Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Fracture-related and metalwork infection
Musculoskeletal medicine and orthopaedics · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
!
Sepsis and unstable infected fixation require immediate assessment
Fracture-related infection can present as an acute leaking wound or late infected non-union; systemic illness, deep abscess, implant failure and compromised cover threaten life, limb and the mechanical pathway to union.
Action: If septic, obtain blood cultures and give parenteral antibiotics immediately while arranging drainage. If stable, withhold empirical therapy, obtain consultant review within 48 hours, define union, fixation, perfusion and soft tissue, and plan five deep cultures, debridement, stability and coverage through the bone-infection multidisciplinary team.
Overview
Recognise confirmatory and suggestive infection around fracture fixation, protect diagnostic yield, integrate union, stability, biofilm and soft-tissue decisions, and coordinate debridement, implant strategy and culture-directed therapy.
Fracture-related infection includes early wound infection, delayed implant biofilm and late infected non-union. Build a timeline from injury energy, open-wound contamination and debridement through fixation, coverage, wound leakage, union progression, later procedures and every antimicrobial. Ask whether symptoms began abruptly after a symptom-free period, which may indicate haematogenous seeding. Record smoking, diabetes, vascular disease, nutrition, renal disease, immune suppression and prior resistant organisms because eradication and reconstruction depend on host biology as much as antibiotic susceptibility.
Assess sepsis first. Then inspect wounds, scars, sinuses, drainage, exposed implants and soft-tissue viability without probing. Document alignment, abnormal motion, limb length, tenderness and function and perform full neurovascular examination. A communicating sinus or wound breakdown and intra-operative pus are confirmatory. Fever, redness, persistent drainage, increasing pain, non-union and implant loosening are suggestive and require a structured work-up; none alone should be used to prescribe repeated empirical courses.
Practice
Two practice questions
Your practice draft is saved in this browser.
Question 1 of 2
0 correct
Musculoskeletal medicine and orthopaedicsOriginal SBA
Stable leaking fixation wound
A systemically well patient has persistent wound leakage three weeks after fracture fixation and has not taken antibiotics. What is the best immediate pathway?
Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.
BOASt separates unstable from stable patients. Systemic sepsis requires immediate medical assessment, blood cultures and parenteral treatment without delay. A stable person should have consultant review within 48 hours and should not start antibiotics beforehand. For non-acute infection, agree an antibiotic-free interval with microbiology, at least two weeks under BOASt when safe. This pause never applies to shock, rapidly spreading infection or threatened tissues. Protect an unstable fracture while diagnostic planning occurs.
Plain radiographs assess union, alignment, fixation failure, loosening, periosteal reaction and bone lysis. CT provides more exact union, sequestrum and implant-position detail. MRI maps marrow and soft tissue but metal artefact and postoperative change reduce specificity. Ultrasound can guide aspiration of a collection when debridement will be delayed. Nuclear imaging is reserved for defined uncertainty. Imaging supports surgical mapping; confirmatory microbiology and histology come from properly obtained deep samples.
At debridement, take five deep samples around the fracture with separate sterile instruments and no-touch technique. In chronic or diagnostically uncertain acute disease, add two histology specimens. Do this before irrigation and antibiotics when physiology permits. Label sites and tell microbiology about implants and prior drugs. At any later surgery for delayed or non-union, repeat the same sampling discipline unless the fracture is soundly united with no infection evidence and metal removal is purely elective.
The operation combines infection and fracture principles. Excise non-viable tissue and sequestra, open collections and assess fixation stability and bone viability. If the fracture is united, infected hardware can usually be removed. If ununited, stable fixation may sometimes be retained temporarily after radical debridement, or exchanged to restore stability; loose or failed implants cannot provide a credible union strategy. Manage dead space and coordinate definitive vascularised soft-tissue cover. Plans for bone defects may include staged grafting or transport.
