In the name of God

How to deal with Infected Total Knee Arthroplasty Mohsen Mardani-Kivi Assistant Professor, Orthopedic Department, Guilan University of Medical Sciences

Background Total joint replacement is one of the most commonly performed and successful operations in Orthopaedics as defined by clinical outcomes and implant survivorship* *

Incidence Infection has occurred in 1% to 2% of primary TKA surgeries and has been the leading cause of failure following TKA. The rate of peri-prosthetic infection has been declining over the last two to three decades, mostly due to operating room environments and operative techniques

Risk Factors for Infected Arthroplasty Prior surgery Surgery time > 2.5 hours Compromised immune status Poor nutrition Diabetes mellitus Obesity Smoking

Risk Factors for Infected Arthroplasty Chronic renal insufficiency Diabetes Neoplasm requiring chemo Tooth extraction Skin ulcerations / necrosis Rheumatoid Arthritis Recurrent UTI Oral corticosteroids

Surgical Techniques lHemostasis lProlonged operating time

Surgical Techniques lAvoid skin bridges lAvoid creation of skin flaps

Clinical Course lPain #1 lSwelling lFever lWound breakdown drainage Windsor et al JBJS; 1990

Work-Up Wound History Physical Exam Serial Radiographs Lab/sed rate/CRP (returns to normal level 3 wk post op.) Bone scan / Indium scan Serum interlukine-6 (100%sensitivity & 95%specifity)

Arthrocentesis Gold standard for infection diagnosis: WBC Cell count more than 2500 cells/mm3 & 60% PMN  Protein  high  Glucose  low

Arthrocentesis direct smear gram strain Aerobic Anaerobic acid fast fungi

Microbacterial Majority of infections : Staphylococci Acute hematogenous infections: –Staphylococcus aureus –Beta-hemolytic streptococci –Enterococcus species Gram-negative bacilli and anaerobes are also seen in chronic infections but uncommon...

Staphylococcus aureus Common cause of musculoskeletal infections: Early postoperative infection Late chronic infection Acute hematogenous infection at the site of a prosthetic joint

Staphylococcus aureus Susceptibility to methicillin treated most effectively with Antistaphylococcal penicillin (e.g., nafcillinor oxacillin) First-generation cephalosporin.

MRSA: Methicillin-resistant Staphylococcus aureus first described in 1961 Extra penicillin-binding protein (PBP2a) which results in a low affinity for beta-lactam antibiotics such as the penicillins and cephalosporins

MRSA poor clinical outcome because of the limited effectiveness of antibiotics. Increase cost for treatment.

MRSA Increasing trend in MRSA infection Staphylococcus aureus (MRSA) from the nosocomial setting and its emergence as a cause of community-acquired infection.

Staphylococcus64 S. aureus, penicillin sensitive 14 S. aureus, penicillin resistant 28 S. epidermis 22 Gram negative12 Pseudomonas7 Escherichia coli5 Anærobic6 Other17 Organism Percent Infection TKR

Treatment of prosthetic infection Long-term antibiotic suppression Surgical débridement with retention of the prosthesis Resection arthroplasty Arthrodesis One-stage re-implantation procedure Two-stage re-implantation procedures Amputation

Treatment of prosthetic infection Two-stage reconstruction is the standard practice for treating patients with infected total joint arthroplasty. The success rate of two-stage reimplantation has ranged from %

Treatment Options –Long-term antibiotic suppression –Surgical débridement with retention of the prosthesis –Resection arthroplasty –Arthrodesis –One-stage re-implantation procedure –Two-stage re-implantation procedures –Amputation

Antibiotic suppression  Indicated in: –med compromised patients that prosthesis removal is not feasible –The prosthesis is not loose –Low virulence micro-organism  Duration: life long

Treatment Options –Long-term antibiotic suppression –Surgical débridement with retention of the prosthesis –Resection arthroplasty –Arthrodesis –One-stage re-implantation procedure –Two-stage re-implantation procedures –Amputation

Surgical Debridement Debridement with antibiotic suppression therapy –Limited success and Arthroscopic irrigation is not effective –< 3 weeks

Surgical Debridement Debridement with antibiotic suppression therapy –Strep/staphepi -- best –Avoid repeated attempts –Frozen tissue section –Suction drains –6 week antibiotic-therapy –Polyethylene exchange

Treatment Options –Long-term antibiotic suppression –Surgical débridement with retention of the prosthesis –Resection arthroplasty –Arthrodesis –One-stage re-implantation procedure –Two-stage re-implantation procedures –Amputation

Two-stage Re-implantation Most successful treatment Procedure of choiceProcedure of choice

Two-Stage Re-implantation Stage III  Reimplantation Stage II  6 weeks IV antibiotics Stage I  Complete debridement

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

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

Two-Stage Re-implantation Spacer Antibiotic Regimen Tobramycin 2.4 gm/3.6 gm per 40 gms of PMMA Vancomycin> 0.5 gm to 1 gm per 40 gms of PMMA

Antibiotic Impregnated Spacer lCidal levels of antibiotic lSpacer to preserve tissue tension lFacilitates re-implant and wound exposure

Local Delivery of Antibiotics Antibiotic cemen bead/spacer local levels of antibiotics that far exceed those attained with systemic antibiotic therapy.

