According to a presentation at Internal Medicine 2011, the annual meeting of the American College of Physicians in San Diego, internists should ask four questions any time they see patients with knee pain:
At a session on “Evaluation of the Weekend Warrior,” C. David Geier Jr., MD, Assistant Professor of Orthopedic Surgery and a sports medicine specialist at the Medical University of South Carolina in Charleston, said that knee injuries are the most common type of sports injury. In young adults, they are typically ligament tears and patellofemoral pain syndrome, while older adults more often have degenerative meniscal tears and osteoarthritis. Anterior cruciate ligament injuries are commonly associated with football players, but are two to eight times more common in female athletes. They generally result from a twisting injury when the foot is planted, and the injured person usually feels or hears a popping sound, according to Dr. Geier. The knee swells immediately, can’t easily bear weight, and gives way with turning or cutting maneuvers. The treatment for ACL tears is almost always surgical, he said. But injuries to the medial collateral ligament, which often result from contact, almost always heal on their own with the use of a brace or immobilizer. Patellofemoral pain and iliotibial band syndrome, the latter of which is common in runners, also respond to nonsurgical treatment, such as physical therapy, home exercises and stretching. Acute meniscal tears, which are due to a twisting injury and present with localized pain and locking or catching, generally don’t heal well without surgery. However, for a degenerative meniscal tear associated with arthritis, surgery isn’t usually a viable option if the arthritis is the actual source of the pain. Dr. Geier cautions against proceeding directly to an MRI for knee injuries. They can show the meniscal tear but not the associated arthritis. And while an X-ray should never be skipped for knee injury, Dr. Geier stressed, a non-weight-bearing, AP lateral X-ray “is not terribly helpful either.” Get weight-bearing views that involve flexion, he advised; X-ray both knees so you can tell the difference side-to-side. His routine X-ray sequence for a right knee includes a standing AP, a lateral right knee, a standing bilateral AP in 45-degree flexion on one cassette, and bilateral Merchant views on one cassette. “What I do isn’t rocket science,” he said. “The surgeries are very technical, but as far as workup, it’s not that hard.”
- Is the knee swollen? Visible swelling is never normal and calls for a thorough workup.
- Does the knee buckle or give way? Such may indicate a torn anterior cruciate ligament (ACL) or quadriceps weakness.
- Does the knee lock or catch? A knee that gets stuck in a certain position can indicate a meniscal tear.
- Does it hurt to go up or down stairs? That indicates a patellofemoral source for the pain.