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Knee Injuries in the Athlete

There are many different types of knee injuries, it could either a soft tissue or bone, the major ligaments you need to be concerned about are the cruciate and collateral ligaments, there are two types of cartilage, meniscal and articular. 

Diagnosis: In your acute patient, you will have a feeling of instability and giving way episodes. I want to make a comment about giving way, many times patientís will come to you and say that I had instability or they will describe a giving way episode. Often times it is not a true instability episode because you can have an effusion with an acute injury which inhibits the quadriceps, and they just feel weak and it buckles, and in a chronic patient, they could have just weak musculature which will also have them buckle.

That is a little more reliable for an actual instability episode. They may hear a pop, this is an acute injury when it first happens. The knee either twists or buckles, and this is important, you have immediate swelling within 12 to 24 hours. With the chronic patientís, you may have swelling with activities, again, the feeling of giving way, twisting or buckling.

Once again, it is an effusion. That is important. In acute hemarthrosis in a patient who describes a traumatic injury from playing a sport or work, when they fell from something or twisted their knee. You have to rule out an anterior cruciate ligament tear, and often times what I will do is, on the first office visit, they will com in with a swollen knee with this type of clinical picture. Even if they feel stable, the could be guarding with their hamstring muscles, try to have them relax, they are very compliant, they are trying to relax, but they canít. I will let them know that I canít rule out an anterior cruciate ligament tear.

The reason why is two-fold, one is, you can tell them itís a more serious injury, they will come back and see you in case it really is an ACL tear and they want to say, well the doctor said it wasnít torn, Iím not going to go back, and two, is often times you miss, even though the best diagnostician will have problems sometimes with your swollen knee. They will have limited motion, loss of extension, you have to check your anterior and posterior laxity, and you have to look for associated injuries, and if you have more than one or two ligaments out, then you should do a thorough examination, you have to be concerned about knee dislocation, not a patellar dislocation, but a true knee dislocation.

Physical examination, besides your standard knee examination, you want to do some special examinations, at some point you want to do the Lachman examination which is30 degrees of flexion, thatís the most specific, thatís the best examination, KT1000 is just instrumented testing. Your x-rays often times are normal, but you can have an avulsion fracture of the ACL at the tibial spine, this here on the right is a lateral capsular sign, which is here, as you can see, the tearing off, that is not an ACL injury or lateral collateral but itís pathopneumonic for an ACL tear.

Specialty studies, MRI is 85 to 90% accurate, the reason why is the ACL does not go completely in the sagittal plane, itís a little off so itís sometimes difficult to catch a complete ACL, this actually is an intact ACL. Arthrogram is not often done, an arthroscopy if you are concerned about a patient that has a true tear by MRI, if you arenít really sure on exam, you think it is, and they are a high active player, they want to go back to sports, you can do an arthroscopy. Natural history, this is a controversial area, the ACL deficient knee does have abnormal kinematics and mechanics and probably leads to degenerative arthritis, you canít completely say that really has been proven. Partial tears, the function depends on secondary restraints and how much percentage of the ACL was torn. You canít really tell on MRI or by examination.

The acute setting, you want to minimize the swelling, so use standard rest, ice, compression, elevation and anti-inflammatories. This is important too because if you think they have an ACL tear, you need to do this treatment, and if they donít have an ACL tear, you need to minimize the swelling, so youíre not missing anything or setting them back by treating them this way in the beginning. Early motion, you avoid activities such as playing basketball, football or anything that is going to cause swelling or pain, they can have a period of nonweight bearing, but putting them in a knee immobilizer and saying, let it all heal down and quiet down is not the way to go, they are going to get stiff and have problems with motion, so once you realize they donít have a knee dislocation, multiple ligaments out or fracture, you start them moving. This is an arthroscopy picture of an intact ACL.

The treatment that is very dependent on the age, the extent of the injury, if itís an isolated injury versus a complete tear or associated injuries, the condition of the articular cartilage and the meniscal fibers, associated lesions as I said, and really the patientís expectations and activities, and if they are a compliant patient or not, you really have to individualize each patient that comes in. Your standard conservative or nonsurgical treatments consist of anti-inflammatories, rehab.