New techniques and concepts in total knee replacement.

Knee replacement constantly is evolving, changing, and improving. Despite the fact that it already is one of the two most successful surgical procedures in the history of orthopaedics (the other being THR) orthopaedic surgeons, bioengineers, and materials specialists continue to develop improvements that will make the benefits of knee replacement available for younger and more active patients, and for patients with special needs. This symposium will discuss some of these new cutting edge technologies, their potential benefits, and potential downsides. Minimally-invasive surgery has become the mantra of surgeons in many subspecialties. There is no doubt that the smaller the incision, the less soft tissue that is disrupted, and the faster the potential for healing. For example, I have been using a minimally-invasive approach to knee replacement with a skin incision of 8 to 10 cm and a minimidvastus approach that does not disrupt the major part of the suprapatellar pouch (Fig 1), and which is done without having to evert the patella. Using smaller instruments, it has become possible to safely and to accurately do knee replacement through such small incisions (Fig 2). I have found that in a review of 45 patients operated on using this system, that the amount of analgesics required in the postoperative period is diminished by approximately 40%. The rapidity of regaining flexion, as shown in Figure 3, has increased as compared with the traditional incision, the blood loss has decreased, and all of these have been obtained while maintaining correct radiographically documented orientation of the implants, and without increasing the surgical time. Patients rehabilitate faster resulting in a diminished hospital stay. Thirty years ago, the image intensifier revolutionized the field of fracture fixation. Can computer-assisted instrumentation do the same for TKR? Computerized surgery may require imaging (fluoroscopic or CT) or may be imageless. What is its accuracy, and what are the logistic constraints attendant to its use? Do the constraints outweigh the potential benefits? My experience in image-guided and imageless computer-assisted surgery has indicated that for the obese patient, the patient with tibial or femoral bowing or with severe deformity, and for patients having revision surgery, surgical navigation can increase the accuracy of the operation. Therefore, should it be used in all patients, or only occasionally? If patients with successful knee replacements are asked what one factor they would like to see improved, almost all will say that they would like to have full motion. Full motion is a relative CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Number 416, pp. 151–153 B 2003 Lippincott Williams & Wilkins, Inc.