Management of Infections About Total Hip Arthroplasty Frank Ebert, M.D. Union Memorial Hospital Baltimore, MD

Infections About THA Range:1.1% % - 60’s Rate 2000 – 0.5% Rate Primary OA – 0.06%

Complications in Arthroplasty Infection – Risk Factors l Skin ulcerations / necrosis l Rheumatoid Arthritis l Previous hip/knee operation l Recurrent UTI l Oral corticosteroids

Complications in Arthroplasty Infection – Risk Factors l Chronic renal insufficiency l Diabetes l Neoplasm requiring chemo l Tooth extraction

Complications in Arthroplasty Infection – Clinical Course- Acute/Chronic Infection – Clinical Course- Acute/Chronic Pain #1 l Swelling l Fever l Wound breakdown drainage Windsor et al JBJS; 1990

Early < 3 months Lab Value l WBCs Mayo Series Mean 7,500 l Differential 67 PMN’s l Sed rate71 mm/hr l Arthrocentesis Infections About THA

Late > 3 months-Chronic  Pain96%  swelling77%  Debride27%  Active drainage27%  Sed rate 63 mm/hr  WBC Windsor et al JBJS; 1990 Infections About THA

Late > 3 months-Acute-Late Hematogenous l Recent Hx-surgery/dental/distal infection l Classic Symptoms of Sepsis l Fever, Pain,ElevatedWBC Infections About THA

Complications in Arthroplasty Infection – Surgical Techniques l Avoid skin bridges-7 cm rule l Avoid creation of skin flaps l Hemostasis l Prolonged operating time

Complications in Arthroplasty Infection – Work-Up – Requires a Combination of Studies l Wound History l Physical Exam l Serial Radiographs l Lab/sed rate/CRP/WBC l Bone scan / Indium scan

Complications In Arthroplasty Indium Scan - Superseded Tech and Gallium - More Specific and More Sensitive - Specificity and Sensitivity > 85%

Complications in Arthroplasty Infection – Work-Up Arthrocentesis – direct smear – gram strain – aerobic – anaerobic – acid fast – fungi

Complications in Arthroplasty InfectionArthrocentesis l Cell count l Diff > 25,000 pmn l Protein – high l Glucose – low

Complications in Arthroplasty Infection l Host Response Glycocalyx Glycocalyx Gristina JBJS; 1983

Prosthetic Joint Infection Biofilm l Biofilm on implants and devitalized tissue causes chronic disease l Understanding biofilm enlightens one to logical treatment

Biofilm Characteristics l All bacteria make biofilm l Foreign and devitalized tissue can succumb to biofilm formation if exposed to bacteria Costerton Science 284:

Biofilm Characteristics l 15% cells, 85% matrix l Matrix – polysaccharide l Biofilms have structure l Cells live in a microecology and communicate! Costerton Science 284:

Biofilm Significance in PJI l In biofilm state, bacteria become 1000x to 1500x more resistant to antibioctics l In biofilm state, bacteria express up to 65 new genes which change cell wall and/or membrane structure Costerton Science 284:

Biofilm State Significance in PJI and Osteomyelitis l Resistant to antibiotics l Biofilm permeable to antibiotics all the way to base within 90 secs l Resistant to WBC’s and Phagocytosis l Resistant to Antibiotics Costerton Science 284:

Biofilm Significance in PJI l Biofilm can colonize, grow and cover a surface within 4-8 days! l Prolonged wound drainage should not be allowed Costergan. W. MSIS 2000

Treatment Prosthetic Joint Infection Chronic Infections l To effectively treat a chronic infection, you must be able to planktonize cells l At present time, effective treatment means prosthetic removal and debridement of surrounding devitalized bone and tissue

Micro Organisms

Staphylococcus64 S. aureus, penicillin sensitive 14 S. aureus, penicillin resistant28 S. epidermis22 S. aureus, penicillin sensitive 14 S. aureus, penicillin resistant28 S. epidermis22 Gram negative12 Pseudomonas7 Escherichia coli5 Anærobic6 Other17 OrganismPercent Complications in Arthroplasty Infection THA

Prosthetic Joint Infection Classification-Treatment Purposes l Early Post-Op (<4 weeks) l Late Hematogenous l Chronic Tsukayama et al: JBJS 78A, 96

