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23 Periprosthetic Joint Infection inMegaprostheses
a
bc d
Prosthetic surface
335
e
Fig. 23.1 Schematic drawing about microbial surface
colonization shows the main stages in surface attachment
and biolm formation. (a) Adsorption, (b) irreversible
attachment and biolm formation, (c) growth and divi-
17]. Biolms are complex communities of micro-
organisms enclosed in a polymeric matrix,
resembling multicellular organisms, in which
microorganisms exhibit structural and functional
heterogeneity [17–18]. A fully formed biolm is
composed of three layers (Fig. 23.1). The rst
layer, known as the linking lm, consists of glycoproteins and exopolysaccharides secreted by
bacteria [18]. This adhesive layer binds the entire
biolm to the surface of tissues or biomaterials.
The second layer, called the base lm, is a compact assembly of microorganisms responsible for
secreting and maintaining the linking lm [18].
Finally, the third layer, known as the surface lm,
exists on the outer side of the biolm, providing
a platform for the emergence and spread of freeoating organisms [17–18].
The importance of biolms in promoting bacterial infections has been attributed to several factors. High microbial density triggers the release
of cell-to-cell signaling molecules (autoinducers,
AIs) in sufcient volume to promote the alteration in genetic expression linked to changes in
the cell envelope and various proteins [17, 19].
This mechanism known as quorum sensing renders bacteria more resilient to current antibiotics
sion, (d) mature macrocolony, and (e) Dispersion White
circles: bacteria in planktonic phase; Grey circles: bacteria producing polymeric matrix; Light blue circles: sessile
resistant core; Dark blue circles: persistent cells.
[20–21]. Furthermore, the growth rates of bacteria within biolms often slow down and this contributes to their increased resistance to
antimicrobial agents [19]. The slower growth of
bacteria also results in a deeper localization
within the biolm, making it challenging for antibiotics to reach and eliminate them effectively.
Consequently, bacteria residing within biolms
can withstand concentrations of antimicrobials
that are 1000–15,000 times higher than those
required to eradicate planktonic bacteria of the
same species [19–20].
23.4 Etiology
Infections in tumor prostheses are associated
with different species of bacteria. Among these,
Aerobic gram-positive bacteria, especially
Staphylococcus aureus, are responsible for
around 82% of cases, making them the most
prevalent culprits [1, 19, 22]. This bacteria reigns
as the top pathogen linked to tutor prosthesis
infections and it typically colonizes implants
through hematogenous spread, originating from
distant skin or soft tissue infections. Other patho-
336
A. Angelini et al.
gens like Streptococcus pneumoniae,
23.5 Classications
Enterobacteriaceae species (including
Salmonella, Bacteroides, and S. Gallolyticus),
Escherichia coli, Klebsiella species, and Viridans
Streptococci can also colonize implants through
hematogenous spread [1]. These infections may
stem from respiratory tract infections, gastroin-
The most common approach to classify PJIs in
megaprostheses is based on the time of onset of
symptoms after implantation. This classication
system categorizes infections into three main
groups: early, delayed, and late-onset infections.
testinal tract infections, urinary tract infections,
or dental procedures, respectively.
• Early-onset infections: these infections typi-
Among the coagulase-negative Staphylococcus
(CoNS) species, S.Epidermidis is the most common pathogen causing PJIs and with
Staphylococcus lugdunensis are part of the normal skin ora in the perineum and hip regions [1,
21–22]. Staphylococcus lugdunensis has the abil-
ity to mutate under stressful conditions, leading
to the formation of genetically modied smallcolony variants (SCVs) [21]. The pathogenicity
of S. lugdunensis is similar to that of S. aureus,
making it a signicant pathogen in periprosthetic
infections. Additionally, Group-D Streptococcus
• Delayed onset infections: these infections
species, Enterobacteriaceae species,
Enterococcus species, Pseudomonas aeruginosa,
and various anaerobic species are frequently
implicated in these infections [1, 22]. In approximately 25% of cases, multi-pathogen infections
are observed in tumor prosthesis infections. The
most common pair of pathogens in these cases
are CoNS and Enterococcus species [19–23].
The management and treatment of tumor
prosthesis infections typically involve a combination of surgical intervention, such as implant
removal or debridement, and antibiotic therapy.
