Table 2 Measurement methods and changes in DDH knees of the significant knee parameters
Study | Measuring plane | Parameters | Image modality | Abbr. | Definition | Change in DDH knees |
|---|---|---|---|---|---|---|
Kandemir 2002 [3] | Coronal plane | mechanical axis deviation | X-ray | MAD | distance from the center of the knee to the mechanical axis of lower extremity | Increase |
| Â | Coronal plane | lateral distal femoral angle | X-ray | LDFA | angle between the mechanical axis of the femur and joint orientation line of the distal part of the femur | Decrease |
| Â | Coronal plane | medial proximal tibial angle | X-ray | MPTA | angle between the mechanical axis of the tibia and joint orientation line of the proximal part of the tibia | Decrease |
| Â | Coronal plane | horizontal dimension of the MFC | X-ray | HDMFC | distances from the anatomic axis of the femur to the most medial point of the medial femoral condyle | Decrease |
| Â | Coronal plane | horizontal dimension of the LFC | X-ray | HDLFC | distances from the anatomic axis of the femur to the most medial point of the lateral femoral condyle | Decrease |
| Â | Coronal plane | vertical dimension of the MFC | X-ray | VDMFC | distances from the line perpendicular to the femoral anatomic axis at the tip of the intercondylar notch to the most distal points of the medial femoral condyles | Increase |
| Â | Coronal plane | vertical dimension of the LFC | X-ray | VDLFC | distances from the line perpendicular to the femoral anatomic axis at the tip of the intercondylar notch to the most distal points of the lateral femoral condyles | Increase |
| Â | Transverse plane | femoral anteversion | CT | FAA | angle between femoral neck axis and posterior bicondyle line | Increase |
| Â | Transverse plane | sulcus angle | CT | SA | angle among most anterior points on the medial and lateral facets and the deepest point in the trochlear groove | Increase |
AkÅŸahin 2012 [10] | Transverse plane | sulcus angle | CT | SA | as described above | Increase |
| Â | Transverse plane | patellar tilt angle | CT | PTA | angle between the coronal axis of the patella and a line tangent to the medial and lateral trochlear ridges | Increase |
| Â | Transverse plane | Lateral shift of patella | CT | LSP | distance between perpendicular line from the apex of the MFC to tangent line of the posterior condyle and perpendicular line from the patella medial edge to the tangent line of the posterior condyle | Increase |
Li 2013 [17] | Transverse plane | femoral anteversion | CT | FAA | as described above | Increase |
| Â | Transverse plane | anteroposterior diameter of MFC | CT | APMFC | anteroposterior diameter of the medial femoral condyle | Decrease |
| Â | Transverse plane | anteroposterior diameter of LFC | CT | APLFC | anteroposterior diameter of the lateral femoral condyle | Decrease |
| Â | Transverse plane | condyle asymmetry | CT | CA | APLFC/APMFC | Decrease |
| Â | Transverse plane | width of femoral condylar | CT | WFC | width of femoral condylar | Decrease |
| Â | Transverse plane | patellar tilt angle | CT | PTA | as described above | Increase |
Li 2014 [16] | Coronal plane | horizontal dimension of the LFC | X-ray | HDLFC | as described above | Decrease |
| Â | Coronal plane | vertical dimension of the MFC | X-ray | VDMFC | as described above | Increase |
| Â | Coronal plane | vertical dimension of the LFC | X-ray | VDLFC | as described above | Decrease |
| Â | Coronal plane | horizontal dimension of the MFC | X-ray | HDMFC | as described above | Increase |
| Â | Coronal plane | lateral distal femoral angle | X-ray | LDFA | as described above | Decrease |
Imai 2018 [7] | Transverse plane | femoral anteversion | CT | FAA | as described above | Increase |
| Â | Transverse plane | knee rotation angle | CT | TRA | angle between the tibial anteroposterior axis and the line perpendicular to the clinical epicondylar axis | Increase |
Hu 2019 [8] | Coronal plane | quadriceps angle | X-ray | QA | angle between a line drawn from the cranial lip of the acetabulum to the center of the patella and a line from the center of the patella to the center of the tibial tuberosity | Increase |
| Â | Transverse plane | femoral anteversion | CT | FAA | as described above | Increase |
| Â | Transverse plane | patellar tilt angle | CT | PTA | as described above | Increase |
| Â | Transverse plane | sulcus angle | CT | SA | as described above | Increase |
| Â | Transverse plane | lateral shift of patella | CT | LSP | as described above | Increase |
Imai 2019 [6] | Transverse plane | femoral anteversion | CT | FAA | as described above | Increase |
| Â | Transverse plane | knee rotation angle | CT | TRA | as described above | Increase |
| Â | Transverse plane | anteroposterior diameter of MFC | CT | APMFC | as described above | Decrease |
| Â | Transverse plane | condyle asymmetry | CT | CA | APLFC/APMFC | Decrease |
Peng 2022 [18] | Transverse plane | sulcus angle | CT | SA | as described above | Increase |
| Â | Transverse plane | femoral trochlear depth | CT | FTD | distance from the deepest point of the femoral trochlear groove to the line connecting the most anterior points on the medial and lateral femur condyles | Decrease |
| Â | Transverse plane | lateral shift of patella | CT | LSP | as described above | Increase |
| Â | Transverse plane | patellar tilt angle | CT | PTA | as described above | Increase |
Fithian 2023 [19] | Transverse plane | femoral trochlear depth | MRI | FTD | difference between the mean height of the cartilaginous facets and the height of the cartilaginous groove relative to the posterior condylar axis. | Decrease |