# Management

Management

Successful treatment requires accurate diagnosis and a multi - disciplinary approach to deliver a package of  care, summarised as follows: /uni25CF Preoperative: /uni25CF patient assessment and clinical staging of  disease; /uni25CF full discussion of  all treatment options with potential complications; /uni25CF diagnostic tests for general health; /uni25CF optimisation of  patients and treatment of  comorbid - ities. /uni25CF Operative: /uni25CF exposure for multiple, deep bone sampling; /uni25CF excision of  all a ff ected tissue; /uni25CF intravenous antibiotics after sampling; /uni25CF bone stabilisation, if  necessary; /uni25CF dead-space management; /uni25CF soft-tissue cover, which may include plastic surgery . /uni25CF Postoperative: /uni25CF functional rehabilitation; /uni25CF continued antimicrobial therapy guided by culture re - sults, with regular clinical monitoring. - The principles listed above dictate that a range of  surgical and medical specialists will be needed to treat patients with bone and joint infections. If  the patient is systemically well, ved tions, optimise patient there is often time to complete investiga health and plan interventions. Complex infections should be referred early to centres that specialise in these cases. Atten - tion to diabetes control, peripheral vascular disease, nutrition and smoking cessation is essential. Many patients will benefit from psychological support or at least good counselling around the di ffi culties of  eradicating infection and the components of treatment. 

Mag
-

Management

Surgical management Medical treatment alone is rarely indicated in joint sepsis. Prompt surgical drainage is a priority to avoid further damage to the cartilage. Arthroscopic washout is commonly performed but it may be di ffi cult to remove loculated areas of infection. Washout should be with Ringer’s solution or of  the risk of  chondrolysis. There should be a low threshold for open arthrotomy , particularly if  a joint is not settling. A synovectomy is recommended if  there is major synovial thickening, aggressive synovitis or subchondral erosions seen on radiology (Gächter stages 3 and 4). Inadequate clearance may lead to chronic infection with destruction of  the joint ( Figure 43.4 ). Treatment may then require joint excision, joint fusion or staged joint replacement. Medical management Antibiotics are usually given for 3–6 weeks (beginning with intravenous therapy). There are sparse data to guide duration. Longer courses should be considered if  the infection is slow to resolve, if  more than one washout is required, if  the patient is bacteraemic and/or if  the infection is caused by S. aureus choice of  antibiotics is as given in Summary box 43.4 . Summary box 43.6 Native joint septic arthritis /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF 

Most common at extremes of age, in patients with rheumatoid
arthritis and in association with immunocompromise
Most commonly affects hips in neonates and knees in adults
and children
The commonest pathogen is
S. aureus
Joints should be aspirated for microbiology before starting
antibiotics, if safe to do so
Management is prompt surgical joint washout, followed by
3–6 weeks of antibiotics

Management

A multidisciplinary approach is required, including ortho paedics, plastic surgery , infectious diseases/microbiology , α pharmacy , nursing, occupational therapy and physiotherapy , centred on the patient’s understanding and wishes regarding their condition. Many patients have other medical comorbid - ities tha t should also be addressed and optimised. PJI can be - associated with a range of  emotional, psychological and mental health issues, ranging from anger about surgical complications to depression arising from chronic symptoms, lack of function and prolonged hospitalisation. T he choice of  surgical strategy for prosthetic joints can be categorised as: /uni25CF salvage of  an infected implant; /uni25CF removal of  the infected implant with or without reimplan - - tation. 

Infection likely
Infection con
/f_i
rmed
Two positive findings
Any positive finding
or
or
C
A
B
C
A
A
B
• Early radiographic
loosening
Sinus tract communication
• Wound-healing problems
with the joint +/–
• Recent fever/bacteraemia
visualisation of prosthesis
• Purulence around
prosthesis
• CRP >10mg/L
• Leukocyte count >3000
• Leukocyte count >1500
• PMN >80%
• PMN >65%
• Positive
-defensin
• Single positive culture
• ≥2 positive samples with
(aspiration or
the same microorganism
intraoperative)
• >50 CFU/mL of any
• > 1 CFU/mL any
organism on sonication
organism on sonication
• Presence of ≥5
Presence of ≥5 neutrophils
neutrophils in ≥5 HPFs
in a single HPF
• Visible microorganisms
Positive white blood cell
labelled scintigraphy
Bone Joint J
2021;
103-B
(1): 16–17.)

