Features October 2012 Issue

Time for a Knee Replacement?

Consider an operation when your quality of life is suffering despite conservative therapies and you understand all your options.

Your knee aches. You have difficulty making the trek around the block, and you can’t play the sports you enjoy. You’re thinking about having knee surgery.

Partial knee replacement (left) often allows for more natural knee function and faster recovery. Total knee replacement (right), considered the only long-term cure, removes everything that is or could be diseased.

But before you take that step, try conservative treatments, understand the different types of surgery, and, with your doctor’s guidance, carefully weigh the pros and cons of each procedure. In opting for surgery, especially knee replacement, consider how knee pain is affecting your quality of life and how much you stand to gain from an operation.

“If you tell me that on the 18th green your knee starts to bug you and you want your knee replaced, I’ll probably advise you not to have surgery,” says Trevor Murray, MD, a Cleveland Clinic orthopaedic surgeon. “But if you tell me you don’t even get your mail out of the mailbox because your knee hurts so bad, I’m going to recommend a knee replacement. You need to have a frank discussion with your physician.”

Before trying surgery
Treatment for knee pain typically begins with oral pain relievers coupled with physical therapy, targeting the quadriceps and hamstring muscles of the upper leg.

If these treatments fail to provide sufficient benefit, your doctor may recommend injections of corticosteroids (such as cortisone) or hyaluronic acid (viscosupplementation). These injections may provide relief for several weeks to several months, although treatment response varies by patient, Dr. Murray says.

You might require surgery sooner if X-rays show significant erosion of the cartilage and bones comprising the knee joint or tears in the meniscus or other structures of the knee, or if your joint has deteriorated to the point where your range of motion is greatly limited.

“One of the best predictors of post-operative range of motion  is pre-operative range of motion,” Dr. Murray says. “If you see that being lost at a rapid rate, you may encourage a patient to have surgery sooner.”

Surgical Options
Arthroscopic surgery. Arthroscopic surgery is indicated primarily for meniscal or cartilage tears and removing bone or cartilage fragments. During this outpatient procedure, the surgeon inserts a tiny scope and surgical instruments though small incisions to visualize the knee and make any repairs. Most patients use crutches for a week or two after the surgery, Dr. Murray says. He also cautions that arthroscopic surgery is not a fix for knee arthritis, nor will it delay a knee replacement.

Osteotomy. The knee consists of three compartments: the medial (inside), lateral (outside), and patellofemoral (kneecap). For some patients with knee osteoarthritis confined to the medial or lateral compartment and caused by poor alignment of the knee bones (tibia and femur), osteotomy may help. In this procedure, either the tibia or femur is cut and reshaped to relieve pressure on the diseased compartment and transfer weight to the healthy compartment. The downside is that pain relief is not as predictable after osteotomy as it is with knee replacement, and osteotomy sometimes can make subsequent knee replacement surgery more difficult. “People who have osteotomy are likely to ultimately need a knee replacement,” Dr. Murray says.

Partial knee replacement. Today, instead of undergoing osteotomy, more patients with arthritis limited to one knee compartment are treated surgically with partial knee replacement, in which the cartilage and meniscus of the damaged compartment are replaced with a metal and plastic implant. Compared to total knee replacement, the partial procedure often allows for more natural knee function, faster recovery, shorter hospital stays, and less post-operative pain. With some partial implants, 90 percent or more still function well up to 10 years. However, a significant proportion of patients will experience a progression of their arthritis in the untreated knee compartments and eventually require a total knee replacement.

Total knee replacement. Many surgeons regard total knee replacement as the only long-term cure for knee osteoarthritis because the procedure removes everything that is or could become diseased, including the cartilage and the ends of the bones. Most patients remain in the hospital for three to four days, walk without assistance in three to four weeks, and are “feeling good in about eight to 10 weeks,” Dr. Murray says.

Realistic expectations
Surgery can produce dramatic improvements, but with any operation comes the small risk of blood clots and infection, as well as some pain as you recover from surgery and rehabilitate your knee.

“You should be able to get back to the majority of the activities you enjoy, but there may be some concessions you have to make,” Dr. Murray says. “I tell my patients that I’m not going to give them the knee they had when they were 16 years old and had no arthritis. The goal is a knee that is much less painful and much higher functioning than the one they have.”