Systematic review of the etiology behind patellar clunk syndrome

Table 2 Table 1 metrics defined

Postoperative knee flexion	After surgery, the degree to which the knee can flex
Prosthesis design	Several prosthesis designs can be implanted in a TKA
Joint line height	Shortest distance between the fibular head and lateral femoral condyle on AP radiograph
Patellar height	Measured as the perpendicular distance from the inferior pole of the patellar implant to the joint line of the prosthesis
Insall-Salvati ratio	Ratio of the length of the patellar tendon to the length of the patella
Position of tibial tray	Measured as the perpendicular distance of the tibial tray from the patellar tendon
Patella thickness	The width of the patella (medial to lateral)
Patellar tendon length	Length of the patellar tendon superior to inferior
Posterior tibial slope	The degree to which the tibia is lateral to the perpendicular line drawn from the prosthesis
Patellar tilt	Angle subtended by the equatorial line of the patella and the line connecting the anterior limits of the femoral condyles
Femoral condyle offset	Distance between the lateral condyle and the vertical line parallel to the lateral edge of the femur