Total Knee Replacement BRINA, PAIGE, TYLER, & EMANUEL
Did you know…?Walking generates a force
of up to 3x the body weight upon the knee.
Running can produce a force of 10x the body weight upon the knee.
Going down stairs can put 5x the force of normal body weight on knees.
The Knee
The knee is the largest and most complex joint in the human body.
Hinge joint- only one direction of movement.
Some rotation is also permitted.
Bony Anatomy Knee joint
Femur Tibia Fibula Patella
Soft Tissue Anatomy
Articular Cartilage Menisci- absorb shock Lateral Collateral Ligament & Medial
Collateral Ligament- stability Anterior Cruciate Ligament & Posterior
Cruciate Ligament- stability Synovial Fluid- lubricates the joint to
eliminate friction
Cartilage Breakdown
Intact cartilage allows knee to function with smooth motion.
Breakdown results in narrowing of joint space, bone spurs, and/or damage to surrounding soft tissue structures.
What caused the joint to become diseased? Osteoarthritis
Rheumatoid arthritis
Osteoarthritis Normal wear and tear of
a joint. Causes:
Age Injury Weight Stress on joint Poorly formed joint
Rheumatoid Arthritis Chronic inflammatory
disorder that affects the joints.
Autoimmune Risk factors:
Age Sex Family History
What can be done for the knee? Indications for a total
knee arthroplasty are: To eliminate or reduce
pain Improve functional
activities Correct deformity
Contraindications include:
Active or recent septic arthritisA “nonfunctioning extensor mechanism or severe neurologic dysfunction that prevents extension or control of the kneeNeuropathic joint
Preparing for surgery
o Pre-Operative Evaluationo Pre-Admission Testingo Scheduling of Surgeryo Medication Adjustmentso X-Rays, possibly an MRIo Anesthesiology Preparationo Option for Blood Bankingo Education on TKRo Muscle Strengtheningo Mental Preparation
Surgical Procedure A vertical incision is
made down the knee to gain access to the surgery site.
For a traditional surgery = 8-10 inches long
The patella is exposed The surgeon rotates
the patella away from the knee to enable admission to the inner tissue of the knee.
Surgical Procedure Femur is exposed and surgeon is able to
carefully remove the area of damaged bone and cartilage.
Once the bone is resurfaced, the surgeon fits the metal femoral component of the implant. Cementless = porous-coated and allows
surrounding bone to grow into and adhere to prosthesis (direct biologic fixation).
Cement = most common due to better survival = ~15 years
Hybrid = advancing approach- cemented tibial component, noncemented femoral component Young, active patients at highest risk for
component loosening.
Surgical Procedure The tibia is rid of all
damaged bone and cartilage. The surgeon fits the plastic
and metal tibial components. The tibial tray is fitted to the
tibia (usually using bone cement).
Polyethylene insert is placed between femur and tibia to act as a buffered articulating surface and to provide support.
Surgical Procedure Before replacing
the original patella, the surgeon may cement an additional component to the backside of it in order to ensure a proper fit with the rest of the implant.
Total Knee Replacement= Total Knee Arthroplasty
Possible ComplicationsSide effects from anesthesiaBlood clotsInfectionComplications from a transfusionAllergy to metal componentsWound and bleeding complicationsNerve or neurovascular damageKnee stiffness or loss of motionProsthesis problems and implant failure
Outcomes of Surgery 99.96% of patients
survive this surgery. 84% are living 10
years after the surgery.
1% get a postoperative infection.
Less than 2% acquire blood clots.
About 85% of implants still work after 20 years.
Prognosis Most people who undergo a
TKR are between the ages of 50-80 years, with the average being about 70 years of age.
Short-term results are excellent. Most patients can stand, with limited weight-bearing, the day after surgery.
With exercise, maintaining a healthy weight, protection against infection, and avoidance of high impact sports, long-term results are optimal.