This document discusses total knee arthroplasty (TKA) for valgus knees. It defines valgus knee deformity and classifications. The lateral parapatellar surgical approach is described as advantageous over the medial parapatellar approach for valgus knees, avoiding additional soft tissue releases. Key challenges include lateral femoral hypoplasia, externally rotated tibia, and lateral tibial defects. Surgical techniques involve lateral releases and pie crusting to balance the knee in extension and flexion. Complications can include common peroneal nerve palsy and hindfoot deformities requiring correction.

1. TKA : Valgus knee
Dr Aditya Apte
Arthroplasty Fellow

2. • 1. definition
• 2. classification
• 3. surgical approach / technique
• 4. complications

3. • Birth – varus – resolves by 3 years
• 3y – Valgus - resolves by 10-12 years
• Normal HKA angle 1.5 deg valgus – 3 deg varus
• 8-10 % of all TKA

4. Etiology
• Post traumatic
• RA
• Metabolic – rickets , renal osteodystrophy
* epiphyseal dysplasias

5. Krackow et al -
• I – lateral femoral bone loss
• lateral tissues contracted
• medial tissues intact

6. • II – lateral tightness + medial laxity

7. • III- severe valgus + malpositioned joint line
• secondary to proximal tibia osteotomy

8. Ranawat et al – 2005 jbjs
I - <10 deg valgus , minimal soft tissue stretching
II - > 10 deg valgus , significant soft tissue stretching , MCL functional
III - severe osseous defect
post HTO
incompetent medial sleeve

9. Lateral subluxation
Femoral hypoplasia

11. Challenges -
• Approach
• Lateral femoral hypoplasia
• Externally rotated tibia
• Lateral tibial tuberosity
• Lateral central tibial defect ( contained )

12. Surgical technique : LPa vs MPa
• Keblish 1990

15. • “ medial dissection is unnecessary and contraindicated “
• Medial displacement of patella – IR of tibia – P/L corner is visualized
clearly
• 94 % success rate at min 2y follow up
• Significant advantage – no additional lateral release required

16. Which is better ??
• Sicot 2015
• 424 knees ( valgus upto 10 deg )
• 109 medial ; 315 lateral
• Lateral – functional scores were better at 1y

17. 79 knees + rol
• Lateral approach :
• Better correction of deformity
• Less need for constrained
implants

18. 48 cases
• WITHOUT tto
• Release ITB in all cases
• Post op flexion at 1 y was 123
deg vs 108 deg in MPA

19. Changes in femoral preparation:
Medial entry
Lateral hypoplasia

20. VCA :
• 503 knees over 6 years
• VCA should be individualized for each case
• For varus knees: 5-7 deg
• For valgus knees : < 5 deg

21. Lateral cut : 0-3mm
medial cut < 8mm

23. • 28 stabilizers
• Superficial : IT band , lateral
gastroc.
• Middle: lateral retinaculum, PF
ligament
• Deep : LCL, popliteus

24. • LCL , Popliteus – both
E + F
• ITB , P/L Capsule –
extension

27. Ranawat et al..inside out
lateral pie crusting
PLC release

29. Frontal cut Axial cut
Sagittal cut , 5mm thick,
LCL insertion
Distalize

30. Single cut ,
sagittal plane
Navigated

31. >10mm medial laxity : medial advancement /
constraint implant

33. Patella maltracking :
• No thumb technique
• Grades :
• 1- normal
• 1a- near normal
• 2- tilted
• 3- subluxated
• 4- dislocated

35. Lateral retinacular release :inside out

37. Cpn palsy :
3-3.5 %
avg. 1.39cm from tibia

39. Predisposing factors :
• Valgus > 18 , FFD > 15
• Postop epidural analgesia
• Previous neuropathy , RA
• Constrictive dressings
• Tourniquet > 120mins

40. • 50% recover spontaneously
• Flexion + removal of constrictive dressings
• Steroids +/-
• Nerve decompression +/-

41. Hind foot alignment :
• Normal hindfoot valgus – 3-6 deg
• Knee varus : hindfoot eversion
• Knee valgus : ….inversion ( tolerated poorly )
• Flexible – orthosis
• Rigid – corrective osteotomy

43. Thank you.