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Perioperative Pain Management inTotal Knee Arthroplasty
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Implant Design
Contents
Chapter 26 Loosening of Total Knee Arthroplasty: An Australian
Perspective – 289
Ruben A. Mazzucchelli and Piers J. Yates
Chapter 27 Cemented, Cruciate-Retaining Total Knee Arthroplasty:
The Evolution of a Technique – 301
Stefano A. Bini and Giulio Santi
Chapter 28 Posterior Stabilized Total Knee Arthroplasty – 317
Musa B. Zaid and Thomas P. Vail
VI
Chapter 29 Bicruciate-Retaining Total Knee Arthroplasty – 327
Michael D. Ries
Chapter 30 Fixed- Versus Mobile-Bearing Total Knee
Arthroplasty – 335
Daniel N. Bracey and Douglas A. Dennis
Chapter 31 All-Polyethylene Tibial Components in Primary Total
Knee Arthroplasty: Why It Works and Why I Do Not Use
It Anymore? – 357
Ahmed Siddiqi, Abdullah Aftab, and Amar S. Ranawat
Chapter 32 Cementless Total Knee Arthroplasty – 365
Bradley A. King and Arthur L. Malkani
Chapter 33 Custom/Patient-Specic Total Knee Arthroplasty – 377
Nana O. Sarpong, Darwin Chen, and H. John Cooper
Chapter 34 Alternative Bearings in Total Knee Arthroplasty – 385
Brian P. Chalmers and Steve B. Haas
Chapter 35 Contemporary Rotating Hinged Prostheses in Primary
Total Knee Arthroplasty – 395
Benjamin M. Wooster and Matthew P. Abdel
Chapter 36 Patellar Component – 409
Yoav S. Zvi and Eli Kamara
Loosening ofTotal Knee
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Arthroplasty: AnAustralian
Perspective
RubenA.Mazzucchelli andPiersJ.Yates
Contents
26.1 Introduction – 290
26.2 Illustrative Cases – 290
26.2.1 Patient 1 – 290
26.2.2 Patient 2 – 291
26.3 Overview oftheAustralian Registry – 291
26.3.1 Revision – 291
26.3.2 Implant Design andBearing Mobility – 292
26.3.3 Patella – 293
26.3.4 Fixation – 293
26.3.5 Patient Age, Gender, andBMI – 293
289
26
26.4 Other National Joint Registries (UK andScandinavia) – 294
26.5 Loosening: TheMost Common Cause ofFailure – 294
26.5.1 Implant Type (Cemented vs. Uncemented) – 295
26.5.2 Implant Design/Constraint/Bearing – 295
26.5.3 Osteolysis andWear – 296
26.5.4 Malalignment – 296
26.5.5 Cement andCementing Technique – 296
26.5.6 Patient-Related Factors forLoosening – 297
26.6 Clinical Presentation, Diagnosis, andTreatment – 298
References – 299
© The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2022
E. Hansen, K.-D. Kühn (eds.), Essentials of Cemented Knee Arthroplasty,
https://doi.org/10.1007/978-3-662-63113-3_26
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R. A. Mazzucchelli and P. J. Yates
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26.1 Introduction
The latest data from the Australian registry (Australian
Orthopaedic Association National Joint Replacement
Registry (AOANJRR) 2018) describes that total knee
replacement (TKR) has been increasingly implanted. In
2017 in Australia, more than 600,000 primary knee
replacements have been recorded on the registry. This is
55,000 more procedures than in 2016; 55% of the
patients are female. The age at primary implantation has
been stable over the years, with only 6% of the patients
being younger than 55years.
Fully cemented implants are used in 68% of the
cases, whereas fully cementless xation has decreased to
11%; 21% of the implants have hybrid xation. The
patellar components are cemented in nearly all cases.
