- Slides: 15
Knee Arthroplasty By: Simranjit Rekhi
History of Knee Arthroplasty • Arthroplasty of the knee was first performed in the late 1960 s • With improvements of arthroscopes and higher-resolution cameras, – the procedure has become highly effective for both the accurate diagnosis and proper treatment of knee problems
Who gets this surgery? • People to experience severe pain in the knee – Restricting ordinary activities of daily living • People usually over 65 that have knee cartilage wearing away • 600, 000 people worldwide have knee replacements every year.
Significance of a Knee Joint • Knee is that largest joint in the body • Upper and lower leg bones are joined by a complex array of ligaments, tendons, muscles and cartilage • Kneecap, or patella, which serves as a bony fulcrum for the knee muscles to slide over and amplify strength and torque – knee can not only bend and flex, it can twist and rotate
Knee Anatomy • Hyaline cartilage - Thick cushioning (cartilage) covers and protects the ends of your bones. • Meniscal cartilage or meniscus, acts like a shock absorber between the bones and keeps the knee joint stable by spreading out the load evenly across the joint • Articular cartilage, a smooth substance that cushions the bones and enables them to glide freely
What causes Knee Arthroplasty • Torn meniscal cartilage • Loose fragments of bone or cartilage • Abnormal alignment or instability of the kneecap • Inflammation of the Synovial membrane – Fluid lubricates knee (reduces friction) • Torn ligaments, including the anterior and posterior cruciate ligaments.
Osteoarthritis • The cartilage that protects and cushions the knee joint breaks down over time. • Bone surfaces rub against each other – Damage to tissue and bone
Knee Arthroplasty Procedure
Non-Constrained Knee Replacement • The artificial components inserted into the knee are not linked to each other • Rely exclusively on the body’s muscles, ligaments, and tendons to keep the kneecap in place. • no stability built into the system. • Most common type of replacement
Constrained Knee Replacement • Used when the knee is highly unstable and the person's ligaments will not be able to support the other type of knee replacements • Severely damaged knees • The two pieces are connected with a hinge-like device that keeps the joint in-line and helps support the kneecap's proper alignment and function. – Though It doesn’t last as long as the other knee replacements
Unicondylar Knee Replacement • It is performed if the damage is limited to one side of the joint only with the remaining part of the knee joint being relatively spared • The incision is only three inches compared to 8 inches for a total knee replacement • Less invasive and more successful
Post Surgery • Physical Therapy • Gradually return to normal activities – Walking, climbing stairs – No running, playing tennis as it may wear the artificial joints • Doctors recommend a CPM (Continuous Passive Motion) – It slowly and smoothly bends and straightens your knee • Stationary Bicycle – regain strength in knee and leg muscles • Swimming
Different models of Knee Replacements • Stryker & Wright Medical Technology Inc. produce metal implants made from nickel chrome alloys – Though there is toughness in these systems, they tend to roughen and scratch over time Scorpio NRG Knee Flexed ™ ADVANCE STATURE® Knee Scorpio TS Revision Implants Front View ™ Triathlon PS Knee System ™
Continued… • Smith & Nephew Orthopaedics – enhanced the Genesis II and Profix, to Oxinium – Durability – Reduced the rate of polyethylene wear by 85% – 93% survival rate 10 years after surgery PROFIX™ GENESIS II ™
Websites used • • • http: //www. ehealthmd. com/library/totalkneereplacement/TKR_types. html#non http: //en. wikipedia. org/wiki/Knee_replacement http: //emedicine. medscape. com/article/1250275 -overview http: //arthritis. webmd. com/knee-replacement-surgery http: //orthoinfo. aaos. org/topic. cfm? topic=a 00299 http: //physicianlink. uams. edu/casestudies/csknee. asp http: //www. ehow. com/about_5501233_semi-constrained-knee-replacementinformation. html http: //www. physicaltherapyweb. com/news/wpcontent/uploads/2010/02/total_knee_arthroplasty_200. jpg http: //www. medcompare. com/spotlight. asp? spotlightid=55 http: //www. stryker. com/enus/products/Orthopaedics/Knee. Replacement/Primary/Scorpio. NRG/index. htm# http: //global. smith-nephew. com/master/OXINIUM_GENESISII_PROFIX_22462. htm http: //global. smith-nephew. com/us/PROFIX_TOTAL_KNEE_SYSTEM_2972. htm