1. Valgus TKA: Balancing Technique
Michael Zlowodzki MD
University of Minnesota
Department of Orthopaedic Surgery

2. HPI 66 y/o male 5 year h/o L knee pain
Tried NSAIDS, Steroid injections,

3. Physical Exam Apparent valgus deformity ROM:
Stable to v/v stress; not correctable
Cms intact

6. 17° combined left knee valgus
11° in femur
6° in proximal tibia

8. VALGUS KNEE: Classification
Type 1: Minimal valgus with medial soft-tissue stretching
Type 2: >10° with medial soft-tissue stretching
Type 3: Severe valgus after prior osteotomy with incompetent medial soft tissue envelope

9. TECHNICAL ASPECTS
Medialize intramedullary alignment guide by 5-10 mm (because valgus deformity is at midshaft femur level)
Overcorrect by setting the valgus angle of the guide to 3° instead of 6°
Align the distal femur cutting guide parallel to the epicondylar axis (instead of posterior condyles)

12. Deformity correction
Stability

13. Too vigorous soft tissue releases might require more constraint implants

14. AFFECT FLEXION AND EXTENSION EQUALLY
Structures that origin close to the epicondylar axis of femur
LCL (slightly more effective in extension)
Popliteal tendon (slightly more effective in flexion)
Posterolateral corner capsule (slightly more effective in extension)
AFFECT FLEXION AND EXTENSION EQUALLY

15. WHITESIDE BALANCING TECHNIQUE
Popliteus tendon
Lateral collateral ligament
Posterolateral corner capsule
Illiotibial band

16. Tight in extension only
IT band (is parallel to joint line in flexion, so it wouldn’t make sense to release it if there is tightness in flexion)
Lateral posterior capsule

17. Illiotibial band

18. Lateral posterior capsule

19. 24% instability N=83 with >10° valgus Min. f/u: 10y Release:
Lateral retinaculum and iliotibial band
When necessary detaching the lateral collateral ligament and popliteus tendon from the femur
24% instability

20. N=35 with >10° valgus
Min. f/u: 5y
0% instability !

21. RANAWAT BALANCING TECHNIQUE
1) TIBIA CUT FIRST
2) EXTENSION GAP BALANCING: SOFT TISSUE RELEASES
3) FLEXION GAP BALANCING: ADJUST FEMUR CUTS

22. EXTENSION GAP BALANCING
Release of posterolateral capsule
Pie-crusting of the iliotibial band

24. FLEXION GAP BALANCING
Adjust external rotation of femur cutting block based on lateral and medial gap

25. POTENTIAL DOWNSIDE OF FLEXION GAP BALANCING BY ADJUSTING FEMUR CUTS
Anterior femur notching - as you adjust the position of the cutting block based on posterior gap
Patella maltracking - as you rotate the cutting block to make the medial and lateral flexion gap equal. - In a valgus knee that shouldn’t be a problem as you would externally rotate the block to make the medial and lateral flexion gap equal. External rotation might actually improve patella tracking. - In a varus knee that might be a problem as you would internally rotate the cutting block to make the medial and lateral flexion gap equal. Internal rotation of the femur component however may cause problems with patella tracking.

27. WATCH OUT FOR PERONEAL NERVE FUNCTION !!!
POST-OP
WATCH OUT FOR PERONEAL NERVE FUNCTION !!!