Local Delivery of Antibiotics Antibiotic bead - difficulty in removing after implantation. Antibiotic impregnated spacers - minimizes limb-shortening - limits scar formation - facilitates reimplantation

Antibiotic for cement spacer Microbial Sensitivity Bactericidal Heat stable Powder form

Antibiotic for cement spacer Gentamycin Tobramycin Vancomycin Fosfomycin

MRSA VancomycinVancomycin is first choice in MRSA Vancomycin bead/cement space Intravenous vancomycin

Block spacers 1.Simple tibio-femoral block 2.Molded arthrodesis block 3.Articulating mobile spacers (especially in bilateral infected TKAs)

Block spacers Simple tibio-femoral block

Block spacers Molded arthrodesis block

Block spacers Articulating mobile spacers (especially in bilateral infected TKAs) Multiple Techniques

Mobile spacer technique

Prosthesis removal

Removal of debris and cement

Cement spacer molding

Insertion with a pack of cement

Final implantation

Postoperative x- ray

PROSTALAC COMPONENTs

Haffmann’s Procedure: –Using of the patients own prosthesis

Stage II – Antibiotic Treatment lHickman catheter lMIC 1:8 / 6 wks lPatient should use knee brace lIn mobile articulating spacers patient is allowed up to 50% PWB and is encouraged ROM Infections About TKR

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

Intra-operative Frozen Section l< 5 PMN’s per HPF– no infection l> 10 PMN’s per HPF–infection

Treatment Options –Long-term antibiotic suppression –Surgical débridement with retention of the prosthesis –Resection arthroplasty –Arthrodesis –One-stage re-implantation procedure –Two-stage re-implantation procedures –Amputation

Resection Arthroplasty lRemoval all components lRemove all cement lEffective in medically compromised patient

Treatment Options –Long-term antibiotic suppression –Surgical débridement with retention of the prosthesis –Resection arthroplasty –Arthrodesis –One-stage re-implantation procedure –Two-stage re-implantation procedures –Amputation

Arthrodesis Indications lExtensor mechanism disruption lResistant bacteria lInadequate bonestock lInadequate soft tissues lYoung patient

Advantages Definitive  Definitive treatment  Little chance of recurrence

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

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

Result of treatment in MRSA infection Yogesh Mittal retrospective cohort study 37 TKA patients with MRSA or MRSE infection Two stage revision: success rate 76% at median duration of follow-up was 51 months (range, twentyfour to 111 months).

MRSA : Antibiotic

Alternate antibiotic Allergy to Vancomycin Pathogen resistance to Vancomycin increase reports of decreasing susceptibility of S. aureus to vancomycin Juan J. Picazo.Activity of daptomycin against staphylococci collected from bloodstream infections in Spanish medical centers.Diagnostic Microbiology and Infectious Disease.2009;64,448–451

MRSA sensitivity Possible alternatives Teicoplanin Daptomycin Leinazolid Fosfomycin Picazo JJ, Betriu C.Activity of daptomycin against staphylococci collected from bloodstream infections in Spanish medical centers.Diagn Microbiol Infect Dis ;64(4): Schintler MV,High fosfomycin concentrations in bone and peripheral soft tissue in diabetic patients presenting with bacterial foot infection. J Antimicrob Chemother Jul 3.

Antibiotic cement in MRSA Boonsin Buranapanithit : in vitro study Gentamycin, Cefalexin bead cannot inhibit MRSA Vancomycin, Fosfomycin bead effectively inhibit growth of MRSA Boonsin Buranapanitkit.In vitro Elution Characteristics of Antibiotic Cement on MRSA organism.The journal of the asean orthopaedic association.2000,

Fosfomycin A synthetic broad spectrum antibiotic Bactericidal antibiotic Heat stable High concentration in bone Boselli E, Allaouchiche B.Diffusion in bone tissue of antibiotics. Presse Med 1999; 28(40):

Conclusions Prevension Adequate surgical debridement Staged revision Adequate &Susceptibility antibiotic