Why Von Miller May Have Failed His Lachman Test … And What It Means To The Broncos
Recent Blog Entries From Dr. Dave Hnida
Von Miller’s season has been one of ups and downs. Monday comes one more test which will deliver his most important report card of the year.
The Broncos linebacker is scheduled for an MRI of the knee –the major reason is to determine if he blew out his ACL (or some other ligament) — and as you’d figure, it’s an imaging test that has huge implications as the team heads into the playoffs.
(To say nothing on how it affects Miller personally.)
So how do you suspect an ACL injury on the field or sideline when someone goes down and doesn’t jump right up?
RELATED: Von Miller Injured Against Texans
Here’s how it happened:
Miller took a shove and went over awkwardly — the next thing you know you have the head trainer and team physician standing over him as he grabs at the knee.
But after some quick screening tests on the turf, Miller gets up and heads off the field under his own power with the slightest of limps. Why are people speculating it could be the dreaded ACL?
It just didn’t seem that bad. In fact, a number of folks travelling with the team say Miller is walking without a limp as the team readies its way back to Denver. Why even think he needs an MRI?
Mainly, it’s because he probably failed the screening tests for a damaged ACL. They are tests that can be 80 percent accurate if you can get to the knee quickly — before it swells — and if a player isn’t in agony and won’t let you within 10 yards of his knee.
The classic tests we use all of the time to check an ACL are called the Lachman test, and the Drawer test. Occasionally we will also do a third called the pivot shift, but it’s the first two which often tell the tale of the tape.
I have some video of one of these tests down below.
In essence, the job of the ACL is the keep the knee stable — mainly by keeping the shin bone from sliding too far forward on the thigh bone. It also helps stabilize over-twisting.
So we test by lying the player on his back — bend the knee, grab the thigh and the shin and then yank — trying to slid the shin bone forward and backward to see how much give it has. It shouldn’t slide far forward. And it should stop abruptly with minimal movement if it is strong and intact. We do the same testing to the normal knee for comparison.
If the bad knee slides and jiggles too much, and it has a “sloppy” endpoint or end motion when it is supposed to stop, we worry it may be a torn ACL.
Try to do these tests a few hours later, or the next day, and the knee swelling makes the exam extra painful — and that swelling makes the knee feels extra tight — and stable.
(We also do a bunch of other tests on the field to test for various structures.)
So … it sounds like Miller was tested on field and locker room, and didnt get a passing grade on the ACL exams– or perhaps other ones that test different ligaments such as the MCL.
Even though Miller could walk, some part of that knee exam wasnt right, and was the reason Miller was declared “out” for the rest of the game quickly — within minutes of leaving the field.
So now we’ll see what the MRI shows, and tell you what it means to Miller and the Broncos.
Fingers crossed. Toes crossed. ACLs intact.
Geez, in our world of instant information, what did we do before we entered the age of MRIs?