Cemented or non-Cemented or non-cemented fixation: an cemented fixation: an

issue?issue? David BeverlandBelfast N Ireland

PROGRAM VOCA LUSTRUM CONGRESS KNEE ARTHROPLASTY

SEPTEMBER 15th – HUIS TER DUIN – NOORDWIJK AAN ZEE

I have used cemented and I have used cemented and cementless LCS Rotating cementless LCS Rotating

Platforms extensivelyPlatforms extensively

So looking at my results should demonstrate if there

are any issues

First of all Ten year results of First of all Ten year results of cemented LCS rotating platformscemented LCS rotating platforms• I started doing LCS RP in Oct 1993• At that time all were cemented• I have never resurfaced the patella as a primary procedure• By the end of 1995 I had done 600• We have now looked at the results of these first 600 consecutive cases• Average age 70.82 years, Range (45 – 89)• Female = 389 Male = 211 • 135 (22.5%) patients (160 knees) deceased• 465 knees reviewed at the clinic or by phone• The fate of every implant is known

Revisions

• Patella resurfaced in 9 patients• One lateral femoral condyle collapsed – revision of

femoral component• One deep infection - revised Dec 1995• One loose Tibial component - collapsed on the medial

side - revised on Nov 95• One of the 9 patellar resurfacings done in 1997 went on

to a full revision in Feb 03 for ? Infection still same pain -

Other re-operations or visits to the operating room

• Two open reductions for spinout

• Eleven MUAs for stiffness (1.83%)

SurvivorshipSurvivorship• 95.6% had no further visits to the operating room for any

reason relating to their knee (includes 11 MUAs)

• 97.5% had no further surgery on their knee (excludes 11 MUAs)

• 99.3% still had their original components either at the time of death or at a minimum follow-up of 10 years

• So the cemented LCS rotating platform works well• What about the cementless LCS?• By Jan 1998 I had done >1100 cemented LCS

Then in January 1998 Then in January 1998 I moved to all cementlessI moved to all cementless

• This was also a change from the LCS Classic to the Universal – same geometry

• The main reason I changed was because cementless was faster to do and therefore I could increase my volume

• And I knew from my good friend Karel Hamelynck that his results of cementless were very good

Date of surgery

1: 06/01/98

2: 10/06/98

3: 12/08/98

4: 08/09/98

5: 10/09/98

6: 10/10/98

7: 19/01/01

Fractures of the proximal tibia

First

Last

Jan 1998

Day 2 Day 5

So what had changed?Was anyone else seeing this?What were the risk factors?

So what had changed?So what had changed?Was anyone else seeing this?Was anyone else seeing this?

• I met Fred Buechel and Karl Hamelynck at the end of September and beginning of October 98

• Fred said he had never seen this early complication. But he commented on the poor bone quality in the examples I showed and said he would use a long stemmed tibial component in such bone

• Karl said he had never seen this and he would pack graft into the proximal tibia in such bone

PublishedJournal of Arthroplasty 2001; 16: 984-990

Case ReportsCase Reports

• Preoperative deformity: 4 valgus1 varus2 neutral

• All female average age 76 (69-83), 5 OA, 2 RA

• All 7 patients underwent primary LCS TKA without cement fixation of the tibial tray

• Day 2 radiographs were satisfactory

• All collapsed into varus

DEXA ResultsDEXA Results

• No more osteoporotic than other Irish females**Donne et al, Irish Med J 3:92, 1998

• In normal subjects medial tibial condyle more dense than lateral

• In Varus knees medial even more dense - therefore generally safe

• In valgus knees lateral more dense and medial relatively osteopaenic - therefore greater risk of medial collapse when deformity corrected and the maximum load is medial

• Preoperative valgus deformity or neutral alignment associated with a highly significant risk of fracture (p=0.0012)

ConclusionsConclusions

• In female patients

• With a preoperative valgus deformity or neutrally aligned knee reinforce proximal tibia

• Options are to use cement, bone graft or a stem

• For some years I changed my practice to use cement in Females with valgus or neutral knees

