The ACL, of course, is well-mentioned in Gray’s Anatomy, which for decades has been a classic reference. It is now used together with Gray’s Anatomy for Students and other anatomy textbooks; all mentioning ACL and all that we presently know about anatomy. However, there is now a rediscovered body part in the human knee. Anatomists called it “ALL” (Antero Lateral Ligament) and they reported its anatomic dimensions and its location, i.e., exact origin and insertion. Also, they delineated a specific function and clinical relevance which previously had been obscure. As well, they revealed that most diagnosed ACL injuries had overlooked concomitant ALL injuries.
After carefully dissecting numerous cadaveric knees from different bodies, the anatomists discovered that the ALL helped connect the femur (thigh bone) and tibia (shinbone) bones. Because of its structure and location (sitting to the front and side of the knee), the doctors concluded by hypothesis that the ALL helps to control internal tibia turning. It, thus, affects something they call the “pivot shift phenomenon”. That’s where the lower side parts of the femur bone called condyles that look like big knuckles on your hand move out of place when they turn your upper and lower leg in certain directions. Doctors say that one type of pivot shift is caused by an ALL injury and it too causes the knee to cave in, buckle, or give way in patients after having previous ruptured ACL surgical repair. However, further studies are needed to understand fully the ALL’s biomechanical function. At any rate they believe it explains why patients with ACL injuries continue to experience complications or secondary problems after surgery and treatment.
Team leaders of the study, Steven Claes and Johan Bellemans of the University Hospitals Leuven were persuaded to do the study because in 1879 a French surgeon named Paul Segond had mentioned a fifth knee ligament in his writings. The ligament had gone under different puzzling names, and thus, gave rise to diminished significance and essentially became lost in the study of medicine. Finally, the Belgian team looked for it and described it well and gave it an acceptable name that we will now find in anatomy textbooks. Their research launched debate and reminded the world that in spite of advancements, our knowledge of the basic anatomy of the human body is not 100 percent complete!
The writer has taught conversational English for 15 years. He currently works for Virginia State University: firstname.lastname@example.org