Revision TKR: Why Knee Fails Basic Surgical Principles Dr.Sandeep Agrawal Agrasen Hospital Gondia Maharashtra India Infection,Quadriceps Rupture,Loosening,Periprosthetic Fractures,Patellar Maltracking,Constrained Prosthesis Rotating Hinged Prosthesis

1. 1
Why TKR Fails:
Revision Total Knee Replacement
Basic Principles
Dr.Sandeep Agrawal
Agrasen Hospital
Gondia
Maharashtra
India
drsandeep123@gmail.com

2. Why Knees Fail
1. Infection
2. Extensor lag
3. Stiffness
4. Tibio-Femoral Instability (Collateral Lig. Incompetence)
5. Fracture
6. Loose of femur or tibia (or progression of disease in uni
knee)
7. Patella instability & Malrotation
8. Breakage
9. Pain- No Diagnosis

3. Why Knees Fail
Infection
!
Standard work up including bloods, aspiration, nuclear
scans
!
Two - Stage Revision

4. Why Knees Fail
Extensor lag
!
Quads rupture probably best treated with allograft.
!
If superimposed infection may need an arthrodesis

5. Why Knees Fail
Stiffness
Global
Flexion contracture
Poor flexion
!
Need to address Quads scarring and balance Flex & Ext gaps

6. Why Knees Fail
Tibio-Femoral Instability
If ligaments are present, they must
be correctly tensioned and
balanced by choosing the correct
prosthesis size and positioning it
correctly.
In many cases, constraint will not
be necessary.
If the ligaments have failed, a
constrained implant still needs
perfect alignment

7. Why Knees Fail
Fracture
!
Commonly of the femur in the supracondylar region.
Risk factors include:
i) osteopenic bone,
ii) a notch in the anterior femoral cortex,
iii) poor flexion.
!
Can be successfully reconstructed with refined techniques
of internal fixation.
!
In others, however, the bone quality is so poor that revision
knee arthroplasty with distal femoral allograft or prosthetic
replacement is essential.

8. Why Knees Fail
Loose femur or tibia
!
Radiolucencies
Subsidence
progression of disease in uni knee

9. Why Knees Fail
Patella instability & Malrotation

10. Why Knees Fail
8. Breakage
!
!
9. Pain- No Diagnosis

12. Principles of Revision
1. Diagnosis
2. Revise… don’t repeat
3. Use Revision Implants
4. Complete Revision
5. Couple tibia to femur
6. Medullary Fixation
7. Control Alignment

13. 3 Step Technique
1.Tibial platform
!
2. Knee in Flexion:
Femoral rotation
!
B. Femoral component size
!
C. Joint line
!
3. Knee in extension

14. !
Couple the tibia & femur
!
Soft tissues
!
Is constraint required?

15. Exposure
Attention to detail
!
• Synovectomy
• Re-establish gutters
• Lateral retinacular release
• Liberate quads from femur
• Gentle manipulation
• Quads split

16. Removal
1. Oscillating saw
2. Reciprocating saw
3. Stacked osteotomes

17. Implantation
!
Tibial with stems.
!
Knee in Flexion
A. Femoral rotation
B. Femoral component size
C. Joint line
!
Knee in extension (tension ligaments)

18. Step 1
Re-establish Tibial Platform

19. Step 2:
Stabilize Knee in Flexion
!
Rotation: Transepicondylar axis
!
B. Stability: Femoral component size
!
C. Joint Line: Inferior pole patella

20. Femoral Component
sizing
Implant to restore ligaments (LCCK)

21. Extension Gap position
Flexion Gap Size
Femur controls the soft tissues

22. Femoral Component
sizing
• Augments to fit bone

23. Joint Line :
Inferior pole patella above Joint Line

24. Step 3
Stabilize in Extension
Distal defect defined

25. Constraint
!
!
Constraint should only be used in revision
total knee arthroplasty after the principles of
extension, flexion gap and medial and lateral
collateral ligament balancing are performed.

26. Constraint
!
As little constraint as possible should be used.
!
If stability cannot be obtained progressive levels of
constraint should be tested and used in the revision
construct.

27. Constraint
!
If there is functional loss of the medial or lateral
collateral ligament or if there is an inability to balance
the flexion or extension gap, a constraining condylar
device that provides varus valgus stability should be
used.

28. Rotating Hinge
!
!
Rotating hinged implant should be considered
when both collateral ligaments are
incompetent because of massive femoral bone
loss and in the elderly patient with genu
recurvatum

29. 95% BW is
loaded through
the condyles
BW load does not shift
posteriorly through full ROM
Shear forces are reduced
with rotation platform

30. Dislocation
!
“RHK designs with a short,tapered central rotating stem should be used
with caution in patients with bone and soft tissue compromise that may
allow excessive distraction and implant dislocation.” (JBJS March 2003)

31. LEARNING MESSAGE
Establish the cause for failure
Have revision implants
Adequate exposure and removal
Build the knee from the Tibia
Femur controls tissue tension and joint line
Use more constraint if needed
Rotating Hinge for gross instabilty and bone loss

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