November 19, 2003

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Knee1 : Welcome to today's Knee1 discussion with Dr. Chadwick Prodromos.

Knee1 : Dr. Prodromos is currently the President of the Illinois Sports medicine and Orthopaedic Center, and an assistant professor at Rush Medical School.

Dr. Prodromos : Good afternoon. Do we have any questions today?

Knee1 : Dr. Prodromos, thank you for joining us. Users, we welcome your questions!

Pat : Can you tell me if there development, if any, on technology coming up with a "RUNNERS KNEE".? What I mean by this is a more "real" knee type prosthetic that would allow an ex-runner to get back into runner, per se.

Dr. Prodromos : There is no current or developmental prosthesis that would allow a "runner" to safely run mileage. However, "unicompartmental knee arthroplasties," that replace only one compartment in the knee instead of the traditional "total knee arthroplasty" that replaces all three knee compartments, is thought to allow more knee activity. For example, a sport such as tennis, which involves some running, is more readily done with a "uni" than a "total" knee. However, for any knee prosthesis the added wear and tear of true mileage running, even if the person were able to do it for a short period, would cause the knee prosthesis to wear out or loosen more quickly and therefore is not recommended. What is a more promising avenue are the current advances in biologic knee restoration as opposed to knee replacement. These include "articular cartilage implantation" and "meniscal allograft implantation." With these techniques we are able to return many patients to full activity including running. We cannot restore all knees but our success rate is improving and should continue to expand the pool of candidate patients in the future.

Scott : 81 year old wife had total knee replacement 2 years ago. Staph infection later found and second surgery performed but failed. No further treatment because patient diagnosed with CML. CML now in remission. Question would cement block followed by reinsertion of prothesis offer hope of fix?

Dr. Prodromos : Yes. The success rate for two-stage knee replacement after gram positive bacterial infection such as staph is very high. The cement block would be antibiotic impregnated to fight the infection.

jc72782 : Dr. Prodromos, I am eight weeks post-op from a 2nd lateral release, debris removal, and a medial excision to remove scar tissue and look for a neuroma on the saphenous nerve on my left knee. This is the 3rd procedure on this knee in the last 21 months. The first procedure was to look in the knee to see what was causing my pain and remove debris. During the second procedure, a lateral release was performed, a cartilage tear was removed, and a lot of debris was again cleaned out. I am working extremely hard at rehab. I am still in pain. I have a constant, dull ache on the lateral side of my left knee, great pain at the bottom of my kneecap, and am experiencing medial pain at the joint again. I still cannot do any type of squats or stairs. I do the treadmill, leg press, and stair climber with pain. Also, I have severely overpronate when walking. The only time I really have relief is when the therapist holds my knee and straightens out my leg from the knee down. Any suggestions as to what my next steps should be? Thank you for your time.

Dr. Prodromos : This is obviously a complicated problem and without seeing you, your X-rays and MRI there is obviously much I do not know. However, let me offer a few suggestions. Your pain below the kneecap, and maybe much of your other pain as well, is related to your patella (kneecap) and/or your patellar tendon. In this circumstance active quadriceps strengthening such as you describe with the leg press, stair climber and squats often aggravates the problem and increases pain. The legs can be conditioned gently with a NordicTrack skier, an elliptical trainer, or possibly a stationery bike at very low resistance, to maintain tone but allow this pain to resolve. You should also avoid squatting, kneeling and stair climbing. Most of my patients with patellar or patellar tendon pain do quite well on such a regimen. The next question would be to define the state of your articular cartilage: the 4mm thick coating of the bones in your knee that allows it to glide. If this is intact your overall prognosis is much better. If it is damaged even down to bone, but only in a small area, there are cartilage restoration techniques that can restore it partially or completely in many cases. Finally regarding the pain below your kneecap, if you modify your activities as described above, and your articular and meniscal cartilage is in good condition and you still have most of your pain below the kneecap, many patients will do well after having their patellar tendon explored and "scar tissue" removed that can cause persisting pain. This is not scar tissue within the knee that can be seen arthroscopically, but actually within the tendon than can be removed through a small incision over the tendon itself.

nicole : I have bilateral TKR's , and need a revision, is there anything new on the subject of revisions?