Start broad-spectrum antibiotics after sampling and review at 48 hours with preliminary results. An infection specialist then defines the exact organism-directed agent, route, interaction monitoring and duration around debridement, retained material and union plan. Biofilm-active therapy is purposeful only when the organism is susceptible and implants remain in a controlled field. Antibiotics without diagnostic work-up should be stopped in stable patients, and prolonged suppression is reserved for explicit goals when eradication or implant removal must wait.
Review all proven and suspected cases in a weekly bone-and-joint infection multidisciplinary meeting, particularly late, recurrent, non-responsive and defect cases. Follow wound closure, CRP where useful, blood-culture clearance, union, hardware, antimicrobial toxicity and function. Give patients written instructions for drainage, fever, escalating pain and mechanical change. Smoking cessation, glucose control, nutrition, vascular optimisation and rehabilitation directly influence union and recurrence. Outcome discussion includes reoperation, non-union, amputation and mortality.
Key points
A sinus, fistula or wound breakdown communicating with the fracture or implant, or purulence at surgery, is confirmatory evidence of fracture-related infection.
Suggestive features include persistent drainage, redness, swelling, fever, increasing pain, radiographic loosening, lysis, non-union and new effusion; they trigger investigation rather than proving infection alone.
Septic patients receive immediate assessment, blood cultures and parenteral antibiotics. Stable patients should have consultant review within 48 hours and no empirical antibiotics before that review.
Assess union, fixation stability, deformity, perfusion, soft-tissue cover, previous cultures and antibiotics and host factors before choosing retention or removal.
Use plain radiographs first for union, loosening, periosteal reaction and lysis; add CT for union and sequestra and MRI or nuclear imaging for a specific extent question.
When debridement is indicated, take five deep microbiology specimens with separate instruments and two histology samples in chronic or uncertain infection.
In stable non-acute infection, discuss an antibiotic-free interval with microbiology; BOASt gives a minimum two weeks before sampling when safe.
After samples, start broad treatment, review at 48 hours, and link definitive antibiotics to debridement, fracture stability, implant strategy and vascularised cover.
Aetiology
01
Initial contamination
Open injury, severe soft-tissue damage or contamination introduces organisms at fracture onset and increases risk despite prompt antibiotics and debridement.
02
Operative inoculation
Fixation surgery can seed an implant or devitalised fracture environment, particularly after haematoma, prolonged leakage or repeated procedures.
03
Contiguous wound spread
Breakdown, ulceration or exposed hardware provides a route from skin to the fracture and may introduce mixed organisms.
04
Haematogenous seeding
Later bacteraemia can colonise existing metalwork or an incompletely united fracture, though this is less common than peri-injury or perioperative acquisition.
Pathophysiology
1
Implant biofilm
Adherent organisms form a protected matrix on metal and devitalised bone, reducing antimicrobial susceptibility and enabling relapse after apparently active therapy.
2
Instability-inflammation cycle
Infection impairs union while fracture motion damages perfusion and tissue, creating an environment in which both biology and mechanics fail.
3
Sequestration and dead space
Non-viable fragments and cavities lack reliable host and drug access and remain reservoirs unless removed or reconstructed.
4
Soft-tissue failure
Poor cover exposes fixation and reduces vascular delivery, allowing contamination and preventing durable closure after debridement.
5
Systemic propagation
An uncontrolled fracture focus can produce bacteraemia, sepsis and metastatic infection, particularly during acute wound breakdown.
Clinical features and red flags
Confirmatory sinus
A sinus, fistula or wound breakdown communicating with the fracture or implant establishes infection irrespective of superficial swab results.
Confirmatory purulence
Pus found around the fracture or implant at surgery is direct evidence and should trigger full deep-sampling and source-control standards.
Early leaking wound
Persistent or increasing postoperative drainage needs prompt consultant review because empirical community treatment can obscure a deep focus.
Infected non-union
Failure of union with pain, loosening, lysis or broken fixation requires infection sampling even without systemic inflammation.
Implant instability
New deformity, abnormal movement or hardware failure means the mechanical environment is unsafe and retention logic must be reconsidered.
