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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
High tibial osteotomy
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.
High tibial osteotomy
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
Lateral close wedge osteotomy
A. line of incisionB. Transverse guideC. Transverse osteotomy D. Oblique osteotomy
Lateral close wedge osteotomy
E. Placement of plateF. Compression clampG. Slow compressionH. Fixation of plate
Lateral close wedge osteotomy
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
Lateral close wedge osteotomy
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
High tibial osteotomy
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
High tibial osteotomy
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
Principle Of Correction For Monocompartmental Arthritis Of The Knee
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
Principle Of Correction For Monocompartmental Arthritis Of The Knee
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
Principle Of Correction For Monocompartmental Arthritis Of The Knee
Varus deformity + fixed flexion deformityThe definition of FFD is radiologic
Cause of FFD Sagital malrotation Cyclops lesion (stem of ACL) Osteophytes Abnormal femoral notch
Principle Of Correction For Monocompartmental Arthritis Of The Knee
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*
Principle Of Correction For Monocompartmental Arthritis Of The Knee
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
Principle Of Correction For Monocompartmental Arthritis Of The Knee
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
Principle Of Correction For Monocompartmental Arthritis Of The Knee
Varus deformity + ACL deficiancyNormal tibial plateau 10* posterioly tilted (PPTA = 80*)
80*
Principle Of Correction For Monocompartmental Arthritis Of The Knee
Varus deformity + ACL deficiency
Due to ACL deficiency, tibia subluxate anteriorly in each step
Principle Of Correction For Monocompartmental Arthritis Of The Knee
Varus deformity + ACL deficiency
T/t of MCOA with ACL deficiency Eliminate the posterior tilt of plateau ( PPTA = 90*) in combination with valgus osteotomy .
Principle Of Correction For Monocompartmental Arthritis Of The Knee
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 + lateral subluxation and medial plateau depression
Principle Of Correction For Monocompartmental Arthritis Of The Knee
Varus deformity +Rotational deformity
• Osteotomy with internal tibial tibial torsion
Principle Of Correction For Monocompartmental Arthritis Of The Knee
• Varus deformity +Rotational deformity
• External rotation deformity present with patellofemoral maltracking.
Principle Of Correction For Monocompartmental Arthritis Of The Knee
• 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