Total Knee Replacement

What it is

Arthritis wears away the cartilage that lets the thigh bone and shin bone glide against each other, and once it is gone, bone grinds on bone. Nothing regrows it. A total knee replacement works around that by resurfacing: the surgeon opens the front of the knee, trims the damaged ends of the femur and tibia to precise shapes, and caps them with metal components, with a plastic insert between them acting as the new bearing surface. The back of the kneecap is generally resurfaced too. The components are held with bone cement or by a press fit that bone grows into. "Total" distinguishes it from a partial replacement, where only the damaged compartment is resurfaced and the rest of the joint is left alone.

Why it is done

• To relieve severe arthritis pain in the knee when medication, injections, weight management, and physical therapy have stopped helping
• When pain interferes with walking, stairs, and sleep rather than only with sport
• When deformity or stiffness has substantially limited what the knee can do
• After damage from injury or from inflammatory arthritis has destroyed the joint surfaces

What to expect

The operation itself generally takes around two hours. Some people go home the same day and others stay one or two nights, depending on their health and their support at home. Standing and walking with assistance begin within hours, not days, because the joint stiffens if it is left alone. Physical therapy is the bulk of the work afterward and continues for months; full recovery is usually described in terms of four months to a year. Most people get lasting pain relief and walk independently again, and most modern knee implants remain in service well beyond fifteen years.

Questions worth asking

• Is the case scheduled as inpatient or outpatient? For the same operation that single designation can move the bill by a large margin and can change how my plan pays.
• Is the implant billed separately from the facility fee, and does the quoted price include it?
• Will a surgical assistant, a physician assistant, or computer navigation or robotic assistance be used, and does each add a charge?
• Is the post-operative care included in the surgeon's fee for a set period, and how long does that period run?
• Where will rehabilitation happen — at home, in outpatient therapy, or in a skilled nursing facility — and what does each option cost under my plan?
• Does my plan require prior authorization, and has it been approved for the specific hospital on the schedule?