TY - JOUR ID - 10834 TI - Different References for Valgus Cut Angle in Total Knee Arthroplasty JO - The Archives of Bone and Joint Surgery JA - ABJS LA - en SN - 2345-4644 AU - Yazdi, Hamidreza AU - Nazarian, Ara AU - Wu, Jim AU - Amiri, Arash AU - Hafezi, Poopak AU - Babikian, Margaret AU - Mohamadi, Amin AU - Pakdaman, Reza AU - Ghorbanhoseini, Mohammad AD - Department of knee Surgery, Firoozgar Hospital, Neuromusculoskeletal Research Center, Iran University of Medical Sciences, Tehran, Iran AD - Center for Advanced Orthopaedic Studies at BIDMC - Harvard Medical School, Boston, MA, USA AD - BIDMC, Harvard Medical School, Boston, MA, USA AD - McLean Hospital, Harvard Medical School, Boston, MA, USA AD - Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA AD - Tufts Medical Center, Boston, MA, USA Y1 - 2018 PY - 2018 VL - 6 IS - 4 SP - 289 EP - 293 KW - Anatomical axis KW - Preoperative planning KW - Total knee arthroplasty KW - Valgus cut angle DO - 10.22038/abjs.2018.26736.1707 N2 - Background: The valgus cut angle (VCA) of the distal femur in Total Knee Arthroplasty (TKA) is measured preoperativelyon three-joint alignment radiographs. The anatomical axis of the femur can be described as the anatomical axis of thefull length of the femur or as the anatomical axis of the distal half of the femur, which may result in different anglesin some cases. During TKA, the anatomical axis of the femur is determined by intramedullary femoral guides, whichmay follow the distal half or near full anatomical axis, based on the length of the femoral guide. The aim of this studywas to compare using the anatomical axis of the full length of the femur versus the anatomical axis of the distal half ofthe femur for measuring VCA, in normal and varus aligned femurs. We hypothesized that the VCA would be differentbased upon these two definitions of the anatomical axis of the femur.Methods: Full-length weight bearing radiographs were used to determine three-joint alignment in normal aligned(Lateral Distal Femoral Angle; LDFA = 87º ± 2º) and varus aligned (LDFA >89º) femurs. Full-length anatomical axismechanicalaxis angle (angle 1) and distal half anatomical axis-mechanical axis angle (angle 2) were measured inall subjects by two independent orthopedic surgeons using a DICOM viewer software (PACS). Angles 1 and 2 werecompared in normal and varus aligned subjects to determine whether there was a significant difference.Results: Ninety-seven consecutive subjects with normally aligned femurs and 97 consecutive subjects with varusaligned femurs were included in this study. In normally aligned femurs, the mean value of angle 1 was 5.05° ± 0.76°and for angle 2 was 3.62° ± 1.19°, which were statistically different (P= 0.0001). In varus aligned femurs, the meanvalue of angle 1 was 5.42° ± 0.85° and for angle 2 was 4.23° ± 1.27°, which were also statistically different (P=0.0047).Conclusion: The two different methods of outlining the anatomical axis of the femur lead to different results inboth normal and varus-aligned femurs. This should be considered in determination of the valgus cut angle on preoperativeradiographs and be adjusted according to the length of the intramedullary guide. UR - https://abjs.mums.ac.ir/article_10834.html L1 - https://abjs.mums.ac.ir/article_10834_6056ca84d1558c1d5316125622ca0bb1.pdf ER -