Prosthetic Joint Infection Treatment Early Post-Op Infection < 4weeks l I&D with retention of components l Change modular parts l Resection of components if I&D fails

Prosthetic Joint Infection Treatment Hematogenous Infection l I&D with retention of components l Change modular parts l 2 stage reimplantation if I&D fails

Complications in Arthroplasty Treatment Options-Chronic l Debridement with antibiotic suppression therapy — Strep/staphepi -- best — Avoid repeated attempts — Frozen tissue section — Suction drains

Complications in Arthroplasty Treatment Options-Chronic l Antibiotic suppression-Acute/Chronic — Indicated in med compromised — Organism - gram+ strep staphepi

Complications in Arthroplasty Two-Stage Reimplantation- Chronic/Failed Acute Treatment l Most successful treatment l Procedure of choice l Remember Biofilm

Complications in Arthroplasty Two-Stage Reimplantation Stage I –Complete debridement Stage II –6 wks IV antibiotics Stage III –Reimplant

Complications in Arthroplasty Two-Stage Reimplantation Procedure l Remove components, cement, I & D l Fabricate and place spacer l 6 weeks of antibiotics l Reimplantation

Complications in Arthroplasty Two-Stage Reimplantation Stage I l remove prosthesis / cement l thorough debridement

Complications in Arthroplasty Two-Stage Reimplantation Stage I l create antibiotic spacer impregnated with antibiotics l wound closure

Complications in Arthroplasty Two-Stage Reimplantation l Spacer Antibiotic Regimen Tobramycin 2.4 gm/3.6 gm per 40 gms of PMMA Tobramycin 2.4 gm/3.6 gm per 40 gms of PMMA Vancomycin> 0.5 gm to 1 gm per 40 gms of PMMA Vancomycin> 0.5 gm to 1 gm per 40 gms of PMMA

Antibiotic Impregnated Spacer l Cidal levels of antibiotic l Spacer to preserve tissue tension l Facilitates reimplant and wound exposure Infections About THA

Complications in Arthroplasty Two-Stage Reimplantation Stage II l Reimplantation after antibiotic regimen

Stage III – Reimplantation  Serial aspirations  Pre-op planning  Bone scan /Indium Scan  ESR/CRP/WBC

Complications in Arthroplasty Intra-operative Frozen Section l < 5 PMN’s per HPF– no infection l > 10 PMN’s per HPF–infection Mirra; JBJS

Complications in Arthroplasty Resection Arthroplasty l Removal all components l Remove all cement l Effective in medically compromised patient

Algorithm THA Clinical Sepsis Acute/Hematogenous (GRAM + Organism) < 4 wks > 4 wks Debridement Antibiotics (6 wks) 2-Stage Replant Infections About THA

Algorithm Debridement Antibiotics Success 2-stage Replant Infections About THA No Success 2-stage Replant 2-stage Replant Success No Success Resection Arthroplasty

Thank You Frank R. Ebert, MD

Stage II – Antibiotic Treatment l Hickman catheter / Pick Line l MIC 1:8 / 6 wks Infections About THA

Complications in Arthroplasty Treatment Options l Debridement with antibiotic suppression therapy — Limited success — < 3 weeks Schoifet JBJS; 1990

Complications in Arthroplasty Treatment Options l Antibiotic suppression l Aggressive wound debridement

Complications in Arthroplasty Treatment Options l Resection arthroplasty l 2 Stage re-implant l Arthrodesis l Amputation

Complications in Arthroplasty Treatment Options Treatment Options Hip (% success)Knee (% success)

Complications in Arthroplasty Debridement with Antibiotic Suppression Debridement with Antibiotic Suppression Hip (% success)Knee (% success) 25 to 3525 to 35

Complications in Arthroplasty Results — Gm positive Windsor et al92 % JBJS 1990 Insall et al97%JBJS 1983 Insall et al97%JBJS 1983

Complications in Arthroplasty Arthrodesis Indications l Extensor mechanism disruption l Resistant bacteria l Inadequate bonestock l Inadequate soft tissues l Young patient

Advantages  Definitive treatment  Little chance of recurrence Arthrodesis

Disadvantages  Difficulty with transfers / small spaces  Increase energy requirements Arthrodesis