During a typical ACL reconstruction procedure, a portion of the athlete’s patellar or hamstring tendon is removed and inserted into the femur (i.e. thigh bone) and tibia (i.e. shin bone) in the location where the ligament was originally located. Over the span of 9-12 months, the tendon transforms structurally until it resembles a ligament—a process known as ligamentization—and the athlete gradually rehabs until they are strong enough to return to play.
The majority of athletes will go on to rebound to their prior levels of success and will continue on with their careers without a hitch. But depending on the sport and type of tendon graft utilized, upwards of 6-31% will go on to either re-tear their ACL or rupture the one in their other knee. Such was the case, unfortunately, for Lewis.
The reasons why ACL re-tear rates are so high are myriad, complex, and up for debate. However, one theory that has rise to prominence over the last handful of years involves the compromise of the anterolateral ligament (ALL).
In terms of anatomical discoveries, the ALL is much like that of Big Foot, except if Big Foot was actually real. The ligament was first described in the 1870s by a French surgeon, but was not officially recognized as actually existing as an isolated structure until the early 2010s. While the ACL is the primary stabilizer against rotation in the knee, the ALL is believed to hold a role in rotational stabilization as well. It has been theorized that the ALL likely ruptures along with the ACL and that individuals who do not have their ALL repaired will continue to suffer from some rotational instability in the knee and, thus, be at a greater risk for re-injury.
Now, I don’t know for sure that this is exactly what happened with regard to Lewis. And, frankly, it doesn’t really matter. Subsequent ACL injuries aren’t uncommon. An athlete, surgeon, rehab team, front office, and coaching staff can “do everything right” and ACL re-injuries can still happen. Such is the unfortunate nature of sport.
But what we do know is that the surgery team in Dallas “basically, [did] something with the IT band,” according to Lewis to help “brace” his knee and improve its stability. The “something” he is likely referring to is known as a lateral tenodesis.
The IT band is a long, thick tendinous structure that runs from the hip to just below the knee. It’s most commonly known as a structure that gives long distance runners one heck of a time if they don’t remain flexible, but it also serves as a key attachment point for various lower extremity muscles and assists in moving the leg.
Due to its inherent strength, it serves as a good candidate for a graft during ACL reconstruction. Additionally, the lower portion of the IT band can be surgically relocated (i.e. tenodesis) to provide rotational stability. In short, the IT band takes over for the compromised ALL to provide extra rotational stability for the knee.
The long-term outcomes for this procedure in the athletic population, and specifically the MLB population, is unknown, but theoretically it should allow Lewis to return to play with greater stability in the knee. The recovery will still take 9-12 months, but the procedure should not reduce Lewis’s speed or power much beyond the natural regression that is expected with aging. Baseball is a fairly linear sport, which reduces the potential impact of multiple ACL surgeries on performance compared to a sport like basketball that relies on quick pivots, explosive jumping, and constant running to be successful.