Current conceptsCurrent concepts in in Unicondylar knee Unicondylar knee arthroplasty arthroplasty and and High tibial osteotomy High tibial osteotomy in management of in management of unicompartmental unicompartmental osteoarthritis of knee.osteoarthritis of knee.

Dr. Sushil Paudel

What is unicompartmental What is unicompartmental knee osteoarthritis?knee osteoarthritis?

What is unicompartmental What is unicompartmental knee osteoarthritis?knee osteoarthritis?

Any recommendations_ _ _?

Yes— the concept of anteromedial arthritis (White et al)-

•A pathologic entity arising in the setting of an intact ACL

What all surgical options do we have What all surgical options do we have for unicompartmental osteoarthritis for unicompartmental osteoarthritis of the knee?of the knee?

Arthroscopic chondral debridement.

Allograft/ autograft surface replacement.

High tibial osteotomy.Unicondylar knee

arthroplasty (UKA).Total (tricompartmental)

knee arthroplasty (TKA).

But why do not all knees need But why do not all knees need treatment?treatment?

?

Natural HistoryNatural History

1. Role of Alignment (Sharma et al, JAMA 2001, 286)

Varus Worsens the problem ◦ Odds for radiological progression increased 4

fold Severity of varus Directly Correlated to radiologic

progression

2. Baseline Stage of Disease (Cerejo et al, Arthritis Rheum 2003 Oct )

◦ K-L score 3 – Risk of progression 10 fold

Varus affects Damaged Knees more3. Dynamic Loading (Miyazaki et al, Ann Rheum Dis 2002 Jul)

Varus (Adductor Moment)=Progression

How do I proceedHow do I proceedBrief understanding of the

procedures.Long term results of each.Intertechnique comparision.Experts’ recommendations.

Brief overview of HTOBrief overview of HTOUsually done for medial

compartment knee osteoarthritis with varus malalignment.

Corrects the malalignment and redistributes the stresses relieving pain and restoring the function.

Types of upper tibial Types of upper tibial osteotomiesosteotomies

Lateral closing wedge osteotomyMedial opening wedge osteotomy

with bone graft.Dual osteotomy.Dome (barrel vault) osteotomy of

Macquet.Osteotomy using external fixators:

◦Ilizarov◦External fixators.

High tibial osteotomyHigh tibial osteotomy

Indications:◦ Classic: age <60 yrs.

varus <150

◦ Absolute: Diffuse osteoarthritis. Tibiofemoral

subluxation. Inflammatory arthritis. Menisectomy in the

compartment. Unrealistic patient.

• Relative:• Age >65 yrs.• Obese (>1.32X

ideal BW).• Poor ROM <900

• Non-specific knee pain.

• Contraindications:

Recommended principles Recommended principles Static and dynamic angle

measurement◦ Gait analysis

Is there IR/ER of lower extremity ? Does patient walk with additional varus / valgus

thrust during stance and acceleration phase?

Ligamentous laxityAnteroposterior instabilityPatient factors

◦ Height of patient!!

Salient features Salient features

Accuracy is the key

Precise planning.

Address ligament laxity.

Lateral closing wedge Lateral closing wedge osteotomyosteotomy

Jackson described the lateral closing wedge osteotomy popularised by Coventry

Lateral closing wedge Lateral closing wedge osteotomyosteotomy

Angle of correction:◦ Classical : Coventry suggested 1mm10

!!Not all patients have tibial width of 56

mm!!

◦More accurate measure is trigonometric

method:

Y=X tan (+b)Chao and Sim (1995) have developed OASIS (osteotomy analysis and simulation software) – for surgical planning of complex deformities.

Types of closing wedge Types of closing wedge osteotomyosteotomy

Above tibial Above tibial tubercletubercle◦ Large cancellous

surface◦ Close to

deformity◦ Time honored◦ Minimal learning

curve◦ Smaller incision

Behind tibial Behind tibial tubercletubercle◦ Stable fixation◦ No step off◦ Can displace tibial

tubercle anteriorly- Macquet effect on patellofem. arthritis

◦ No patellar tendon scarring

• Below tibial Below tibial tubercletubercle• Large proximal

fragment• Allows correction

in multiple planes• No bone removed• Minimal incision• No retropatellar

scarring• Normal Q-angle

Depending upon site of osteotomy - advantages compared.

