Radiographic landmarks for femoral tunnel placement in medial patellofemoral ligament reconstruction.
BACKGROUND
Reconstruction of the medial patellofemoral ligament has recently become popular for restoring patellofemoral stability. Femoral insertion site anatomy of the medial patellofemoral ligament has been described. This anatomical insertion has been inferred to be the isometric point in medial patellofemoral ligament reconstruction, but data about radiographic landmarks for a postoperative or intraoperative control are missing.


OBJECTIVE
To determine the radiographic landmarks for control of postoperative and intraoperative femoral medial patellofemoral ligament insertion.


METHODS
Descriptive laboratory study.


METHODS
Eight fresh-frozen human knees were dissected, and the medial patellofemoral ligament was exposed. After identification of the femoral medial patellofemoral ligament insertion site, the insertion center was marked with a lead ball of 2-mm diameter. Straight lateral radiographs were taken, and posterior-anterior as well as proximal-distal position were evaluated.


RESULTS
Six of 8 insertion points were anterior to a line representing an extension of the posterior cortex, 1 point was touching this line, and 1 point was posterior to it. All points were situated distal to the posterior origin of the medial femoral condyle and proximal to the most posterior point of the Blumensaat line.


CONCLUSIONS
A reproducible anatomical and radiographic point, 1 mm anterior to the posterior cortex extension line, 2.5 mm distal to the posterior origin of the medial femoral condyle, and proximal to the level of the posterior point of the Blumensaat line on a lateral radiograph with both posterior condyles projected in the same plane, shows the mean femoral medial patellofemoral ligament center.


CONCLUSIONS
This radiographic point may be useful both intraoperatively and postoperatively.
Schöttle
Philip B
PB
Sports Traumatology and Arthroscopy Service, Center for Musculoskeletal Surgery, Charité, Campus Virchow-Klinikum, Free and Humboldt-Universität in Berlin, Berlin, Germany. philip.schoettle@charite.de
Schmeling
Arno
A
Rosenstiel
Nikolaus
N
Weiler
Andreas
A
D002102:Cadaver; D005269:Femur / Q000601:surgery*; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000601:surgery*; D007718:Knee Injuries / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D008023:Ligaments, Articular / Q000000981:diagnostic imaging / Q000601:surgery*; D031222:Patellar Dislocation / Q000601:surgery*; D017847:Patellar Ligament / Q000000981:diagnostic imaging / Q000601:surgery; D011857:Radiographic Image Interpretation, Computer-Assisted; D019651:Plastic Surgery Procedures / Q000379:methods*