0fb9high tibial osteotomy

High Tibial Osteotomy

Principle Of Correction For Monocompartmental Arthritis Of The Knee

Suresh DhakarGMC, Kota(Raj)

High tibial osteotomy

• Established procedure for the t/t of unicompartmental OA knee

• Aim is unloading of involved joint compartment

• Preserve the joint and delay the need of TKR as long as possible

biomechanics

• Normaly medial plateau force is 70% in a single limb stance when the mechanical axis passes through the centre of knee .

• It is 95% , only 6* of varus and reduced to 50% with 4* of valgus and 40% with 6*of valgus.

biomechanics

Static analysis

Dynamic analysis

biomechanics

B, When genu varum presentC, When LCL laxity is present

biomechanics• Load transmission across knee can be altered by adjusting the location of

centre of gravity e.g.

Use of external supportPut upper body wt directly over affected limb

Gait modification Short stride length Toe out position in stance

biomechanics

•The best result from HTO obtained when the mechanical axis line passed through the 30% to 40% lateral tibial plateau

Fujisawa point


Indication• Monocompartmental OA of knee – MC

Contraindication Narrowing of lateral compartment joint space. Lateral tibial subluxation > 1 cm. Medial plateau bone loss > 2 or 3 mm. Flexation contracture > 15 *. Knee flexion < 90*. More than 20* of correction needed. Rheumatoid arthritis. Advanced age and obesity.


Four basic type of valgus proximal tibial osteotomy

1) Lateral close wedge osteotomy - Coverntry

2) Medial open wedge osteotomy - Hernigou

3) Barrel vault or dome osteotomy - Maquet

4) Medial opening hamicallotasis - Turi

Lateral close wedge osteotomyOsteotomy made proximal to the tibial tubrocity Normal alignment 5 – 8 * valgus

3 - 5 overcorrection done = 10 * valgus

Calculation of size of bone wedge

2 cm

Width of base = diameter X 0.02 X angle

Lateral close wedge osteotomy

Leaving a thin posteromedial lip of bone on the proximal fragment give added support and stability to the osteotomy


A. line of incisionB. Transverse guideC. Transverse osteotomy D. Oblique osteotomy


E. Placement of plateF. Compression clampG. Slow compressionH. Fixation of plate


Aftertreatment

• Passive knee motion 0-30* flextion +10* each day

• Ambulation (50% wt bearing)with crutches 6 wk

• Full weight bearing after 6 wks

• Removal of plate usually after 6 to 12 months


Advantage1) It is made near to deformity.

2) It is made through cancellous bone , which heals rapidly.

3) It permit the fragment to be held firmly in position by staples or plate and screw construct

4) It permits exploration of knee by same incision

Medial open wedge osteotomy

Indication• 2 mm or more shortening of involve limb• Laxity in MCL

Osteotomy proximal to tibial tubercle begins3.5 cm distal to the joint line

Barrel vault, dome osteotomy• More accuracy and readjustability of correction• Inherent stability• Allow postoperative readjustment in cast

Disadvantage Technically difficult Intraarticular fracture Scaring around patellofemoral ext. mechanism

Open wedge hemicallotasis• Osteotomy is done distal to tibial tuberosity• No patella infra or loss of proximal tibial bone• After osteotomy , it is progressively distracted to correct alignment

Schwartsman use llizarov techniqueDisadvantage– Poor pt acceptance– Pin tract infection

– Require close follow up

Open wedge hemicallotasisTuri use dynamic external fixator

A. positioning of fixatorB. provisionally fixed wit K wireC. proximal pin insertion D. medial & lateral pin

Open wedge hemicallotasis

E. Placement of distal pinF. attachment of guideG. Drilling at osteotomy siteH. Completion of osteotomy

Open wedge hemicallotasis

Aftertreatment Passive knee mobilization

0-45* from first day + 20* every day Pin tract care Distraction started after 7 day Locking after appropriate correction Removal of fixator usually after 12 wks

Open wedge hemicallotasis• Distracted 0.25 mm four time a day until correction achieved• High frequency gps 0.125 mm eight time a day show higher mineral

density

Advantage Little change in patellar tendon length and direction angle of the tibial

plateau

Superficial pin tract infection require local care and antibiotics


Complication• Recurrence of deformity• Peroneal nerve palsy• Nonunion, infection, knee stiffness or instability• Intraarticular fracture• Deep vein thrombosis, compartment syndrome • Patella infra • Osteonecrosis of proximal fragment


Classification of deformity in monocompartmental arthritis

1. Bone deformity of femur / tibia Varus ,valgus Recurvantum, procurvantum Torsion limb, length discrepancy

2. Joint deformity MCL laxity LCL laxity Plateau depression Patellar maltracking Flexion contracture


Varus deformity only• Centre of rotation of angulation (CORA) is

almost at the level of joint or just distal to it

Osteotomy proximal to tubrosity only angulation require

Osteotomy distal to tuberosity requires angulation + translation


Varus deformity only Close wedge HTO decrease distance b/w joint to tuberosity, making

further TKR more difficult.

Open wedge osteotomy tighten the lax MCL.

Osteotomy made distal to tuberosity have poor healing potential,preserve the periostium with minimal invasive approach


Varus deformity + fixed flexion deformityThe definition of FFD is radiologic

Cause of FFD Sagital malrotation Cyclops lesion (stem of ACL) Osteophytes Abnormal femoral notch


Varus deformity + fixed flexion deformity

FFD is an indication for arthroscopy combined with osteotomy

Mild FFD -

notchplasty & osteophytes resectionGreater * FFD –

distal femoral ext. osteotomy

90*


Varus deformity + MCL pseodolaxity Due to medial plateau bone loss

After osteotomy with lax MCL, pt c/o --“ wobbly feeling” -- cause of osteotomy failure

MCL ContractedLax

osteotomy does not further stretch

Osteotomy can be use to retention


Varus deformity + LCL laxity• Secondary to chronic stretching in a varus knee

Mild valgus osteotomy – no need of correction

LCL tightening1) Gradual transport of distal fibula

with a oblique osteotomy2) Fixing of head of fibula distally


Varus deformity + ACL deficiancyNormal tibial plateau 10* posterioly tilted (PPTA = 80*)

80*


Varus deformity + ACL deficiency

Due to ACL deficiency, tibia subluxate anteriorly in each step


Varus deformity + ACL deficiency

T/t of MCOA with ACL deficiency Eliminate the posterior tilt of plateau ( PPTA = 90*) in combination with valgus osteotomy .


Varus deformity + lateral subluxation and medial plateau depression

Treated by retensioning the MCL & LCL with osteotomy

If no plateau depression T/t-- Varus osteotomy of femur + valgus osteotomy of tibia

If plateau depression The knee is very unstable.If tibia reduce with valgus stress, indicating it would reduced with medial plateau elevation

Varus deformity + lateral subluxation and medial plateau depression


Varus deformity +Rotational deformity

• Osteotomy with internal tibial tibial torsion


• Varus deformity +Rotational deformity

• External rotation deformity present with patellofemoral maltracking.


• The incidence of HTO is decreasing• Biggest reason is economic• Joint replacement is akin to joint amputation. Once fail, it is a

disaster

• All pt with MCOA osteotomies first line procedure before uncondylar knee arthroplasty or TKR

T H A N K Y O U

0fb9high tibial osteotomy

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