Then in 2001 the LCS Then in 2001 the LCS complete was launchedcomplete was launched

• In Belfast we did the post marketing surveillance study for this modified implant

• A prospective, non-comparative study to evaluate the performance of the LCS Complete rotating platform total knee system using cementless porocoat fixation

• The LCS complete had the same patello-femoral and tibio-femoral articulation as the original LCS

• Number of refinements

No change in femoral geometry but dimensions changed

Condylar width reduced- less over hang

BigImprovement

Patello-femoral flange 5mm longer

Initially one new tibia and femur now Initially one new tibia and femur now the Duofix option has a full range of the Duofix option has a full range of

half sizes in the Tibiahalf sizes in the Tibia

•Size 1•Size 2•Size 2.5•Size 3•Size 4•Size 5•Size 6

Femoral Components

•Small•Small+•Medium•Standard•Standard+•Large•Large+

TibialComponents

LCS complete studyLCS complete study

• The patient cohort consisted of 233 patients • who were all recruited to the study in 2002 • and now have a minimum follow-up of 5 years • The mean age at surgery was 73 years, (range, 39 – 90)

• 152 females - 94 males • The diagnosis was primary osteoarthritis in 94% cases • The fate of every implant is known

LCS complete studyLCS complete study• 32 (13.7%) patients were deceased at the time of their 5-year review

– all died with a functioning TKR in situ • 162 patients (69.6%) have been reviewed to date - 137 in person at

a clinic and a further 25 have been assessed by telephone review, as they were too ill or unwilling to attend

• 39 (16.7%) have still to be seen at a clinic – again all have been contacted by phone and have no reported problems with their knee

• Mean pre-operative Oxford score was 45.7• Mean 60-month Oxford score was 24

LCS complete studyLCS complete study

Surgical complications requiring a further visit to the operating room to date

• 4 knees (1.7%) required further surgery - All 4 were infected knees that had a washout and intravenous antibiotics

• None of these 4 knees to date have had removal of implants as a result of the infection

• After a minimum follow-up of five years

LCS complete studyLCS complete study• To date there have been no revisions of any components for

any reason and none are planned

• On the five-year x-rays there has been no evidence of osteolysis or wear although there are radiolucencies especially under the tibial tray

• This is a well recognised finding with the LCS cementless RP

• Does not appear to have clinical significance but does not look good

LCS complete studyLCS complete studyIn particular as compared to our previous problems there were:-

• no spinouts

• no cases of secondary patellar resurfacing

• no cases of tibial subsidence

• no MUAsWith regard to tibial subsidence I no longer use cement in soft bone I just use

bone graft – same as Karel Hamelynck

MUAs were 1.85% for 10 year results now 1% so I should have had 2 cases

So what about the spinouts and patellar resurfacings?

500

1000

0

1500

2000

2500

3000

3500

4000

93 94 95 96 97 98 99 00 01 02 03 04 05

Years

Num

ber

of p

roce

dure

s

First

575

10 Spinouts out of 900

Cases - 1.1%

Change inpractice

3 Spinoutsout of 3025 cases

0.1%

My experience with Rotating Platform Spinouts

Summary - Rotating Platform spinoutsCORR 425: 207-211; Aug 2004

• Generally caused by Surgical error

• Which usually produces Flexion Gap Instability

• Leave the collateral ligaments alone! 9 of the 13 were valgus

• Seldom a problem in mild deformity

• Management should notnot involve major revision

• Ideally should be treated closed - cast in extension for 8 weeks

• Is generally not recurrent

• 2 recurrent dislocations out of 4500 cases (0.04%)

Why is spinout more common in valgus knees

LATERAL SIDESlack in flexion

Popliteus

LCL

Gastrocnemius

Flexion gap

Normal ligamenttension

What about patellar resurfacing? What about patellar resurfacing?

In my series of 600 cemented LCS knees I had 9 cases of patellofemoral resurfacing

I then had a further 4 cases giving me a total of 13 cases of secondary patellar resurfacing

I had none in this series Why?

