The surgery involves exposure of the front of the<unk> , with detachment of part of the quadriceps muscle (vastus medialis) from the patella. The patella is displaced to one side of the joint, allowing exposure of the distal end of the femur and the proximal end of the tibia. The ends of these bones then are cut accurately to shape, using cutting guides oriented to the long axis of the bones. The cartilages and the anterior cruciate ligament are removed; the posterior cruciate ligament also may be removed but the tibial and fibular collateral ligaments are preserved. Whether the posterior cruciate ligament is removed or preserved depends on the type of implant used, although there appears to be no clear difference in<unk>  function or range of motion favoring either approach. Metal components are then impacted onto the bone or fixed using polymethylmethacrylate (PMMA) cement. Alternative techniques exist that affix the implant without cement. These cement-less techniques may involve osseointegration, including porous metal prostheses. Finally, stability and range of motion are checked, followed by irrigation, hemostasis, placement of hemovacs, and closure. Femoral replacement A round-ended implant is used for the femur, mimicking the natural shape of the joint. On the tibia the component is flat, although it sometimes has a stem that goes down inside the bone for further stability. A flattened or slightly dished high-density polyethylene surface is then inserted onto the tibial component so the weight is transferred metal to plastic, not metal to metal. During the operation any deformities must be corrected, and the ligaments balanced so the<unk>  has a good range of movement, and is stable and aligned. In some cases the articular surface of the patella also is removed and replaced by a polyethylene button cemented to the posterior surface of the patella. In other cases, the patella is replaced unaltered.Model of total<unk>  Technology In recent years, there has been an increase in technology assistance with implantation of total<unk> s. Traditionally,<unk> s were performed using mechanical jigs, not unlike those used in carpentry. These mechanical jigs rely on vision and human judgment. Using computer assistance to provide navigation, navigated<unk> s provide assistance in more accurate placement of implanted<unk> s based on mechanical axis. While these implants are placed more accurately, there has not been much improvement in long-term outcomes. Similarly, sensor-based guidance provides accurate feedback to demonstrate soft-tissue tension to assist in guidance of insertion of<unk> s. Robotic-assisted<unk> s take into account both mechanical axis and soft-tissue balancing in order to assist the surgeon in placement of a<unk> . Short-term outcomes of robotic-assisted<unk> s are promising. Post-operative pain control The regional analgesia techniques (neuraxial anesthesia or continuous femoral nerve block or adductor canal block) are used most commonly. Local anesthesia infiltration in the pericapsular area using liposomal bupivacaine provides good analgesia in the post-operative period without increasing the risk for instability or nerve injury. A combined approach of local infiltration analgesia and femoral nerve block to achieve multimodal analgesia is common. Modified intervastus approach Introduced in 2018, a modified intervastus approach to the anterior<unk>  may be used for total<unk>  arthroplasty. The procedure is intended to preserve the quadriceps tendon and vastus medialis. Tourniquet use The current body of evidence suggests if a tourniquet is used in<unk>  surgery, it probably increases the risk of severe side effects and postoperative pain. The evidence did not show any clear benefit on patient function, treatment success or quality of life.
Knee replacement
Joint replacement
Ankle replacement
Unicompartmental knee arthroplasty
Finger joint replacement
Shoulder replacement
Hip replacement
Arthroplasty