26.2 Illustrative Cases
26.2.1 Patient 1
A 57-year-old male patient with aseptic loosening of a
hybrid right total knee arthroplasty 5 years after primary implantation. Infection has been previously
excluded with blood tests and joint aspiration.
On the preoperative radiographs, osteolysis can be
observed around the tibial component medially and
anterior to the keel. In addition to that, radiolucent lines
suggestive of loosening are noted behind the femoral
component (. Fig.26.1).
Revision TKR is performed (. Fig. 26.2). On the
tibial side a metaphyseal sleeve achieves xation in Zone
2 and a short, undersized, uncemented stem is used to
. Fig. 26.1 Pre-revision X-rays of an aseptically loose hybrid right
total knee replacement 5 years after primary implantation. a AP
X-ray demonstrates radiolucencies around the medial tibial bone–
implant interface. b Lateral X-ray demonstrates similar ndings
anterior to the tibial keel and around the femoral component
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26
. Fig. 26.2 Post-revision X-rays. a AP view and b lateral view demonstrate the revision rotating platform total knee replacement per-
formed. Metaphyseal xation is utilized with PMMA cement used only at the joint surface (zone 1)
ensure alignment. Antibiotic-loaded PMMA cement is
used only on the joint zones (Zone 1) to deliver some
antibiotics and help seal the interfaces. A rotating platform is used to further reduce the chances of loosening
through decoupling of rotation and exion motion, and
to eliminate the chance of tibial malrotation. It also
maximizes tibial bone coverage.
26.2.2 Patient 2
A 69-year-old obese female patient suffering from severe
bilateral tricompartmental osteoarthritis of the knees
with varus deformity (. Fig.26.3). The patient’s weight
is 120kg with a BMI of 55kg/m2. The patient is active
and independent in her daily activities.
Primary-cemented TKR is performed on the right
side using a PS implant with rotating platform. The
patella is resurfaced. On the tibial side, considering
patients risk factors for loosening (weight and activity)
we optimize xation with a primary uncemented sleeve
(. Fig.26.4).
26.3 Overview oftheAustralian Registry
26.3.1 Revision
> Cumulative revision rates of primary TKR for osteo-
arthritis at 17years is 8.4%.
26
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R. A. Mazzucchelli and P. J. Yates
. Fig. 26.3 a AP and b lateral X-rays of a 69-year-old obese female with severe bilateral tricompartmental osteoarthritis of the knees with
varus deformity
. Fig. 26.4 a AP and b lateral X-rays of the primary cemented posterior- stabilized rotating platform total knee replacement used in this
patient. A primary uncemented sleeve was utilized to optimize xation considering patient’s risk factors for loosening (weight and activity)
In Australia, loosening is the most frequent cause of
revision (25.3%), followed by infection (22.9%) and
patellofemoral pain (10.4%). Infection is the most common cause for revision in the rst 6years, after this time
loosening predominates.
commonly implanted in 2017 at 69%, PS prostheses
account for 23%, and medial pivot for 7%.
PS implants have a slightly higher cumulative revision rate if compared to CR prostheses (at 17years 8%
vs. 9%). By looking specically at loosening rates for different implant designs it is noted that CR knees are less
prone to loosening at the 17-year mark (just below 2%)
26.3.2 Implant Design andBearing
Mobility
compared to PS implants (2.3%) (.
Considering the bearing mobility there are two major
Fig.26.5).
