Knees Archive

What Is It?

The posterior cruciate ligament (PCL) and the anterior cruciate ligament (ACL) are two tough bands of fibrous tissue that connect the thighbone (femur) and the large bone of the lower leg (tibia) at the knee joint. Together, the ACL and PCL bridge the inside of the knee joint, forming an "X" pattern that stabilizes the knee against front-to-back and back-to-front forces. In particular, the PCL prevents the lower leg from slipping too far back in relation to the upper leg, especially when the knee is flexed (bent).

A PCL injury includes a stretch or tear of the ligament. The PCL most often is injured when the front of the knee hits the dashboard during an automobile accident. During sports activities, the PCL also can tear when an athlete falls forward and lands hard on a bent knee, which is common in football, basketball, soccer and especially rugby.

On call

Q. I have osteoarthritis. My right knee is especially painful and stiff. How do I know when the time is right for knee replacement surgery?

A. Timing is key. If you get the procedure too soon, you might not see enough improvement to make the surgery worth it. In addition, the younger you are when you have knee replacement surgery, the greater the chances it will not last and another surgery may be needed. But if you wait too long, you may subject yourself to unnecessary pain and disability.

You've tried nearly everything for your worn-out knee. But the remaining possibilities may include some risky options.

Knee osteoarthritis affects about half of us in older age. The cartilage that acts as a cushion between the bones wears away, and it hurts when the bones grind against each other. In many people, arthritis can become severe enough that they consider a knee replacement. Since surgery is an expensive and complicated option, you may wonder what else you can do to reduce knee pain. Beware: some treatments are bogus and even dangerous.

Stay away from these

The first sign that a knee pain treatment isn't the best choice: an ad promising that it's the surefire solution.

If you're having the occasional twinge of joint pain when you go for a walk or climb stairs, or you're worried about arthritis because a parent had it, one step toward prevention is to check your weight.

There are two ways that being overweight raises your risk for developing osteoarthritis (the most common joint disorder, which is due to wear and tear on a joint). First, excess weight puts additional stress on weight-bearing joints (the knee, for example). Second, inflammatory factors associated with weight gain might contribute to trouble in other joints (for example, the hands).

Thinking about a total knee replacement? There are a few different kinds of knee implants that are used in this procedure. The different types are categorized by the materials that rub against each other when you flex your knee:

Metal on plastic. This is the most common type of implant. It features a metal femoral component that rides on a polyethylene plastic spacer attached to the tibial component. The metals commonly used include cobalt-chromium, titanium, zirconium, and nickel. Metal-on-plastic is the least expensive type of implant and has the longest track record for safety and implant life span. However, one problem that can happen with plastic implants is an immune reaction triggered by tiny particles that wear away from the spacer. This can cause bone to break down, leading to loosening and failure of the implant. Advances in manufacturing have greatly reduced the rate of wear in the plastic.

Research we're watching

If you have an arthritis-related condition called Heberden's nodes, you may be at higher risk for arthritis-related knee problems, according to a study published online January 9 by Arthritis & Rheumatology.

Heberden's nodes develop when cartilage in the fingers wears away, causing the bones to rub against one another. This prompts new bone to form, creating bony nodules in the knuckles closest to the fingertips.

Hip and knee pain can keep you from the activities you love, as well as make routine tasks difficult. But there are many ways to get you moving again pain-free, without surgery. Here are some of the treatments that can help relieve hip and knee pain.

Ultrasound, phonophoresis, and iontophoresis

Therapeutic ultrasound is a simple procedure that uses sound waves to increase blood flow, relax muscle spasms, and aid healing that leads to faster hip pain relief and knee pain relief. The therapist applies gel to your skin and moves an ultrasound wand over your skin around the painful area. In a special ultrasound technique called phonophoresis, medication (often hydrocortisone) is added to the gel. In a survey of orthopedic physical therapists, more than half said they would use ultrasound and phonophoresis to reduce soft-tissue inflammation (in tendinitis or bursitis, for example). These techniques are also used to manage pain, heal tissue, and help muscles stretch.

A desire to stay active and a natural aversion to pain send nearly 800,000 Americans to orthopedic surgeons each year for a hip or knee replacement. And we're seeking these operations much earlier in life. According to Dr. Scott Martin, associate professor of orthopedic surgery at Harvard Medical School, this isn't a healthy trend. "A lot of joint replacements are being done because they can be," says Dr. Martin.

Every surgical procedure carries the risk of complications — or even death. Because the average joint that's replaced only lasts 10 to 15 years, having the procedure done at age 50 instead of 70 means there's a good chance you'll need a second procedure when you're older and at higher risk for complications.

In the journals

Corticosteroid injections are used to ease short-term knee osteoarthritis pain, but a new study in the May 16, 2017, Journal of the American Medical Association suggests the treatment may not help in the long term.

Researchers recruited two groups of 70 people, average age 58, with knee osteoarthritis. One group received 40 milligrams of the steroid triamcinolone (Kenacort, Kenalog, Artistocort) every three months for two years, while the other group got placebo injections. By the end, pain scores — measured on a scale from zero for no pain to 20 for extreme pain — had dropped by only 1.2 points among the steroid group, while the placebo group's score dropped by 1.9 points, neither of which was clinically significant.

News briefs

 Image: © Wavebreakmedia/Thinkstock

Many older adults have pain from knee osteoarthritis, a condition in which cartilage in the joints wears away. But when is it time for joint replacement? An observational study published March 28, 2017, in The BMJ suggests that a new knee improves quality of life only in certain cases. The study included over 7,400 middle-age and older adults who already had knee arthritis or were at high risk for the condition. Compared with people who didn't have knee replacement, those who had the surgery during the 26-year study period appeared to have a better quality of life afterward. However, the improvements were minimal, except in people who were less physically functional before the surgery because of more severe arthritis symptoms. The authors suggest that the high costs of knee replacement may be justified only in those who are severely affected by arthritis. What if your symptoms aren't severe? As we reported last month, it may be possible to delay or avoid knee surgery by strengthening your leg and core muscles, losing weight, and improving range of motion.