• Late-onset infections: these infections develop
The choice of antibiotics is usually based on the
suspected pathogens and their antibiotic susceptibility patterns [22]. However, the overall success of treatment is inuenced by various
factors, including the extent of infection, the
patient’s immune response, and the ability to
effectively eradicate the biolm-associated bacteria. It is also important to note that there is no
specic correlation between the presence of certain pathogens and favorable treatment
outcomes.
approach to understanding the timeline and
potential causes of PJIs. It helps guide clinical
cally occur within 4weeks after implantation.
They are often related to perioperative contamination during surgery or hematogenous
spread of bacteria. Early-onset infections are
commonly caused by more virulent organisms, such as Staphylococcus aureus, and
often have an abrupt onset of clinical symptoms. If left untreated, early infections can
progress to chronic infections characterized
by the presence of sinuses, bacteremia, and
sepsis [9, 24].
occur between 1and 24months after implantation. They are usually associated with lowgrade infections, often caused by organisms
with lower virulence, such as Coagulasenegative Staphylococci [9]. Delayed onset
infections can result from a variety of factors,
including persistent contamination, biolm
formation, or hematogenous spread. These
infections may present with more subtle signs,
such as persistent chronic inammation and
postoperative discomfort.
more than 24months after implantation and
are often associated with hematogenous
spread from a distant site or contiguous spread
from a nearby infected focus. Late-onset
infections are commonly caused by lowvirulence organisms as well as by the reactivation of dormant bacteria [10].
This classication provides a practical
T
N
M
23 Periprosthetic Joint Infection inMegaprostheses
337
management decisions, such as the choice and
duration of antibiotic therapy and the need for
surgical intervention. It is important to note that
this classication system is not comprehensive
and may not capture all possible variations and
complexities of PJIs. Therefore, it is often used in
combination with other classication systems,
such as the PJI-TNM classication, to provide a
more holistic understanding of the infection [25].
This system is inspired by the conventional TNM
oncologic score for malignant tumors, considering that there are certain similarities between
tumors and PJIs such as the need for wide
removal of affected tissue. Just as tumors require
the removal of malignant cells to prevent further
spread, PJIs necessitate the removal of infected
tissue to eradicate the infection and promote
healing [25]. In 2020 Alt and coworkers proposed
a standardized framework for evaluating and
classifying PIJs, the PJI-TNM classication
(Table 23.1) [25] This system builds upon the
principles of the TNM system in oncology and
Table 23.1 The PJI-TNM classication system
T Tissue and implant conditions
T0 a Stable standard implant without important soft tissue defect
b Stable revision implant without important soft tissue defect
T1 a Loosened standard implant without important soft tissue defect
b Loosened revision implant without important soft tissue defect
T2 a Severe soft tissue defect with standard implant
b Severe soft tissue defect with revision implant
N Non-human cells (bacteria and fungi)
N0 a No mature biolm formation, directly postoperatively
b No mature biolm formation, late haematogeneous
N1 a Mature biolm formation without “difcult to treat bacteria”
b Mature biolm formation, with culture negative infection
N2 a Mature biolm formation with “difcult to treat bacteria”
b Mature biolm formation, with polymicrobial infection
c Mature biolm formation with fungi
M Morbidity of the patient
M0 Not or only mildly compromised (CCI: 0–1)
M1 Moderately compromised patient (CCI: 2–3)
M2 Severely compromised patient (CCI: 4–5)
M3 a Patient refuses surgical treatment
b Patient does not benet from surgical treatment
c Patient does not survive surgical treatment
r Reinfection
If the infection involves a previously infected implant, the situation is considered as “reinfection”
and an “r” is put in front of the classication
a
CCI: Charlson Comorbidity Index
incorporates crucial parameters specic to periprosthetic joint infections such as the type of
implant, surrounding soft tissue conditions, the
causative microorganism, and the host [25–26].
This categorization system utilizes three signicant letters: T, N, and M. ‘T’ represents the local
situation of the tissue and the indwelling implant.
This includes factors such as the extent of tissue
involvement and the severity of implant-related
complications. ‘N’ stands for the causative nonhuman bacterial and/or fungal organisms, indicating the type and virulence of the infecting
microorganism. Lastly, ‘M’ represents the morbidity of the patient, taking into consideration
factors such as the patient’s overall health status
and the presence of comorbidities that may
impact the management and outcome of the
infection [25–26]. Each item is further specied
by numbers indicating the severity or extent. The
PJI-TNM classication system includes the name
of the affected joint in front of the TNM letters to
clearly indicate the body region involved. In
a
338
A. Angelini et al.
cases of recurrent infections, the letter ‘r’ is
added to emphasize reinfection.
