total knee arthroplasty

Question 1

Overview
Q: What is total knee arthroplasty?

Answer 1

A: Removal of the proximal and distal joint surfaces of the knee and replacing them with an implant.

Question 2

Q: What is the most common reason for total knee arthroplasty?

Answer 2

A: Advanced arthritis of the knee.

Question 3

Classification
Q: How is total knee arthroplasty classified by compartments replaced?
.
.

Answer 3

A:

Unicompartmental: Replaces medial or lateral joint surface.
Bicompartmental: Replaces the entire surface of the femur and tibia.
Tricompartmental: Includes the femur, tibia, and patella

Question 4

Classification
Q: How is total knee arthroplasty classified by implant design?

Answer 4

A:

Unconstrained: No inherent stability, relies on soft tissue.
Semiconstrained: Offers some stability without compromising mobility (most common).
Fully constrained: Provides the most stability but restricts motion, leading to higher stress on the implant.

Question 5

Surgical Techniques
Q: What is the benefit of minimally invasive total knee arthroplasty?

Answer 5

A:

Smaller incisions (3-5 inches vs. 8-12 inches).
Less soft tissue trauma.
Minimal quadriceps damage.
Stronger initial quadriceps contraction.

Question 6

Surgical Techniques
Q: Why is quadriceps strength important after knee arthroplasty?

Answer 6

A: Weakness is correlated with an increased risk of falling.

Question 7

Fixation Methods
Q: What are the methods of fixation for total knee arthroplasty?

Answer 7

A:

Cemented (most common).
Uncemented (bone ingrowth).
Hybrid.

Question 8

Fixation Methods
Q: What factors influence the type of fixation chosen?

Answer 8

A: Patient activity level, co-morbidities, life expectancy, and femoral component fit during surgery.

Question 9

Complications
Q: What are potential complications of total knee arthroplasty?

Answer 9

A:
Deep vein thrombosis.
Infection.
Pulmonary embolus.
Peroneal nerve palsy.
Restricted range of motion.
Periprosthetic fractures.
Chronic joint effusion.

Question 10

Etiology
Q: What conditions are commonly associated with the need for total knee arthroplasty?

Answer 10

A: Osteoarthritis and osteomyelitis.

Question 11

Signs and Symptoms
Q: What are the symptoms before surgery?

Answer 11

A:
Severe pain with weight bearing.
Loss of mobility.
Gross instability or limited range of motion.
Marked knee deformity.
Failure of non-operative management or prior surgery.

Question 12

Treatment
Q: What is the initial focus of physical therapy post-surgery?

Answer 12

Decrease inflammation.
Adhere to knee precautions.
Minimize muscle atrophy.
Regain full passive range of motion.

Question 13

Treatment
Q: What degree of knee flexion is needed for daily living and sitting comfortably?

Answer 13

A: 90 degrees for daily living; 105 degrees for sitting comfortably

Question 14

Treatment
Q: What activities are included in advanced therapy?

Answer 14

A: Wall slides, controlled lunges, stationary cycling, and step-ups.