Periprosthetic Joint Infection: Infected Hip Replacement Treatment in Birmingham
Periprosthetic joint infection (PJI) is one of the most serious complications after hip replacement. Bacteria colonise the implant surface and form a biofilm that the immune system cannot penetrate without surgical help. Mr Shakir Hussain, Consultant Orthopaedic Surgeon at the Royal Orthopaedic Hospital Birmingham, manages infected hip replacements with specialist two-stage revision surgery at a dedicated specialist orthopaedic centre.
What is periprosthetic joint infection of the hip?
Periprosthetic joint infection is infection of the tissues and implant surrounding a hip replacement. Bacteria attach to the metal and ceramic components and build a protective biofilm that white cells and antibiotics cannot penetrate. Because the hip joint lies deep in the body beneath substantial muscle and adipose tissue, the clinical signs of PJI are far less obvious at the hip than at the knee, making laboratory and imaging investigations especially important for an accurate diagnosis.
The hip's deep anatomical position means that swelling, surface warmth, and redness, which are reliable signs of knee PJI, may be entirely absent even when a hip prosthesis is heavily infected. A patient with a hip replacement infection may present with nothing more than persistent groin pain and slightly elevated blood tests. This is why specialist assessment with a structured diagnostic pathway is essential.
PJI is classified by timing. Early infection occurs within three months of surgery, typically from organisms introduced at the time of the primary operation. Delayed infection occurs between three and 24 months, often with less virulent organisms and a more insidious, gradual presentation. Late infection occurs after 24 months, most commonly via haematogenous seeding from a remote site such as a urinary tract infection, dental procedure, or skin wound.
Once bacteria establish a biofilm on the implant surface, systemic antibiotics cannot penetrate the protective matrix. This is the fundamental reason that surgical intervention is required for cure in almost all cases of hip PJI. The choice between implant-retaining surgery and staged revision depends on the timing of infection, the identity and virulence of the organism, the security of the existing implant fixation, and the overall condition of the patient.
Specialist management at a dedicated orthopaedic infection centre, with access to full microbiology support and complex revision implant systems, is associated with substantially better outcomes than treatment at a general orthopaedic unit.
What are the signs of an infected hip replacement?
The most consistent warning sign is pain that has not settled as expected, or that returns after initial improvement. Because the hip joint is deep, external signs such as swelling and redness are often absent or subtle. Elevated blood inflammatory markers, a wound that discharges persistently, and systemic unwellness all warrant urgent orthopaedic assessment.
Persistent or returning groin pain
Pain in the groin or deep in the thigh that fails to improve on the expected post-operative trajectory, or that returns after a comfortable period, is the cardinal symptom of hip PJI across all timing categories. It should not be attributed to rehabilitation difficulties without exclusion of infection.
Wound discharge or sinus tract
A wound that continues to leak fluid, or a sinus that develops weeks or months after surgery connecting the skin surface to the deep tissues, is a strong indicator of deep infection and requires immediate surgical assessment. The deep hip anatomy means such a sinus may not appear close to the implant even when tracking from it.
Fever and systemic illness
Acute haematogenous PJI typically presents abruptly, with fever, chills, rigors, and general unwellness. Any patient with a joint replacement who develops a septic picture must be assumed to have prosthetic joint infection until proven otherwise, and should be assessed urgently.
Swelling and warmth (when present)
The hip's depth means that warmth and swelling are less prominent and less reliable signs than at the knee. When these features are present alongside elevated inflammatory markers, they add weight to the diagnosis, but their absence does not exclude deep hip infection.
Elevated inflammatory blood markers
Raised CRP (C-reactive protein) and ESR (erythrocyte sedimentation rate) that persist beyond the expected post-operative normalisation period, or that rise again after initial improvement, are important supporting findings. A normal CRP makes PJI substantially less likely.
Stiffness that did not resolve
Persistent stiffness and reluctance to bear full weight beyond the expected recovery period, particularly in the absence of mechanical loosening on X-ray, may indicate a chronic low-grade infection that has been smouldering since the primary surgery.
Who is at risk of periprosthetic hip infection?
PJI after hip replacement affects approximately 1 per cent of patients at high-volume specialist centres, but individual risk is substantially higher in patients with diabetes, obesity, immunosuppression, or rheumatoid arthritis, and in those with a remote site of infection at the time of surgery or a prolonged primary operation.
