Knee Surgery – Procedures
Total Knee Replacement
Total knee replacement is very successful in over 90% of well-selected patients. On average, replacements last 15-20 years. With the advent of improved wear properties of modern materials, it is anticipated that many if not most patients will enjoy full use of their prosthesis for years longer. Occasionally, however, an implanted prosthesis does not function as well as anticipated. This can be traced back to older materials, trauma, or unforeseeable infection. In such cases, revision surgery may be performed to adjust or replace the implant. Dr. Meere specializes in such cases, which can be quite complex, involving removal of failed or infected implants, cleansing of the joint and reconstruction with more elaborate implant designs.
Dr. Meere specializes in muscle-sparing surgery. Here, the key muscle of the knee, known as the vastus medialis, is not divided from the rest of the quadriceps muscle. Instead, it is lifted from its inferior boundary and gently retracted without any cutting. This allows for remarkably improved speed of recovery, strength, and less pain.
An added cosmetic advantage is a smaller scar, which is individualized to the patient’s size and needs but generally measures around four inches. The minimally invasive surgery technique should not be used in complex cases involving correction of severe deformity, revision of failed implants. In such cases, the exposure is determined by the existing wound and the need for greater exposure. Dr. Meere strongly believes in selecting the best surgical technique to spare tissue and minimize dissection whenever feasible, yet is prepared to extend the incision if necessary to perform the work adequately and safely.
This refers to the use of a computer as a tool to assist in the positioning and insertion of a hip or knee implant. It is important to realize that unlike a robot, it is not intended to replace the actual human performance of the procedure. Severe cases are especially suited to this adjunctive technology. Dr. Meere has been involved with the development of computer-assisted navigation since its early inception. He supports the view that computer-assisted navigation ensures a more predictable result through enhanced precision in positioning and balancing the joint. Overall this should lead to a better, more stable and more predictable outcome and potentially increased mechanical longevity of the implant.
The use of sensors is revolutionizing the method by which knee implants are inserted into the body. Through the use of embedded pressure sensors and accelerometers into trial components, it is now possible to quantify and validate the pressure loads and the mechanical alignment instantaneously at the time of surgery.
OrthoSensor, Inc is a leading developer of such sensor technology with the VeraSense smart tibial trial system. Dr. Meere is a member of the Surgical Advisory Board and an investor/developer in the company. His special interest and background experience in the biomechanical field has led him to found and co-direct with Prof. Peter S. Walker the independent Advanced Arthroplasty Research Laboratory (AARL) at the NYU Langone Hospital for Joint Diseases Musculoskeletal Research Center.
The mission of the AARL research projects is to develop the unexplored field of pressure mapping technology and knee kinetics to create new industry calibration standards and surgical algorithms for better knee implantation.
For multiple reasons, knee implants can fail. Some failures are the product of prolonged use with a mechanical breakdown of the more fragile elements such as the polyethylene plastic liner, which substitutes for the cushioning of natural cartilage, while some other failures are the product of instability or infection. In cases of instability, there is now a new tool to better assess the source of the problem: Kinetic analysis. Dr. Meere’s research efforts center on this new approach to better understand and quantify the effect of soft tissue imbalances on the function of the knee. Numerous cases are now salvageable by this non-invasive approach. Cases that would traditionally require a full revision with the dismantling of the hard metallic components from the bone, with a commensurate risk of fracture and damage, can now be successfully revised with preservation of the implant and recalibration of the soft tissue envelope. This naturally provides a much shorter and less painful recovery.
Complex deformities are typically referred to as tertiary university centers. Over the last twenty years, Dr. Meere and other seasoned colleagues in pediatric and plastic reconstructive surgery have had the opportunity of handling these very difficult, yet so rewarding cases. Typical examples include pediatric deformities and their adult consequences, severe bone destruction though osteomyelitis infections, and traumatic injuries.