Results of 13 resurfaced patientsResults of 13 resurfaced patientsAt 3 month reviewAt 3 month review

• 7 patients improved• 4 patients no better but not worse• 2 worse (1 had delayed wound healing)

So well worth doing!

In April 2003 we reviewed the In April 2003 we reviewed the thirteen resurfaced patientsthirteen resurfaced patientsOne patient died at 3 monthsOne patient died at 3 months

• Follow-up 9 to 78 mths (Avg 37.4 mths)

• 3 patients improved (38, 15 and 10 mths)

• 6 patients no better but not worse

• 3 worseHas lost 4 stone in weightHas lost 4 stone in weight

Back to original symptoms

Category 1- 4

1 - Very happy

2 - Happy

3 - OK (not perfect)

4 - Never Happy

So l have patients with anterior knee pain on whom I don’t re-operate!

Category 1- 4 Number of Total KNEES at 10 years = 440

1 - Very happy

2 - Happy

3 - OK (not perfect)

4 - Never Happy

Category 1-4 Number of Total HIPS at 10 years = 565

1 - Very happy

2 - Happy

3 - OK (not perfect)

4 - Never Happy

KNEES

HIPS

Category 1- 4 Number of Total KNEES at 10 years = 440

1 - Very happy 17 (3.86%)

2 - Happy

3 - OK (not perfect)

4 - Never Happy 29 (6.59%)

Category 1-4 Number of Total HIPS at 10 years = 565

1 - Very happy

2 - Happy

3 - OK (not perfect)

4 - Never Happy

KNEES

HIPS

Category 1- 4 Number of Total KNEES at 10 years = 440

1 - Very happy 17 (3.86%)

2 - Happy

3 - OK (not perfect)

4 - Never Happy 29 (6.59%)

Category 1-4 Number of Total HIPS at 10 years = 565

1 - Very happy 309 (54.69%)

2 - Happy

3 - OK (not perfect)

4 - Never Happy 6 (1.06)

KNEES

HIPS

Further developments in fixation Further developments in fixation LCS complete - DUOFIXLCS complete - DUOFIX

• The LCS complete family also includes a Duofix option which combines porocoat and hydroxyapatite

• The aim of Duofix is to further improve cementless fixation

• In particular to eliminate the radiolucent lines that are often seen below the tibial tray with porocoat only fixation

LCS Complete - DUOFIXLCS Complete - DUOFIX

• At the end of 2006 we therefore embarked on a prospective, randomised controlled single blinded study

• With the LCS complete duofix tibia being compared to the standard tibial component with porocoat – same femur

• 100 patients in each group• Essentially to see whether the radiolucent lines are abolished and

whether there is less pain in the first few months because of more rapid bony ingrowth

• The definitive results will not be available until 2008.

So cemented or cementless – So cemented or cementless – why are the results so good in why are the results so good in terms of loosening and wear?terms of loosening and wear?

• Traditional theory of LOW CONTACT STRESS

• S2 curve

• Congruent 0-30 degrees

• Large surface area

Mean Wear Rates

Transactions of 50th Annual Meeting of the Orthopaedic Research Society,

Vol. 29, San Francisco, California, March 7-10 2004.

Linear wear is much less than multi-directional!

Fixed bearingMultidirectional motion of femoral component

relative to bearing

RP Mobile bearingBearing rotation decoupled:

Linear rotation at tibial counterface with reduced

rotation at femoral counterface

Wear in Fixed vs Rotating Platform

The LCS Rotating Platform reduces wear and cross shear by decoupling multidirectional motions to more linear motions at two interfaces

Cemented or non-cemented Cemented or non-cemented fixation: an issue ?fixation: an issue ?

No major clinical issuesAlthough there are radiolucent lines under the tibial tray

with porocoatThese may be addressed by Duofix

But porocoat is more expensive and duofix is even more expensive!

In the future I think we should strive for BETTER FASTER CHEAPER

Thank you