However, there are limitations to this classication system. One limitation is the use of biolm formation maturity in the ‘N’ section. While
it is a step forward in classifying PJIs, accurately
determining the exact time differentiation
between immature and mature biolm formation
is challenging with current diagnostic methods.
Additionally, the complexity of the use of three
letters and further sub-specication can make it
more difcult to use in daily clinical practice
compared to the simple differentiation between
early, delayed, and late classications [25–26].
23.6 Diagnosis
Early diagnosis is extremely important for the
successful treatment of PJIs, especially in megaprostheses. However, the diagnosis of these
infections can be quite difcult due to the wide
range of symptoms that can occur and the absence
of specic laboratory tests and procedures. To
address these challenges, a comprehensive and
multidisciplinary approach is often required.
This approach typically involves the collaboration of orthopedic surgeons, infectious disease
specialists, and microbiologists. By working
together, these professionals can utilize a combination of different methods to establish an accurate diagnosis.
The symptoms of PJIs can vary widely and
may overlap with other postoperative complications. In fact, pain, swelling, redness, warmth, and
limited range of motion can also be present in
aseptic loosening or other non-infectious complications [9, 12]. This overlap makes it challenging
to differentiate between infectious and non-infectious causes. To conrm the diagnosis of a PJI the
presence of pus, sinus discharge, or positive cultures from the affected area is required [9–10].
23.6.1 Lab Test
Laboratory tests play a crucial role in the diagnostic process. While there may not be specic
tests for periprosthetic infections, various blood
tests can help indicate the presence of inammation or infection in the body. These tests may
include a complete blood count (especially white
blood cell count WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP)
levels [10, 12].
Considering the lack of specicity, it is crucial
to interpret these results in conjunction with clinical ndings. For example, during the early postoperative period (within the rst 2weeks), these
markers can be elevated as part of the normal
inammatory response to surgery, whereas after
the initial 2-week period, consistently high levels
of CRP and WBC count become more indicative
of an ongoing infection [12]. Furthermore, the
conventional laboratory procedures used to detect
and identify bacteria are mainly designed to
detect planktonic bacteria (which are freely oating in a liquid medium), but they may not effectively identify bacteria that are present within
biolms [12, 20–21]. This limitation poses a signicant challenge in identifying and diagnosing
biolm-related infections, further complicating
the problem.
23.6.2 Imaging
Imaging studies are also commonly used to aid in
the diagnosis. X-rays, magnetic resonance imaging (MRI), computed tomography (CT), ultrasonography (US), and bone scintigraphy scans can
provide valuable information about the condition
of the prosthesis, surrounding tissues, and potential signs of infection such as uid collections or
bone destruction [24, 27]. While simple radiographs can be useful in ruling out other causes of
periprosthetic pain, they have limitations when it
comes to early infection detection [27]. A series
of plain radiographs taken over a period of time
after implantation can demonstrate loosening of
the implant and periprosthetic osteolysis, but it
can also occur without an infection development
[27–28]. Computed tomography (CT) offers a
comprehensive evaluation of bone structures,
including a detailed analysis of cortical and trabecular anatomy. The administration of intrave-
23 Periprosthetic Joint Infection inMegaprostheses
339
nous contrast during a CT scan further enhances
the contrast between various soft tissues, facilitating the identication and highlighting of pathological changes. Dual-energy CT is an advanced
technique that can detect bone marrow edema,
making it particularly valuable in the context of
infection [28]. Ultrasound (US) is an invaluable
diagnostic tool that offers a wealth of detailed
information about the soft tissues surrounding a
prosthetic joint [29]. Unlike other imaging techniques that may be hindered by metallic artifacts,
the US offers clear visualization of these tissues
allowing for a comprehensive examination of the
painful site [27–29]. While it may not be the ideal
method for evaluating the prosthesis and periprosthetic bone due to the limitations of sound
beams in penetrating metal or bone, US excels in
detecting joint effusion and identifying extraarticular uid collections. In cases where it is feasible to perform aspiration or biopsy on the
affected joints, it is highly recommended to do
so.