determine this (i.e. salvage for early infection versus removal and revision for late infection). Others regard any firmly fixed implant as potentially salvageable, irrespective of  the timing (and there are now several studies showing that this is feasi ble). However, it is agreed that loose infected implants should always be removed ( Figure 43.6 ). Furthermore, it is essential to achieve soft-tissue cover of  bone and pr osthetic material. This may be di ffi cult around the knee, requiring local muscle flaps. Management options can be divided into the following broad approaches. /uni25CF Debridement, antibiotics and implant reten tion - ‘DAIR’ . This can only be undertaken if the pros thesis is well fixed. DAIR is not a form of  washout as all infected soft tissue and necrotic bone must be fully excised and modular components exchanged. This cannot be achieved by arthroscopic surgery . Good soft-tissue cov is essential. Following debridement, the patient is treated with long-term antibiotics (frequently 6 weeks of  intra venous therapy followed by 6 months or more of  oral anti biotics). Prolonged infection-free intervals can be achieved in 80% of  patients but success with this strategy may be lower in infections caused by S. aureus or with multiresis tant organisms. /uni25CF Two-stage joint revision surgery . A thorough ex cision is undertaken and all cement and loose foreign ma terial is removed. An antibiotic-impregnated spacer may be implanted (which may be articulating). This is a tem porary measure and cannot withstand full weight-bearing. The patient is treated with oral or intravenous antibiotics, Gathorne Robert Girdlestone , 1881–1950, Nu ffi eld Professor of  Orthopaedics, University of  Oxford, UK, described excision arthroplasty of  the hip for septic arthritis. ed after the course of  antibiotics has been completed. In recent years ther e has been a trend towards shorter inter - vals between stages, often within the 6-week antimicrobial - therapy . /uni25CF Single-stage joint revision surgery . The procedure is the same as above, but removal and reimplantation are undertaken in the same operating session. Healthy soft tissues around the new implant are essential to prevent reinfection. Some centres consider single-stage revisions when less florid signs of  infection are present (i.e. absence of  collections or sinus tracts), or for frail patients for whom - the risk of a second operation is higher. There are no ad - - equate trial data comparing outcomes with the two-stage approach. /uni25CF Joint removal or fusion . When reconstruction options are not technically possible or are ruled out by comorbid er conditions, removal of  the prosthesis without reimplanta - tion may palliate symptoms. An example is the Girdlestone - excision arthroplasty of the hip. In prosthetic infections of - the knee, ankle or wrist, it may be possible to create a joint fusion after pr osthesis removal. This is complex surgery , which may involve major bone reconstruction. Amputa - - tion may be necessary for knee or ankle implants. /uni25CF Suppressive therapy with antibiotics . In patients - who are not medically fit for any operative intervention, or - who choose to decline all surgical options, long-term treat - ment with antibiotics may help to suppress the symptoms - of  infection. There are limited data, but anecdotally the success rate of  this approach is low . 

(a)
Figure 43.6
(a)
Sinus draining from the scar over the lateral side of the hip. This patient had a total hip replacement 14 years before that had
been complicated by a wound haematoma and infection.
(b)
Radiograph of both hips of same patient. Both hips are loose but only the right
side has de
/f_i
nite infection (arrows).
(b)

Prosthetic joint infection /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF 

Well-
/f_i
xed prostheses may be Debrided, treated with
Antibiotics and the Implant Retained (‘DAIR’ approach)
Loose prostheses must be removed
Replacement can be made at the initial surgery (one stage) or
after a delay to allow infection to be eradicated with antibiotics
(two stage)
Multiple surgical samples are crucial for identifying a pathogen
Thorough excision of infected tissue is a key determinant of
outcome
Long-term antibiotics may be used for patients who are not
suitable for major revision surgery

Management

- Acute osteomyelitis can be treated with antibiotics alone, when the diagnosis is made within 2–3 days of  onset of  symptoms, . Sta - there is no dead bone on imaging and there is no adjacent - septic arthritis. Culture results help to guide therapy , so blood cultures should be taken, and radiologically guided sampling should be considered. Empirical intravenous therapy against Gram-positive organisms is given (cephalosporins or flucloxa - ). cillin), adding gentamicin to cover Gram-negative organisms in children under 1 year. The limb should be splinted and good analgesia given. Intravenous antibiotics should be converted to oral therapy , depending on clinical progress and the results of cultures, and therapy is continued for a total of 2–3 weeks. If  the patient does not respond rapidly , if  the limb deteriorates or if  there is imaging evidence of  progression of  disease, surgery is indi - cated to prevent bone destruction and the onset of  chronic osteomyelitis. With prompt treatment, acute bone infection has a good - prognosis with a 90% cure rate. Failure to tr eat adequa tely pro - duces chronicity , with recurrent infection over many years. In children, the adjacent growth plates and joints may be a ff ected with subsequent deformity and joint destruction. Summary box 43.8 Acute osteomyelitis /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF Gavriil Abramovich Ilizarov , 1921–1992, orthopaedic surgeon, Kurgan, Western Siberia, Russia, pioneered this eponymous approach to bone reconstruction in the 1960s for the management of  osteomyelitis, fractures and limb deformities. 

(c)
Figure 43.7
(a)
Radiograph of a complex distal tibia fracture that was internally
/f_i
xed but complicated by deep infection.
plate was loose and grossly infected.
(c)
The plate and all infected tissue was excised. Deep samples were sent for microbiology and histology.
The defect at the lower end was
/f_i
lled with an absorbable antibiotic carrier.
and the skin primarily closed.
Presents in children with toxaemia, fever and unwillingness to
move the limb
May affect the vertebral column in adults, where back pain
may be the only symptom
Radiographs may be normal for up to 1 week so are of limited
value in early diagnosis
MRI is the investigation of choice
WCC and CRP are usually raised
Early diagnosis is treated with high dose intravenous
antibiotics, started empirically and modi
/f_i
ed with culture
results
Late diagnosis and/or failure of medical treatment requires
surgical debridement
(d)
(b)
At operation, the
(d)
The bone was stabilised with an Ilizarov circular external
/f_i
xator

Management

The BACH classification divides patients into ‘uncomplicated’, ‘complex’ and ‘limited options available’ based on the four important features of  the infection ( Figure 43.9 ). These are: the anatomical location in the bone (B), the antimicrobial profile (A), the need for soft-tissue cover (C) and the health of  the host (H). Treatment must always address all four parts of  the classification to achieve good outcomes. All infected unhealed fractures and infected non-unions are complex. As with PJI, comorbidities should be optimised before sur - gery . The interaction between the patient’s health status and the extent of  the bone infection greatly a ff ects the outcome after surgery . In chronic infection, it is essential to address med - ical conditions that ma y impair wound healing (e.g. smoking, peripheral vascular disease, diabetes, steroid use) prior to sur - gery . This approach has been shown to improve cure rates. A joint assessment by an orthopaedic sur geon, plastic surgeon and infectious disease physician will allow good preoperative planning. 

