Paul, a hefty 39-year-old triathlete, came into the office complaining of knee pain.
"Hey Doc", he said in a friendly Midwestern tone, "my knee is aching like crazy. I used to be able to run pretty well, but now I'm having trouble getting out of bed in the morning."
When thinking about a painful knee, there are several things to consider. These are reflected in the types of questions I asked Paul.
- How does your knee hurt you, when does it hurt you and where does it hurt?
- Is there any swelling in your knee?
- Does your knee catch, pop or get stuck?
- Does your knee seem to give out or give way?
In general, knee pain experienced during activity is a more serious sign than pain experienced after activity. There are several areas where knees hurt, including underneath the kneecap, on the side and deep inside the knee. These types of symptoms are often linked to specific diagnoses: Pain under the kneecap is often caused by patellofemoral pain, while pain on the side of the knee is often caused by iliotibial band syndrome.
Swelling is an important thing to look for as well. Swelling in the knee, especially the day after exercise, is often the harbinger of an arthritic condition in the knee. Swelling is often noticed by a feeling of tightness in the knee, with difficulty bending.
Popping or getting stuck tends to be indicative of damage to the menisci, plates of cartilage between the bones that can sometimes tear and cause the knee to pop and/or get stuck. Any sense of a knee giving out or giving way is a bad sign as well, often reflecting injury to one of the stabilizing components in the knee, including the menisci or the ligaments, ropelike structures that connect the bones together.
So putting together all of these questions, let's see what happened to Paul. He described pain underneath his knee that worsened after exercise, with a minimal amount of tightness the next day. He told me that his knee didn't ever tend to give out, there was no sense of popping or catching and that it had hurt him for about a year. He described running as causing the most pain, both during and afterward.
By reviewing these questions in my mind, I had a clearer idea of what my physical examination might be able to show me. In Paul's case, this included pain beneath his kneecap, poor muscle flexibility in his quads and hamstrings, as well as pain underneath the kneecap when I asked him to squat down.
This was then followed by an X-ray of his knee, which showed the beginnings of arthritis under his kneecap.
The diagnosis for Paul was patellofemoral pain with some early patellofemoral osteoarthritis. The treatment included physical therapy to build strength around the knee, the use of glucosamine and chondroitin sulfate with anti-inflammatory intermittently to reduce swelling and an increase in biking and cross-training to reduce the loading force around the knee.
Within three months, Paul was back to training without problems. He now runs a bit less, cross-trains a bit more and will keep his program going for years to come. The key to properly diagnosing and treating knee injuries often lies in the questions.
Jordan D. Metzl, MD, is a nationally recognized sports-medicine specialist at Hospital for Special Surgery in New York City. In addition, Dr. Metzl is a 25-time marathoner and four-time Ironman finisher.