A history of recurrent patellar dislocations suggests the presence of patellofemoral malalignment, which may need to be corrected before patellofemoral arthroplasty.

• 周期性的膝关节错位史提示存在髌骨股骨排列不整，这可能需要在实行髌骨股骨关节成形术前得到纠正。