groups: “mobile” and xed bearings. However, “mobile”
The registry denes three major categories of implant
design: minimally stabilized (CR), medial pivot design,
and posterior-stabilized (PS). CR knees are the most
combines rotating platforms and true mobile bearings,
which behave differently. Of all the TKR implanted
since the introduction of the registry 80% are xed bear-
Minimally Stabilised
Cumulative Incidence
Years Since Primary ProcedureYears Since Primary Procedure
17
Loosening ofTotal Knee Arthroplasty: AnAustralian Perspective
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5.0%
4.0%
3.0%
Loosening
Infection
Patellofemoral Pain
Pain
Instability
5.0%
4.0%
3.0%
Posterior Stabilised
Loosening
Infection
Patellofemoral Pain
Pain
Instability
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26
2.0%
1.0%
0.0%
012 345678910 11 12 13 14 15 16 17
. Fig. 26.5 Cumulative incidence revision diagnosis of total knee replacement by stability (primary diagnosis OA)
ing and 20% are “mobile” bearing. Looking at the
cumulative revision rates xed-bearing implants have a
lower revision rate after 17years compared to mobilebearing TKR (8.1% vs. 9.5%). Although xed bearings
perform better in the rst 7years, after this time mobilebearing TKR have the lower rate of revision if adjusted
for age and gender.
> This said, it must be added that it can be difcult to
compare results of CR and PS implants since there is
always a selection-bias component due to the fact that
some surgeons prefer to use PS design for less stable
knees or anatomically more challenging situations.
2.0%
Cumulative Incidence
1.0%
0.0%
012345678910 11 12 13 14 15 16
Cemented CR implants have a 7.6% cumulative revision
rate at 17years, cementless get revised in 9.4% of the
cases.
PS implants with cemented xation lead to a lower
revision rate compared to uncemented and hybrid xation. Medial pivot design cemented prostheses perform
better in the registry compared to cementless implants.
26.3.5 Patient Age, Gender, andBMI
Revision rate of TKR clearly decreases with increasing
patient age. Patients younger than 55 years have more
than seven times the rate of revision after 10years than
Also, the use of PS knees is more common in certain
brands.
patients older than 75years. One of the reasons for this is
probably activity related. Males also have a higher revision rate than female patients due to their higher incidence of infection (1.7% in 17years compared to 0.9%).
26.3.3 Patella
The Australian joint registry has only recently started
collecting data about BMI.In the available dataset, revi-
The use of patella resurfacing is increasing (67% in
2017). Cumulative revision rates are higher when
patella is not resurfaced for all implant designs. The
worst- performing knees without patellar resurfacing is
the PS design (11% at 17years). No information can be
found in the registry about loosening of the patellar
component.
sion rates are increased for BMI >40. What can be
observed is a constant increase in revision for infection
with increasing BMI.No clear registry data is available
at the moment for loosening in this group.
Patients Older Than 80Years
z
In patients aged 80years or older, loosening is a less frequent reason for revision. The most common reason for
implant failure is infection. According to the latest data,
26.3.4 Fixation
infection accounts for 35% of the revisions in patients
aged 80–89 years and 61% of the revisions in patients
> CR prostheses perform better if cemented (or hybrid)
compared to cementless use.
older than 90 years. In fact, most of the revisions performed in these age groups are changes of the polyethyl-
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26
ene insert whereas tibial and femoral components get
revised in only 30% of the cases. This can also be explained
by the fact that being faced with a frailer patient cohort,
major revision surgery is more frequently avoided.
In the most-aged patient group (>80 years) (CR)
implants are preferred (73%) compared to posteriorstabilized (PS) prostheses. Revision rates are almost
equal, with cruciate-retaining implants having a slightly
lower revision rate (2.3% compared to 2.7%). Fixation
method has no inuence on the revision rate of the different implant designs in this age group. Fixation type
does inuence the reason for failure: while cementless
xation was associated with a higher revision rate for
loosening, cemented xation increased revisions for
infection. Patella resurfacing signicantly reduced the
revision rate for all implant designs regardless of xation technique.
26.4 Other National Joint Registries
(UK andScandinavia)
The UK National Joint Registry(National Joint Registry
for England, Wales Northern Ireland and the Isle of
Man 2018) has even less uncemented xation, with
about 85% of fully cemented prostheses and less than
5% cementless and hybrid procedures.
Design-wise the trend is similar: in the cemented
group 70% of the implants are CR, 25% are PS, whereas
in the uncemented/hybrid group more than 90% of the
prostheses used are CR design.
