Anterior Cruciate Ligament (ACL) Reconstruction
High impact sports like football always expose athletes to injuries. Unfortunately, joints like the knee end up suffering the most. The Anterior Cruciate Ligament (ACL) is definitively one of the most vulnerable areas. In the following video, orthopedic surgeon, Leon Mead, MD, performs an anterior cruciate ligament reconstruction to a 16 year-old athlete and guide us trough the process. Please check it out:
A transcription of the narration perfumed by Dr. Mead:
This is the torn Anterior Cruciate Ligament (Reconstruction) of a 16 year-old high school football player, who injured his knee while performing a cut back maneuver. We are probing the torn and injured anterior cruciate ligament remnant and see how it’s hemorrhagic, reddened and their unstable segments. We also notice there is no continuity between the tibial aspect and the femoral aspect and I will demonstrate this in a few minutes. Here we introduce a shaver under the knee, is 3 ½ millimeter in diameter and its been used to remove the unstable segment of the cruciate ligament. We do this because it will cause mechanical symptoms if left in place. We also need to identify the base of the cruciate ligament attachment so that we can anatomically reconstruct this. Here we see the tibial aspect. There should be tissue coming from this area all the way up to the area of the femoral aspect, which is right up here. And you can appreciate that there is no continuity of this tissue. You can see the gap in between.
We use this to more fluidly remove the footprint of the cruciate ligament here on the tibial side. If we don’t do this, the remnant can become enlarge and cause mechanical symptoms preventing the knee to fully extend. Behind the device is the posterior cruciate ligament we are looking directly at. Now, we created us a bare area that is in the optimal position pro-placement of our tibial tunnel. This device is traditionally placed right next to the posterior cruciate ligament, but recent studies have shown that is an inaccurate position for optimal placement. We use this to place a guided pin into the joint which is what we use to create our tunnels. Here we see the guided pin. It is traversing the joint going directly towards the area where the cruciate ligament would normally attach. We can see the posterior cruciate ligament behind it as a white fiber tissue extending from 3 o clock to approximately 9 o clock.
Here we are using a coring reamer. It is a reamer to create the tibial tunnel. It is hollow and the bone that is in the central core will be used to grasp the donor areas of the patella an tibia. We have used a central third bone-patella-bone auto graft of the patella tendon. Must NFL players receive this graft particularly if they are a skilled player needing sudden cut backs and changes. The advantage of this graft is that it can be secured immediately with a screw fixation long rapid rehabilitation. We have now placed a guide trough the tibial tunnel, placing a guided pin into the femur. The tibial tunnel is crucial in this operation. In that if it is off several millimeters we can not place the femoral tunnel in its anatomic position. We will use the guided pin to guide the reamer which we now placed trough the tibial tunnel. We do this without fluidity because is actually easier to see.
We are ensuring there is a posterior wall. We can see it at 9 o clock. We want there to be a socket, not and ellipse with portion bone missing. This reamer is 10 millimeters in diameter. We have chosen a 10 millimeters graft. In here we are being extra certain there is no bone in the back. We will ream this approximately 30 to 35 millimeters to allow the full sealing of the bone graft. The advantage of this particular graft is because it can be secure with screws. It allows for immediate fixation in athletes to return to a high level activity.
The downside to the graft is a little bit more painfull due the harvest of the graft itself. It involves an incision on the front of the knee and there is some pain with kneeling. There is also some thinking that there is some risk of osteoarthritis 10-15 years down the road. Although, this is not statistically significant.
Here we are using our shaver to remove all the debris we have generated. We have a good look of the femoral tunnel here and we can see that there is a little bit of bone in the back. The tunnel starts right next to the joint surface. It is low on the wall. The prior place of the graft is more at the 11 to 12 o clock position. And this has been shown recently as an inadequate position. In order to place the graft across the joint, we place a guide pin, which exits the tight. It has the sutures that are attached to the bone graft. We can see the sutures here just to the left on the screen. These go trough the tibial tunnel and now trough femoral cortex. We will tighten up these sutures and bring the graft in place. Here we can see the bony aspect of the graft. Its been fashioned to fit precisely into the tunnel. We can see the patella tendon portion of this.
An important aspect of this is that the graft ended at a lower angle on the femur and not in pinch when the knee is placed in extension. We see a nice relationship between the anterior and the posterior cruciate ligament on this particular view. As we go into the extension, we can see that there is some contact between the graft and the wall of the femur. From this view point we can see that at the 9 o clock position on this screen it appears there is an inward protuberance. We are going to remove it. This is not a normal anatomic configuration and likely predisposed this particular athlete to a cruciate ligament injury.
Rarely is it necessary to remove bone if the graft is placed in the low anatomic position as we have done with this athlete. Now, we check this again and as we fully extend the knee, there is some degree of contact between the bone and this area and the graft itself. We can see that right here as it tends to pinch so slightly. We can see the bone overlapping a portion of the graft. We removed a little bit more. We can see the graft in front of us and as we fully extend the knee it now has no abnormal contact with the bone, which is desirable.
We now are going to fix the graft and place in the femoral socket. We will place a guide pin coming trough the arthroscopic portal and that is wedged between the socket that we created and the bone block of the graft. This will be fixed with a screw so we get immediate fixation. The graft is protected with a sheath. You can see the sheath as the bluish non-rotating part. The rotating grey part is the screw. But the threats are not sharp. We don’t want them to injure the graft in any way. This is more difficult to see because we have to hyper flex the knee in order to get the proper angle for the screw to come in directly in the interface between the graft and the socket. I want to make sure the screw is fully seated and no extended into the joint at all, so that the soft tissue that have been brought up by the screw will be removed with a shaver to allow better visualization.
The tibial aspect is secure in a similar fashion. This allow us to really aggressively rehabilitate the knee without concerns of the graft slipping in place. Soft tissue graft such as a hamstring graft or an allograft can’t be fixed with the same bone to bone contact. And this grafts sometimes become a little bit loser and is for this reason that this graft is the preference for NFL athletes. Here we see the graft expanding the two bones. I am actually jerking the patient on the table on this to make sure that we got good fixation if the interference screw.
Orthopedic Corner | Leon Mead MD Orthopedic Doctor | 730 Goodlette Road North, Suite 201 Naples Florida 34102 | Phone: (239) 262-1119