Medial opening wedge Medial opening wedge osteotomyosteotomy

Closing vs. opening wedgeClosing vs. opening wedgeAdvantages:

◦ Time honored◦ Commonly

available jig◦ Higher union rate◦ Fixation covered

with soft tissue◦ Decreases tibial

slope

Advantages:◦ Easy exposure◦ No fibular

osteotomy required

◦ Options of fixation wide

◦ May increase MCL tension

◦ Restores bone stock

Ilizarov methodIlizarov method

Ilizarov methodIlizarov method

Opening Wedge - OrthofixOpening Wedge - Orthofix

Complications after HTOComplications after HTOUndercorrectionThromboembolic disease.Peroneal palsyNonunion.InfectionVascular injuryProblems inherent to internal fixation.Intra-articular fracture

The Skeptics sayThe Skeptics say

But even if you do an HTO,

7 years later,

an arthroplasty will be needed,

so don’t spoil the knee for the future!!

Long term result - HTOLong term result - HTONaudie et al, Clin Orthop 1999

Oct 10-22 year FU Closing wedge osteotomy

◦Probability of Failure ◦Age>50 years ◦Lateral thrust ◦Insufficient Valgus

80% survivorship at 10 years

Long term result - HTOLong term result - HTOSprenger et al, JBJS 2003, Mar 76 osteotomies Closing wedge with internal

fixation Mean FU 10.8 yrs

◦90% survivorship at 10 years ◦Femoro-Tibial angle 8-16 degrees

Long Term result - HTO Long Term result - HTO Choi et al, J Orth Sci, 2001

◦10-24 years Yasuda et al, Bull Hosp Jt Dis, 1991 ◦10-15 years

Aglietti et al, J Knee Surg, 2003 Jan ◦10-21 years Precise Restoration of Valgus Angle equals better survivorship

TKR after HTOTKR after HTO

Ideal HTO for TKR:◦Opening wedge osteotomy above the tibial

tubercle and the lax medial collateral ligament (MCL). Obviates the problems:

Patella infera Scarred patellofemoral ligament.

Lifts the medial tibial condyle. Tightens MCL.

Restores almost normal alignment in relation to tibial shaft.

TKR after HTOTKR after HTORitter et al

◦39 bilateral TKR ◦Avg 8 years after unilateral HTO

FU of 7 years ◦No difference in

Knee Score Function Score Xray

Ritter et al JBJS 2000, Sep

TKR after HTOTKR after HTO

20 patient TKR post HTO, 20 matched primary TKR

Mean FU 5 yrs TKA after HTO technically challenging

but No statistical difference in Functional

Scores

Karabatsos et al, Can J Surg 2002, Apr

HTO: problems of conversion

• Prior incisions • Hardware • Joint line distortion • Malunion / nonunion • Patella baja • Offset tibial shaft • Retropatellar tendon adhesions • Peroneal palsy • Infection

Deformity Tibial offset

Patellar distortion

Klinger et al

• Hemicallotasis in 22 cases, FU 16 m

• 79 days in fixator (2-4 m)

• 9% pin tract infection

• 9% hematomas (requiring surgery)

Klinger et al; AOTS 2001

Revision of HTO to TKR

• Jackson et al; Journal of arthroplasty 1994

• 30% serious complications • 20% deep infection after revision of HTO to

TKA

• Madan et al; Bull H J D 2003

• 29 HTO, 17% poor results • 21% of TKRs revised in < 8 y

TKR after HTO technically demanding, significant balancing problems, results inferior to primary

Conversion of HTO to TKR

• Technical difficulties & subtle clinical differences (Haddad JoA 2000)

• Results approach not equal those of primary (Katz JBJS 87)

• Technically more challenging, results inferior (Karabatsos Can JS 2002)

• No difference ( Meding JBJS 2000, Staeheli 87)

Unicondylar knee Unicondylar knee arthroplastyarthroplasty

A resurgence !

Unicondylar knee Unicondylar knee arthroplastyarthroplasty“Unicondylar”: refers to a device

with two components that resurface the tibiofemoral articulation.

“Unicompartmental”: refers to the philosophy of resurfacing only the medial or lateral compartment, with a unicondylar implant.Now used interchangeably !!! Why?

Unicondylar knee Unicondylar knee arthroplastyarthroplasty

Indications:◦ Classically: unicompartmental osteoarthritis of the

knee in a low-demand, elderly, thin patient (>60yrs) with:** competence of both the cruciates and collateral

ligaments**◦Currently accepted patient selection criteria

Patients >60 yrs <82 kg wt. Low level of activity Minimal rest pain. ROM- minimum arc of 900

Flexion contracture <50

Passively correctible angular deformity ≤ 100 varus or 150 valgus.

