Anatomical Confirmation of the Use of Radiographic Landmarks in Medial Patellofemoral Ligament Reconstruction

Abstract

Background A recent study has described radiographic landmarks for femoral insertion of the medial patellofemoral ligament. Clinical relevance and application of these landmarks for surgical reconstruction have yet to be determined. Hypothesis Radiographic landmarks can be used to accurately determine the femoral insertion of the medial patellofemoral ligament in a percutaneous fluoroscopically guided surgical technique. Study Design Descriptive laboratory study Methods The femoral insertion of the medial patellofemoral ligament was estimated using fluoroscopy in 8 fresh-frozen human cadaveric knees. The knees were dissected and the true anatomical medial patellofemoral ligament femoral insertion was identified. Radiographic markers were placed on both the estimated and anatomical medial patellofemoral ligament and a repeat lateral radiograph was performed. Using imaging software, the distance between the true anatomical insertion and the fluoroscopically determined insertion was calculated. Results All 8 points determined by fluoroscopically guided pin placement averaged less than 4 mm from the anatomical insertion. The radiographic landmark method consistently placed the origin on average 2.5 mm anterior and 0.6 mm distal to the anatomical insertion. Conclusion Radiographic landmarks determined by fluoroscopy can be used to accurately reproduce the femoral insertion of the medial patellofemoral ligament in ligament reconstruction. Clinical Relevance Confirming the use of radiographic landmarks to determine the medial patellofemoral ligament femoral insertion may help to increase accuracy and precision in ligament reconstruction and minimize surgical dissection.