The same patient and procedural risk factors that increase the risk of knee PJI apply to hip PJI, with some additional hip-specific considerations:
- Obesity. Adipose tissue around the hip is relatively poorly vascularised, reducing immune surveillance at the wound site and increasing the technical complexity of the operation. Both factors contribute to a higher infection risk in patients with elevated BMI.
- Diabetes mellitus. Impaired neutrophil function and reduced tissue healing in diabetic patients increase susceptibility to infection. Optimising glycaemic control before elective hip replacement surgery is an established risk-reduction measure.
- Immunosuppression. Patients taking corticosteroids, biologic agents for rheumatoid or inflammatory arthritis, or post-transplant immunosuppression have a reduced capacity to contain bacterial contamination and require careful peri-operative management.
- Metal-on-metal hip bearings. Some patients with metal-on-metal hip replacements develop adverse local tissue reactions (ALTR) that can mimic PJI clinically, and the metal debris produced can obscure interpretation of standard PJI investigations. MARS MRI (Metal Artifact Reduction Sequence) is particularly important in this group to characterise soft tissue changes and pseudotumour formation.
- Prior hip surgery. Each previous operation on the same hip introduces organisms, reduces tissue quality, and alters local anatomy. The number of prior hip operations is an independent risk factor for PJI in revision hip surgery.
- Remote site of infection. Any active infection at the time of surgery, including dental, urinary, or skin infections, substantially increases the risk of haematogenous seeding of the new prosthesis. Elective hip replacement should be deferred until all remote infections are fully treated and resolved.
How is a periprosthetic hip infection diagnosed?
Because clinical signs are often subtle at the hip, the diagnostic workup for suspected PJI relies heavily on blood tests (CRP, ESR), hip aspiration under image guidance, alpha-defensin testing, and nuclear medicine imaging. MSIS criteria combine these results to confirm or exclude the diagnosis. Tissue cultures at revision surgery provide the definitive bacteriological identification.
The structured diagnostic pathway for hip PJI mirrors the approach used for the knee but places greater weight on laboratory and imaging investigations, because external clinical signs are less reliable:
- Blood tests: CRP, ESR, WCC. CRP above 10 mg/L (after the acute post-operative period has resolved) and ESR above 30 mm/hr are the most sensitive screening markers. These tests are straightforward, inexpensive, and should be the first investigation in any patient with unexplained pain after hip replacement.
- Hip joint aspiration under image guidance. Because the hip lies deep, aspiration is always performed under fluoroscopic or ultrasound guidance to ensure accurate needle placement. Synovial fluid is sent for white cell count and differential, culture and sensitivity (including prolonged culture for slow-growing organisms), and alpha-defensin. Alpha-defensin is a highly specific biomarker for PJI that is not affected by recent antibiotic use.
- MARS MRI (Metal Artifact Reduction Sequence). In patients with metal-on-metal hip bearings, or where soft tissue involvement or pseudotumour formation is suspected, MARS MRI provides detailed characterisation of periprosthetic soft tissue changes that cannot be assessed on standard MRI sequences or CT.
- Nuclear medicine imaging (labelled white cell scan). A leucocyte scintigraphy scan identifies areas of active white cell accumulation around the implant. This investigation is particularly valuable in chronic or low-grade PJI where CRP and ESR may be only mildly elevated.
- Tissue cultures at revision surgery. Multiple periprosthetic tissue samples taken at the time of revision, cultured for at least two weeks to allow for slow-growing organisms such as Cutibacterium acnes, provide the definitive bacteriological result and guide targeted antibiotic therapy after surgery.
How is an infected hip replacement treated?
Treatment depends on the timing of infection and whether the implant remains well-fixed. Early PJI with a well-fixed implant and recent symptom onset may be treated with DAIR (debridement, antibiotics, and implant retention), including exchange of the femoral head and acetabular liner. Established or late PJI requires two-stage revision: removal of all components, an antibiotic spacer, systemic antibiotics, and later re-implantation of a new hip replacement.
The surgical strategy is determined by the timing and type of infection, the security of the existing implant, the organism identified on aspiration, and the patient's overall fitness for major revision surgery. Long-term suppressive antibiotics may be considered in patients who are not fit for any further surgery, but this does not eradicate the infection and is a palliative approach only.
DAIR with Femoral Head and Liner Exchange
DAIR is appropriate when the implant is confirmed well-fixed on X-ray, symptoms have been present for fewer than three to four weeks, and the causative organism is sensitive to antibiotics including biofilm-active agents. The hip is opened, all infected and devitalised tissue is thoroughly debrided, the femoral head and acetabular liner are exchanged for new components, and a prolonged antibiotic course (including rifampicin for staphylococcal infection) is given. Technical success requires a complete synovectomy and meticulous wound closure. Success rates of 50 to 70 per cent are achievable in carefully selected patients.