Preference of bearing mobility in the UK is heavily
toward xed bearing when using cemented implants
(91%) and is 50% when cementless/hybrid procedures
are performed.
Looking at the revision rates in the UK the bestperforming implants at the 14-year mark are cemented
CR xed bearing (revision rate below 4%) whereas
cemented PS implants and CR with mobile bearing have
revision rates around 5%. The worst-performing appear
to be uncemented or hybrid PS/FB prostheses with revision rates of 9% at 14years.
The Norwegian arthroplasty register (Norwegian
National Advisory Unit on Arthroplasty and Hip
Fractures 2018) shows 70% fully cemented primary TKR,
15% hybrid procedures (cementless femur only), and 15%
fully cemented. The patellar component is always
cemented in Norway. From 1994 to 2017, cemented and
hybrid perform better than uncemented implants, but the
difference is apparent only later, after 10years. Hybrid
implants are the ones with the best survival rate.
Particularly interesting is the inverse trend compared
to the UK and Australia to not resurface the patella.
The Norwegian registry shows only 8% of the total knee
replacements to have patellar resurfacing.
In the time period between 2013 and 2017 looking at
the seven most commonly used implants, 28% of the
TKR were rotating platforms. The vast majority of the
surgeons preferred CR designs, these accounting for
95% of the implants used.
A recent study based on the Norwegian registry
(Gothesen etal. 2017) shows an increased relative risk
for aseptic loosening up to almost 7% in rotatingplatform knees compared to xed bearings in the time
between 2003 and 2014.
In the Swedish arthroplasty registry (The Swedish
Knee Arthroplasty Register 2018), a very high incidence
of fully cemented TKR with rates around 95%is
observed. Leaving the patella un-resurfaced is also common in Sweden, as it is in Norway (>m95% of TKR
without patella). Posterior-stabilized implants are less
commonly used in Sweden, with CR being used in 91%
of the cases across the country. Loosening accounts for
approximately 30% of the revisions performed, similar
to the Australian cohort.
26.5 Loosening: TheMost
Common Cause ofFailure
Aseptic loosening and infection are the most common
reasons for a TKR to be revised (Sharkey etal. 2013).
Furthermore, it is accepted that an unknown proportion
of aseptic loosening cases are in fact undiagnosed lowgrade septic cases not identied at the time of revision.
Septic loosening is usually observed in low-grade periprosthetic joint infections with low virulence pathogens
(e.g., Cutibacterium acnes) causing a chronic inammatory process. This leads to an activation of a bone
resorptive cascade ultimately resulting in component
loosening. It is one of the most common causes of late
TKR failures and must always be considered before
revision surgery is performed.
Aseptic loosening affects more commonly the tibial
component; it has multiple etiologies and can be grossly
differentiated into early and late loosening. Early loosening can be understood as failure to achieve primary
stability and is, therefore, linked to implant type
(cemented vs. uncemented) and correct preparation and
cementing technique whereas late loosening is a result of
bone resorption and/or failure at the bone–implant or
cement–bone interface. Osteolysis is bone loss from the
result of a harmful combination of mechanical and biological events (Gallo 2013).
Many factors can contribute to loosening of an initially well-xed implant.
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26.5.1 Implant Type (Cemented vs.
Uncemented)
Ideal xation of TKR is still controversial. Historically
TKR were designed to be cemented to the bony surface
in order to guarantee immediate, stable xation.
> Cementing the tibia and femur is still considered the
gold standard by many authors and has delivered
excellent results and low loosening rates across all age
groups in all the registries.
However, cementless implants with biological xation
and preservation of bone stock have also had some good
results. Cementless TKR relies on good bone quality
and is, therefore, more commonly indicated in younger
patients with healthy bone stock and bone metabolism.