MRI is widely considered the most effective
imaging technique for diagnosing musculoskeletal infections [30], but while it is highly effective
in diagnosing infections on native bone, its use in
cases of PJIs has traditionally been limited due to
susceptibility artefacts produced by metallic
implants [28]. To overcome this challenge, modied and advanced MRI pulse sequences have
been developed to minimize the metal artefacts
between the implant components and the neighboring tissues. These pulse sequences are specically designed to enhance the performance of the
1.5 Tesla MRI system, allowing for a substantial
reduction in artefacts around metallic implants
[28]. MRI with intravenous gadolinium-based
contrast agents provides more anatomical detail,
spatial resolution, and soft tissue contrast, allowing for accurate and precise imaging. One of the
key strengths of MRI is its ability to detect pathological processes by imaging edema, which often
leads to an increase in water content. This is
especially valuable in identifying infectious
pathologies, which can be best visualized using
uid-sensitive, fat-suppressed sequences. For
more specic situations, additional sequences
like diffusion-weighted imaging (DWI) and gra-
dient echo (GRE) sequences can be employed to
investigate uid collections, and tumors and
identify blood products respectively [27–29].
Despite its many advantages, MRI does have
some drawbacks. Limited availability, long scanning times, and high costs can make it less accessible for some patients. Bone scintigraphy, in
combination with 111In-labeled leukocytes and
radiotracers such as 99mTechnetium-sulfur colloid or Gallium citrate 67 can be used to aid in the
diagnosis of PJIs [31–33].
23.6.3 Cultures
Microbiological analysis is an essential component of the diagnostic process. This involves
obtaining samples from the affected area and
sending them to the laboratory for culture and
sensitivity testing. This allows the healthcare
team to identify the specic bacteria or other
microorganisms causing the infection, as well
as determine the most effective treatment
options. In order to identify the specic pathogens causing PJIs, tissue cultures from multiple
sites have long been regarded as the most
dependable method [12, 24, 34]. However,
these cultures have been found to have a sensitivity ranging from 70% to 90% and a specicity ranging from 67% to 91% [35]. Additionally,
it typically takes 7–9 days to receive results
from these cultures.
Joint aspiration is highly recommended for
the evaluation of PJIs, as it allows for thorough
histological and microbiological testing of the
synovial uid [34]. However, there are certain
factors that can affect the accuracy of these tests:
(1) it is important to discontinue the use of antimicrobial agents at least 14days before surgery
[34–35]; (2) it is important to understand that a
negative result from joint aspiration does not necessarily rule out the presence of infection (in up
to 50% of PJI cases, the infecting organism is not
isolated in cultures) [35]; (3) it is also important
to avoid relying solely on sinus tract cultures for
diagnosis, as they have a high risk of contamination by normal skin ora, which can lead to false
positive results [35].
340
A. Angelini et al.
Cultures and diagnostic tests are valuable
tools in the evaluation of periprosthetic infections, but they are not foolproof. False positive
results can occur due to the detection of contaminants or secondary microorganisms, as well as
indirect signs of infection that may not accurately
guide treatment decisions [34].
23.6.4 Polymerase Chain Reaction
(PCR) andNext-Generation
Sequencing (NGS)
There has been a growing interest in exploring
faster and more accurate molecular techniques to
improve the sensitivity of diagnosing PJIs. PCR
is a non-culture-based method that utilizes specic oligodeoxynucleotide primers to enzymatically amplify bacterial DNA, allowing for its
detection [36–38]. It requires a small volume of
synovial uid, tissue samples, or uid from sonicated implants, and can deliver results within
5–24h of collection. It has been found to have
higher diagnostic accuracy in terms of sensitivity
and specicity compared to tissue cultures [34,
38, 39]. In addition to traditional quantitative
PCR, another alternative method for detecting
bacterial pathogens is broad-range PCR, which
targets the 16S ribosomal DNA (rDNA) [40, 41].
Metagenomic next-generation sequencing
(mNGS) technology is a powerful tool that can
directly detect pathogens and other functional
genes in clinical samples without the need for
pre-amplication of target sequences [42]. It utilizes DNA sequencing to identify a wide range of
pathogens, including bacteria and fungi but
reports a higher rate of false positive results [43].