- Implant components retained if confirmed well-fixed on X-ray
- Thorough debridement of all infected and devitalised tissue
- Femoral head and acetabular liner exchanged for new components
- Prolonged antibiotic course (typically 3 to 6 months)
- Success rate approximately 50 to 70 per cent in carefully selected patients
Two-Stage Revision Hip Replacement
Stage 1 removes all implant components, including cement if present (which is technically demanding at the hip due to the long femoral stem and well-integrated cement mantle), debrides all infected tissue, and places an antibiotic-loaded cement spacer. At the hip, articulating moulded cement spacers allow some mobility between stages, reducing soft tissue contracture and the difficulty of Stage 2. Following 6 to 12 weeks of systemic antibiotics and confirmed eradication (normalised CRP, ESR, and clinical improvement), Stage 2 re-implants a new hip replacement, typically using revision-grade femoral stems and acetabular reconstruction components to achieve secure fixation in bone that has been weakened by infection and the previous surgery. Success rates of 80 to 90 per cent at specialist centres.
- All infected components and cement removed at Stage 1
- Articulating antibiotic-loaded cement spacer to maintain mobility between stages
- 6 to 12 weeks of systemic antibiotics tailored to the causative organism
- Infection eradication confirmed before Stage 2 reimplantation
- Revision-grade stems and acetabular components for secure fixation in compromised bone
In exceptional circumstances where reimplantation is not possible, Girdlestone excision arthroplasty (removal of the femoral head without replacement) may be performed as a salvage option. This eliminates infection but leaves the patient with significant leg length discrepancy and ongoing mobility difficulty, and is reserved for cases where no other option exists.
Mr Hussain performs complex revision hip surgery for PJI at the Royal Orthopaedic Hospital Birmingham. See the dedicated revision hip surgery page for full details of the operative approach, recovery, and outcomes across the full range of hip replacement failure modes.
What are the outcomes of revision surgery for hip PJI?
Two-stage revision for hip PJI achieves infection eradication in 80 to 90 per cent of cases at specialist centres with dedicated infection pathways. Outcomes are best when a single organism is identified, the organism is sensitive to standard antibiotics, bone loss is limited, and the patient's modifiable risk factors have been optimised before Stage 2 surgery.
The hip-specific challenges of PJI revision include the technical difficulty of cement removal from a long femoral stem, the greater depth of the joint requiring extended exposure, and the higher complexity of acetabular reconstruction where infection has caused additional bone loss on top of any pre-existing deficit. These are precisely the factors that make specialist centre treatment at a high-volume unit so important.
Reinfection after two-stage hip revision is more likely when the causative organism is resistant to standard antibiotics, when bone loss is severe, or when patient-related risk factors such as obesity, diabetes, or immunosuppression are not optimised before Stage 2. Mr Hussain works closely with microbiology and the multidisciplinary infection team at the Royal Orthopaedic Hospital to plan antibiotic therapy and timing for each patient.
Specialist expertise in infected hip replacement in Birmingham
Consultant at the Royal Orthopaedic Hospital
Mr Hussain practises at the Royal Orthopaedic Hospital Birmingham, with dedicated orthopaedic infection pathways, specialist microbiology support, and access to the full range of complex revision implant systems required for PJI reconstruction.
3,000+ arthroplasty cases from 5,000+ procedures
A high operative volume including complex primary and revision cases across the full range of hip failure modes. Read more about Mr Hussain's training and background.
British Hip Society Travelling Fellowship at ENDO-Klinik Hamburg
Mr Hussain trained under Professor Thorsten Gehrke and Professor Mustafa Citak at ENDO-Klinik Hamburg, specifically in complex hip revision surgery and infection management at one of Europe's leading periprosthetic infection centres.
Complex revision hip surgery expertise
Mr Hussain performs revision hip replacement for PJI, aseptic loosening, instability, and periprosthetic fracture. See the revision surgery page for the full scope of revision work.
Doctify Outstanding Patient Experience 2024, 2025, and 2026
Three consecutive years of recognition for consistently high patient-reported outcomes and communication throughout the surgical journey.
4.98 out of 5 from verified reviews on Doctify. Outstanding Patient Experience Award 2024, 2025, and 2026.
Frequently asked questions about hip replacement infection
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