ContraindicationsContraindicationsGeneral:

◦ Age <60yrs.◦ Weight >95 kgs.◦ High activity level.◦ Patello- femoral pain.◦ Contralateral tibiofemoral joint arthritis:◦ Inflammatory arthritis.◦ Symptomatic ACL insufficiency.◦ PCL insufficiency.◦ Collateral ligament insufficiency.◦ Varus >150; valgus>150; flexion contracture >

100.

PrinciplesPrinciples

Anteromedial arthritisOsteonecrosis

◦ Presently indicated for osteonecrosis localised to subchondral bone.

Rheumatoid arthritis.◦ Best results when both compartments are

replaced (Kay and Martin; McIntosh prosthesis)

◦ Knutson reported increasing failure rates. Pain due to ongoing synovitis. Degeneration in C/L compartment.

**Currently not recommended**

PrinciplesPrinciples

Lateral vs. medial diseaseBoth can be treated.

◦Lateral prosthesis 5-15% only.◦Higher failure rate (Gunther et al, Ansari

et al) Dislocation of the bearing

? Due to variable elastic properties of MCL. Sloutions:

Lateral parapatellar arthrotomy. Release of popliteus tendon Increase height of posterior lip around meniscal

bearing.

Selected implantsSelected implantsMcintosh acrylic prosthesis (1950)

Mckeever prosthesis.St. Georg sledge (1960); {Waldemar link, Hamburg,Germany}Marmor modular UKA (1970’s) {smith and nephew, Memphis, In}Brigham (1974) {Johnson and Johnson, New Brunswick, NJ}Oxford mobile bearing prosthesis (1978) {Biomet, Warsaw, IN)Porous coated anatomic Knee (PCA knee, 1980’s) {Howmedica,

Allendale, NJ}Miller Galante UK system (Zimmer, Warsaw, IN)Repicci UKA prosthesis (Biomet) Interpositional implants

◦Unispacer interpositional knee prosthesis {Sulzer, Austin, TX}

Teflon↓

Titanium↓

Vitallium (1964)

UKA: Joint Preserving

• ACL & PCL, lateral meniscus retained • Minimal bone resection: 2-4 mm resected • No overcorrection – load sharing

Function

• Rapid recovery after minimally-invasive UKA

• Twice as fast as open UKA, thrice as fast as TKR

• Home in 24-48 h

• No difference in accuracy

(Price JoA 2001)

MIS UKA

Erect

Postop xrays

Results of UKA

Author No. FU y Survivorship Revised

Pennington ‘03 46 11 93% 2

Yang ‘03 47 10-15 95% @ 10y, 85% @ 15y

Argenson ‘02 147 3-10 94% at 10 y

Romanowski ‘02 136 Av 8 11

Squire ‘99 140 15-22 849% @22yr 14

Murray ‘98 143 Av 7 98% at 10 y 5

Cartier ‘96 60 10-18 93% at 10-12y

Swedish Registry, Lewold Acta 98

• 14,772 UKA

• UKA is ‘safe primary procedure, good patient satisfaction, range, pain relief and few serious complications’

Conversion of UKA to TKRConversion of UKA to TKR

Conversion of UKA to TKR

• Revision of UKA less difficult than revision of TKR (Chesnut CORR 91)

• As successful as primary if minimal resection initially; graft, cement, stems in 50% (Barrett & Scott JBJS 87)

McAuley et al

• 30 revisions of UKA to TKR • Autograft (not allograft) in 10, primary

femoral components in all; 25 CR • 14 stemmed tibial components; 8

wedges • Mean ROM 111 deg • Revisions ‘straightforward’

McAuley et al CORR 2001

The unispacerThe unispacer®®

Metallic tibial hemiarthroplasty.◦ Translates freely on tibial plateau as

determined by conforming articulation of its top surface with femoral condyle. NOT useful in lateral compartment OA

Femoral rollback causes posterior dislocation/ soft tissue impingement or both.

◦ Richard hallock showed overall 1yr revision rate to be 21%

50% higher than McKeever arthroplasty.

Eventual role uncertain (Scott R.D; CORR 416, 164-166;2003)

Benefits of UKA

1. Short hospital stay

2. Full range of motion

3. Speedy recovery and ability to walk unaided

4. Sit cross-legged and on the floor

5. Reciprocal stair-climbing, brisk walking, jogging, golf

6. Joint preserving minimally-invasive operation 7. Documented 10y success >90% 8. Future surgery facilitated, not compromised 9. Functional results are optimum and recovery

speedy 10. Cosmetically acceptable for isolated medial OA

So how do we decide?So how do we decide?

