Yasser Farid, MD, director of the Chicago Bone Metastases Center and a practicing orthopedic surgeon at the Chicago Center for Orthopedics at Weiss Memorial Hospital discusses the latest techniques and instruments being used for total joint replacements and how surgeons can incorporate these into their practice.
Question: What are some of the most exciting new techniques in total joint replacement surgery?
Dr. Yasser Farid: The most exciting new techniques are in total hip replacements. New technologies facilitate more efficient surgeries with better long-term outcomes, especially in younger and more active patients.
These advancements have been prompted by Baby Boomers who are getting more total hip replacements while they strive to stay active as they age. These technologies have been tested in concept for several years and became recently optimized to further address some challenges in hip replacement surgeries.
Q: What are some of the latest technologies facilitating these new TJR techniques?
YF: The old orthopedic standbys are new again. Some enhanced traditional technologies are proving to be more effective than "newer" technologies, such as metal-on-metal in total hip replacement, which caused significant problems. Focusing on the durability and longevity of the implants is key in having these implants stand the test of time for younger and more active patients.
For example, the short stem total hip arthroplasty is an emerging technology that helps to preserve bone stock, which is crucial for younger patients likely to need a revision procedure 20 to 30 years following their primary surgery.
The short stem is an advancement of the traditional long stem inserted into the femur. The short stem is a little more than three inches long, about half the size of the traditional stem, and it is porous and uncemented. The short, porous stem attaches to the bone in the canal of the femur. The longer, traditional stem does not only impact a greater area of the bone but also causes stress-shielding and osteoporosis, which further reduces the bone quality. The short stem prevents this bone loss, which benefits younger patients.
There's a good indication using shorter stem with the anterior approach. The short stem accommodates the angle in which the implant is inserted and allows a smaller incision.
Another benefit of the newer-design short stem implant is that there are no left-and right-specific components or custom-made implants needed. This cuts costs and improves availability.
Another technology is the advancement of the plastic used in the liner for the ball and socket hip joint. The new Vitamin-E treated plastic is bone-conserving in the long term because it reduces the concerning free radicals, stabilizes the biomaterial used and improves resistance to wear. Wear particles have been shown to damage bone stock and limit long-term success. These liners have a more durable articulation and an enhanced longevity, so they benefit younger and more active patients the most.
These Vitamin-E treated polyethylene liners are also thinner without compromising strength, so they allow for a bigger ball to avoid dislocations, which are the most common cause of revision surgeries. We've moved away from metal-on-metal bearings, and even ceramic-on-ceramic is not considered standard by many surgeons. We're going back to metal-on-plastic and adding a hint of modernization.
Q: What are some challenges of learning and incorporating these techniques?
YF: A big difference between the short and long stem implants is in the preparation of the femur for implant placement. With the long stem, you would have to crush the spongy substance inside the shaft of the femur and ream the canal before inserting the stem. With the short stem, we remove the weak spongy bone to enable the now porous stem to fixate inside the strong femur cortex. There is less bone preparation and less concern that the bone may be damaged during surgery. It's also quicker and more efficient, which is especially better for sicker patients. The less time in the operating room, the better.
Q: What are some best practices for incorporating these techniques into practice?
YF: Select patients that would benefit the most from them. In the case of short stems and Vitamin-E polyethylene liners, younger patients in need of a hip replacement would benefit the most because they have a longer, more active life ahead of them. The bone quality should be adequate enough to support the short stem, which is the case in most young patients undergoing hip replacement.
Also, explain the different options to patients. An informed patient is a more appreciative patient. Explain why you're using the short stem and why you prefer metal-on-plastic rather than other highly marketed technologies that may be newer but have not proven the test of time.
Q: What advice would you give orthopedic surgeons looking to keep abreast of the latest technologies & techniques in TJR?
YF: Be wise when offered a new technology or technique into your practice. Don't be reactive just because it's said to be the latest and greatest. Use common sense.
Any new technology or technique needs to be affordable, testable and durable. The best test is time. Many specialists don't want to wait. But orthopedic treatments now have evolved to a point where it might be best to hold off on a new technology proposed for the sake of making something new and wait until we can promise something better.