B
one involvement
A
ntimicrobial options
Ax
B1
Unknown/culture negative
Cavitary
ed
involvement
cat
A1
(including medullary,
pli
<4 resistant tests
cortical and
om
≥
80% susceptibility tests
non-segmental
Unc
sensitive
corticomedullary)
A2
B2
>4 resistant tests
Segmental
<80% susceptibility tests
involvement
lex
sensitive
Any infection with
Comp
joint involvement
A3
B3
Sensitivity to either 0 or 1
Whole bone
susceptibility test
involvement
Limited options
Figure 43.9
The BACH classi
/f_i
cation of osteomyelitis.
(a)
Coronal computed tomography scan of the femur
(b)
A transverse section
C
overage of soft tissue
H
ost status
H1
C1
Patient
/f_i
t and well or has
Direct closure possible
well-controlled disease
Plastic surgery expertise
not
required
H2
C1
Patient with either poorly
Direct closure not possible
controlled disease, severe
Plastic surgery expertise
disease or recurrent
required
osteomyelitis
H3
Un
/f_i
t for anaesthetic
Patient declines surgery
Surgery not indicated

In uncomplicated disease, excision of  the dead bone, with local and systemic antibiotics and direct wound closure, is highly e ff ective ( Figure 43.10 ). If  more than one-third of  the cortical circumference is excised, splintage is essential, often with external fixation to prevent fracture. Secondary bone grafting may be needed. When the infection is segmental (BACH complex), or when the soft-tissue envelope cannot be closed directly , major recon struction will be required. Curative resection must be segmen tal and bone stabilisation will always be required. The Ilizarov method, which uses distraction osteogenesis to fill bone defects, is a powerful and successful technique in these cases. It can be combined with free tissue transfer. T his allows reconstruction to proceed in parallel with rehabilitation. After surgery , patients should be given antibiotics. In total segmental excision of  infection a short course may be indicated, but in most chronic infections 6–12 weeks is often advised. If there is any doubt about the adequacy of  removal of  the dead bone , a long antibiotic course will be needed and recurrence will be more likely . In chronic fracture-related infection, anti biotics should continue until fracture union. There is now increasing interest in the use of  local antibiotic absorbable carriers. These can deliver high doses of  antibiotics into the bone, without systemic e ff ects. Some ceramic ma (with hydroxyapatite) can form new bone in the defect, avoid ing the need for secondary bone grafting. Chronic osteomyelitis /uni25CF /uni25CF /uni25CF 

Figure 43.10
(a)
This magnetic resonance imaging scan shows a
BACH uncomplicated medullary osteomyelitis of the femur.
(b)
infected bone has been removed by reaming and the central defect
/f_i
lled with absorbable calcium sulphate pellets with gentamicin.
Chronic disease requires specialist surgery with excision,
stabilisation and reconstruction
Host status should be optimised before surgery
Following surgery, antibiotic therapy is typically continued for
at least 6 weeks

Management

Successful treatment requires accurate diagnosis and a multi - disciplinary approach to deliver a package of  care, summarised as follows: /uni25CF Preoperative: /uni25CF patient assessment and clinical staging of  disease; /uni25CF full discussion of  all treatment options with potential complications; /uni25CF diagnostic tests for general health; /uni25CF optimisation of  patients and treatment of  comorbid - ities. /uni25CF Operative: /uni25CF exposure for multiple, deep bone sampling; /uni25CF excision of  all a ff ected tissue; /uni25CF intravenous antibiotics after sampling; /uni25CF bone stabilisation, if  necessary; /uni25CF dead-space management; /uni25CF soft-tissue cover, which may include plastic surgery . /uni25CF Postoperative: /uni25CF functional rehabilitation; /uni25CF continued antimicrobial therapy guided by culture re - sults, with regular clinical monitoring. - The principles listed above dictate that a range of  surgical and medical specialists will be needed to treat patients with bone and joint infections. If  the patient is systemically well, ved tions, optimise patient there is often time to complete investiga health and plan interventions. Complex infections should be referred early to centres that specialise in these cases. Atten - tion to diabetes control, peripheral vascular disease, nutrition and smoking cessation is essential. Many patients will benefit from psychological support or at least good counselling around the di ffi culties of  eradicating infection and the components of treatment. 

