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OrthopaediCStOdayEUROPE l
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Heario.com/Orthopaedics
COVER STORY
Active patients prefer total ankle arthroplasty,
but fusion is still indicated in many cases
continued from page 1
Jan-Willem K. Louwerens, MD,
president of the European Foot and
Ankle Society, performs 20 to 25 TAA
cases a year at St Maartenskliniek i n
Nijmegen, The Netherlands. According
• to Louwerens, there is no exact coimt of
how many TAAs are performed i n The
Netherlands because no register currently exists. Dan-Henrik Boack, MD, of the
Foot and Ankle Center Berlin, Germany,
told
ORTHOPAEDICS
TODAY
survivorship after Swedish orthopaedists
performed their first 30 cases.
Although TAA design improvements
were made after problems with the balland-socket ankle prostheses surfaced in
the 1970s, design is a factor that remains
EUROPE
he treats about 350 patients with ankle
arthritis each year and i n those he implants about 100 to 120 ankle prostheses.
Boack's practice includes patients from
Germany and elsewhere in Europe.
Obstacles to success
Hintermann, Louwerens, Boack and
Sunil Dhar, MS, MCh(Orth), PRCS,
FRCS(Orth), of Nottingham University
Hospitals "in Nottingham, United Kingdom, told ORTHOPAEDICS TODAY E U -
ROPE the TAA learning curve is steep and
an experienced foot and. ankle orthopaedist is essential to a successful outcome.
"If you do not balance the hindfoot, if
you do not understand what the muscles
are doing that are adjacent to the anHe,
your ankle replacement may have been
put in wonderfully, but it is likely to fail
because there are so many other things
• going on around it," Dhar said.
To learn the technique, Hintermann
recommends performing about 50 of
these procedures with an experienced
surgeon before attempting one. I n fact,
Henricson and colleagues who studied
531 TAA cases in the Swedish Ankle Arthroplasty Register reported increased
Talar cartilage loss a n d osteophytes in a varus arthritic anl<le required TAA (left). After
medial, lateral gutter debridement and bone cuts, a Hintermann distractor is mounted on
the ankle's anterolateral aspect (middle). Ankle balancing is performed v i a a lengthening
osteotomy o f t h e medial malleolus before the Implants are placed (right).
mar Link; Hamburg, Germany), the
Mobility implant (DePuy International;
Leeds, United Kingdom) and the Ramses
prosthesis (FH Orthopedics; Chicago).
Overall ankle replacement survival
was 89% at 5 years and 76% at 10 years in
a study Fevang and colleagues conducted
of 250 ankles i n the Norwegian Arthroplasty Register i n 2007. The overall failure rate was 11%. Their analysis included
the STAR prosthesis and the Thompson Parkridge Richards or TPR implant
(Smith & Nephew; Memphis). Head-tohead survivorship results were the same
for both designs.
Henricson and' colleagues studied
531 prostheses in the Swedish Ankle Arthroplasty Register, including the STAR
prosthesis, the Buechel-Pappas implant
(Endotec, Inc., Orlando, Fla., USA), the
Ankle Evolutive System or AES design
(Transystème; Nimes, France), the Hin-
"One of the problems we have not solved yet and we do
not fully understand are the cystic deformities in the bone
surrounding the prosthesis."
— JAN-WILLEIVl K. LOUWERENS, IWD
tegra prosthesis (Integra LifeSciences;
an obstacle to successful TAA results,
Plainsboro, N.J., USA) and DePuy's MoLouwerens said. Second-generation conbÜLty device. They reported 78% overall
strained two-component polyefhylenesurvival at 5 years and 62% survivorship
on-metal prostheses were associated
after 10 years.
with many compHcations, he added.
"With a two-component system, the
OtKer complications
polyethylene is fixed to the tibial compoPhysicians who spoke with ORTHOnent, so it might be that you have to exPAEDICS
TODAY EUROPE said the comchange the tibial component as well, and
pHcations
with which they regularly
it is a major surgery^ Hintermann said.
contend
include
mechanical loosening
Modem three-component nonconfollowing insufficient implant/bone fixastrained, meniscal-bearing TAA systems
tion, low grade infection, instabüity of
infroduced i n the 1980s achieved good
the artificial joint, asymmetrical polyethresults, according to Boack.
The Swedish, Norwegian and New ylene meniscus wear, bony impingement,
• malleolar fracture and cystic deformity.
