Fig. 1From: Surgery simulation teaching based on real reconstruction aid versus traditional surgical live teaching in the acquisition of an adult total hip arthroplasty surgical technique for developmental dysplasia of the hip: a randomized comparative studySchematic diagram of normal hip and Croweās classifications for adult developmental dysplasia of the hip (DDH); red dots represent the center of rotation of the femoral head; multi-colored area represents the degree of subluxation of the femoral head: 0, 50, 75, and 100% from bottom to top. a Front view of the normal hip joint, the femoral head is not dislocated, and has a normal structure; b Front view of Croweās classification I DDH, subluxation of the femoral head less than 50%; c Front view of Croweās classification II DDH, subluxation of the femoral head 50ā75%; d Front view of Croweās classification III DDH, subluxation of the femoral head 75ā100%; e Front view of Croweās classification IV DDH, subluxation of the femoral head more than 100%Back to article page