(rock music)
- How do we fix it?
Well, let's first of all say,
"What do we fix it with?"
Well, the gold standard
or one of the choices that you have
is using a piece of this patellar tendon
with a little piece of bone on this end
and a little piece of bone on this end.
So, if we take the kneecap and look
at the front view once again,
it looks something like this.
And then we have the kneecap tendon
that looks something like this.
And this little bump of bone that it attaches to,
that would look something like this.
What we would use to replace this
anterior cruciate ligament
would be the middle portion
of this patellar tendon, with a little piece
of bone on this end and a little
piece of bone on this end.
So if we take that piece out,
it looks something like this,
bone,
tendon, bone.
The bone allows us to drill a little hole
through it on each end and pass
a little suture through it so we have
something to control it with.
This being side A and this being side B.
Well, we now have our
ACL graft.
Well, let's look once again
at the front view of the knee.
Again, our thigh bone
and top of our leg bone.
And now arthroscopically we have removed
that torn anterior cruciate ligament
to replace it with this ACL graft.
The next step is to drill some tunnels,
arthroscopically, from the outside
of this bone, the leg bone,
and surfacing in the joint here,
and then a second tunnel
part of the way through the bone
on the femur, or thigh bone, here.
The idea is to place these tunnels
exactly where God originally attached the tendon
for the best result.
So then we can bring our graft in,
arthroscopically, and it'll end up something like this.
Graft, piece of bone in this tunnel,
piece of bone in that tunnel.
A, B.
How do we firmly attach the graft in those tunnels?
First of all, let's take this tunnel
and magnify it, and it looks something like this.
We have the bone.
This is where we drilled the tunnel in bone,
and our graft, that is the bone part of the graft
that we placed in the tunnel.
This is A.
We then take a specially designed screw
and wedge it up into this area
between the bone and the graft.
So here's the head of the screw,
here's the shaft of the screw,
here are the threads of the screw.
This prevent our graft from pulling out.
And indeed, we call this an interference,
interference,
screw.
Down here on the leg bone, we also have
to attach our graft.
And how do we do that?
Well, again, here's our tunnel
and here's the graft poking its way
a little bit outside the tunnel.
Just outside the tunnel in the bone
we place a different type of screw.
Here's the shaft, here are the threads,
here's the head.
And we leave it just a little bit proud.
Then we take the stitches that we have kept
through this little bony graft and we pull
and tie it around that screw, just like
tying the reins of your horse around the post.
We call this a post screw.
Now, some surgeons prefer, even on this tunnel,
to use an interference screw.
In either case, we now have firm fixation
of our graft in the tunnels
and we can start moving the patient's knee immediately.
(rock music)