The 2023 NFL Draft has concluded; as always, there is no shortage of drama. While analysts around the country scramble to grade each team’s draft, fans of the Tennessee Titans and fantasy players are stuck in a quandary following troubling reports on Tulane running back Tyjae Spears knee health. Knee injuries are always a concern for football players, and Tyjae Spears knee injury history is nothing short of concerning. How will his injury history impact the trajectory of his career?
Shortly after being drafted in the 3rd round, Ian Rapoport confirmed that the Tulane back, who has suffered two ACL tears, presently does not have an intact ACL, has full thickness cartilage loss, and early onset of knee arthritis. This information would concern any medical professional, as the ACL plays a massive role in athletics. Additionally, full-thickness cartilage loss and early onset of arthritis do not bode well for a lengthy NFL career.
Tyjae Spears Knee: Boney Changes
Let’s start with the bones here. Cartilage is a layer of tissue that protects bone, essentially a shock absorber. ACL injuries render knees prone to losing cartilage at a much faster rate (everyone’s cartilage will wear away at some point, usually not until much later in life). With a full-thickness loss of cartilage, the bone underneath the cartilage now takes on direct impact. The cartilage loss will facilitate the early onset of arthritis, which Spears is confirmed to be dealing with. Again, everyone will develop arthritis if they live long enough, but this does not typically happen to someone in their early 20s.

What do cartilage loss and arthritis have to do with athletics? Sometimes, nothing. Todd Gurley and Jay Ajayi dealt with knee arthritis early in their careers, and both had several productive years. However, both had their careers end early due to their knees. Arthritis leads to inflammation and pain, and over the course of an NFL season, an NFL career, will only worsen. Inflammation and pain alter how an athlete moves, influencing running, cutting, jumping, etc. Load management is key in players with knee arthritis to reduce inflammation as much as possible.
A backdoor benefit of arthritic changes in Tyjae Spears knee is that arthritis leads to extra bone growth, which will actually make his knee more stable. Clinically, when I am working with a patient with knee arthritis, they have very little extra motion in the knee. The ACL is the primary stabilizer of the knee. Since Spears knee does not have an intact ACL, this arthritis is likely allowing him more stability with athletic movements, therefore actually working in his favor in the short term.
Tyjae Spears Knee: No ACL
This one is absolutely wild. His last ACL tear was in 2020, suggesting he played his final two college seasons with no ACL. How is this possible? The ACL is the primary stabilizer of the knee and essential for an athlete to change direction, right?
Typically, this is correct, but a small subset of the population is termed ACL-deficient “copers” and can function without an intact ACL. The ACL is a ligament that passively keeps the tibia (shin bone) in line with the femur (thigh bone), but it’s not the only structure that can do this. The quadriceps and hamstrings cross the knee and can provide knee stability; the glute and groin muscles also control the position of the leg and foot when it lands, which aids in knee stability as well.

Research on ACL-deficient “copers” is spearheaded by the team out of the University of Delaware and began over 20 years ago. In brief, these researchers have identified criteria that may predict an athlete’s ability to return to their full athletic capacity without ACL reconstruction surgery. The criteria include scores on two patient self-report surveys, various single-leg hop tests, quad and hamstring strength, and one or fewer “giving way episodes” where the knee buckles.
Rehab focuses on reducing swelling, restoring range of motion, restoring strength and coordination, and, when ready, returning to sport-specific training. Not all study participants can return to high-level athletics without surgery, but it is interesting that some are.
Tyjae Spears knee being ACL-deficient, yet rushing for 863 yards in 2021 and 1,581 yards in 2022 with no ACL, suggest he certainly is an ACL-deficient “coper.”
Tyjae Spears NFL Outlook
With all the medical complications, it is hard to imagine Tyjae Spears knee holding up for a long NFL career. Arthritis will continue to worsen; there is no stopping that, and over time will lead to more pain and swelling, which may impact his ability to stay on the field. As discussed above, his muscles predominately control his knee stability now. In the event he suffers a muscle strain or contusion, his ability to control his knee may suffer more so than an athlete who has an intact ACL.

It is, however, reasonable to expect him to play just fine in his first several seasons bearing any additional injuries. Gurley and Ajayi are the closest comparisons (though not perfect comps), and they played 5-6 seasons each. He does fall behind workhorse Derrick Henry on the depth chart, which will make it difficult for anyone to see the field consistently.
From a fantasy standpoint, Spears is a risk to take early in dynasty rookie drafts; he just simply is not expected to have as long of an NFL career as others, and who knows how long he will be behind Derrick Henry. He is a worthwhile hand-cuff for Henry owners or a nice late-round rookie draft pick, as he clearly flashed upside in his time at Tulane.
As a medical professional, I am fully rooting for Spears to defy all odds and create a lasting NFL career. The odds and medical history are stacked against him, but in this age medical breakthroughs are always happening.