Update in Joint Replacement Surgery: What??s New ?

Since its invention more than a half century ago, total joint replacement surgery has become one of the most successful surgeries in orthopaedics. With advancing techniques, patients at younger and older age are benefitted from this surgery. The advance in fast-track surgery is unstoppable with the popularity of local infiltrative analgesics, blood saving surgery and even out-patient surgery. Patient satisfaction has become one of the most important outcome measures, and new measuring tools such as the Forgotten Joint Score have emerged. Despite this, there are still 15-20% of patients dissatisfied with their surgery. One of the main goals of recent research and development in joint replacement surgery is to tackle the dissatisfaction, particularly in knee replacement. Dissatisfaction could be caused by surgical technique and implant design. The last decade search for a perfect mechanical alignment by the use of navigation in total knee replacement has met some twists and turns. Newer targets could be patient-specific “kinematic” alignment or a deliberate varus alignment and the use of robotics may help not just in navigation but also in execution. New researches on the kinematic of a normal and replaced knee have raised some interest on knee prostheses which are aimed to reproduce normal kinematics. Examples are medial pivot knee, ultra-congruent insert and bicruciate-retaining or bicruciate-stabilized knee. Since more young patients are receiving knee replacement, there are recent researches on cementless tibial monoblock which has been designed for better fixation and implant longevity. Dislocation in total hip replacement is always a concern. One area of research is in the direct anterior approach. Despite the concern of possible higher intraoperative complication rate, there is increasing popularity of such surgical approach, particularly in US. Another area of interest is the spinopelvic sagittal balance. The research on this makes some rethinking on the conventional “safe zone” in acetabular cup orientation. The use of robotics may also help putting the cup in an optimum position with fewer outliers. How all these new interests translate into clinical benefits remain to be seen in a longer term.