Surgical treatment of a patellar dislocation is the target treatment for recurrent (habitual) patellar dislocation and when it is damaged:

cartilage-bone fragment of the patella
medial patellar retinaculum,
cartilage surfaces
In the above cases, knee surgery is necessary, because leaving the unstable kneecap and not covering the resulting damage may consequently lead to inflammation of the patellofemoral joint with synovial swelling and numerous exudates, as well as destruction of the articular cartilage by abnormal abrasive forces.