Updated HTO vs UniKnee for Postgraduate Orthopaedic Course in Newcastle March 2015

OA in the ‘Young”

HTO & Uni Knee

Professor Deiary Kader

Consultant Orthopaedic & Trauma Surgeon

Knee Surgeon

Newcastle Nuffield Hospital

Postgraduate OrthopaedicsFRCS(Tr&Orth) Revision Course

Newcastle Upon Tyne 16-21 March 2015

•

Professor Deiary KaderConsultant Orthopaedic & Trauma Surgeon

Knee Surgeon

Nuffield Hospital Newcastle

NGMV Charity

PostGrad Orth Deiary Kader

HTO vs Uni??

What is the outcome of HTO and Uni?

What do you require for a successful

osteotomy?

PLAN

Varus OA in the Young

Must Know

What is the

None-operative

Treatment for OA?

OA Nonoperative treatment

Strategies may include

Weight loss

Exercise

Patient education

Analgesia, (NSAIDs)

Bracing

Intra-articular (IA) injections. Cochrane reviews

Steroids (better than placebo but not longer than 4wks

HA more prolonged effect than steroids

Weight loss causes a significant risk reduction of knee

OA in the general populationThe reduction was greater in severe symptomatic OA than in asymptomatic radiographic

OA

Meta-analysis of 47 studies involving 446000 pts

m,Muscle strengthening and aerobic exercises are effective in

reducing pain and improving physical function in mild to

moderate OA of the knee

A total of 180 patients with osteoarthritis of the knee were

randomly assigned to receive arthroscopic débridement,

arthroscopic lavage, or placebo surgery

Population was older male veterans

The prevalence of mechanical symptoms was not provided

Malalignment was not reported

OSTEOTOMY

9

Osteotomy

around the knee

Aims of valgus osteotomy

Unload the medial compartment by slightly

overcorrecting into valgus

Unloading any ligament reconstruction in patients

with a varus thrust

To change the tibial slope in order to reduce

translational forces and improve AP instability

HTO for varus Malalignment


Lateral closed-wedge high tibial osteotomies have

been the treatment of choice since 1965

(Coventry, 1965).


OPEN Wedge HTO 1987

The open-wedge high tibial osteotomy

gained recognition after the encouraging

reports of (Hernigou et al., 1987).

Wedges of bone that were obtained from

the iliac crest were inserted into the

defect

Open W HTO

TOMOFIX

Proximal or High Tibial Osteotomy (HTO)

The IDEAL candidate for HTO

Age <60 years

Isolated medial OA

Good ROM

Less than 5° FFD knee

>120° flexion knee

Patients should be

able to use crutches

Have no major varicose veins or peripheral vascular disease

The International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine

PostG

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Distal Femur Osteotomy for

Valgus Malalignment

Lateral Open W DFO

Distal Femur Osteotomy

Valgus deformity of 12º or more needs distal femoral

varus producing osteotomy to address a lateral femoral

condyle deficiency and to prevent joint line obliquity and

gradual lateral tibial subluxation.

≈

Planning

Standing, long leg radiographs in neutral rotation

Measure the mechanical axis (normal = 1.2o varus)

Anatomical axis (60-70 valgus)

Measure the degree of deformity

& plan the size of wedge necessary

Planning

62.5% across tibial plateau from medial side

Final alignment should create 10º–13 valgus.

Overcorrection of 3º–5º above the 6º–7º normal valgus

angle

Medial tibial cortex represents the apex of the

bony wedge and should be left intact


Tibial bone varus angle

(TBVA) constitutional tibia varus malalignment when

the TBVA angle measured more than 5º

Mid TibiaEpiphysis

Compensating for Abnormal AP Laxity

ACL Rupture PCL Rupture


Compensating for Abnormal AP Laxity


Closed wedge HTOSurgical technique

Arthroscopy

Computer-aided measurement of the wedge size or

A 10-mm wedge excision leads to

10º corrections in 57-mm-wide tibia

An angular jig is more accurate

Closed wedge HTOSurgical technique

Curved incision from the head of the fibula to 2 cm below the tibial

tubercle. Peroneal nerve protected

Excise the bare area of the fibula head Or proximal tibiofibula joint

separated using a cob elevator

A calibrated osteotomy guide must be used for the bone cut

Leave 15–20 mm of tibial plateau to avoid fracture

Fix with a plate or staples

Rigid fixation+ early mobilisation eliminates patella ligament contracture

DVT prophylaxis similar to post TKR

Sulzer Orthopedics,

Zimmer



Fibular osteotomy, Separating tibiofibular joint

Contracture of the patellar tendon, patellar baja

leg shortening

High Tibial Osteotomy with a Calibrated Osteotomy Guide, Rigid Internal Fixation, and Early Motion. Long-Term Follow-up*ANNETTE BILLINGS, M.D.†; DAVID F. SCOTT, M.D.‡; MARCELO P. CAMARGO, M.D.§; AARON A. HOFMANN, M.D.§, SALT LAKE CITY, UTAHJ

Bone Joint Surg Am, 2000 Jan

Closed wedge HTODisadvantages

OPEN W HTO

Surgical Techineque

The MCL mobilize.

