Knee Arthroplasty By: Simranjit Rekhi

History of Knee Arthroplasty Arthroplasty of the knee was first performed in the late 1960s 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 http://www.webmd.com/hw-popup/knee-replacement-surgery

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 http://www.webmd.com/hw-popup/knee-replacement-surgery

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 TS Revision Implants Front View ™ Scorpio NRG Knee Flexed ™ ADVANCE STATURE® Knee 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=a00299 http://physicianlink.uams.edu/casestudies/csknee.asp http://www.ehow.com/about_5501233_semi-constrained-knee-replacement-information.html http://www.physicaltherapyweb.com/news/wp-content/uploads/2010/02/total_knee_arthroplasty_200.jpg http://www.medcompare.com/spotlight.asp?spotlightid=55 http://www.stryker.com/en-us/products/Orthopaedics/KneeReplacement/Primary/ScorpioNRG/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