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Fig. 2 | BMC Musculoskeletal Disorders

Fig. 2

From: Distalization of tibial tubercle osteotomy is not necessary for patients with recurrent patellar dislocation accompanied by patella alta and increased TT–TG distance

Fig. 2

Schematic diagram of measurement of PTA, CA, and TTTG. b PTA: Patellar Tilt Angle; The angle between the line connecting the highest points of the medial and lateral condyles of the femur (B) and the line extending the maximum transverse diameter of the patella (A) is the PTA. c CA: Congruence Angle; Line A is the angle bisector of the trochlear groove of the femur, line B is the line connecting the deepest point of the trochlear groove of the femur and the lowest point of the patella, and the angle between the two lines of AB is CA. d TT-TG: Tibial Tuberosity-Trochlear Groove; Plane 1: the roof of the femoral intercondylar fossa is the “Roman arch”. Plane 2: near the proximal end of the tibial tubercle. Overlap the two planes. The line (CD) connecting the posterior femoral condyle is the marker point, marking the lowest point of the femoral trochlea and the midpoint of the tibial tubercle. Project them on the reference line respectively, and measure the distance between AB. It’s TT-TG

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BMC Musculoskeletal Disorders

ISSN: 1471-2474

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