HTOUKA

UKA

UKAUKA

UKA

UKA

UKA

UKA

UKA

HTO

HTO

HTO

HTO

HTO

HTOHTO

HTO

HTO

HTO

Idealism for choosing Idealism for choosing treatmenttreatment

Proven Efficacy of Treatment◦ Pain relief: durable, predictable,

reproducible success rate◦ Preserve bone & tissues ◦ Should not compromise future Surgery ◦ Function optimal ◦ Recovery speedy ◦ Cosmetically acceptable

Infrastructure Training Cost Lifestyle

HTO: Long-term results

Author No. FU y Results

Vainionpaa 81 103 5-10 18% -> TKR @ 7y

Coventry 93 87 3-14 66% survival @ 10y

Holden 88 45 10 70% exc-good

Hernigou 87 93 10-13 45% exc-good @ 10y

Matthews 88 40 50% @ 5y, 28% @9y

Ritter 88 78 Survival 58% @15y

Insall 84 83 5-15 63%, 23%->TKR @ 9y

Aglietti et al

• 120 closing wedge HTO, 10-21 y FU • @ 15 y 49% exc-good, 51% fair-poor • 14% varus recurred, 19% patella baja • 1/3 revised to TKR @ 11 y • 96% @ 5y, 78% @ 10y, 57% @ 15y

Aglietti et al; J Knee S, 2003

Is there any direct Is there any direct comparison available?comparison available?

UKA superior to HTO

• Better results, less late deterioration

(Broughton JBJS 86) – extended study.

(Weale and Newman)

• Better gait velocity & muscle strength

(Ivarsson & Gillquist CORR 91)

• Better pain relief (Jackson JoA 94; Katz

JBJS 87)

Stukenborg - Colsman

7-10 y prospective, randomised study of HTO vs UKA • More intra- and post-op complications after

HTO • Survivorship @ 7-10 y:

• 77% UKA vs 60% HTO

Stukenborg-Colsman; Knee 2001

Is UKA that Is UKA that innocent?innocent?

#!@?

Can we revise HTO to Can we revise HTO to UKA?UKA?

NO{Rees et al; JBJS 2001}

HTO is a contraindication to UKA.

“Demanding

procedure, needs special expertise, risk of early failure” (Lindstrand JoA 2000)

Unicondylar knee arthroplasty

Unicondylar knee arthroplasty

• 10,474 UKA Swedish Registry (Robertsson JBJS 2001)

• ‘Long-term results related to number performed by the unit, probably expressing the standards of management in selecting patients and performing the operation’

Long Term Results - UKALong Term Results - UKA

• Patient Age – 60+ • i.e. TKR age

• Stress Very Strict Patient selection

• Stress Attention to alignment

The REAL DEBATEUKA vs TKA

• Patient Age – 60+ • i.e. TKR age

• Stress Very Strict Patient selection

• Stress Attention to alignment

The REAL DEBATEUKA vs TKA

TKR after UKA

• It’s a Revision • Significant

• Incidence of Bone loss • Requirement for Grafting • Requirement for wedge augmentation

• It’s a Revision • Significant

• Incidence of Bone loss • Requirement for Grafting • Requirement for wedge augmentation

Some questions Some questions unansweredunanswered1. Are there any specific

contraindications for UKA?◦ PCL deficiency◦ ACL deficiency:

ACL defeciency leads to early arthritic changes

Do not expect UKA to perform better in ACL deficient knee (Murray et al – showed inferior results)

Similarly avoid in cases of previous patellectomies.

Some questions Some questions unansweredunanswered

2. The amount of correction required.◦ Previously physiologic correction or slight

overcorrection recommended. Lead to early C/L compartment OA.

◦ So, now leaving slight varus recommended.

Ecker et al showed that one of the greatest risk factors for tibial component

loosening is residual varus.

So the question is what is the amount of correction required?

Some questions Some questions unansweredunanswered3. What configuration of implant is

optimal?◦ Barkel et al showed that stress in knee

prosthesis increases exponentially when implant <6mm. To accommodate > poly resect more. In metal back-up – still a thinner poly.

◦ Is this the Achilles heel of UKA?

Can stresses be reduced by using a conforming upper surface in a mobile

bearing implant? awaiting reply!

Some questions Some questions unansweredunanswered4. Does patient truly have

unicompartmental osteoarthritis?◦ Can clinical examination only be sufficient?

Does pain in C/L compartment C/I surgery? What about S/S referred to patellofemoral joint?Cartier et al performed UKA + PF replacement

abandoned for favour of TKA.

◦ Should arthroscopy be routinely done? Simultaneous arthroscopy! Arthroscopy done several weeks prior!

Some questions Some questions unansweredunanswered

MRI◦ No role in pre-op planning-

Overestimates ACL insufficiency and degree of OA (Sharpe et al; Knee 2001;8, 213-218)

Bone scan.Problem Not all patients have localised

degenerative arthritis to one compartment- they may be more marked in one!!