Mag
-

Management

Surgical management Medical treatment alone is rarely indicated in joint sepsis. Prompt surgical drainage is a priority to avoid further damage to the cartilage. Arthroscopic washout is commonly performed but it may be di ffi cult to remove loculated areas of infection. Washout should be with Ringer’s solution or of  the risk of  chondrolysis. There should be a low threshold for open arthrotomy , particularly if  a joint is not settling. A synovectomy is recommended if  there is major synovial thickening, aggressive synovitis or subchondral erosions seen on radiology (Gächter stages 3 and 4). Inadequate clearance may lead to chronic infection with destruction of  the joint ( Figure 43.4 ). Treatment may then require joint excision, joint fusion or staged joint replacement. Medical management Antibiotics are usually given for 3–6 weeks (beginning with intravenous therapy). There are sparse data to guide duration. Longer courses should be considered if  the infection is slow to resolve, if  more than one washout is required, if  the patient is bacteraemic and/or if  the infection is caused by S. aureus choice of  antibiotics is as given in Summary box 43.4 . Summary box 43.6 Native joint septic arthritis /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF 

Most common at extremes of age, in patients with rheumatoid
arthritis and in association with immunocompromise
Most commonly affects hips in neonates and knees in adults
and children
The commonest pathogen is
S. aureus
Joints should be aspirated for microbiology before starting
antibiotics, if safe to do so
Management is prompt surgical joint washout, followed by
3–6 weeks of antibiotics

Management

A multidisciplinary approach is required, including ortho paedics, plastic surgery , infectious diseases/microbiology , α pharmacy , nursing, occupational therapy and physiotherapy , centred on the patient’s understanding and wishes regarding their condition. Many patients have other medical comorbid - ities tha t should also be addressed and optimised. PJI can be - associated with a range of  emotional, psychological and mental health issues, ranging from anger about surgical complications to depression arising from chronic symptoms, lack of function and prolonged hospitalisation. T he choice of  surgical strategy for prosthetic joints can be categorised as: /uni25CF salvage of  an infected implant; /uni25CF removal of  the infected implant with or without reimplan - - tation. 

Infection likely
Infection con
/f_i
rmed
Two positive findings
Any positive finding
or
or
C
A
B
C
A
A
B
• Early radiographic
loosening
Sinus tract communication
• Wound-healing problems
with the joint +/–
• Recent fever/bacteraemia
visualisation of prosthesis
• Purulence around
prosthesis
• CRP >10mg/L
• Leukocyte count >3000
• Leukocyte count >1500
• PMN >80%
• PMN >65%
• Positive
-defensin
• Single positive culture
• ≥2 positive samples with
(aspiration or
the same microorganism
intraoperative)
• >50 CFU/mL of any
• > 1 CFU/mL any
organism on sonication
organism on sonication
• Presence of ≥5
Presence of ≥5 neutrophils
neutrophils in ≥5 HPFs
in a single HPF
• Visible microorganisms
Positive white blood cell
labelled scintigraphy
Bone Joint J
2021;
103-B
(1): 16–17.)

determine this (i.e. salvage for early infection versus removal and revision for late infection). Others regard any firmly fixed implant as potentially salvageable, irrespective of  the timing (and there are now several studies showing that this is feasi ble). However, it is agreed that loose infected implants should always be removed ( Figure 43.6 ). Furthermore, it is essential to achieve soft-tissue cover of  bone and pr osthetic material. This may be di ffi cult around the knee, requiring local muscle flaps. Management options can be divided into the following broad approaches. /uni25CF Debridement, antibiotics and implant reten tion - ‘DAIR’ . This can only be undertaken if the pros thesis is well fixed. DAIR is not a form of  washout as all infected soft tissue and necrotic bone must be fully excised and modular components exchanged. This cannot be achieved by arthroscopic surgery . Good soft-tissue cov is essential. Following debridement, the patient is treated with long-term antibiotics (frequently 6 weeks of  intra venous therapy followed by 6 months or more of  oral anti biotics). Prolonged infection-free intervals can be achieved in 80% of  patients but success with this strategy may be lower in infections caused by S. aureus or with multiresis tant organisms. /uni25CF Two-stage joint revision surgery . A thorough ex cision is undertaken and all cement and loose foreign ma terial is removed. An antibiotic-impregnated spacer may be implanted (which may be articulating). This is a tem porary measure and cannot withstand full weight-bearing. The patient is treated with oral or intravenous antibiotics, Gathorne Robert Girdlestone , 1881–1950, Nu ffi eld Professor of  Orthopaedics, University of  Oxford, UK, described excision arthroplasty of  the hip for septic arthritis. ed after the course of  antibiotics has been completed. In recent years ther e has been a trend towards shorter inter - vals between stages, often within the 6-week antimicrobial - therapy . /uni25CF Single-stage joint revision surgery . The procedure is the same as above, but removal and reimplantation are undertaken in the same operating session. Healthy soft tissues around the new implant are essential to prevent reinfection. Some centres consider single-stage revisions when less florid signs of  infection are present (i.e. absence of  collections or sinus tracts), or for frail patients for whom - the risk of a second operation is higher. There are no ad - - equate trial data comparing outcomes with the two-stage approach. /uni25CF Joint removal or fusion . When reconstruction options are not technically possible or are ruled out by comorbid er conditions, removal of  the prosthesis without reimplanta - tion may palliate symptoms. An example is the Girdlestone - excision arthroplasty of the hip. In prosthetic infections of - the knee, ankle or wrist, it may be possible to create a joint fusion after pr osthesis removal. This is complex surgery , which may involve major bone reconstruction. Amputa - - tion may be necessary for knee or ankle implants. /uni25CF Suppressive therapy with antibiotics . In patients - who are not medically fit for any operative intervention, or - who choose to decline all surgical options, long-term treat - ment with antibiotics may help to suppress the symptoms - of  infection. There are limited data, but anecdotally the success rate of  this approach is low . 