Whenever possible, the best way to obtain a diagnostic material is the sonication of implants after
removal and the culture of the sonication uid
[44–47].
23.7 Risk Factors
Identifying and understanding the key risk factors associated with infections in megaprostheses
is crucial for healthcare professionals to develop
effective strategies for prevention and management. By considering patient-related, diseaserelated, and procedure-related risk factors,
healthcare professionals can optimize patient
outcomes and reduce the incidence of infections
in patients undergoing reconstructive surgery for
tumors.
Patient-Related Risk Factors Malnutrition,
male gender, advanced age, diabetes mellitus,
obesity, smoking, alcohol abuse, previous native
joint infection, skin diseases, peripheral vascular
disease, and, pre-existing joint disease (particularly rheumatoid arthritis) have been identied as
signicant risk factors for infections in tumor
prostheses [12, 48–50]. About lab exams, lower
preoperative hemoglobin and albumin levels,
neutropenia [51–55], elevated C-reactive protein
(CRP) levels and a decreased white blood cell
count have been associated with an increased risk
of infection following reconstructive surgery [1,
51, 56].
Disease-Related Risk Factors Tumor site is an
important predictor, with the proximal tibia,
proximal femur, and pelvis being associated with
a higher risk of infection [13, 16, 50, 57].
Conversely, the distal femur and proximal
humerus are linked to a lower infection rate [50,
58–59]. Interestingly, periprosthetic joint infec-
tions in the knee have been found to have a worse
prognosis compared to infections in other locations [1, 50, 60–62]. The connection between the
tumor’s metastatic spread and its histological features, along with the occurrence of infections,
remains ambiguous. Several studies suggest a
continuing discussion on whether primary tumors
or metastatic sites are more prone to infection
development. [59, 63]. Tissue damage caused by
radiation therapy [20, 64–65], as well as
chemotherapy- induced leukocytopenia and neutropenia [59, 66–68] are believed to increase the
risk of postoperative deep infection. Patients who
receive radiation therapy have an infection rate of
9.8%, compared to 20.7% in those who receive
preoperative radiation therapy, and 35.3% in
those who receive postoperative radiation ther-
23 Periprosthetic Joint Infection inMegaprostheses
341
apy [64]. The available evidence on the link
between infection rates and the time lapse
between neoadjuvant therapy and prosthetic
reconstructions in tumor patients is scarce.
[69–72]. Currently, the decision on the timing of
surgery after neoadjuvant treatment is typically
based on individual hospital protocols and physician preferences. However, it is generally recommended to avoid surgery immediately after
radiotherapy, and a waiting period of 4–6weeks
is often necessary to allow for the restoration of
normal tissue properties [69–72].
Procedure-Related Risk Factors
Surgical proce-
dures and surgical techniques performed can also
affect the risk of infections in megaprostheses
[73–74]. For example, an inadequate debridement
of infected tissues, improper wound closure, and
poor surgical technique can increase the risk of
infection. Surgeons must ensure meticulous surgical technique and adhere to strict aseptic protocols to minimize the risk of any kind of
complications. The association between the duration of surgery and infection risk is controversial
and may vary depending on various factors, such
as patient population, surgical technique, and
infection prevention measures [75–79]. Moreover,
the amount of blood loss during the procedure and
the resulting need for blood transfusion, preoperative hospitalization for more than 48h, or postoperative access to intensive care have been
identied as potential risk factors [1]. The use of
surgical drains in musculoskeletal tumor surgery
is a common practice even though there is limited
evidence supporting its benecial effect and/or its
link to an increased risk of infection [80–87].
Certain characteristics of the implant itself can
contribute to the risk of infection. For example,
prostheses with rough surfaces or those made of
materials that promote bacterial adhesion can
increase the risk of infection [50] whereas silvercoated prostheses have been found to have antibacterial properties that disrupt DNA synthesis
and cellular membranes [88–90]. Several studies
on silver-coated prostheses have shown promising
results, with a signicant decrease in infection
rates (7,9% silver-coated prosthesis vs 11,6%
uncoated ones) and a higher success rate of twostage revision surgery for infected silver-coated
prostheses compared to infected uncoated
implants [87–90]. The association between infection rates and the type of xation (cemented vs.
cementless) in musculoskeletal tumor surgeries
has been investigated in several studies, but the
results are highly variable [48, 91–95].
