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Published on: July 2, 2021
Comparison of five different fluoroscopic methods for identifying the MPFL femoral footprint
Tuluhan Yunus Emre1, Hakan Cetin2, Huseyin Selcuk2
1Department of Orthopaedics and Traumatology, Kadikoy Hospital, Acıbadem University, Istanbul, Turkey.
Purpose:
The success of medial patellofemoral ligament (MPFL) reconstruction is closely linked to the precise positioning of the femoral tunnel. Intraoperative fluoroscopy is commonly utilized to identify the MPFL footprint. This study aimed to ascertain the most accurate fluoroscopic method among the five previously described methods used to determine the MPFL femoral footprint.
Materials And Methods:
Using 44 well-preserved dry femur bones, the MPFL femoral insertion site was demarcated using anatomical bony landmarks, namely the center of the saddle sulcus between the medial epicondyle, adductor tubercle and gastrocnemius tubercle. Fluoroscopic true lateral knee images were acquired and measurements taken, referencing established methods by Schottle et al., Redfern et al., Wijdicks et al., Barnett et al., and Kaipel et al. The distance between anatomic and fluoroscopic MPFL footprints was then measured on digital fluoroscopic images. The accuracy of the locations was compared using a margin of error of 5 and 7 mm.
Results:
The Schottle method consistently emerged superior, showcasing the smallest mean distance (3.2 ± 1.2 mm) between the anatomic and radiographic MPFL footprints and a high in-point detection rate of 90.9% under 5 mm criteria. While the Redfern method displayed perfect accuracy (100%) within the 7 mm criteria, the Schottle method also performed 97.7% accuracy.
Conclusions:
For intraoperative identification of the MPFL footprint using fluoroscopy, the Schottle method is the most consistent and accurate among the assessed methods. Thus, its accuracy in detecting the MPFL footprint makes it recommended for MPFLR to ensure optimal outcomes.
Level Of Evidence:
Level IV, cadaveric study.
Insights
The Schottle method is the most accurate fluoroscopic technique for identifying the medial patellofemoral ligament (MPFL) footprint during surgery. This method ensures precise femoral tunnel placement for successful MPFL reconstruction.
Area of Science:
- Orthopedic Surgery
- Radiology
- Anatomy
Background:
- Medial patellofemoral ligament (MPFL) reconstruction success depends on accurate femoral tunnel placement.
- Intraoperative fluoroscopy is crucial for identifying the MPFL footprint.
Purpose of the Study:
- To compare the accuracy of five fluoroscopic methods for determining the MPFL femoral footprint.
- To identify the most reliable method for intraoperative guidance.
Main Methods:
- Anatomical MPFL insertion sites were identified on 44 dry femur bones.
- Fluoroscopic images were taken, and measurements were compared to five established methods (Schottle, Redfern, Wijdicks, Barnett, Kaipel).
- Accuracy was assessed using 5 mm and 7 mm error margins.
Main Results:
- The Schottle method showed the smallest mean distance (3.2 ± 1.2 mm) between anatomic and radiographic footprints.
- Schottle method achieved 90.9% accuracy within 5 mm and 97.7% within 7 mm.
- Redfern method achieved 100% accuracy within 7 mm, but Schottle demonstrated superior consistency.
Conclusions:
- The Schottle method is the most consistent and accurate fluoroscopic technique for intraoperative MPFL footprint identification.
- Accurate identification via the Schottle method is recommended for optimal MPFL reconstruction outcomes.
