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

Infections About TKR Range:1.1% % Mayo Series:1.2% - 3,000 Brigham/Women’s Hospital:1.6% - 4,171

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

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

Complications in TKR Infection – Clinical Course Infection – Clinical Course l 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 TKR

Late > 3 months Symptoms: 52 patients  Pain96%  swelling77%  Debride27%  Active drainage27%  Sed rate 63 mm/hr  WBC Windsor et al JBJS; 1990 Infections About TKR

Late > 3 months l More common l Hematogenos spread Infections About TKR

Complications in TKR Infection – Surgical Techniques l Avoid skin bridges l Avoid creation of skin flaps l Hemostasis l Prolonged operating time

Complications in TKR Infection – Work-Up l Wound History l Physical Exam l Serial Radiographs l Lab/sed rate/CRP l Bone scan / Indium scan

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

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

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

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 TKR Infection TKR

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

Complications in TKR Treatment Options l Antibiotic suppression — Indicated in med compromised — Organism - gram+ strep staphepi

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

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

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

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

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

Complications in TKR Two-Stage Reimplantation l Most successful treatment l Procedure of choice

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

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

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

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

Complications in TKR 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 TKR

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

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

Stage III – Reimplantation  Serial aspirations  Pre-op planning  Bone scan / Sed rate

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

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

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

Complications in TKR 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

Algorithm TKA Clinical Sepsis (GRAM + Organism) < 3 wks > 3 wks Debridement Antibiotics (6 wks) 2-Stage Replant Infections About TKR

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

Thank You Frank R. Ebert, MD