Metacarpophalangeal fracture is a common fracture in hand trauma, accounting for about 1/4 of the patients with hand trauma. because of the delicate and complex structure of the hand and the fine motor function, the management of hand fractures is far more important and technically complex than the treatment of other long tubular fractures.

Hip fractures are estimated to affect 500,000 adults in the United States each year. They have a tremendous impact on quality of life, currently accounting for 3-7% of in-hospital mortality and a one-year mortality rate of 19.4-58%. Approximately half of all hip fractures are intertrochanteric (IT)

Posterior shoulder instability is usually caused by traumatic posterior dislocation or repetitive minimally invasive injury during exercise or other activities, with an annual incidence rate of 4.64 cases per 100000 people per year. Several surgical techniques for the treatment of posterior shoulder

Patellofemoral instability (PFI) is common in children's knee joint injuries. PFI is caused by the imbalance of patellar dynamic relationship in femoral trochlear groove. External dislocation of the patella is the extreme of PFI, which is caused by the injury of the medial stabilizer, resulting in the patella hitting the lateral femoral condyle.

Closed reduction is the minimally invasive technique that can be used for stable fractures of extremities with no loss of blood flow, no risk of infection, fast functional recovery, significantly reduced medical costs, and can be used for closed reduction hollow nail and intramedullary pin fixation treatment of various unstable fractures, such as femoral neck fractures, femoral stem fractures, tibiofibular fractures, humeral stem fractures, etc., eliminating the destruction of blood flow by incisional reduction.