1. Planning a total knee arthroplasty
Lecture
Edited and updated, April 2019 by PD Dr. med. Philipp v. Roth
AORecon Course—Principles of Total Hip and Knee Arthroplasty

2. Disclosure

3. Learning objectives Describe the principles of alignment
Describe the x-ray views to obtain
Recognize deformities/malalignment
Describe the steps in a total knee arthroplasty (TKA) templating

4. Gold standard?
90°
90° - 95°

5. Anatomical alignment Goal: tibial cut with 3°varus = medial slope
Why 3°medial slope at the tibia?

6. Gait cycle Standing on both legs
Weight bearing: centering of the leg under the upper body

7. Which x-rays?
Is appropriate planning possible?

8. Full-length hip-to-ankle AP
Which x-rays?
Navigation/PSI
Full-length hip-to-ankle AP
weight-bearing view

9. Which x-rays? Evaluation of ligaments?  AP stress view
Unicondylar vs bicondylar knee replacement
Reference:
Beaufils et al. The Knee Joint. ????
Beaufils et al

10. Which x-rays? Rosenberg view
Reference:
Melnic et al. A Systematic Approach to Evaluating Knee Radiographs with a Focus on Osteoarthritis. J Orthopedics Rheumatol. 2014;2(1): 6.
Melnic et al (J Orthopedics Rheumatol, 2014;2(1):6)

11. Which x-rays? Rosenberg view
Reference:
Melnic et al. A Systematic Approach to Evaluating Knee Radiographs with a Focus on Osteoarthritis. J Orthopedics Rheumatol. 2014;2(1): 6
Melnic et al (J Orthopedics Rheumatol, 2014;2(1):6)

12. Which x-rays?
Patella

13. Which x-rays?
Patella

14. Which x-rays? Important for planning and choice of implant design
Varus-valgus constrained:
Linked femoral and tibial components (hinged)
Prosthesis allows rotational stability

15. Deformity—intraarticular
Correction with bone resection

16. Deformity—extraarticular
No correction possible with a bone resection  ligament instability

17. Deformity—extraarticular
No correction possible with a bone resection
 ligament instability
Osteotomy with Center of Rotation and Angulation (CORA) method
TKA implantation: 1- or 2-stage procedure

18. Preoperative planning?
Cutting plane
Femoral valgus cut angle
Femoral entry point

19. Preoperative planning?
Cutting plane
Femoral valgus cut angle
Femoral entry point
Tibial slope
(posterior-cruciate retaining vs posterior-stabilized)

20. Preoperative planning?
Cutting plane
Femoral valgus cut angle
Femoral entry point
Tibial slope
(posterior-cruciate retaining vs posterior-stabilized)
Implant size

21. Take-home messages Anatomical alignment:
3° tibial varus cut = medial slope
X-ray views:
Full-length hip-to-ankle AP weight-bearing view
AP stress view
Patella view
Rosenberg view
Extraarticular deformity: no correction possible with bone resection  CORA method