Most of the joint remains original
Resurfacing generally implies less bone loss than a partial knee replacement but - especially when talking about the contact surfaces between patella and femur - sometimes they may mean the same thing. So, for example, in a partial knee replacement of the patellofemoral joint, the back of the patella is resurfaced and the groove of the trochlea of the femur is resurfaced. The rest of the knee remains intact.