Dr. Prodromos : Revisions are complicated procedures and must be done with great care. There are many different prostheses available but no recent major breakthroughs in technique or design. The biggest problem is lack of longevity of the revision procedure. To establish greater longevity requires long follow-up. Thus it is impossible to know if a "new" prosthesis is better until many years have passed to prove whether the survivorship of the prosthesis is indeed better than that of its predecessors.

Pat : If jogging is out of the question for someone who has a partial knee replacement, what other type of activity could I benefit from?

Dr. Prodromos : The best activity is swimming or walking in shallow water. Next best is a stationery bike. Next would be an elliptical trainer. Walking is good too but on a relative basis involves more cycles of wear to the knee while producing less cardiovascular benefit per cycle or step. This is increasingly true the more fit the person.

katbear : I have been diagnosed with a discoid lateral meniscus and meniscal cysts. How are these actually treated?

Dr. Prodromos : A discoid lateral meniscus that is not torn should not be treated. It does not cause pain. A torn discoid meniscus should have arthroscopic excision of the torn fragment. A meniscus with a meniscal cyst should have arthroscopic exploration. Usually there is a horizontal tear in the meniscus that allows fluid to leave the knee and fill the cyst on the outside of the knee but not escape from the cyst. At arthroscopy, the torn area can be trimmed back from within. This both removes abnormal tissue and increases the size of the "mouth" of the cyst so that fluid can drain from the cyst, thus eliminating the pain. In unusual cases where there is no such tear within the knee, the cyst can be explored from the outside through a small incision directly over the cyst.

Lauren537 : Dear Dr. Prodromos: My husband has a hard, half-dollar-sized mass on his kneecap that was not seen on the x-rays or MRI. It appears to be solid as attempted aspiration was unsuccessful. What could this be? Why didn't it show up on the radiographic studies? Thank you. Lauren

Dr. Prodromos : Any mass, whether bony or soft tissue, should be visualized on the MRI and/or the X-rays. I would suggest you have the films re-read by the radiologists with special attention to the affected area. In difficult cases a marker can be put directly over the mass for both the X-rays and the MRI. In particular, the MRI should be able to tell you whether the mass has worrisome characteristics or not. This information, combined with the history and physical exam by the orthopedic surgeon, will tell you the nature of the mass and whether any further steps, such as biopsy, need be taken.

kathy : Thank you for your response. Is the pattelar/patellar tendon causing the constant, dull ache on the lateral side of the knee or caused by some other underlying reason?

Dr. Prodromos : In some people the patella is shifted ("subluxated or tilted") laterally. Often there is increased wear on the lateral side of the patella and the lateral side of the "trochlea": the socket in which the patella resides. In such cases lateral knee aching is common and this can occur even without lateral patellar subluxation. Lateral pain can also be caused by lateral meniscus tear or by damage to the articular cartilage of the lateral femoral condyle or the lateral tibial plateau. In some people who run long distances, which does not seem to be the case here given the magnitude of the knee disability described, lateral knee aching can also be seen for reasons that have not been fully proven. The patellar tendon usually does not cause lateral aching but rather pain and especially tenderness directly over the attachment of the patellar tendon to the patella.

Carlos : how long it takes for meniscal bucket handle tear injuries to heal?

Dr. Prodromos : A torn bucket handle meniscal tear left untreated seldom, if ever, heals on its own. If it is arthroscopically excised then full recovery usually takes place in about five weeks in a younger patient with an otherwise normal knee. A bucket handle tear that is repaired can usually be walked on immediately. I allow running at four months and full return to athletic activities in six months. If it is repaired and there is also an anterior cruciate ligament (ACL) tear, the healing rate will be drastically reduced unless the ACL is concomitantly reconstructed.

Knee1 : Users, we are just about out of time. Dr. Prodromos, do you have any parting thoughts for our users regarding knee care?

Dr. Prodromos : Yes. We have had many recent scientifically proven advances in our ability to restore, rather than replace, degenerating knees if the damage is not too far advanced. Therefore, it is important to see an Orthopedic Surgeon sooner, rather than later, if there is a significant knee problem, before the problem is so advanced that total knee replacement is the only answer.

Knee1 : Thank you, Dr. Prodromos, for your insightful answers today. Users, thank you for joining us and we look forward to having you join us in future Knee1 discussions. Thanks again!