Human Knee Anatomy
In your knee, there are several anatomical structures: the cruciate ligaments, the collateral ligaments, menisci, and the articular (joint) cartilages. When someone injures their knee, there can be simultaneous insult to more than one of these structures.
What Are The Cruciate Ligaments?
There are two separate cruciate ligaments in a person's knee: the anterior cruciate ligament (located in the front) and the posterior cruciate ligament (located at the back). These two ligaments can be referred to as the ACL & PCL respectively. It is important to note that the cruciate ligaments help to secure the stability in the knee, which is assisted also by other ligaments, the menisci and the muscles.
How do injuries to the cruciate ligaments occur?
Injuries to the anterior cruciate ligament (ACL) are more common than injuries to the posterior cruciate ligament (PCL). The posterior cruciate ligament (PCL) is more commonly damaged in an accident on the road. When the person is sitting down and their knees hit the dashboard, driving the lower leg backward in an unnatural manner. When the posterior cruciate ligament is torn across, your shin bone will move be able to move backwards on the thigh bone.
Kind of a gruesome thought to imagine that happening, right?
On the other hand, a lesion of the anterior cruciate ligament (ACL) happens more commonly in sporting activities when a person's foot is planted on the ground. As a result, if a person's ACL is torn across, the knee can become unstable and the shin bone will move forwards on the thigh bone.
Some examples of a lesion to the ACL might occur when :
1.)The body is pushed forward, and the leg is locked.
2.) When the knee is forced into the opposite direction to its natural motion, when it is bent.
3.) An aggravating twist to the knee when you are skiing or playing in sports.
What are the symptoms of an anterior cruciate ligament lesion?
Often times a "click" can be felt, and possibly a loud "Popping" sound will occur - followed by pain. The knee can swell due to blood from the bleeding anterior or posterior cruciate ligament. There is a good chance that their will be pain in the knee in the following days or weeks.
How Does The Physician Make A Diagnosis?
The physician will look for all possible injuries that could have happened to the knee. It is possible that in the phase shortly after the injury (the acute phase), the knee may be so swollen that it is impossible to examine properly. If this injury has happened to you, your physician may decide to put a splint on the leg and examine the leg again after several days. In order for a physician to diagnose a cruciate ligament lesion, the he/she will look for instability of the knee joint. One test the doctor may do is to determine if the shin bone can move slightly forward, in relationship to your femur (thigh bone). This is called the anterior drawer test.
Is surgery always necessary?
No, this is not always the case. Having surgery will depend on the patient's activities of daily living, as well as their job, age and especially how much of an issue the patient is having with their injury (ie. how much pain exists & how much function is lost.) Many times, a person's cruciate ligament injury can be treated with that of training and strengthening exercises, and the use of a well designed knee brace to help prevent the need for complex surgery.
If surgery is needed, what can a person expect?
Surgery is usually carried out under a general anesthetic. The physician will perform an arthroscope of the knee and will look for any other damage that can be repaired. The physician will construct a new cruciate ligament, possibly using either the patella tendon or two of the hamstring tendons. This new ligament will be placed in the knee joint in a manner that attempts to give it the same shape and function as the original ligament.
What kind of recovery can be expected after surgery for a cruciate ligament injury?
The patient will usually be able to walk again shortly after surgery, unless they have other injuries that complicate their condition. Often times a person may be provided with post operative knee brace to wear. This brace has hinges at the knee and can be adjusted for increased or decreased range of motion (ROM), per the physician's orders. These braces are usually longer than your average knee brace in order that they really control the way the leg is functioning while you recover.