Advantages of cementless TKR are reduced operative
time, preservation of bone stock with easier revisions
and no cement-associated complications like loose bodies, third body wear, and cement-related osteolysis
(Aprato 2016).
Cementless TKR relies on very accurate bone cuts in
order to improve host–implant contact and maximize
stability whereas when using cemented implants, the
cement will ll in these gaps resulting in a more forgiving
situation.
> A proper cementing technique is essential to the good
outcome of a cemented TKR (Cawley et al. 2013;
Vanlommel etal. 2011).
The rst generation of cementless implants encountered
many complications leading to higher revision rates for
aseptic loosening mostly on the tibial side (Hungerford
etal. 1982; Dodd etal. 1990; Ebert et al. 1992). These
were due to poor press-t design leading to micromotion and lack of osteoconductive surfaces resulting in
failure to gain primary xation. The new generation of
implants have improved design and utilized bioactive
surfaces (e.g., porous coating, trabecular metal) offering
more reliable options. However, this use of newer technology has led to modern cementless implants being signicantly more expensive compared to cemented
prostheses, triggering the discussion if they are worth
being used since the overall performance does not differ
in the registries. Looking at the literature (Nakama etal.
2012) it can be stated that cemented implants show less
motion within the rst 2years on RSA studies and tend
to migrate “late.” This can be understood as a continuous remodeling process at the bone–cement interface.
Cementless implants, on the other hand, have an initial
migration phase that settles as soon as bone in-growth
has been achieved and it is postulated that they guarantee a better long-term stability. Current evidence, includ-
ing prospective randomized trials (Park and Kim 2011)
and a meta-analysis (Gandhi et al. 2009) still cannot
prove which of these two options leads to better results
in terms of loosening rates with fully cemented TKR
still being the mainstay in most countries (68% in the
latest Australian Joint Registry) but improved uncemented implants are certainly a viable option for selected
patients.
> In our practice, we currently believe that fully
cemented TKR provides the most secure and consistent long-term results (Gandhi et al. 2009) and the
higher costs of cementless implants do not justify the
after-all minimal operative time saved during the procedure itself (11min on average according to (Nam
etal. 2019)).
26.5.2 Implant Design/Constraint/Bearing
With increasing degrees of constraint, the interface
between implant and prosthesis potentially have more
forces transferred to them, logically increasing the risk
of component loosening (Easley et al. 2000). This
becomes important mainly in the setting of complex primary TKR and revision arthroplasty where higher
degrees of constraint are required to compensate for
instability. It is, therefore, sensible to consider ofoading
the interfaces by obtaining metaphyseal and/or diaphyseal xation with the use of stems and/or sleeves when
implanting semi- or fully constrained TKR.
In primary TKR the difference in constraint between
cruciate-retaining (CR) and cruciate-sacricing,
posterior- stabilized (PS) implants is minimal and has
almost no inuence on the revision rate for loosening
(2% vs. 2.3% in the Australian NJR).
When considering bearing mobility, we should differentiate between xed-bearing TKR, rotating platforms, and mobile-bearing implants. The original idea
of a rotating platform was a more conforming tibiofemoral articular surface with lower contact stress combined with bearing rotational freedom in order to
improve kinematics and increase articular congruity
throughout the range of motion. In theory, this should
reduce polyethylene wear through minimizing shear
forces and increasing linear motion and reduce aseptic
loosening by reducing strain transference to the interfaces. Also, the phenomenon of backside wear in xed
bearings should be reduced. However, there has been
little good clinical evidence to back this up as yet in primary knee, although in the revision literature there is
increasing evidence that rotating platforms have better
results in terms of loosening (Kim etal. 2017). At the
moment there is little evidence that mobile/rotating
bearings are superior to xed-bearing TKR regarding
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pain, range of motion, function, and failure rate
(Gøthesen etal. 2013). On the contrary in some specic
implant brands, the relative risk for failure due to loosening is increased (Gothesen etal. 2017).
