Thing is: no “new body part” is found/discovered, it’s media exploitation. That fibrous structure was already acknowledged by scientific community and was always in our knees. In past years, problem was grasping the real functionality-structure relationship of anterolateral ligament in co-relation with other knee fellas around. Believe it or not, all what was needed to end this part of the mystery was additional research/experimenting (one part of mystery – it’s yet to be seen what implications on future surgeries/implants/interventions awaits us in future).
To cut the long story short: look at these new findings as new perspectives on functionality of anterolateral ligament in knee. Of course recovery/surgery/implants/robotcs… (the list these days is long) will be as much interesting as new speedy recoveries and implants.
Nonetheless, these findings are exciting and big stuff indeed – but NOT that much big to be considered as a “new body part”.
Here, take a look at the short “history” of anterolateral ligament understanding and interpretation:
Functional mappings of these knee region…
1958. – functional describing of a distal tendon part of IT band, in other words: extra-capsular knee ligament (this latter to be mapped as: anterolateral ligament)
“At the knee joint, the band acts as a stabilizing ligament between the lateral femoral condyle and the tibia in continuity with the proximal part of the band.”
Read abstract: The Iliotibial Tract Clinical and Morphological Significance – http://jbjs.org/article.aspx?articleID=12941
1982. – an early (and early early early) understanding of anterolateral ligament
“The earliest reference given by Kaplan (1958) is dated 1552 and concerns Vasalius’ description of the tensor fasciae latae who grouped this muscle, because of its relation to the tractus iliotibialis, with others of the tibia and consequently called it the sixth muscle of the tibia.”
Read the abstract: In-Vivo Investigations on the Mechanical Function of the Tractus Iliotibialis – http://link.springer.com/chapter/10.1007/978-94-009-7678-8_14
1983. – analysing that area of knee in order to optimize implants and their kinetics
“The data obtained allow proper positioning of anterolateral re constructions so that this mode of stretching will not be encountered as a result of normal knee motion.”
Read abstract: Optimization of knee ligament position for lateral extraarticular reconstruction – http://ajs.sagepub.com/content/11/5/293.short
1986. – here hypothesizing the function (aside the naming)
“The superficial layer of the iliotibial tract, combined with the deep, and capsulo-osseous layers, is hypothesized to function as an anterolateral ligament of the knee.”
Read abstract: The anatomy of the iliopatellar band and iliotibial tract – http://ajs.sagepub.com/content/14/1/39.short
1993. – analysis of “shelf” movement in injured knee, relationship with IT band, anterior crucate ligament (important intracapsular ligament) and the rest of the lateral ligaments. not explicit anterolateral ligament analysis, rather the function of that very same area.
“Eighty-two consecutive patients with acute knee in juries were classified as anteromedial-anterolateral rotatory instability (anterior cruciate ligament-deficient) based on the abnormal motion demonstrated by clinical examination tests for instability.”
Read abstract: How iliotibial tract injuries of the knee combine with acute anterior cruciate ligament tears to influence abnormal anterior tibial displacement – http://ajs.sagepub.com/content/21/1/55.short
2007. – just one leap toward “modern” understanding of functionality
“Clinical Relevance: The iliotibial tract can be considered as an anterolateral knee stabilizer, particularly its capsular-osseous layer, which, together with the anterior cruciate ligament, constitutes a functional unit forming a spatial “horseshoe” form.”
Read abstract: An Anatomic Study of the Iliotibial Tract – http://www.arthroscopyjournal.org/article/S0749-8063%2806%2901443-5/abstract
2012. – last year’s anatomic/histologic study of the very anterolateral ligament
“Results: The anterolateral ligament was noted to be present in all 40 knees.”
Read abstract: The anterolateral ligament of the human knee: an anatomic and histologic study – http://link.springer.com/article/10.1007/s00167-011-1580-3
2013. (august) – the role of anterolateral ligament along with many other ligaments in providing stability to knee joint (from the arcuate ligament perpsective:D)
“Purpose: To determine the involvement of the posterolateral structures including the lateral collateral ligament, the popliteus muscle–tendon unit, the arcuate ligament (popliteofibular ligament, fabellofibular ligament, popliteomeniscal fascicles, capsular arm of short head of the biceps femoris and anterolateral ligament) and the posterior cruciate ligament in providing restraint to excessive recurvatum, tibial posterior translation and external tibial rotation at 90° of flexion.”
Read abstract: The arcuate ligament revisited: role of the posterolateral structures in providing static stability in the knee joint – http://link.springer.com/article/10.1007/s00167-013-2643-4
2013. (october) – the “news” you read these days
“The ALL was found to be a distinct ligamentous structure at the anterolateral aspect of the human knee with consistent origin and insertion site features. By providing a detailed anatomical characterization of the ALL, this study clarifies the long-standing enigma surrounding the existence of a ligamentous structure connecting the femur with the anterolateral tibia. Given its structure and anatomic location, the ALL is hypothesized to control internal tibial rotation and thus to affect the pivot shift phenomenon, although further studies are needed to investigate its biomechanical function.”
Read abstract: Anatomy of the anterolateral ligament of the knee – http://onlinelibrary.wiley.com/doi/10.1111/joa.12087/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false
So, this massmedia-made famous anterolateral ligament (ALL) was already known and present in our knees. Again — no new body part was found.
I must add that cunning formulation in this most recent study may be considered to be a media-trigger for such big statement about human body in 2013. For my money – too cheap to buy.