, with an isometric rate of 29.2%.The femoral tunnel isometric rate was significantly higher in the palpation group, at 75%, compared to 29.2% in the fluoroscopy group. among the two positioning methods, there was no statistical difference in the positioning of the femoral footprint at the anterior and posterior ends of the standard point, but there was a statistical difference at the proximal and distal ends (P < 0.05).

Conclusion: Clinical outcomes significantly improved and were similar in both groups. Nevertheless, the palpation of femoral anatomical landmarks exhibited superior convenience and efficiency for experienced sports medicine practitioners, and additionally, it frequently achieved a more isometric femoral footprint than fluoroscopic positioning in certain scenarios.