> It is our belief that, generally associating aseptic loos-
ening with a particular primary bearing design is not
correct. It is necessary to analyze the single brands for
long-time performance before drawing anticipated
conclusions.
> In our practice, we rely on rotating platform, PS
implants because we believe that these theoretically
reduce wear, off-load the interfaces, improve patellar
tracking, improve kinematics, and reduce the chance
of malrotation of the tibial component.
26.5.3 Osteolysis andWear
Periprosthetic osteolysis may be a factor in aseptic loosening. The process is very complex and still not fully
understood; polyethylene, PMMA and metal wear particles initiate chronic inammation and subsequent bone
resorption by following the path of least resistance
within the joint driven by hydrodynamic pressure (Gallo
2013). This is similar to that which has been observed
for loosening patterns after total hip replacement. In
addition to this, mechanical forces contribute to weaken
the bone bed so that component alignment, the patients’
bodyweight and activity must be considered when discussing osteolysis. A TKR offers a larger bearing surface compared to a prosthetic hip, so the amount of
polyethylene wear particles generated will be higher but
also very variable in size (Shanbhag etal. 2000). The different wear mechanisms, particle number and size as
well as the fact that the volume within the joint is usually
bigger in a knee than in a hip, are all reasons that limit
the comparison of wear processes between hip and knee
replacements.
26.5.4 Malalignment
Component malalignment is one of the major surgeonrelated contributors to loosening. Malpositioning of the
implants leads to pathological load transfer of the components to the interface regardless of implant design,
constraint, bearing, or patient-related factors. In particular, the bone–cement interface can be degraded by
excessive forces. In addition to that, malalignment
increases polyethylene wear and, therefore, can trigger
osteolysis. Different studies have demonstrated that tibial varus of >3° already causes accelerated wear and
increases failure rate (Srivastava etal. 2012; Berend etal.
2004). Also, a valgus femoral cut of >8° increases the
revision rate by ve times (Ritter etal. 2011). It is, therefore, mandatory to assess a lose TKR for component
malpositioning. Many studies in the last years have
shown that the use of computer navigation in TKR can
improve the accuracy of component positioning without clear evidence for an increased implant survival
compared to conventional surgery (Jones and Jerabek
2018). Nevertheless, the trend toward computer-
navigated TKR is evident with 33% of navigated joints
in Australia in 2017 according to the registry.
> At this state, we currently limit the use of navigation
to cases where conventional alignment cannot be reli-
ably achieved because of extra-articular deformities,
intramedullary implants, etc. We perform intramed-
ullary alignment of the tibia in nearly all cases.
In particular for overweight patients with abundant soft
tissues it can be difcult to correctly assess the anatomical axis of the tibial shaft. Therefore, inserting an intramedullary rod, in our opinion is the most reliable
technique to correctly align the tibia. If IM-alignment
of the tibia is performed, we restrict the medullary canal
prior to cementing in order to prevent cement to migrate
too distally down the tibia and improve cement pressurization and lling, optimizing xation.
26.5.5 Cement andCementing Technique
Cement type and consistency, bone quality at the interface, cement application, penetration, and thickness of
the mantle are all factors contributing to an optimal primary xation.
> In our practice, we currently use fully cemented
implants, as supported by the registry data.
There has recently been an increased interest in improving the effectiveness of cementing our implants in TKR
(Cawley etal. 2013; Saari etal. 2009), and quite a few
papers have been written about the inuence of cementing technique on the outcome after TKR (Cawley etal.
2013; Vanlommel etal. 2011; Bannister and Miles 1988).
It appears that a poor cementing technique results in
insufcient initial xation which automatically increases
micromotion at the interface. Poor cementing may also
impair the mechanical properties of the cement through
fat, air, and uid contamination.
In our opinion, evidence does not justify the use of a
tourniquet for the whole length of the procedure, as it
often reduces access, does not reduce blood loss, and
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