Osteotomy for Varus Malalignment
Luís Eduardo P. Tírico, MD
Attending Physician, Knee Surgery
Orthopedic and Traumatology Institute
University of São Paulo, Brazil
Tibial Osteotomy
• Medial Osteoarthritis
– Biological alternative to knee replacement
– Active patients
– Relatively young
– Does not preclude a future arthroplasty
• Symptomatic articular cartilage injuries and ligament reconstruction
– Protect repair
– Neutralize axial load
Tibiofemoral
– Progression of OA (18 months)
• Medial - 4x higher with > 2° Varus
• Lateral – 5x higher with > 2° Valgus
• Malalignment > 5° = greater
deterioration
Sharma et al. JAMA 2001
Importance of Alignment
Varus Malalignment Osteotomy
Indications for HTO:
- Mild to moderate medial OA
- Varus osseous malalignment
- Focal medial cartilage lesion
- Ligament reconstruction
- Menical repair or transplantation
- Patients desire to remain active; refusal of arthroplasty
Meidinger G et al. KSSTA 2011
Prodromos CC, Amendola A, Jakob RP.. Instr Course Lect. 2015
Noyes, F. Knee Disorders 2016, 2ed
Where to?
OA Cartilage
Lesion
Focal chondral lesion (treated)
Large degenerative lesion
Extensive Meniscectomy
Osteoarthritis
Where to correct?
Gomoll, A. 15 CBOT,
2014
Neutral alignment
Overcorrect 1-2°
Overcorrection (Fujisawa)
Clinical Evaluation
- Gait (Dynamic
component – thrust)
- Ligament laxity
- Full limb aligment - Supine
- Double leg stance
- Single leg stance
Wang et al. 2016
Preoperative Planning
• Identify source of malalignment
• Decide on femoral or tibial osteotomy
– Default is tibia in most cases
• Choose type of osteotomy
• Determine magnitude of correction
– Fujisawa point (30-40% lateral midpoint)
– Jakob modification (correction based on amount
cartilage remaining on medial side)
– Customized
• Choose type of fixation
Fujisawa et al. Orthop Clin North Am. 1979
Jakob and Murphy. Instr Course Lect, 1992
Bugbee WD.. 12 CBCJ , 2012
Varus Malalignment Osteotomy
- Opening Wedge - Puddu
- Medial
- Graft
- Easier, more precise
- Closing Wedge - Coventry
- Lateral
- Fibula osteotomy, release TF
- Dome - Bigger deformities
- Supra tuberosity
- Infra tuberosity
Preoperative Planning
6º 8º
47o Problem of Euclid The Pythagorean Theorem
How big is my wedge?
8º
How big is my Wedge?
91mm
Correct for
magnification 91mm – 11% = 81mm
Magnif.
Correct for
ligament
laxity, if
present
1 degree = 1 mm not for everyone!
Preoperative Planning
56mm – 1º = 1mm
81mm – 1º = X
Dome Osteotomy
15º Varus right
knee
Left size =
15mm Puddu
plate
Estimated
wedge 20mm
Preoperative Planning
Sagittal Plane
• Tibial Slope
• Increase: ACL Strain
• Decrease: PCL Strain
• Ligament Status (ACL, PCL)
• Simultaneous ligament reconstruction
• Increase in tibial slope:
• Most commom technical error
• Benefit of navigation
• Nha et al. AJSM 2016 – Meta-analysis • OW – increase 2º, CW – decrease 2º
4º
2º
• Estimate alignment
• Not very accurate
• Straight line
• Rotation sensitive
• Underestimate correction
if ligament laxity
Intraoperative Planning
Alignment
Rod Bovie Cord
Intraoperative Planning
Navigation - Mechanical alignment
- Posterior slope
46 patients total
Under 0,5º - 6 patients - 13.0%
0,5º<x<1.5º - 9 patients – 19.6%
1.5º<x<2.5º - 17 patients - 37.0%
Over 2.5º - 14 patients – 30.4%
Preop Planning vs Navigation
Demange MK, Tirico LE et al. Simultaneous anterior cruciate ligament reconstruction and computer-assisted open-
wedge high tibial osteotomy: a report of eight cases. The Knee. 2011; 18: 387-91
Knee, 2011 • Prospective Study – HTO + ACL reconstruction (Anthony Plate)
• Radiographic Long Limb X-Rays preop vs Navigation alignment intra-op
• Postop Mechanical Axis (Mean) – 1.2º (SD 1.04º)
• Tibial slope
• Preop – 8.8º (SD 3.2º)
• Postop – 9.4º (SD 2.4º)
• Comparison estimated wedge vs used wedge (9 surgeons)
• 27% wedges ≤ 1mm
• 53% wedges 2 ≤ x ≤ 4mm
• 20% wedges ≥ 5mm No difference
≤1mm
2≤x≤4mm
≥5mm
Opening Wedge Technique
• Small incision
• Single osteotomy
• Precise correction
• Corrects medial tibial deformity
• Preserves bone stock
• Simultaneous cartilage repair
and ligament reconstruction
• Defect management can be an
issue
Opening Wedge Technique
Types of Grafts
Bone graft (Auto or Allograft)
✔ Osteoconductive, osteoinductive, osteogenic properties, easy access
✖ Increase operative time, donor site morbitity
Synthetic bone substitute (Hydroxyapatite, β-tricalcium phosphate, both)
✔ Easy access
✖ Resistance to compressive loads, difficult to evaluate bone consolidation, biological degradability, cost
PRP and BMAC
✔ Bone graft augmentation, alone
✖ Cost, time to consolidate
D’Elia et al. Cartilage.2010
HTO – Bone graft vs PRP
Complications
Lateral cortex
fracture
Intra-articular fracture
Sagital alignment
Complications
Results of HTO
Results of HTO
• HTO is useful in managing medial compartment OA
and cartilage lesions
• Correct preoperative planning is extremely important
• Some kind of intraoperative alignment verification
• Favorable long-term clinical outcomes
Summary
Thank you
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