(a)
Figure 43.6
(a)
Sinus draining from the scar over the lateral side of the hip. This patient had a total hip replacement 14 years before that had
been complicated by a wound haematoma and infection.
(b)
Radiograph of both hips of same patient. Both hips are loose but only the right
side has de
/f_i
nite infection (arrows).
(b)

Prosthetic joint infection /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF 

Well-
/f_i
xed prostheses may be Debrided, treated with
Antibiotics and the Implant Retained (‘DAIR’ approach)
Loose prostheses must be removed
Replacement can be made at the initial surgery (one stage) or
after a delay to allow infection to be eradicated with antibiotics
(two stage)
Multiple surgical samples are crucial for identifying a pathogen
Thorough excision of infected tissue is a key determinant of
outcome
Long-term antibiotics may be used for patients who are not
suitable for major revision surgery

Management

- Acute osteomyelitis can be treated with antibiotics alone, when the diagnosis is made within 2–3 days of  onset of  symptoms, . Sta - there is no dead bone on imaging and there is no adjacent - septic arthritis. Culture results help to guide therapy , so blood cultures should be taken, and radiologically guided sampling should be considered. Empirical intravenous therapy against Gram-positive organisms is given (cephalosporins or flucloxa - ). cillin), adding gentamicin to cover Gram-negative organisms in children under 1 year. The limb should be splinted and good analgesia given. Intravenous antibiotics should be converted to oral therapy , depending on clinical progress and the results of cultures, and therapy is continued for a total of 2–3 weeks. If  the patient does not respond rapidly , if  the limb deteriorates or if  there is imaging evidence of  progression of  disease, surgery is indi - cated to prevent bone destruction and the onset of  chronic osteomyelitis. With prompt treatment, acute bone infection has a good - prognosis with a 90% cure rate. Failure to tr eat adequa tely pro - duces chronicity , with recurrent infection over many years. In children, the adjacent growth plates and joints may be a ff ected with subsequent deformity and joint destruction. Summary box 43.8 Acute osteomyelitis /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF Gavriil Abramovich Ilizarov , 1921–1992, orthopaedic surgeon, Kurgan, Western Siberia, Russia, pioneered this eponymous approach to bone reconstruction in the 1960s for the management of  osteomyelitis, fractures and limb deformities. 

(c)
Figure 43.7
(a)
Radiograph of a complex distal tibia fracture that was internally
/f_i
xed but complicated by deep infection.
plate was loose and grossly infected.
(c)
The plate and all infected tissue was excised. Deep samples were sent for microbiology and histology.
The defect at the lower end was
/f_i
lled with an absorbable antibiotic carrier.
and the skin primarily closed.
Presents in children with toxaemia, fever and unwillingness to
move the limb
May affect the vertebral column in adults, where back pain
may be the only symptom
Radiographs may be normal for up to 1 week so are of limited
value in early diagnosis
MRI is the investigation of choice
WCC and CRP are usually raised
Early diagnosis is treated with high dose intravenous
antibiotics, started empirically and modi
/f_i
ed with culture
results
Late diagnosis and/or failure of medical treatment requires
surgical debridement
(d)
(b)
At operation, the
(d)
The bone was stabilised with an Ilizarov circular external
/f_i
xator

Management

The BACH classification divides patients into ‘uncomplicated’, ‘complex’ and ‘limited options available’ based on the four important features of  the infection ( Figure 43.9 ). These are: the anatomical location in the bone (B), the antimicrobial profile (A), the need for soft-tissue cover (C) and the health of  the host (H). Treatment must always address all four parts of  the classification to achieve good outcomes. All infected unhealed fractures and infected non-unions are complex. As with PJI, comorbidities should be optimised before sur - gery . The interaction between the patient’s health status and the extent of  the bone infection greatly a ff ects the outcome after surgery . In chronic infection, it is essential to address med - ical conditions that ma y impair wound healing (e.g. smoking, peripheral vascular disease, diabetes, steroid use) prior to sur - gery . This approach has been shown to improve cure rates. A joint assessment by an orthopaedic sur geon, plastic surgeon and infectious disease physician will allow good preoperative planning. 

B
one involvement
A
ntimicrobial options
Ax
B1
Unknown/culture negative
Cavitary
ed
involvement
cat
A1
(including medullary,
pli
<4 resistant tests
cortical and
om
≥
80% susceptibility tests
non-segmental
Unc
sensitive
corticomedullary)
A2
B2
>4 resistant tests
Segmental
<80% susceptibility tests
involvement
lex
sensitive
Any infection with
Comp
joint involvement
A3
B3
Sensitivity to either 0 or 1
Whole bone
susceptibility test
involvement
Limited options
Figure 43.9
The BACH classi
/f_i
cation of osteomyelitis.
(a)
Coronal computed tomography scan of the femur
(b)
A transverse section
C
overage of soft tissue
H
ost status
H1
C1
Patient
/f_i
t and well or has
Direct closure possible
well-controlled disease
Plastic surgery expertise
not
required
H2
C1
Patient with either poorly
Direct closure not possible
controlled disease, severe
Plastic surgery expertise
disease or recurrent
required
osteomyelitis
H3
Un
/f_i
t for anaesthetic
Patient declines surgery
Surgery not indicated

