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