Background

 

Young varus with OA                                       Failed medial OCD with varus

 

Indications 

 

Young active patient with

- medial compartment OA + varus malalignment

- medial cartilage restoration procedure with varus malalignment

- posterolateral instability with varus knee

 

Rationale

 

Provides realignment of limb

- reduces abnormal loading stresses on damaged cartilage and bone

- redistributes forces to unaffected lateral compartment

 

Contra-Indications

 

Lateral or PJF compartment OA

Inflammatory arthritis

Smoker

Obesity

Lateral subluxation of tibia >1cm

Fixed flexion deformity

Flexion < 120^o

Varus > 15°

Instability

 

Options

 

Lateral Closing Wedge HTO

Medial Opening Wedge HTO

 

Lateral Closing Wedge Osteotomy

Advantages	Disadvantages
Inherently stable	Technically more difficulty as two osteotomies
Higher union rates	Decrease proximal tibial bone stock Shortens leg
Better for larger corrections	Patella baja
	Disrupt proximal tib-fib joint and risk injury CPN

 

Medial Opening Wedge

Advantages	Disadvantages
Technically easier / single osteotomy	Relatively unstable
Maintains bone stock especially with larger corrections	Risk delayed / nonunion
Able to correct coronal and sagittal planes	Lengthens leg
Can adjust correction more easily	Risk lateral hinge fracture
No fibular osteotomy	May increase PFJ pressure with large corrections

 

Results 

 

Outcomes with medial OA

 

Dal Fabbro et al Arch Orthop Trauma Surg 2024

- systematic review of HTO for medial OA

- 18 studies and 1300 knees

- 75% 10 year survival

 

Coventry et al JBJS Am 1993

- 87 knees with varus OA, minimum 10 year

- valgus > 8^o: 87% 5 years and 66% 10 years survival

-  valgus angle < 8^o: 38% 5 year and 18% 10 year survival

 

Naudie et al CORR 1999

- minimum 10 year follow up 106 HTO

- patients < 50 years with flexion > 120^o: 95% 5 year, 80% 10 year, 60% 15 survival

 

Opening v Closing wedge HTO

 

Kim et al Sci Reports 2017

- meta-analysis of OW v CW with minimum 5 years

- no difference in 5 year survival

- OW: 92% 10 year survival

- CW: 85% 10 year survival

 

Duivenvoorden et al JBJS Am 2014

- RCT of OW v CW in 92 patients with 6 year follow up

- increased complications in OW

- increased conversion to TKA with CW (22%) compared to OW (8%)

 

Cazor et al KSSTA 2023

- 183 patients with minimum 10 years follow up

- conversion to TKA lower for opening wedge versus closing wedge

 

Computer navigation

 

Technique PDF

 

Wu et al Int J Surg 2018

- meta-analysis of computer navigated versus conventional HTO

- reduced outliers with computer navigation

 

HTO versus Unicompartment Knee Arthroplasty

 

Outcome

 

Zhang et al Ortho Surg 2023

- meta-analysis of 38 studies and 9000 patients

- UKA less pain, fewer complications, better outcome scores

- HTO better ROM and lower revision

 

Revision to TKA

 

 

Lee et al KSSTA 2023

- Korean database

- 10 year revision rate TKA: 2%

- 10 year revision rate TKA after HTO: 2%

- 10 year revision rate TKA after UKA: 4%