In uncomplicated disease, excision of  the dead bone, with local and systemic antibiotics and direct wound closure, is highly e ff ective ( Figure 43.10 ). If  more than one-third of  the cortical circumference is excised, splintage is essential, often with external fixation to prevent fracture. Secondary bone grafting may be needed. When the infection is segmental (BACH complex), or when the soft-tissue envelope cannot be closed directly , major recon struction will be required. Curative resection must be segmen tal and bone stabilisation will always be required. The Ilizarov method, which uses distraction osteogenesis to fill bone defects, is a powerful and successful technique in these cases. It can be combined with free tissue transfer. T his allows reconstruction to proceed in parallel with rehabilitation. After surgery , patients should be given antibiotics. In total segmental excision of  infection a short course may be indicated, but in most chronic infections 6–12 weeks is often advised. If there is any doubt about the adequacy of  removal of  the dead bone , a long antibiotic course will be needed and recurrence will be more likely . In chronic fracture-related infection, anti biotics should continue until fracture union. There is now increasing interest in the use of  local antibiotic absorbable carriers. These can deliver high doses of  antibiotics into the bone, without systemic e ff ects. Some ceramic ma (with hydroxyapatite) can form new bone in the defect, avoid ing the need for secondary bone grafting. Chronic osteomyelitis /uni25CF /uni25CF /uni25CF 

Figure 43.10
(a)
This magnetic resonance imaging scan shows a
BACH uncomplicated medullary osteomyelitis of the femur.
(b)
infected bone has been removed by reaming and the central defect
/f_i
lled with absorbable calcium sulphate pellets with gentamicin.
Chronic disease requires specialist surgery with excision,
stabilisation and reconstruction
Host status should be optimised before surgery
Following surgery, antibiotic therapy is typically continued for
at least 6 weeks

Management

Successful treatment requires accurate diagnosis and a multi - disciplinary approach to deliver a package of  care, summarised as follows: /uni25CF Preoperative: /uni25CF patient assessment and clinical staging of  disease; /uni25CF full discussion of  all treatment options with potential complications; /uni25CF diagnostic tests for general health; /uni25CF optimisation of  patients and treatment of  comorbid - ities. /uni25CF Operative: /uni25CF exposure for multiple, deep bone sampling; /uni25CF excision of  all a ff ected tissue; /uni25CF intravenous antibiotics after sampling; /uni25CF bone stabilisation, if  necessary; /uni25CF dead-space management; /uni25CF soft-tissue cover, which may include plastic surgery . /uni25CF Postoperative: /uni25CF functional rehabilitation; /uni25CF continued antimicrobial therapy guided by culture re - sults, with regular clinical monitoring. - The principles listed above dictate that a range of  surgical and medical specialists will be needed to treat patients with bone and joint infections. If  the patient is systemically well, ved tions, optimise patient there is often time to complete investiga health and plan interventions. Complex infections should be referred early to centres that specialise in these cases. Atten - tion to diabetes control, peripheral vascular disease, nutrition and smoking cessation is essential. Many patients will benefit from psychological support or at least good counselling around the di ffi culties of  eradicating infection and the components of treatment. 

Mag
-

Management

Surgical management Medical treatment alone is rarely indicated in joint sepsis. Prompt surgical drainage is a priority to avoid further damage to the cartilage. Arthroscopic washout is commonly performed but it may be di ffi cult to remove loculated areas of infection. Washout should be with Ringer’s solution or of  the risk of  chondrolysis. There should be a low threshold for open arthrotomy , particularly if  a joint is not settling. A synovectomy is recommended if  there is major synovial thickening, aggressive synovitis or subchondral erosions seen on radiology (Gächter stages 3 and 4). Inadequate clearance may lead to chronic infection with destruction of  the joint ( Figure 43.4 ). Treatment may then require joint excision, joint fusion or staged joint replacement. Medical management Antibiotics are usually given for 3–6 weeks (beginning with intravenous therapy). There are sparse data to guide duration. Longer courses should be considered if  the infection is slow to resolve, if  more than one washout is required, if  the patient is bacteraemic and/or if  the infection is caused by S. aureus choice of  antibiotics is as given in Summary box 43.4 . Summary box 43.6 Native joint septic arthritis /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF 

Most common at extremes of age, in patients with rheumatoid
arthritis and in association with immunocompromise
Most commonly affects hips in neonates and knees in adults
and children
The commonest pathogen is
S. aureus
Joints should be aspirated for microbiology before starting
antibiotics, if safe to do so
Management is prompt surgical joint washout, followed by
3–6 weeks of antibiotics

Management

A multidisciplinary approach is required, including ortho paedics, plastic surgery , infectious diseases/microbiology , α pharmacy , nursing, occupational therapy and physiotherapy , centred on the patient’s understanding and wishes regarding their condition. Many patients have other medical comorbid - ities tha t should also be addressed and optimised. PJI can be - associated with a range of  emotional, psychological and mental health issues, ranging from anger about surgical complications to depression arising from chronic symptoms, lack of function and prolonged hospitalisation. T he choice of  surgical strategy for prosthetic joints can be categorised as: /uni25CF salvage of  an infected implant; /uni25CF removal of  the infected implant with or without reimplan - - tation. 

