 | Robert Cusick, M.D. M.D., is a partner in the Kansas Joint & Spine Institute, Chartered with a specialty in reconstructive surgery of the hips and knees, and orthopedic trauma surgery. He received his BS from the University of Illinois, and graduated from the University of Illinois College of Medicine. After a five-year Orthopaedic Residency program at the University of Kansas-Wichita, he spent one year completing a fellowship in Adult Reconstructive Surgery at the Institute for Bone and Joint Surgery in Phoenix, Arizona. Dr. Cusick is on the teaching faculty at the University of Kansas School of Medicine-Wichita, and is an active lecturer in the medical community. The Kansas Joint and Spine Institute can be contacted at (316) 858-1900. |
Health & Medicine
2002-04-01 12:14:00
Replace ‘replaced’ knees?
Question: If a person has a knee replaced at age 60, what are the chances he or she will need the same knee replaced again?
Answer: The chances of requiring a second surgery after an original total knee replacement, a procedure we term 'revision of a total knee,' is quite variable and dependent on several main factors. Probably the most important factor affecting the longevity of a total knee is patient activity following the replacement surgery. A knee replacement is a mechanical device made of metal and plastic, and as a result will tend to wear out over time based on how it is used. A younger patient who enjoys athletics will likely wear out the plastic portion of the replacement much faster than an elderly patient who leads a more sedentary lifestyle. Likewise, a patient who is overweight will also tend to wear out the device faster than a smaller, lighter patient. These are the reasons we often encourage our patients to lose weight and give up their more demanding activities following replacement surgery.Other factors which can have a significant effect on durability of a total knee prosthesis include: surgical technique, postoperative rehabilitation, damage to the device through injury, or late infection of the knee. Each of these factors can significantly limit the life expectancy of a total knee and cause wear of the parts requiring revision.In today's environment, using the most modern techniques and materials, it is felt that a total knee replacement should last at least 12-15 years before requiring a second surgery for worn out plastic. Fortunately, the devices are now designed in a way that allows for simple removal of the plastic liner and replacement with a new liner without removing the well-fixed metal pieces. The materials used in these replacements have certainly improved over the years, and a high percentage of the knee replacements done today never require a second surgery for worn plastic. It is important, however, to remember that these devices have certain limitations, and one should be prepared for revision if wear of the plastic ever becomes apparent.
