Objective To introduce the concept and clinical applications of rotational alignment of the femoral prosthesis in total knee arthroplasty (TKA) so as to avoide the postoperative complications caused by rotational alignment. Methods The clinical and experimental research literature about rotational alignment of the femoral prosthesis in TKA was extensively reviewed and analyzed. Results Femoral prosthesis malrotation can lead to flexion gap unbalanced and undesirable patellar track. Rotation alignment of the femoral prosthesis is defined with radiological and computer assisted technique at pre- and post-operation, which can make the rotation alignment of the femoral prosthesis and the function of the knee favorable. Conclusion In recent years, many surgical skills and new techniques of defining the rotational alignment are developed, and good clinical results are achieved.
The technical deficiencies in traditional medical imagining methods limit the study of in vivo ankle biomechanics. A dual fluoroscopic imaging system (DFIS) provides accurate and non-invasive measurements of dynamic and static activities in joints of the body. This approach can be used to quantify the movement in the single bones of the ankle and analyse different morphological and complex bone positions and movement patterns within these organs and has been widely used in the field of image diagnosis and evaluation of clinical biomechanics. This paper reviews the applications of DFIS that were used to measure the in vivo kinematics of the ankle in the field of clinical and sports medicine. The advantages and shortcomings of DFIS in the practical application are summarised. We further put forward effective research programs for understanding the movement as well as injury mechanism of the ankle in vivo, and provide constructive research direction for future study.