Two 2.5-mm Kirschner wires mark the oblique osteotomy

Starting proximal to the pes anserinus

4-5 cm distal to the joint line

The wires to the tip of the fibula 10-15mm

The osteotomy of the posterior two-thirds of the tibia

Leave a 10-mm lateral bone bridge intact.

Hinge on the lateral - not posterolateral - side of the tibia

The second osteotomy begins in the anterior one-third of the

tibia at an angle of 135° while leaving the tibial tuberosity intact




Lateral Open Wedge Distal Femur

single cut

easier approach to femur

easily adjustable correction

supratrochlear area disrupted

weak medial hinge point

plate location complaints

very unstable if hinge point fractures

slowest bone healing

role of grafts unclear

Methods of osteotomy Fixation

Cast immobilisation

Staples

Plate and screw

External fixator

Distraction osteogenesis. Correction can be

adjusted after surgery. But pin tracts create a

potential problem for subsequent TKA

Complications

Inadequate valgus correction

Overcorrection – PFJ derangement

Alteration in patella height

Intra-articular fracture

Osteonecrosis of the tibial plateau

Complications

Vascular injuries – anterior tibial artery, popliteal artery

Peroneal nerve palsy

Delayed or non-union

Compartment syndrome

TKR more difficult

Varus laxity (loose LCL)

Open wedge HTO Advantages

Easier to achieve precise angular correction

Preserves bone stock (subsequent TKR is technically easier)

Makes tightening of the MCL easier

Preserve the lateral side for LCL or posterolateral

reconstruction if insufficient

No risk to peroneal nerve

Less dissection

Requires a bone graft (substitute, autograft,

allograft)

Increased incidence of non-union and delayed

union

Large correction may affect leg lengthening

Loss of fixation and recurrence of varus deformity

Worsens patella Baja

Open wedge HTODisadvantages

OW-HTO

Delayed union/nonunion rates were 2.6%, 4.6%, and

4.5% for autograft, allograft bone, and synthetic bone

substitutes, respectively

Non-locking plates (n = 2,148) had a rate of delayed

union/nonunion of 3.7% and a mean loss of correction

over time of 0.5°

Locking plates (n = 681) had a rate of delayed

union/nonunion of 2.6% and a loss of correction of

2.3°.

Coventry report

Outcome

5-year survival of 87%

10-year survival of 66%

However the 5-year survival was reduced down to 38% when valgus angulations at 1 year was less than 8º in a patient whose weight was more than 1.32 times the ideal weight.

Outcome

Obesity and inadequate correction were

negative prognostic factors.

Age < 50 years to be a positive prognostic

factor

Joint line preservation is key to success.

OW-HTO vs CW-HTO

RCT 92 pts and 6 years FU

More Complications in open WHTO & more conversion to TKR in closed WHTO

SEPT 2014

Valgus high tibial osteotomy reduces pain and

improves knee function in patients with medial

compartmental osteoarthritis of the knee.

Principles

Uni Knee Appropriate for 25% of osteoarthritic knees needing

replacement

Never release the MCL

Polyethylene dislocation rate is 1/200 after medial

compartment UKR (Oxford)

Polyethylene dislocation rate is 10% after lateral

compartment UKR

Dislocation rate can be reduced by using a fixed

bearing UKR.

?

What are the Absolute contraindications

for Unicompartmental knee replacement?

What are the Advantages and

disadvantages?

Uni Knee Advantages

• Retains knee kinematics

• Restores function and range of movement

• Rapid recovery: 3X faster than TKR

• Less blood loss

• Cost less than TKR (all factors considered)

• Quicker operation than TKR

• Quicker return to work than after TKR

• High flexion lifestyle.

Uni Knee

Advantages

• Lower infection rate (halved) compared with TKR

• Allows minimally invasive approach

• Easier to revise than HTO?

• No patellar fractures or dislocations

• Maximises the longevity of total knee arthroplasty

• Reduced incidence of DVT

• Reduced mortality from pulmonary embolism

Prerequisites

Intact ligaments (especially ACL and PCL)

Correctable varus deformity

Less than 10° FFD

Flexion beyond 100°

Clinically asymptomatic PFJ and contralateral

compartment.

Contraindications

Inflammatory arthritis

Sepsis

Young age

High level of activity.

Relative contraindications

ACL degeneration

Chondrocalcinosis

Lateral meniscectomy

Osteonecrosis

Combined obesity and small bone

size in some women.

Management options for medial

compartment OA

HTO suitable for high-demand, young

patients

UKA (better functional results, much

better 10-year survival – 98% versus

66%)

THANK YOU

Health & Medicine

Updated HTO vs UniKnee for Postgraduate Orthopaedic Course in Newcastle March 2015