So, the question is – How many/ few degenerative changes can be accepted in

other compartments for which a UKA is indicated?

Are we overloaded ?Are we overloaded ?

The principle a surgeon The principle a surgeon should keep in mindshould keep in mind

“ An arthroplasty has an unknown but finite life whereas an osteotomy has the potential to last the patient a life time”

– Wagner H.

Any Indian perspectiveAny Indian perspectiveOsteotomy still relevant in third

world countries. Devgan et al: med J. Malaysia 2003 Mar; 58

(1); 62-8.

What the experts have to What the experts have to say?say?Factors assessed in deciding between

HTO and UKA◦ Age ◦ Weight◦ Occupation◦ Avocation◦ Range of movements◦ Deformity◦ Subluxation

What experts have to say?What experts have to say?Favour HTO in

◦Young, heavy, active (particularly male) with functional range of motion.

Prefer UKA in ◦An old, light, sedentary patient or a

middle aged female.Severe deficiency and

subluxation◦Do TKR.

ReferencesReferences1) Jamali A.A; The adult knee (vol I-II); Callaghan et al

eds; Lippincott- Williams-Wilkins Ist edition; 20032) Mckeever; CORR; 1960; 18; 86-953) Marmor L.; CORR; 1983; 94: 242-2484) Callaghan et al ; Instr course lect; 2001; 50: 431-

4495) Laskin R. S: CORR 2001, 392: 267-2716) Cartier et al : J Arth; 1996: 11; 782-7867) Ansari et al : Acta orthop scand 1997: 68: 430-4348) Scott R.D. JBJS (A) 1981; 63: 536-5349) Marmor et al: CORR: 1993: 294; 147-15310) Kozinn et al. JBJS (A) 1989; 71: 145-15011) Barnes et al: Instr course lect 1993; 42: 309-31412) White at al. JBJS(B); 1991; 73 582-586.

ReferencesReferences13) Sharpe et al :Knee 2001; 8: 213- 1814) Berger et al : CORR 1999: 367: 50-6015) Squire et al : CORR 1999: 367: 61-7216) Ohden et al: J. Arth.: 2001: 16; 196- 20017) Ansari et al: AAOS ; Atlanta 199618) Gunther et al : Knee 1996; 3; 33-3919) Ecker et al: J AAOS: 1994, 2: 173-7820) Weale et al : CORR; 1994; 302: 134-3721) Stuckenberg-Colsman et al : Knee 2001; 8: 187-19422) Rees et al; Orthop rev:1988; 17; 983-98823) Price et al: J. Arth: 16; 970-976.24) Ivarsson et al: CORR 1992: 279; 194-20025) Lindstrand et al: Acta orthop scand: 1992; 63: 256-

259.

ReferencesReferences26) Romanowski et al :AAOS; Dallas; 200227) McAuley et al: CORR 2001; 392: 279-28228) Bartel et al: CORR 1995; 317: 76-8229) Hyldahl et al: J. Arth 2001; 16: 174-17930) Dennis et al: JBJS (A); 2002; 83 (supple 2): 1104-

110531) Coventry: JBJS (A) 1973; 55: 23-4832) Jackson et al: JBJS(B) 1974: 56: 23633) Berman et al: CORR 1991; 272: 19234) Coventry et al: JBJS (A)1993; 75 (2): 196-20135) Aglietta et al: CORR 198736) Chao et al: Iowa orthop J.: 1995: 154-15837) Rudan et al: CORR 1991: 268:15738) Ritter et al: J. Arth :88: 3; 147: 309-311.

ReferencesReferences39) Wagner et al : Orthopade 1989: 118; 637-4640) Naudie et al: CORR 1999: 367 (3-8): 445-44941) Sprenger et al: CORR 1979:140: 103-10842) Broughton et al: JBJS 68B:447; 198643) Haddad et al: J. Arth: 2000 Aug; 15(5): 597-60344) Katz et al: CORR Apr 229: 1988; 193-6045) Meding et al: JBJS (A):2000 Sep; 82 (9); 1252-125946) Aglietti et al: J knee Surg: 2003 Jan; 16(1): 21-647) Jackson et al: J. Arth: 1994 Oct; 9(5); 539-54248) Sprenger et al: JBJS (A) May 2003: 85; 469-47449) Karabatsos et al: Can J Surg.: 2002 Apr. 45(2): 116-

950) Ritter et al: JBJS 2000: 82; 125251) Madan et al: Bull hosp. Jt. Dis.: 2002-2003, 61(1-2);

5-10