Antibiotic Prophylaxis The standard guidelines
for antibiotic prophylaxis in total joint arthroplasty
suggest a single preoperative dose of antibiotics to
be administered 60min prior to the procedure and
should be discontinued within 24h after the completion of the surgery [96–98]. In musculoskeletal
oncology, it is generally recommended to administer additional doses of antibiotics during the procedure if it exceeds the half-life of the prophylactic
antimicrobial agent or lasts longer than 3–4h [97].
The selection of an antibiotic for prophylaxis during surgery is primarily determined by its spectrum of action [99]. Numerous studies have
indicated that the most suitable antibiotic for perioperative prophylaxis is a rst- or second-generation cephalosporin, such as cefazolin or
cefuroxime, administered intravenously in a dose
adjusted according to the patient’s weight
[100–101]. Due to their effectiveness against
gram-positive bacteria that are resistant to other
antibiotics, glycopeptide antibiotics like vancomycin and teicoplanin have been recommended as
alternative prophylactic agents [102–103]. While
methicillin-sensitive Staphylococcus aureus
(MRSA) remains largely susceptible to cephalosporin antibiotics, the prevalence of MRSA infections is on the rise [104–106]. Bone cement is
commonly used to secure implants. To prevent
infection, antimicrobial agents are often added to
the bone cement (i.e. vancomycin, gentamycin,
clindamycin) [107–109].
23.8 Surgical Treatment
The aim of treating PJIs associated with megaprostheses is to eliminate the infection while preserving the functionality of the affected limb
342
A. Angelini et al.
[110]. Currently, there are various treatment
options available, including non-operative methods such as long-term antibiotic suppression,
debridement, and implant retention (DAIR), as
well as surgical interventions like one- or twostage revision arthroplasty [111]. It is still uncertain which approach is superior between the
two- stage replacement, one-stage exchange, or
debridement with retention since these different
options have not been tested in a randomized
fashion in a homogenous patient population. The
choice of surgical approach relies on the surgeon’s personal experience, postoperative lag,
infection classication, condition of the implant
and surrounding soft tissues, as well as the
patient’s comorbidity.
23.8.1 Debridement, Antibiotics,
andImplant Retention (DAIR)
The approach known as DAIR is a treatment
option for infected prostheses that involves several key principles. To begin with, antibiotics are
withheld prior to surgery, and the joint is aspirated to identify the specic organism causing the
infection [112]. The surgical procedure itself
consists of surgical irrigation, debridement, antibiotic therapy, and the decision to either retain
the existing implant with or without exchanging
the polyethylene component [12, 112]. During
debridement, various elements are removed,
including hematoma, brous membranes, sinus
tracts, as well as any devitalized bone and soft
tissue [12, 110]. The DAIR treatment approach
offers several advantages compared to more invasive options: (1) it is less technically demanding,
resulting in lower morbidity for the patient; (2) it
also allows for shorter hospital stays and better
preservation of bone stock; (3) the economic burden associated with this approach is lower.
However, it is important to note that DAIR is
suitable only if the infection occurs within
14–28days after the initial surgery, if it is conrmed through histopathology and microbiology,
if the implants remain stable, and if the isolated
pathogen is susceptible to an effective oral antibiotic [113]. When all these criteria are met, the
reported rate of infection eradication following
this procedure is 42.8% [113]. Intravenous antibiotics are typically administered for a period of
at least 2–6weeks following the DAIR procedure
[110]. Several studies have evaluated the
effectiveness of this protocol in cases of infected
megaprostheses, with success rates ranging from
39% to 70% [11, 62, 113–116]. These studies
have reported eradication rates of 42% with irrigation and debridement without implant
exchange, 70% after a single-stage debridement
with the exchange of modular components, and
62% after a two-stage revision surgery [117].
In cases where the DAIR procedure fails to
eradicate the infection, alternative surgical
options become necessary. The two-stage revision surgery has long been considered the “gold
standard” in these cases. However, for patients
with relatively healthy bone and soft tissue, no
prior revision surgeries, or treatment involving
effective antibiotics against biolm-active microorganisms, a one-stage exchange would be the
treatment of choice [110, 118–120].
23.8.2 One-Stage Revision Surgery
There is a shortage of high-quality studies examining the outcomes of single-stage revision surgery PJIs [14, 19, 61–62]. Single-stage revision
treatment entails comprehensive debridement
and revision of all implants simultaneously, with
the aim of improving infection eradication rates.
