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