By Lindsey Christie, Knee1 Staff
More than 21 million Americans are afflicted with a debilitating and painful condition known as osteoarthritis (OA), the most common form of arthritis. The condition is a degenerative disease associated with wear and tear, injury or excessive use. People suffering with OA often have pain and a limited range of motion in one or both knees. This pain and inflammation causes significant discomfort, and because there is no cure for arthritis, patients rely on medications such as aspirin, ibuprofen, naproxen, or other non-steroidal anti-inflammatory drugs (NSAIDS) to control pain. If NSAIDS fail to provide long-term relief of pain, the next logical step may be a joint replacement. However, osteoarthritis may not affect the entire knee joint; instead it may affect a portion, or chamber, of the joint. In this case, it is now possible for a patient to have a unicompartmental knee replacement instead of a total knee replacement. Dr. Mitchell Sheinkop has been instrumental in bringing this unique treatment to the United States and turning it into a minimally invasive surgical procedure.
Dr. Sheinkop received his medical degree from the Chicago Medical School and did his orthopedic residency at Northwestern Memorial Hospital in Chicago. He has helped pioneer cementless knee and hip surgery and has over 30 years of joint replacement experience. Currently, Dr. Sheinkop is Director of the Rush Joint Replacement Program at Rush-Presbyterian St. Luke’s Medical Center in Chicago. He is a Fellow of the American Academy of Orthopaedic Surgeons and has written numerous papers, abstracts, and book chapters. Dr. Sheinkop hopes to provide each of his patients with a quality outcome to ensure their satisfaction.
Knee1: How did you choose orthopedic surgery as your specialty?
Dr. Sheinkop: During week three of my internship at Chicago Cook County Hospital in 1968, I was informed,” You have two choices, either you will be drafted and go to Vietnam as a general medical officer the day you finish your internship or you can apply for deferment for four years to finish specialty training and serve during the war as a specialist." I received deferment so I could become a specialist and orthopedic surgery had the largest number of deferment slots available.
Knee1: What role have you played in the development of joint replacement surgery in the US?
Dr. Sheinkop: I was in training when the first hip replacements were introduced to the United States. I did the first knee replacement in Chicago in 1972. In 1981, I was part of a team of three doctors who introduced cementless hip replacement surgery to the Midwest. I pioneered the clinical work on cementless hip replacement in the US using the titanium fiber metal prosthesis with Jorge Galante and Glenn Landon. In 1983, I helped introduce the contemporary design of the unicompartmental knee prosthesis into clinical practice. I have personally performed over 5,000 joint replacements.
Knee1: You have been very involved with bringing unicompartmental knee replacement to the US. Could you tell me a little more about it?
Dr. Sheinkop: The unicompartmental knee prosthesis has been used extensively in Europe but it has only recently gained attention in the United States. When Dr. Gunnar Andersson, the present chairman of orthopedics at Rush Presbyterian St. Luke's Hospital, immigrated to the US in 1983, the Miller Galante knee prosthesis was being developed by Zimmer (a medical device company). At this time, Dr. Andersson influenced Drs. Joe Miller and Jorge Galante to offer a unicompartmental option with the new generation of knee prostheses.
Knee1: How does unicompartmental knee replacement differ from total knee replacement?
Dr. Sheinkop: The knee is tricompartmental, or three chambered, and approximately one third of patients have arthritis that is confined to one of the three chambers. The unicompartmental re-surfacing methodology allows the surgeon to address the diseased chamber of the joint. In addition, minimally invasive unicompartmental knee replacement reduces the size of the surgical incision from 18 inches in conventional knee replacement surgery to about three inches. As a result, the patient spends less time in the operating room, and has a shorter hospital stay, both of which reduce the chance of complications as well as cost.
Post-operatively, the “uni” replacement allows the patient greater functionality and more normal functional capacity when compared to the standard total knee replacement.
Knee1: Who, in your opinion, would be the ideal candidate for unicompartmental knee replacement?
Dr. Sheinkop: A well-informed patient who presents with unicompartmental osteoarthritis that is too advanced and painful to be treated with conventional therapies, including: medications, cellular and cartilage transfers, arthroscopy or less complex procedures. The patient must have an intact anterior cruciate ligament, and a preoperative range of motion wherein there is no more than a 10-degree flexion contracture and at least 120 degrees of flexion. Unicompartmental knee replacement is not recommended for people with rheumatoid arthritis.
Knee1: What type of rehabilitation is involved following a unicompartmental knee replacement?
Dr. Sheinkop: Uni knee replacement therapy will be similar to the therapy that follows total knee replacement; however, it can be completed in one-third to one-quarter the length of time it takes to rehabilitate a total knee replacement.
Knee1: Have your patients been pleased with their recoveries after unicompartmental knee replacement?
Dr. Sheinkop: They love it. The patient demand is becoming exponential. Many patients who receive the unicompartmental knee replacement through the small incision can play doubles tennis, ride a bicycle, bowl, dance and in some cases ski.
Knee1: What is the average "lifespan" of a unicompartmental knee replacement? Do people ever have to have it done twice?
Dr. Sheinkop: At present, our actual outcome studies are approaching 12 years of survivorship; but our statistical projections suggest the “uni” may last as long as a total knee replacement. Of importance is the fact that when repeat surgery is necessary, the “uni” can be converted to a primary knee prosthesis rather than having to be extended to a revision constrained prosthesis.
Knee1: Currently, there are only a handful of surgeons performing unicompartmental knee replacement, do you think that this will become a standard procedure?
Dr. Sheinkop: The patient demand is forcing the American Orthopedic Surgical community to become informed and knowledgeable about this procedure. Instructional “uni” courses are becoming commonplace.
Knee1: Are you currently involved in any exciting research?
Dr. Sheinkop: The minimally invasive surgical approach to unicompartmental knee replacement is still under study and the instruments we are using (and that I helped introduce) are still evolving. The all-polyethylene tibial component must be followed for another 10 years so its performance may be compared to the metal-backed tibia. My participation in outcome studies of hips and knees consumes my research agenda.
Knee1: With the progress of technology and the arrival of tissue engineering, what changes do you foresee within the specialty of orthopaedic surgery?
Dr. Sheinkop: I do not predict any changes now or for the next five years. Genetic manipulation of arthritis is in an embryonic state; pharmacological management of arthritis is palliative, not curing and cartilage restoration surgery is still anecdotal without long-term outcomes.
For more information regarding unicompartmental knee replacement, please contact Rush-Prebyterian St. Luke's Medical Center at 1-312-942-5000 or visit the website at www.rush.edu.
To contact Dr. Sheinkop, send e-mails to [email protected]