The success of resolving these infections is
closely linked to the extent of soft tissue debridement and subsequent reduction in bioburden
[14]. Nevertheless, the question remains as to
whether it is necessary to remove and revise all
implants during a one-stage revision surgery, or if
some implants can be retained. In cases where
complete removal of all implants is not feasible,
it is recommended to thoroughly irrigate the
retained implants using solutions such as
povidone- iodine or chlorhexidin [121]. One of
the potential advantages of one-stage reimplantation is the reduction in the waiting period for
delayed reimplantation, leading to improved joint
function. Additionally, it eliminates the need for
23 Periprosthetic Joint Infection inMegaprostheses
343
a second complex procedure, which carries inherent risks and complications, including the possibility of developing a new infection. However,
there is a higher risk of persistence or recurrence
of the original infection if the debridement is
inadequate or if the antibiotic treatment is
insufcient.
This is why the decision to perform a onestage revision surgery is typically based on the
patient’s characteristics and circumstances.
Generally, patients with PJIs caused by unknown
microbial organisms, difcult-to-treat organisms
(such as multi-resistant strains), the presence of a
stula, or the need for bone reconstruction are
Fig. 23.2
Chondrosarcoma of the
distal femur in a
73-year-old male. (a)
Coronal MRI shows the
intramedullary extension
of the disease. (b)
Postoperative
radiographs after distal
femur resection and
reconstruction with
megaprosthesis. (c)
Removal of the
prosthesis and
implantation of an
antibiotic cement spacer
for an early infection.
(d) 5-year follow-up
after reimplantation of
similar megaprosthesis
4months after the rst
revision stage
ab
cd
excluded from undergoing one-stage revision
surgery. In these cases, a two-stage revision surgery is preferred [122].
23.8.3 Two-Stage Revision Surgery
Two-stage revision surgery is widely considered
the most effective treatment approach for infections in megaprostheses, with reported success
rates ranging from 63% to 100% [61, 115].
During a two-stage revision surgery, the implants
are initially removed and replaced with antibioticloaded bone cement spacers (Fig. 23.2). These
344
cd
ab
A. Angelini et al.
Fig. 23.3 Osteoblastic osteosarcoma of the distal femur
in a 57-year-old male. (a) AP and lateral radiographs
show the extensive involvement of bone and soft tissue.
(b) Postoperative radiographs after wide resection and
megaprosthetic reconstruction combined with chemother-
spacers remain in place for a period of
2–3 months, during which systemic antibiotics
are administered [123]. The choice and duration
of antibiotics may vary depending on the results
of microbial cultures. In the second stage, the
spacers are removed and replaced with the nal
implants after a minimum of 2 weeks without
antibiotics [61, 123]. Re-implantation is typically
recommended at least 2–6 weeks after the
infected prosthesis has been explanted [61], but is
not always possible to preserve the joint function
(Fig. 23.3). Patients who are recommended to
undergo a two-stage revision surgery include
those with persistent or high-grade infections,
infections caused by antibiotic-resistant pathogens, or individuals who have previously undergone unsuccessful one-stage revision surgery
[61, 124]. In cases where cementless modular
megaprostheses are securely xed, infected
implants can be revised in two stages while
retaining the anchorage stem [124]. However, the
apy. (c) Removal of the prosthesis and implant of a vancomycin and tobramycin cement spacer after 4 months
follow-up due to S.Epidermidis infection. (d) Modular
arthrodesis with silver implant (MUTARS system,
Implantcast Ltd., Buxtehude, Germany) 6months later
use of the two-stage revision surgery technique
remains controversial due to several factors.
These include the extended duration of hospital
stay, increased bone loss and risk of osteoporosis
resulting from lack of use, and the potential for
limb shortening [125–126].
23.9 Conclusions
The prevention of postoperative infections in
prosthetic reconstruction is crucial, particularly
in tumor patients. A comprehensive and multidisciplinary approach involving orthopedic surgeons
and specialists from various disciplines is essential to recognize risk factors, make a proper diagnosis, and plan the best therapeutic approach.
The treatment goals include resolving the infection and preserving the functionality of the
affected limb. Various treatment strategies have
been employed for managing megaprosthetic