1 fracture related infection where are we now

UNIVERSITY OF MEDICINE & PHARMACY AT HO CHI MINH CITY INTERDISCIPLINARY CME CONGRESS Fracture – Related Infection Where are we now? Do Phuoc Hung, M.D, Assoc.Prof Department of Orthopaedics and Rehabilitations Ho Chi Minh City, September 16th, 2023 Why are we here? What’s the matter?! How significant is definition of FRI? • Accurate diagnosis: critical for preventing poor outcomes • Limitations with gold standards: further complicate diagnosis and management process Which condition does ‘Fracture – Related Infection’ (FRI) most likely refer to? A Surgical Site Infection (SSI) B Infected Nonunion/Septic Nonunion C Infection After Fracture Fixation D Posttraumatic Osteomyelitis Surgical Site Infection (CDC) Surgical site infection = infection of the incision / organ / space that occur after surgery Source: CDC – National Healthcare Safety Network (NHSN) 2023 Diagnostic Criteria – SSI NHSN orthopedic procedure only ORIF • > 90 days? • Other procedures than ORIF? No surgery? Source: CDC – National Healthcare Safety Network (NHSN) 2023 Osteitis or Osteomyelitis? • Mostly exogenous, but remember hematogenous! • Difficult to distinguish • More important is the presence of bacteria at fracture site ! Source: Fang et al J Orthop Surg 2017;25(1):2309499017692712 Depypere et al Clin Microbiol Infect 2020;26(5):572-578 What is FRI? “ a more comprehensive term encompassed infections with and without implants & included infection of all parts of the bone (cortical, medullary, epiphyseal).” FRI = all infections occur in the presence of a fracture, including: – Early infection around fx implants – Infection in fx with no internal fixation – Infected nonunion – Haematogenous infection arising after fx healing (?) Source: Metsemakers et al Injury 2018;49(3):505-510 McNally et al EFORT Open Rev 2020;5(10):614–619 Case presentation • Male, 23 years old • ORIF right proximal humerus fx months ago • Swelling, warm, redness, painful scar for month, unconfirmed purulent drainage, fever (-) • Exam: tenderness (+), restricted shoulder ROM • WBC 8.32 G/L, Neu 58.7%, CRP 13.1 mg/L Can FRI be diagnosed at this time? Clinical Diagnosis – FRI Confirmatory Criteria ≥ • Fistula, sinus or wound breakdown (communication to bone / implant) • Purulent drainage or presence of pus Note: presence of pathogens via culture is NOT an absolute requirement, esp in chronic antibiotic-use cases Source: Govaert et al J Orthop Trauma 2020;34:8-17 10 Clinical Diagnosis – FRI PO 8m Suggestive Criteria ≥ Radiological signs Bone lysis (at fracture, around implant) Implant loosening PO yr Sequestration (occurring over time) Failure of progression of bone healing (non-union) Periosteal bone formation (≠ fracture site / in case of a consolidated fracture) Source: Govaert et al J Orthop Trauma 2020;34:8-17 Bosch et al Clin Transl Imaging 2020;8:289-298 14 Come back to the case • Male, 23 years old • ORIF right proximal humerus fx months ago • Swelling, warm, redness, painful scar for month, unconfirmed purulent drainage, fever (-) • Exam: tenderness (+), restricted shoulder ROM • WBC 8.32 G/L, Neu 58.7%, CRP 13.1 mg/L • Imaging Suggestive criteria (+)  Then, what should we do? 15 Diagnostic Flowchart Source: Govaert et al J Orthop Trauma 2020;34:8-17 16 Post-op Diagnosis – FRI Confirmatory Criteria ≥ • Culture: phenotypically indistinguishable pathogens from ≥ separate deep tissue / implant specimens • Histopathology: – Microorganisms in deep tissue specimen Preferably samples: • Ideally from implant – bone interface • Avoid superficial, skin, or sinus tract samples • By separate clean, unused instruments • ‘No touch’ the skin • Put in separate pieces of gauze • Transferred in separate containers – > polymorphonuclear neutrophils via high-power field (Govaert et al, 2020) Source: Govaert et al J Orthop Trauma 2020;34:8-17 17 Post-op Diagnosis – FRI Implant Sonication Confirmatory Criteria ≥ • Culture: phenotypically indistinguishable pathogens from ≥ separate deep tissue / implant specimens • Histopathology: – Microorganisms in deep tissue Only in chronic / late-onset cases (nonunion) specimen – > polymorphonuclear neutrophils via high-power (x400) field (Govaert et al, 2020) Source: Govaert et al J Orthop Trauma 2020;34:8-17 Morgenstern et al Bone Joint J 2018;100-B:966–972 18 Post-op Diagnosis – FRI Suggestive Criteria In combination with other suggestive criteria there should be a high suspicion of FRI Culture: pathogenic organism from a single deep tissue / implant specimen Source: Govaert et al J Orthop Trauma 2020;34:8-17 19 The patient underwent surgery 20 Source: Onsea et al Injury 2022;53(6):1867-1879 21 Timing Classification of IAFF • Early (< weeks): – Highly virulent organism – Biofilm: may ‘immature’ – Bone: ‘inflammatory’ or ‘soft callus’ • Delayed (2 – 10 weeks): – Less virulent organism – Biofilm: ‘mature’, more resistant – Bone: ‘hard callus’ • Late (> 10 weeks): – Low virulent organism – Periosteal new bone formation, involucrum Source: Metsemakers et al Injury 2018;49(3):511-522 22 Classification of Osteomyelitis • 12 clinical stages • Guide treatment strategies • NO correlate with prognosis • NO reference to soft tissue coverage & microbiology Source: Cierny et al Chin Orthop Relat Res 2003;414:7-24 23 The new BACH Classification • High reproducibility • Can be applied accurately by users with a variety of clinical backgrounds • Need further evaluation for prognosis & management Source: Hotchen et al Bone Joint Res 2019;8(10):459-468 24 The Joint-Specific BACH classification 25 Everything is not perfect ! • Lack of evidence regarding value & validity of parameters for diagnostic criteria • Definition based on consensus of small group of experts Meeting of 35 experts on diagnosis for FRI in 2018 However, the definition: (AO Foundation) • Offers opportunity to standardize clinical reports &  quality of published literature • Leads to a standardized clinical approach toward diagnostic workup of patients with suspected FRI Source: Govaert et al J Orthop Trauma 2020;34:8-17 26 FUTURE DIRECTIONS FOR CLINICAL MICROBIOLOGY FRI DIAGNOSTICS • Optimized culture techniques • Molecular diagnostics 27 Take–home messages • Fracture – Related Infections = all infections occur in the presence of a fracture • FRI diagnosis is a step-wise approach, based on confirmatory criteria & suggestive criteria • FRI classification should involve the timing, extent of bone involvement, host status, microbiology & soft tissue coverage 28