Lindsey Vonn is managing to ski with a ruptured ACL because her knee is being aggressively braced, supported by intense short‑term rehab, and she’s accepting a very high level of risk that most doctors would never recommend for ordinary people.

What actually happened to her knee

  • Vonn has a completely ruptured ACL in her left knee, plus bone bruising and meniscus damage from a crash in Crans‑Montana shortly before the 2026 Olympics.
  • She was on crutches right after the injury and had significant swelling, but this improved enough within a few days to let her start skiing again.
  • Despite that diagnosis, she has publicly said she is “confident” she can race in the downhill at Milan‑Cortina as long as there is still a chance to compete.

How can she ski with no ACL?

In everyday sports medicine, a fully torn ACL usually means you stop pivoting sports until surgery and rehab are done. Vonn is an extreme exception, and she can attempt this because:

  • Powerful muscles as “backup ligaments”
    • Years of elite training give her unusually strong quadriceps, hamstrings and glutes that can help stabilize the knee when the ACL is gone.
* One sports‑medicine analysis noted that at race speeds she’ll have to constantly tighten every leg muscle to keep the knee “locked,” which is brutally demanding but partly compensates for the missing ligament.
  • Rigid bracing and external support
    • She is using a knee brace to add mechanical stability and limit how far the tibia can shift forward under load.
* The brace doesn’t replace the ACL, but it can reduce “give” in the joint enough for very short‑term performance if everything else (muscle control, pain tolerance, conditions) is close to perfect.
  • Ultra‑intensive, short‑window rehab
    • Within days she moved from crutches to doing box jumps, pool workouts with a weighted vest, and high‑speed skiing in training, all aimed at quickly restoring strength and neuromuscular control.
* Her team has focused heavily on swelling control, physical therapy and gym work to get the knee stable _enough_ for a single Olympic run, not a full season.
  • Course choice and tactics
    • She is targeting the downhill, a mostly gravity‑driven event where you can sometimes prioritize aerodynamics and line over explosive lateral cutting like in team sports.
    • Even so, at those speeds she must carve turns and absorb jumps with extremely precise technique to avoid sudden twisting loads on the injured knee.

Why doctors say it’s so risky

  • A sports‑medicine doctor who discussed her situation said that while she can likely ski practice runs at reduced intensity, full‑gas racing is “too risky” and could worsen the knee or cause other injuries.
  • With a ruptured ACL plus bone bruise and meniscus damage, an awkward twist or crash can mean:
    • More cartilage and meniscus tearing
    • Additional ligament damage
    • Longer‑term arthritis and chronic pain
  • The online medical breakdowns and forum discussions emphasize that what she’s doing is possible for a unique outlier but absolutely not a blueprint for normal athletes.

“Many athletes have done it, but the challenge is that it happened so close to the Olympics,” one commenter summarized, echoing a former racer’s view that it’s achievable but incredibly hard.

The mindset piece

  • Vonn has a long history of comebacks from major knee injuries and even had a partial titanium replacement in her other knee before she returned to racing last season.
  • She has said her odds of medaling dropped after the crash, but as long as there is “still a chance,” she wants to race—essentially accepting permanent‑damage risk for one last Olympic shot.
  • Fans and fellow racers on forums describe her as “willing to risk worsening her injury for one final chance” and “absolutely incredible,” capturing the mix of admiration and concern around this decision.

Important reality check (for everyone else)

If you’re wondering “Could I play or ski with a ruptured ACL?” the practical answer for normal people is almost always no :

  • Standard medical advice is to avoid pivoting, cutting, and high‑speed twisting sports with a fully torn ACL until it’s reconstructed and properly rehabbed.
  • Vonn’s situation combines:
    • Unusual strength and conditioning
    • A custom medical team and equipment
    • A one‑off Olympic goal where she accepts risks most patients—and most doctors—would consider unacceptable.

TL;DR: Lindsey Vonn can ski with a ruptured ACL only because of extreme leg strength, a rigid brace, intense crash‑course rehab, and a willingness to accept serious long‑term risk for a final Olympic run—something that is unique to someone at her level and not a realistic or safe model for regular skiers.

Information gathered from public forums or data available on the internet and portrayed here.