How did doctors miss this one for so long? Two Belgium orthopedic surgeons have discovered the existence of a previously unknown ligament that may be responsible for many common knee injuries.
Finding the new body part didn't involve a high resolution scanner, subatomic laser or any other sort of fancy technology. Instead, the docs employed elbow grease and some good old-fashioned detective work.
Starting with an 1879 article by a French surgeon that theorized the existence of an additional ligament located on the front part of the knee, the doctors began dissecting numerous cadavers to track it down. Their search uncovered a tiny band of connective tissue they've named the anterolateral ligament, or ALL for short.
Writing in the Journal of Anatomy, the doctors said they believe the ALL is found in 97 percent of all human knees. It appears to give way during anterior cruciate ligament tears, a common sports injury that usually occurs when someone stops short or makes a sudden sharp turn.
Despite having surgery and rehabilitation, a small percentage of patients with ACL-repaired knees continue to experience so-called "pivot shift," or incidences when their knee "gives way" during activity. When ACL surgery is unsuccessful, patients sometimes endure chronic joint pain and knee instability. Fixing the ALL could solve the problem.
Dr. Scott Rodeo, co-chief of the sports medicine at Hospital for Special Surgery, in New York City, and associate team physician for the NY Giants, said he'd like to think the ALL is more of a rediscovery than an outright new discovery.
"We've known for years that a thickening around the area where the ALL is located has a role in knee stability," he said. "While I don't think this is necessarily a breakthrough, I think it's a good reminder that we need to refocus some attention on ACLs that don't respond well to surgery."
The Anatomical Society, which published the article in their journal, praised the research as "very refreshing" and commended the researchers for reminding the medical world that, despite the emergence of advanced technology, we don't know everything there is to know about the human body.