Infection likely
Infection con
/f_i
rmed
Two positive findings
Any positive finding
or
or
C
A
B
C
A
A
B
• Early radiographic
loosening
Sinus tract communication
• Wound-healing problems
with the joint +/–
• Recent fever/bacteraemia
visualisation of prosthesis
• Purulence around
prosthesis
• CRP >10mg/L
• Leukocyte count >3000
• Leukocyte count >1500
• PMN >80%
• PMN >65%
• Positive
-defensin
• Single positive culture
• ≥2 positive samples with
(aspiration or
the same microorganism
intraoperative)
• >50 CFU/mL of any
• > 1 CFU/mL any
organism on sonication
organism on sonication
• Presence of ≥5
Presence of ≥5 neutrophils
neutrophils in ≥5 HPFs
in a single HPF
• Visible microorganisms
Positive white blood cell
labelled scintigraphy
Bone Joint J
2021;
103-B
(1): 16–17.)

determine this (i.e. salvage for early infection versus removal and revision for late infection). Others regard any firmly fixed implant as potentially salvageable, irrespective of  the timing (and there are now several studies showing that this is feasi ble). However, it is agreed that loose infected implants should always be removed ( Figure 43.6 ). Furthermore, it is essential to achieve soft-tissue cover of  bone and pr osthetic material. This may be di ffi cult around the knee, requiring local muscle flaps. Management options can be divided into the following broad approaches. /uni25CF Debridement, antibiotics and implant reten tion - ‘DAIR’ . This can only be undertaken if the pros thesis is well fixed. DAIR is not a form of  washout as all infected soft tissue and necrotic bone must be fully excised and modular components exchanged. This cannot be achieved by arthroscopic surgery . Good soft-tissue cov is essential. Following debridement, the patient is treated with long-term antibiotics (frequently 6 weeks of  intra venous therapy followed by 6 months or more of  oral anti biotics). Prolonged infection-free intervals can be achieved in 80% of  patients but success with this strategy may be lower in infections caused by S. aureus or with multiresis tant organisms. /uni25CF Two-stage joint revision surgery . A thorough ex cision is undertaken and all cement and loose foreign ma terial is removed. An antibiotic-impregnated spacer may be implanted (which may be articulating). This is a tem porary measure and cannot withstand full weight-bearing. The patient is treated with oral or intravenous antibiotics, Gathorne Robert Girdlestone , 1881–1950, Nu ffi eld Professor of  Orthopaedics, University of  Oxford, UK, described excision arthroplasty of  the hip for septic arthritis. ed after the course of  antibiotics has been completed. In recent years ther e has been a trend towards shorter inter - vals between stages, often within the 6-week antimicrobial - therapy . /uni25CF Single-stage joint revision surgery . The procedure is the same as above, but removal and reimplantation are undertaken in the same operating session. Healthy soft tissues around the new implant are essential to prevent reinfection. Some centres consider single-stage revisions when less florid signs of  infection are present (i.e. absence of  collections or sinus tracts), or for frail patients for whom - the risk of a second operation is higher. There are no ad - - equate trial data comparing outcomes with the two-stage approach. /uni25CF Joint removal or fusion . When reconstruction options are not technically possible or are ruled out by comorbid er conditions, removal of  the prosthesis without reimplanta - tion may palliate symptoms. An example is the Girdlestone - excision arthroplasty of the hip. In prosthetic infections of - the knee, ankle or wrist, it may be possible to create a joint fusion after pr osthesis removal. This is complex surgery , which may involve major bone reconstruction. Amputa - - tion may be necessary for knee or ankle implants. /uni25CF Suppressive therapy with antibiotics . In patients - who are not medically fit for any operative intervention, or - who choose to decline all surgical options, long-term treat - ment with antibiotics may help to suppress the symptoms - of  infection. There are limited data, but anecdotally the success rate of  this approach is low . 

(a)
Figure 43.6
(a)
Sinus draining from the scar over the lateral side of the hip. This patient had a total hip replacement 14 years before that had
been complicated by a wound haematoma and infection.
(b)
Radiograph of both hips of same patient. Both hips are loose but only the right
side has de
/f_i
nite infection (arrows).
(b)

Prosthetic joint infection /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF 

Well-
/f_i
xed prostheses may be Debrided, treated with
Antibiotics and the Implant Retained (‘DAIR’ approach)
Loose prostheses must be removed
Replacement can be made at the initial surgery (one stage) or
after a delay to allow infection to be eradicated with antibiotics
(two stage)
Multiple surgical samples are crucial for identifying a pathogen
Thorough excision of infected tissue is a key determinant of
outcome
Long-term antibiotics may be used for patients who are not
suitable for major revision surgery

Management

- Acute osteomyelitis can be treated with antibiotics alone, when the diagnosis is made within 2–3 days of  onset of  symptoms, . Sta - there is no dead bone on imaging and there is no adjacent - septic arthritis. Culture results help to guide therapy , so blood cultures should be taken, and radiologically guided sampling should be considered. Empirical intravenous therapy against Gram-positive organisms is given (cephalosporins or flucloxa - ). cillin), adding gentamicin to cover Gram-negative organisms in children under 1 year. The limb should be splinted and good analgesia given. Intravenous antibiotics should be converted to oral therapy , depending on clinical progress and the results of cultures, and therapy is continued for a total of 2–3 weeks. If  the patient does not respond rapidly , if  the limb deteriorates or if  there is imaging evidence of  progression of  disease, surgery is indi - cated to prevent bone destruction and the onset of  chronic osteomyelitis. With prompt treatment, acute bone infection has a good - prognosis with a 90% cure rate. Failure to tr eat adequa tely pro - duces chronicity , with recurrent infection over many years. In children, the adjacent growth plates and joints may be a ff ected with subsequent deformity and joint destruction. Summary box 43.8 Acute osteomyelitis /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF Gavriil Abramovich Ilizarov , 1921–1992, orthopaedic surgeon, Kurgan, Western Siberia, Russia, pioneered this eponymous approach to bone reconstruction in the 1960s for the management of  osteomyelitis, fractures and limb deformities. 

