Total knee arthroplasty (mechanical alignment) скачать в хорошем качестве

Total knee arthroplasty (mechanical alignment)

General information Medical experts: Mikko Rantasalo (orthopedic surgeon) Name of procedure: Total knee replacement (TKR), Total knee arthroplasty (TKA), knee replacement Goal of operation The goal is to replace the distal femur and proximal tibia with a prosthesis to restore the function of the knee. In addition, the goal is to align the prosthesis with the mechanical axis of the limb. Problem Wear of articular knee cartilage causes pain and/or restriction in range of motion, significantly reducing the patients' quality of life. Diagnosis Osteoarthritis of knee (ICD-10: M17)  Short pathophysiological description Knee osteoarthritis causes the cartilage on the knee to wear down. This leads to bone-on-bone contact, causing inflammation, pain, swelling, stiffness, and difficulty in movement.   Though nonoperative treatment methods are preferrable, the natural course of chondral damage is to advance in time. Possible deformities develop because of the osteoarthritis. In total knee arthroplasty, the damaged parts of the knee joint (distal end of the femur, proximal end of the tibia, and sometimes part of the patella) are replaced with prostheses. These prostheses are designed to mimic the function of a healthy knee, reduce pain, and improve mobility.  Potential pitfalls Insufficient understanding of knee biomechanics and procedure goal Most challenges are related to implant positioning which are again related to rightly placed and angled saw cuts. Understanding the basic principles of mechanical alignment and how the anatomical axis of the femur and tibia are related to the mechanical axis are crucial for avoiding complications. Additionally, the rotation of the implant in relation to landmarks, such as the transepicondylar line are critical to understand to avoid malrotation of the components. It is critical to achieve a properly balanced knee which mainly achieved through well planned and executed saw cuts. It's important to check the saw cuts before doing any soft tissue releases/balancing. If the stability isn’t restored with additional cuts, then soft tissue releasing might be needed. Sometimes asymmetricity occurs despite perfect bone cuts due to soft tissue imbalance. Incorrect site of incision  If the incision is made too laterally, extensive dissection of subcutaneous tissue attached to the patellar tendon is needed to reach the medial border of the patella.  If the incision is made too medially, extensive dissection of subcutaneous tissue attached to the vastus medialis is needed to reach the medial border of the patella.  Make sure to place the skin incision over the patella, slightly medially from the midline to get adequate visibility of the medial border of the patella for the arthrotomy.  Careless tissue handling Extensive dissection of the subcutaneous tissue can produce problems with circulation and thus wound healing. Make sure to position the incision correctly to reduce the amount of subcutaneous dissection.  Inadequate placement or lack of retractors can lead to soft tissue damage during the saw cuts. Ensure that the retractors are correctly placed to protect all surrounding structures during saw cuts. Otherwise neurovascular structures such as the popliteal artery and common peroneal nerve or ligaments such as MCL and LCL may be damaged. If using the tourniquet the recommendation is to use 100 mmHg above systolic pressure max 90-120 minutes to avoid possible nerve damage.  Incorrect sizing and alignment Incorrectly sizing or aligning the components can lead to instability, limited range of motion, early wear, patellar maltracking and luxation and potential failure of the prosthesis. Preoperative planning and precise surgical techniques are crucial to avoid these issues. 00:00 Intro 01:48 Patient positioning, anesthesia and preparation 02:56 Landmarks and incision site 04:07 Skin incision and advancing to the fascial layer 05:49 Exposure of the joint 10:42 Determining the angle of the distal femoral cut 14:46 Distal femoral cut 16:13 Rotation and size anterior and posterior cuts 19:29 Anterior, posterior and chamfer cuts 22:15 Exposure for the tibial cut 24:47 Angle, slope and thickness of the tibial cut 28:41 Tibial cut 30:18 Preparations for the component trialing 34:03 Initial assessment of the balance 34:40 Inserting the trial components 37:51 Trialing 41:14 Preparing for final components 43:55 Cementing and implanting 51:00 Closure More information on this procedure and other full content items can be found at www.osgenic.com #orthopaedics #ortho #surgery #totalkneereplacement #totalkneereplacementsurgery #kneesurgey