The Cruciate Ligaments of the Knee: ACL, MCL and PCL
Ross Hauser, M.D.
 

ACL
These are the deepest ligaments of the knee. They are approximately two inches long and primarily give the knee its anterior/posterior stability. There are in the neighborhood of 200,000 ACL injuries each year. These are one of the best publicized of knee injuries. There is actually a very good reason for this. While cruciate ligament tears are not the most common knee injury, they very commonly do not heal well. The blood supply is from within the ligament itself, not from around it, and therefore when the ligament is torn, the blood supply is commonly disrupted during the injury. (Rowley, D. The Musculoskeletal System. New York, NY: Chapman & Hall Medical, 1997, p. 246.)

The cruciate ligament is unique in that it is inside the joint yet outside the synovial lining of the joint. This is possible because the capsule of the joint makes a kind of tube around both the anterior and posterior cruciate. They are not bathed in the joint fluid.
 

ACL & MCL Injuries
The anterior cruciate is frequently injured during sports such as football, soccer, and basketball. The most common cause of isolated ACL injury is a deceleration, cutting movement. When an athlete is struck by another player from behind and the outside, the ACL and medial collateral ligament (MCL) may both be injured. Injury is often accompanied by an audible "pop" usually with, and occasionally without, pain. If this injury occurs while bearing weight on the knee, the meniscus is regularly affected as well. The length and weight of downhill skis combined with failure of the bindings to release during a fall are a common cause of this type of injury during skiing, despite improved equipment.

In one study, investigators looked at what happens if you do physical therapy and external bracing to treat a transected ACL. The results were dismal, even one and a half years after injury there were a total of 32 percent who did "good" or "excellent," with a staggering 54 percent who did poorly! Thirty-five percent went ahead and had surgical reconstruction during the follow-up period. (Clin Orthop. 1990; 259:192-199.)

ACL injuries need to be taken very seriously. On this point surgeons and Prolotherapist agree. The only difference is how you repair it. If the ACL is completely torn, surgery is needed. For everything else, Prolotherapy should be instituted. Prolotherapy can tighten up loose knees as long as the two ends of the ligament are still attached.

Untreated, relaxed, or torn ACLs have clearly been shown to lead to degeneration of the meniscus and eventual degenerative arthritis. Whereas treatment of the ACL seems to save the meniscus and preserve the joint from osteoarthritis. (Scott, W. Dr. Scott's Knee Book. New York, NY: Fireside, 1996, p.75. Feretti, A. Osteoarthritis of the knee after ACL reconstruction. Int Orthop. 1991; 15:367-371.)

 

PCL
The posterior cruciate ligament (PCL) is also about two inches long. It limits backward motion of the tibia, the large bone just below the knee. It is uncommon to injure the PCL during sports. More commonly, it is injured during a motor vehicle accident when the knees hit the dashboard. A person who sustains a PCL injury without other associated ligament disruption will probably remain symptom free. (Torg, J. Natural history of the posterior cruciate ligament-deficient knee. Clinical Orthopaedics. 1989; 246:208-216.)

If pain does occur, Prolotherapy to the two attachments of the PCL inside the knee is effective at tightening these ligaments.

MRI scans are quite inaccurate at diagnosing cruciate ligament injury. They are not as accurate as one would think in differentiating between a complete tear and a partial tear. (Scott, W. Dr. Scott's Knee Book. New York, NY: Fireside, 1996, p. 74.)

We have had plenty of occasions where the MRI - (Knee Research Study) showed extensive knee damage and Prolotherapy completely relieved the pain. Obviously, the more extensive injuries in and around the knee require more Prolotherapy injections per visit, and often an increased number of visits.

Of course, surgery is repeatedly recommended for torn cruciate ligaments.  For anything except complete rupture (grade 3 injury) of the anterior cruciate ligament, avoid surgery if possible. The fact that there are so many ways to perform the surgery is an indication that there is no one excellent method. The repair of a transected cruciate ligament was successful in only two-thirds of 175 patients who were treated surgically, when followed up one to eight years later. (Lysholm, J. Long-term results after early treatment of knee injuries. Acta Orthop Scand. 1982; 53:109-118.) In our opinion, there is a better way and that way is Prolotherapy

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