Zealand TAA registers — three of four
"One of the problems we have not
such registers worldwide — noted avsolved
yet and we do not fully understand
erage TAA failure rates of 10% in 2007,
are
the
cystic deformities in the bone surLouwerens said.
rounding
the prosthesis," Louwerens told
In a 2007 study, Hosman and colORTHOPAEDICS TODAY EUROPE. "Someleagues examined a cohort of 202 ankles
times we think it is polyethylene wear or
in the New Zealand National Joint Regit might be a form of stress shielding, or
ister and found a 7% failure rate across
four models of TAA implants. The de- a combination, or it is joint fluid- getting
into these cysts."
signs studied were the Agility prosthesis
Frequently TAA fails due to ongoing
(DePuy, a Johnson & Johnson company;
deformity
and instability i n patients
-Warsaw, Ind., USA), the Scandinavian Toin
whom
that was present prior to
tal Ankle Replacement or STAR (Walde-
OrthopaediCStOdayEUROPE l
VOLUME15>NUMBER4'2012 I
arthroplasty, according to Dhar. "But,
there are implants that have ... high
failure rates because of aseptic loosening
and cyst formation and osteolysis aroimd
the implant — the AES, which was
withdrawn from the market earher this
year," he said.
Respect the indications
Sources interviewed agreed that the
main TAA indication is symptomatic
end-stage osteoarthritis, with or without
deformity. However, systemic types of arthritis, such as rheumatoid arthritis, may
also require TAA, Hintermann said.
TAA may also be indicated if there are
no other reasonable conservative or surgical options, or when these options fail or
are no longer acceptable for the patient In
case the ankle is not sufficiently aligned and
stabilized, this problem must be solved prior to or in addition to the TAA, Louwerens
said. The procedures contraindications include infection, poor soft tissue coverage,
' insuSicient bone stock, or older, sick patients with much comorbidity, he said.
In terms of patient age, there are currently no pubHshed studies supporting
upper or lower age limits or a particular
specific gender being associated with
better TAA outcomes. Furthermore,
the consensus among the surgeons who
spoke with ORTHOPAEDICS TODAY E U -
ROPE was there is no upper age limit for
patients undergoing TAA.
. Louwerens said older, homebound pa-tients maybe more suitable candidates for
the procedure since the recovery time is
quicker for TAA than fizsion, and its 10year survival rate is good. However, the
surgery may also be indicated in younger
patients agedfirom30 years to 50 years old
who are more likely to develop degenerative changes after a fusion, he said.
According to Boack, regardless of age,
patients that require a more mobile ankle
may be ideally suited for .TAA, although
he advised against TAA in children who
are stiH growing.
TAA revision may be necessary
should problems occur postoperatively.
Revisions are commonly performed for
pain, loosening, instabihty, or malahgnment, Louwerens said, but he added that
there are few studies detailing TAA revi- sion rates and their outcomes.
When fusion is indicated
Before TAA prostheses and siurgical
techniques became more commonplace,
fusion was the only option for patients.
Today, ankle fusion may still be better
suited for individuals with poor range of
motion, previous trauma or pain due to
softtissuechanges, accorduig to BoacL
"Some of the sofi:tissuechanges could
also lead to pain and i f you try to bring
motion into the joint, it could lead to
more softtissuepain," he said.
A patients occupation affects Dhars
decision for fusion over TAA. Therefore,
he does not recommend TAA for pa-
•V
COVER STORY
Heaiio-com/Orthopaedics
tients in physically demanding jobs irrespective of their chronological age.
"If I get a 60-year-old farmer who is
still pretty active, M s stuif, goes up and
down his tractor, and has to walk on tmeven plowed land, then clearly an arthroplasty is not going to last him very long,"
Dhar said.
Of note, no pubHshed studies currently recommend fusion over TAA. A
recently presented study by Daniels and
coUeagues using the Canadian Orthopaedic Foot and Ankle Society ankle reconstruction database found no significant difference between TAA or fusion i n '
patients with end-stage arthritis.
POINT / COUNTER
Should there be upper and lower age
limits for patients eligible to undergo
total ankle arthroplasty? Why?
POINT
No age limitations needed
My short answer, when it comes to adults, is no.
The discussion has for years been concentrating on the indications, as well as
contraindications for total ankle replacement (TAR). Age is just one of
^^^^^^^B
several parameters. Suggestions have ranged from 67-year-old and
older patients with very limited walking demands to young people
Use smallest implant size possible
The success of TAA depends on
implant type, anatonucal positioning of
components, patient selection, and using
an image intensifier or fluoroscopy for the
bony cuts, according to ORTHOPAEDICS
TODAY EUROPE sources. Louwerens and
•Dhar rely on such.imaging to ensure
correct component and joint aHgnment.
However, " i f you do not have a normal
situation, [such as] deformity, instabflity,
contracted joints, then it is not possible
to use the aiming device," Boack said.
During surgery, Hintermann prefers
positioning the patient in the supine position and uses an anterior approach. "You
have to plan the surgery carefully with a
standardized weight-bearing axis," he said.
Hintermancn also advises against using bulky implants with big pegs, keels,
bars or cement
"The implants are so small, and the
surrounding bone is smaïï, when you add
cement between the interface and the
bone, you automatically increase the size
of the implant The bigger the implants,
the bigger are the moments created during gait," he said.
In the future, implant designs are expected to become more physiological.
