The principles of management of primary patellar dislocation may be confusing to many sports medicine physicians, who do not know how to introduce good treatment to their patients, and we now summarize the current newer advances and combine them with our own work. Primary patellar dislocation (initial) often injures the medial patellar ligament (MPFL), a major medial patellar soft tissue stabilizing structure, which may lead to recurrent patellar instability. And we know that recurrent patellar dislocations are common and often require surgical intervention. The variability in the location of the MPFL injury and the presence of an osteochondral fracture make it difficult for the physician to decide whether to treat the initial dislocation nonoperatively or surgically, and whether the surgical approach should be to repair or reconstruct the MPFL. MPFL reconstruction may be theoretically more reliable than repair, but MPFL reconstruction may be more costly than repair, and the optimal timing of bony surgery is unclear. A normal or mild patellofemoral dysplasia may be amenable to non-surgical treatment, whereas surgical treatment may be better for more severe talar dysplasia or other significant abnormalities. The principles of management of initial patellar dislocation are summarized below. Detection of initial patellar dislocation 1. Clinical and radiological examination, including axial patellar films. 2, Osteochondral fracture is found, add MRI examination, surgical treatment, fixation of fracture fragment, MPFL in situ repair or reconstruction. 3.No fracture, high patella, outward instability in extension or flexion (may be pushed to lateral dislocation), fixation, MRI examination, surgical treatment, MPFL reconstruction or addition of other methods to correct dysplasia. 4. No fracture, stable patella, active movement in flexion and extension, braking with movable knee brace, MRI within 2 weeks (axial images need to be included) to assess MPFL injury.