Compromised envelope
Necrotic skin, exposed metal or poor arterial flow predicts failure unless perfusion and vascularised coverage are restored.
Red flags requiring action
Shock, spreading erythema, rapidly increasing drainage or deep fluctuance requires immediate medical and surgical source-control assessment and antibiotics after blood cultures.
New deformity, abnormal movement, broken hardware or inability to load suggests fixation failure or infected non-union and requires protection and urgent imaging.
Investigations
01Initial plain radiographsFirst step
Why
Assess union, alignment, lysis and implant integrity.
Interpretation and limitations
Loosening, periosteal reaction and non-union are suggestive rather than independently confirmatory and should be compared with earlier images.
02FBC, CRP and organ profile
Why
Measure systemic response and treatment safety.
Interpretation and limitations
Normal markers do not exclude biofilm infection; renewed CRP rise and wound change are more informative than one postoperative value.
03Blood cultures in sepsis
Why
Identify bacteraemia before immediate treatment.
Interpretation and limitations
Take promptly and repeat clinically important persistent positives while searching endovascular and metastatic sources.
04CT or MRI for a defined question
Why
Map union, sequestrum, abscess and soft tissue.
Interpretation and limitations
CT excels at cortex and mechanics; MRI shows soft tissue and marrow but artefact and postoperative inflammation can mislead.
05Five deep cultures
Why
Identify organisms from independent fracture and implant sites.
Differential diagnosis
01
Aseptic non-union
Mechanical instability, smoking and poor biology can prevent union without infection, but every revision should use a planned deep-sampling strategy.
02
Sterile wound reaction
Suture or haematoma reaction may drain superficially, yet persistent leakage or deep communication requires infection exclusion.
03
Expected postoperative inflammation
Early pain and CRP rise may be physiological; failure to improve, renewed rise and wound change are more concerning than one value.
04
Implant prominence
Mechanical irritation causes focal pain or skin risk without infection, though impending exposure can create a future microbial route.
05
Tumour or inflammatory lesion
Destructive bone change and non-healing can reflect malignancy or sterile disease and require histology when the pattern is atypical.
Management
01SepticTreat systemic danger and drainFirst stepOrgan dysfunction, bacteraemia or rapidly progressive fracture-site infection is present.+
1Obtain blood cultures, start parenteral therapy and call orthopaedic, anaesthetic and infection teams immediately.
2Protect unstable fixation and assess perfusion, soft tissue and deep collections urgently.
3Debride and drain without avoidable delay, obtaining five deep samples and histology where feasible.
4Review blood-culture clearance and plan stability and coverage after physiological rescue.
02StablePreserve diagnosis and plan reconstructionDrainage, pain, loosening or non-union suggests infection without systemic illness.+
1Withhold antibiotics and arrange consultant review within 48 hours, documenting prior agents and wound chronology.
2
Complications
01
Infected non-union
Persistent organisms, bone loss and instability prevent union and require staged reconstruction, prolonged rehabilitation and repeated surgery.
02
Implant failure
Loose or broken fixation causes deformity, soft-tissue injury and loss of alignment and can abruptly convert a contained infection into an emergency.
03
Bone and soft-tissue loss
Radical debridement may leave segmental defects or exposed structures needing graft, transport, flap or other specialist reconstruction.
04
Recurrent infection
Retained biofilm, incomplete excision, poor vascularised cover or unsuitable therapy causes repeated drainage, renewed bone loss and future operations.
05
Amputation and death
Uncontrolled sepsis, non-reconstructable perfusion or function and extensive tissue loss can make amputation necessary and systemic infection fatal.
Monitoring and follow-up
Track observations, wound leakage, erythema, pain and blood-culture clearance through acute treatment.
Review union, alignment and hardware integrity on serial radiographs and protect loading when fixation is unsafe.
Inspect flap or soft-tissue cover and reassess arterial supply when healing stalls.
Review deep cultures, histology and antibiotic plan at 48 hours and in the weekly bone-infection MDT.
