One of the most common knee problems is an injury to the anterior cruciate ligament.  Dr. Zechmann is an expert in this type of knee injury.  He uses the latest technology to reconstruct the ACL.  Some information about the surgery is provided below.

What is the ACL?

The anterior cruciate ligament (ACL) is one of a pair of ligaments in the center of the knee joint that form a cross, and this is where the name "cruciate" comes from. There is both an anterior and a posterior cruciate ligament (PCL). Both of these ligaments function to stabilize the knee from front-to-back.   

In medical terms, the ACL is the primary restraint to anterior displacement of the tibia on the femur. This means that when the ACL is injured, the shinbone can slide forward on the thighbone, causing the knee to "give way".

What happens when the ACL is torn?

Most people who rupture their ACL can recall the exact moment at which they felt it tear. This usually happens when changing direction quickly in pivoting or cutting sports like soccer, landing from a jump in sports such as basketball, or falling while skiing. The four "classic" symptoms that people may feel when they tear their ACL are:

They hear a "pop" from inside the knee

They feel the knee give away at the time of injury

They develop a swollen knee immediately, or within a few hours

The pain is bad enough that they cannot continue play that day.

When the ACL ligament is stretched too far and ruptures, the blood vessels inside the ligament rupture as well, and this blood fills the knee joint, causing the knee to swell. While the ACL injury itself is usually not terribly painful, the swelling that results from blood inside the knee prevents most people from returning to the game or the athletic activity they were involved in at the time of injury. Examining an athlete immediately after they have had a knee injury can sometimes be difficult and it is often not possible to tell what structures, if any, have been injured. This is because the quadriceps and hamstring muscles "guard" the knee, preventing the examiner from testing the ligaments accurately. A better examination can usually be obtained after the swelling has gone down and the pain from the injury has subsided. Although accurate diagnosis of the exact injury can be difficult, it is relatively certain that an athlete who develops a swollen knee immediately after an injury should not return to play and should seek medical evaluation.



Where does the new ligament come from?

Once you have decided to have your ACL surgically reconstructed you should talk to Dr. Zechmann about how he performs the surgery and what type of graft he likes to use to reconstruct a torn ACL. During this surgical procedure, the remnants of your torn ACL need to be removed, and a similar ligament from somewhere else around your knee needs to be inserted in the place of the original ACL.

Hamstring tendon -- the gracilis and semitendinosus muscles, which are part of the hamstrings that help to flex your knee, have long tendons that insert into the tibia just below the level of your knee joint. These tendons can be removed, doubled over, and then used to replace the ACL. These tendons are easier to harvest than the patellar tendon, they require smaller drill holes in the femur and the tibia for fixation, and they do not predispose patients to patellar tendinitis. Most athletes never notice any decrease in strength or agility after their hamstrings have been harvested. The drawback to this procedure, however, is that hamstring grafts are more challenging to anchor in the femur and tibia because they do not have blocks of bone at either end.
 

ACL knee surgery explained

ACL surgery begins with an arthroscopic examination of the inside of your knee. In many ways, arthroscopic surgery has revolutionized the process of ACL reconstruction (and orthopedic sports medicine in general). This surgical technique uses two very small incisions that are about 1/4 of an inch in length to create "portals" into the knee. A fiber-optic light source illuminates the inside of the knee and a video camera feeds an image to a monitor so that Dr. Zechmann can see inside the knee. A sterile saline solution is continuously pumped through the knee via a cannula so that the operative field is always clear.
 

The term "arthroscopic" comes from two Greek words that mean "to look inside a joint." During arthroscopic knee surgery, Dr. Zechmann can maneuver and use the tools by watching the image (provided by the arthroscope) displayed on a video monitor.
 

After Dr. Zechmann inspects the knee for damage to the cartilage or the menisci, the remnants of the torn ACL are removed with a high-speed shaver. This tool is a very specialized device that is used to remove torn ligaments or torn pieces of cartilage from the knee. The surface of the intercondylar notch where the ACL normally attaches to the femur is then prepared with a high-speed burr so that the proper location for the tunnel for femoral fixation can be seen clearly.

Tunnels are then drilled through the bone in the femur and the tibia so that the graft can be placed in the center of the knee in the same position as the original ACL. A separate incision that is about 2 to 3 inches long also has to be made in order to harvest the graft from the hamstring tendons. After the graft has been harvested, it is then prepared by placing several very strong surgical sutures through the graft that are used to fix it in place.

After the graft is passed through the tunnels, it is then tensioned and fixed in place.
Once the graft has been fixed in place and any additional damage has been addressed, the incisions are closed and a sterile dressing is used to cover the knee. This dressing will usually stay on for several days while the wound begins to heal.