DEAR DR. ROACH: I am thinking of having a total knee replacement done, as recommended by my doctor. I have bone on bone in my knee. What is your opinion?
A friend of a friend had one done three months ago and has had nothing but trouble. He has had two manipulations because he cannot bend past 95 degrees. He goes to physical therapy, but has seen no results. Does this happen often with knee replacement? How about stiffness? How long before a patient is as good as new? Would you recommend the surgery, and what percentage of patients have the issues he is having? — Anon.
ANSWER: Knee replacement (also called "total knee arthroplasty") is one of the most effective surgeries performed, in terms of improving quality of life. Studies have shown that about 80% of people are satisfied with the outcome of their knee replacement. The reasons that the remainder are dissatisfied generally have to do with complications of surgery, including infection, nerve injury, instability and stiffness (the inability to properly flex the knee), which is the issue for your friend of a friend. Only about 5% of people have stiffness, according to a 2006 paper, and these mostly improved with manipulation, although some needed a second operation.
It is important to recognize the limitations of the surgery. You are never going to be as good as new — that is, as good as before the arthritis in the knee developed. But most people are much better than where they started within three to six weeks of the surgery. Physical therapy after surgery is critical for success (but, as your friend shows, not a guarantee of success).
My own patients' experiences have been largely favorable. I have seen some bad complications, but most people are very satisfied, and the most common regret I hear is that they had not done the procedure earlier. Eighty to 90% of knee replacements are expected to last 15-20 years.
DEAR DR. ROACH: Last year, my husband was seriously ill from a bacterial infection in his gallbladder. After inserting a drainage tube, they removed his gallbladder. He has done quite well, except for a strange side effect: Whenever he eats, it causes his left shoulder to hurt. Also, when he lies on his right side, it seems to hurt his left shoulder. Do you have an explanation for this mystery? — L.F.
ANSWER: I have a possible explanation. The pain nerves to your skin and bones are referred to as parietal pain fibers, and these localize very well: If your left toe hurts, there's usually a problem with your left toe. The nerves to the organs are visceral fibers, and they do not localize well in the brain. Pain in the heart can feel like it's in the left upper arm, the left side of the chest or the upper abdomen, depending on who you are.
Pain from the gallbladder most commonly shows up in the right upper quadrant of the abdomen, where it is located directly under the liver, but frequently feels like it is coming from the shoulder. This is called "referred" pain. Right-shoulder pain is more common than left, but I still think that your husband is feeling some referred pain, perhaps from some scar tissue.