"There are actually too many ankle [designs] on the market; just copies, or mostly
copies," Hintermann said. "We know firom
history that some designs do not work.
There are some concepts that allow for too
much of the motion on non-physiological
planes, such as the firont plane."
Louwerens expects the number of
TAA surgeries performed to steadily increase in the future.
"It is clear total ankle arthroplasty
now has a defiuaite place in our armamentarium," he said". " I have the feeHng that in
the future, less and less fusions wiH be
performed and more replacements wül
be done." - hy Renee Blisard Buddie
Si
Visit Healio.com/0rthopaedics for the
full article and a list of references.
E H Dan-Henrilc Boack, IMD, can be reached at
Kieler StraBe 1, D-12153 Berlin, Germany; email:
[email protected].
ü
Sunil Dhar, IWS, IVlCh(Orth), PRCS,
FRCS(Orth), can be reached at Nottingham
University Hospitals, Queen's IVledical Centre
Campus, Derby Rd., Nottingham NG7 2UHZ
England; email: sunil.dhar@btintemetcom.
13
performing sports. For elderly patients, a fusion with unloading and
^^H|^^^|
^^H||^^H
wÊ^^^^^m
3 months to 4 months in a cast implies a serious impact on their
• muscle power compared to a TAR with immediate weight-bearing in
an orthosis for 3 weeks to 4 weeks. So, for the older generation with
end-stage arthritis, sufficient blood supply, and no diabetes, I would
^BG^BBII
\
^
Mlt
Hakon Kofoed
certainly recommend a TAR.
On the other end ofthe scale, it could be an 18-year-old with juvenile arthritis and
the usual hindfoot varus. In such cases, I would also perform aTAR and a calcaneus
osteotomy, whereas in a soccer player ofthe same age, other procedures (distraction,
osteotomies, even necrotransplants) should be tried instead of TAR. The worries about
the young patients are that the TAR will not last a lifetime. This is probably true, but
today's results with a 90% success rate at 10 years, and the option for an ankle fusion
later on in case of failure, a TAR as the first choice is probably better than a fusion.
Ankle fusions do lead to secondary degeneration ofthe neighboring joints after
10 years to 20 years necessitating fusion of these joints, as well.This means that for all
patients one must individualize the treatment depending on diagnosis, level of activity,
neuromuscular power and mental status. Age is not the limitation.
S Hakon Kofoed, MD, inventor of the STAR ankle replacement prosthesis, is atSkodsborg Private Hospital, Skodsborg, Denmark
Disclosure: Kofoed has no relevantfinancialdisclosures.
Reference:
Kofoed H, Lundberg-Jensen A Ankle arthroplasty in patients younger and older than 50 years: A
prospective series with long-term follow-up. Foot Ankle Int 1999;20:501 -506.
COUNTER
Younger age limit may be warranted
The longer life expectancy and higher level of activity in younger patients place
higher demands on any total joint replacement. Several total hip and total knee
replacement studies report inferior results and higher revision rates in
patients aged younger than 55 years or 60 years. There are also several
series of total ankle replacement (TAR) reporting higher risk of revision
in younger patients. In the Finnish, Norwegian and New Zealand total
ankle registers, age did not influence the revision rate. However, in a
recent study I and my colleagues conducted using the Swedish Ankle
Arthroplasty Register, we found a statistically significantly higher
revision rate in patients aged younger than 60 years. Detailed analysis
Anders Henricson
revealed this higher risk only was statistically significant concerning
women with osteoarthritis. In patients with rheumatoid arthritis or in men, the revision
rate was not influenced by age. Even if there are some medium-term reports of sports
activity in patients with TAR, I believe we have to be cautious in patients younger than 55
year to 60 years old, especially in women, at least until we have longer follow-up studies.
Any upper limit concerning age does not seem to be necessary, although severe
osteopenia constitutes a contraindication of TAR.
tSAndersHenricson,MD,isatFalunCentra!HospitalandCenterforClinical
Research Dalama,inSweden.
Disclosure: Henricson has no relevantfinancial disclosures.
Reference:
Henricson A, Nilsson jA, Carlsson A. 10-yearsurvival of total ankle arthroplasties: a report on 780 cases
from the Swedish Ankle Register. Acta Orthop. 2011 ,-82:655-659.
Eü Beat Hintermann, IVID, can be reached at
Chefarzt Orthopadische Klinik, Kantonsspital,
Rheinstrasse 26, C H ^ I O Liestal, Switzerland;
email: [email protected].
^ Jan-Willem K. Louwerens, IVID, can be reached
at PO Box 9011, 6500 GM Nijmegen, Netherlands;
email: j.louwerensiamaartenskliniek.nl.
Disclosures: Boack is a paid consultant to Smith
& Nephew. Dhar is a paid consultant to DePuy.
Hintermann receives royalties from Integra LifeSciences. Louwerens has no relevantfinancial disclosures.