Orthopedic deformity correction is a very meaningful and challenging topic for orthopedic surgeons. In the past, the surgical treatment of bone and joint deformities was left to the clinical judgment of the surgeon due to the lack of objective and specific implementation criteria. The development of the surgical plan is mainly based on the experience of the surgeon, and it is difficult for even a very experienced orthopaedic surgeon to give a detailed plan and explanation to the patient. Chen Jianwen, Department of Orthopedics, Rehabilitation Hospital, National Rehabilitation Assistive Devices Research Center In recent years, with the application of high technology and the development of newer concepts of limb deformity correction, in Europe and the United States and other developed countries, digital minimally invasive orthopedic technology has replaced the traditional orthopedic surgery model that used to rely on physician experience, mainly in the following ways: 1. Digital acquisition, simulation, and analysis of the patient’s deformity characteristics before surgery. With reference to the morphology of the normal limb, bone and joint, the direction of joint line travel, the mechanical axis of the limb and the anatomical axis of the bone, the orthopedic target and treatment plan are proposed, the surgical plan is formulated, and then the simulation of the surgery and treatment process is performed to predict the final treatment results. It greatly avoids the blindness of relying solely on experience to cure the disease. 2. The application of intelligent external fixation orthoses (computer-assisted spatial external fixation brackets – orthopedic robots) allows digital monitoring and prediction of the entire treatment process to precisely and steadily achieve the goal of limb deformity correction set jointly by the doctor and the patient. It is capable of simultaneous correction of four-dimensional deformities (angulation, displacement, rotation and shortening), and its theoretical error of correction is <0.7° and 2mm, which cannot be achieved by any other means and orthopedic devices. 3. The application of digital and intelligent means realizes the simultaneous correction of complex deformities, shortens the treatment cycle and simplifies the surgical operation process. It makes the treatment of complex bone and joint deformities simple and precise, and truly reflects the minimally invasive nature of orthopedic orthopedics. Digital limb deformity correction, mainly represented by the Taylor Spatial Frame TSF, is the clinical application of computer-assisted spatial external fixation brace-orthopedic robot technology, combined with Paley's Center of rotation of angulation (Center of rotation of angulation CORA) concept, which enables the treatment of complex orthopedic deformities to be simple and precise, truly reflecting the minimally invasive orthopedic surgery. angulation CORA concept, any complex deformity can be perfectly corrected. The Taylor Spatial External Fixation Brace consists of two full or partial rings with six retractable support rods, assembled by a special universal joint connection. A specific angulation and displacement complex deformity can be corrected simply by adjusting the length of the support rods and applying the same frame. When applying TSF to correct osteoarticular deformities, it is necessary to set the reference bone segment and the reference ring, usually the proximal bone segment and the proximal ring as the reference. John E. Herzenberg and Dror Paley used CORA, the center of angular rotation, as the starting point and named these methods CORAgin and CORA-sponding. J. Charles Taylor proposed the Line of Closest Approach LOCA, a method of determining the position of the osteotomy to reduce the displacement of the bone ends during deformity correction. There are currently five planning methods for deformity correction: (1) the fracture method, (2) the CORAgin method, (3) the CORAsponding method, (4) the virtual hinge method, and (5) LOCA. For the fracture method, the surgeon selects the starting point and the corresponding point at the contralateral fracture end, respectively, and these identified points should represent the matching points of the two fracture ends. For the CORAgin method, the surgeon selects the CORA as the starting point, which in turn identifies the corresponding point. For the CORAsponding method, the surgeon selects the corresponding point in the CORA and then finds the starting point. For the virtual hinge method, both the starting point and the corresponding point are located at the CORA, at the edge of the convex side of the deformed bone. By pre-setting the reference segment and the reference ring, the spatial bone fixation system with a six-link device is placed on the deformed limb according to the procedure, observing the principle of threading the pin in the ring external fixation brace. Postoperatively, the deformity status (orthogonal, lateral and axial angulation, anterior-posterior, lateral and axial displacement) is analyzed based on standard radiographs, and the mounting parameters of the brace (offset distance of the reference ring in the orthogonal, lateral, axial and rotational directions with respect to the starting point and the reference segment) are measured; the angulation values and mounting parameters of the deformity, as well as the internal diameter of the reference ring and the mounting length of the six support rods, are entered into the software program. The program will calculate the final adjustment length of each support rod after the deformity is completely corrected; after setting the number of days for adjustment, the program will give the adjustment scale of each support rod every day, and implement the slow drafting so that the deformity can be corrected precisely and perfectly. The six-axis spatial movement implemented with the aid of the computer program's external spatial fixation bracket synchronizes the correction of four-dimensional deformities (angulation, misalignment, rotation and shortening or separation); it is not necessary to change the frame during the correction process, and its frame structure makes the fixation more reliable; thus realizing the simplicity, minimally invasive and precision of the correction of complex deformities.