Monitor renal, liver and marrow indices and interaction-sensitive medicines during prolonged therapy.
Infection cannot be planned separately from mechanics because unstable bone perpetuates inflammation and determines whether implants can be removed.
Normal markers do not clear metalwork
Biofilm infection and infected non-union may generate little systemic inflammatory response despite progressive loosening.
Five samples need five instruments
Multiple containers alone do not create independence if one tool carries the same contaminant across every site.
Antibiotic-free time is conditional
The BOASt minimum two weeks applies to safe non-acute sampling, never to sepsis or threatening wound progression.
Retention is sometimes temporary
Stable fixation may be kept to achieve union, with later removal, rather than assumed to be permanent eradication.
Coverage changes microbiology success
Vascularised tissue closes the route of contamination and delivers immune and antimicrobial access to the reconstructed site.
Common pitfalls
01
Giving repeated empirical antibiotics for a leaking wound before consultant review and deep sampling.
02
Equating one positive superficial swab with the fracture-site organism.
03
Planning infection surgery without knowing whether the fracture is united or fixation is stable.
04
Taking pooled or single deep samples and overinterpreting a possible contaminant.
05
Retaining loose hardware or removing essential fixation without an alternative stability plan.
06
Ignoring perfusion, soft-tissue cover, smoking and glucose while extending antimicrobials.
Exposed metalwork, skin necrosis, threatened flap or absent arterial signals indicates a combined infection, perfusion and coverage emergency.
Persistent wound leakage after fixation needs prompt consultant-led investigation; repeated community antibiotic courses can suppress cultures while biofilm and non-union progress.
Interpretation and limitations
Use fresh instruments and no-touch technique before irrigation; concordant results are stronger than one possible contaminant.
06Two histology specimens
Why
Confirm tissue inflammation in chronic or uncertain infection.
Interpretation and limitations
Histology complements culture and can reveal alternative pathology; label anatomical sites precisely.
07Perfusion and host assessment
Why
Determine capacity for union, antimicrobial delivery and coverage.
Interpretation and limitations
Doppler and vascular studies, glucose, nutrition, smoking and immune status change the reconstruction and failure risk.
Discuss at least a two-week antibiotic-free interval for non-acute sampling with microbiology when safe.
3Define union, fixation, perfusion and cover with radiographs and targeted cross-sectional imaging.
4Plan debridement, five cultures, two histology samples, implant strategy and reconstruction through the infection MDT.
03DefinitiveJoin eradication to unionDefinitiveSamples, anatomy and host capacity are known after adequate debridement.+
1Remove non-viable tissue and unnecessary or loose implants and manage all dead space.
2Retain or exchange essential fixation only within a documented stable path to fracture union.
3Provide durable vascularised cover and start post-sampling therapy, reviewing preliminary cultures at 48 hours.
4Track union, wound, toxicity and recurrence weekly in MDT until responsibility and endpoints are clear.
Key medicines and prescribing safety2 treatments · regimens, roles and cautions+
Provides initial systemic cover while debridement, independent samples and fixation anatomy establish definitive treatment.
Post-sampling broad-spectrum therapy
After five deep cultures and indicated histology, give the full adult fracture-related-infection protocol regimen and review it at 48 hours with preliminary results; in sepsis, give parenteral therapy after rapid blood cultures even if deep sampling must follow.
Choice depends on allergy, renal and hepatic function, local resistance and prior isolates; avoid empirical treatment of a stable leaking wound before consultant review, and never substitute breadth for stability, perfusion or cover.
Targets residual planktonic and biofilm organisms in relation to the debridement and planned time to union or implant removal.
Directed implant-associated regimen
Use the narrowest organism-active regimen with exact dose, route, monitoring and duration agreed by the infection specialist after culture review, adding any biofilm-active component only for a susceptible organism and a deliberate retained-implant strategy.
Check all interactions, renal, hepatic and marrow toxicity and oral absorption; suppression until union requires written failure criteria and an implant-removal plan rather than open-ended unreviewed prescribing.