(c)
Figure 43.7
(a)
Radiograph of a complex distal tibia fracture that was internally
/f_i
xed but complicated by deep infection.
plate was loose and grossly infected.
(c)
The plate and all infected tissue was excised. Deep samples were sent for microbiology and histology.
The defect at the lower end was
/f_i
lled with an absorbable antibiotic carrier.
and the skin primarily closed.
Presents in children with toxaemia, fever and unwillingness to
move the limb
May affect the vertebral column in adults, where back pain
may be the only symptom
Radiographs may be normal for up to 1 week so are of limited
value in early diagnosis
MRI is the investigation of choice
WCC and CRP are usually raised
Early diagnosis is treated with high dose intravenous
antibiotics, started empirically and modi
/f_i
ed with culture
results
Late diagnosis and/or failure of medical treatment requires
surgical debridement
(d)
(b)
At operation, the
(d)
The bone was stabilised with an Ilizarov circular external
/f_i
xator

Management

The BACH classification divides patients into ‘uncomplicated’, ‘complex’ and ‘limited options available’ based on the four important features of  the infection ( Figure 43.9 ). These are: the anatomical location in the bone (B), the antimicrobial profile (A), the need for soft-tissue cover (C) and the health of  the host (H). Treatment must always address all four parts of  the classification to achieve good outcomes. All infected unhealed fractures and infected non-unions are complex. As with PJI, comorbidities should be optimised before sur - gery . The interaction between the patient’s health status and the extent of  the bone infection greatly a ff ects the outcome after surgery . In chronic infection, it is essential to address med - ical conditions that ma y impair wound healing (e.g. smoking, peripheral vascular disease, diabetes, steroid use) prior to sur - gery . This approach has been shown to improve cure rates. A joint assessment by an orthopaedic sur geon, plastic surgeon and infectious disease physician will allow good preoperative planning. 

B
one involvement
A
ntimicrobial options
Ax
B1
Unknown/culture negative
Cavitary
ed
involvement
cat
A1
(including medullary,
pli
<4 resistant tests
cortical and
om
≥
80% susceptibility tests
non-segmental
Unc
sensitive
corticomedullary)
A2
B2
>4 resistant tests
Segmental
<80% susceptibility tests
involvement
lex
sensitive
Any infection with
Comp
joint involvement
A3
B3
Sensitivity to either 0 or 1
Whole bone
susceptibility test
involvement
Limited options
Figure 43.9
The BACH classi
/f_i
cation of osteomyelitis.
(a)
Coronal computed tomography scan of the femur
(b)
A transverse section
C
overage of soft tissue
H
ost status
H1
C1
Patient
/f_i
t and well or has
Direct closure possible
well-controlled disease
Plastic surgery expertise
not
required
H2
C1
Patient with either poorly
Direct closure not possible
controlled disease, severe
Plastic surgery expertise
disease or recurrent
required
osteomyelitis
H3
Un
/f_i
t for anaesthetic
Patient declines surgery
Surgery not indicated

In uncomplicated disease, excision of  the dead bone, with local and systemic antibiotics and direct wound closure, is highly e ff ective ( Figure 43.10 ). If  more than one-third of  the cortical circumference is excised, splintage is essential, often with external fixation to prevent fracture. Secondary bone grafting may be needed. When the infection is segmental (BACH complex), or when the soft-tissue envelope cannot be closed directly , major recon struction will be required. Curative resection must be segmen tal and bone stabilisation will always be required. The Ilizarov method, which uses distraction osteogenesis to fill bone defects, is a powerful and successful technique in these cases. It can be combined with free tissue transfer. T his allows reconstruction to proceed in parallel with rehabilitation. After surgery , patients should be given antibiotics. In total segmental excision of  infection a short course may be indicated, but in most chronic infections 6–12 weeks is often advised. If there is any doubt about the adequacy of  removal of  the dead bone , a long antibiotic course will be needed and recurrence will be more likely . In chronic fracture-related infection, anti biotics should continue until fracture union. There is now increasing interest in the use of  local antibiotic absorbable carriers. These can deliver high doses of  antibiotics into the bone, without systemic e ff ects. Some ceramic ma (with hydroxyapatite) can form new bone in the defect, avoid ing the need for secondary bone grafting. Chronic osteomyelitis /uni25CF /uni25CF /uni25CF 

Figure 43.10
(a)
This magnetic resonance imaging scan shows a
BACH uncomplicated medullary osteomyelitis of the femur.
(b)
infected bone has been removed by reaming and the central defect
/f_i
lled with absorbable calcium sulphate pellets with gentamicin.
Chronic disease requires specialist surgery with excision,
stabilisation and reconstruction
Host status should be optimised before surgery
Following surgery, antibiotic therapy is typically continued for
at least 6 weeks