Management of the Infected Total Knee Arthroplasty


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Management of the Infected Total Knee Arthroplasty


Ewout S. Veltman MD, and Dirk Jan F. Moojen MD PhD


OLVG, Department of Orthopaedic and Trauma Surgery, Amsterdam, The Netherlands


Clinical scenario



  • A 78‐year‐old female presents herself at the Emergency Department of your hospital. Patient’s history mentions a primary total knee arthroplasty (TKA) of the right knee 12 months earlier and type two diabetes treated with oral antidiabetics.
  • The patient mentions initial unremarkable recovery, with discharge out of the hospital on the third postoperative day. In the past months, the knee has been alternatingly swollen and painful after long walks. During the last two days, the patient has developed a fever and the knee has become swollen, painful, and warm.
  • Physical examination reveals a body temperature of 38.8 °C. You see a diffuse red erythema surrounding the scar on the right knee. There is no wound effusion. Flexion of the knee is painful and limited to 80°. A plain radiograph of the right knee shows an uncomplicated situation after TKA, without signs of loosening.

Top three questions



  1. What is the role of debridement, antibiotics, and implant retention in patients with early/acute hematogenous versus chronic prosthetic joint infection?
  2. Which type of revision surgery strategy provides the better outcome in chronically infected TKA: one‐stage or two‐stage revision?
  3. Which type of spacer leads to superior outcome after two‐stage revision TKA: a static or a dynamic knee spacer?

Question 1: What is the role of debridement, antibiotics, and implant retention in patients with early/acute hematogenous versus chronic prosthetic joint infection?


Rationale


Laboratory findings show an elevated C‐reactive protein (CRP; 137 mg/L) and normal erythrocyte sedimentation rate (ESR; 18 mm/h). Sterile aspiration of synovial fluid reveals the aspect of a purulent hematoma, the fluid is sent for culture. You have now confirmed your suspicion of a periprosthetic joint infection (PJI).


Clinical comment


If untreated, the patient will become increasingly ill. Systemic antibiotics will treat the infection but will not eradicate it, as antibiotic penetration into synovial fluid is low. The patient’s complaints have changed recently, matching a suspicion for hematogenously spread infection to the TKA of the right knee, even though some complaints have already been present during the past year. You want to know if duration of infection influences chance of success of a DAIR (debridement, antibiotics, and implant retention) procedure.


Available literature and quality of the evidence



Findings


The reported success rates of DAIR range between 16 and 100%.6 Because of heterogeneity of and significant methodological inconsistencies between studies, it is not possible to find more precise numbers for early, acute hematogenous and chronic infection, respectively. However, the duration between onset of symptoms and treatment seems to be important; for each additional day that treatment is delayed the odds of success decrease by 7.5%.1 Another study showed that if the infection were treated more than eight weeks after implantation, the RR for success decreased to 0.6 (95% confidence interval [CI]: 0.3–0.95).8


The consensus statement advocates a DAIR procedure as the first treatment option in case of early or acute hematogenous PJI.7 Multiple (at least three, preferably six) intraoperative tissue samples should be taken for culture.7 All mobile parts of the prosthesis (the insert) should be replaced during the DAIR procedure.2,9 In patients with acute hematogenous infection, the same treatment algorithm can be chosen as for early infection.9,10


In chronic PJI, there is no role for DAIR procedures, as the chance of success diminishes with longer duration of infection.1,3,8,9


Resolution of clinical scenario



  • We advise a DAIR procedure with exchange of modular parts in case of an early or acute hematogenous TKA infection.
  • Multiple intra‐articular tissue samples should be taken for culture to determine the exact causative micro‐organism and its antibiotic susceptibility.9
  • Antibiotics should be continued for three months.9,11 If the causative bacteria are susceptible to rifampin, it should be administered as co‐therapy.12,13
  • In case of a chronic infection there is no role for a DAIR procedure and one should proceed to an implant revision.3,7,8

Question 2: Which type of revision surgery strategy provides the better outcome in chronically infected TKA: one‐stage or two‐stage revision?


Rationale


The patient is treated with a DAIR procedure and antibiotics for three months. Sixteen months after cessation of antibiotics the patient visits you at the outpatient clinic, complaining of knee pain while walking and intermittent swelling of the knee. Laboratory results show a CRP of 25 mg/L and ESR of 31 mm/h. A plain radiograph of the knee shows a radiolucent line under the medial side of the tibial component. Culture of sterile aspirate shows growth of the same bacteria the knee was originally infected with.


Clinical comment


In case of persisting or chronic infection of a knee prosthesis, eradication of infection without revising the prosthesis is not possible.9,11,14 In patients who do not wish further surgery, or cannot safely be operated on, suppressive antibiotics can be considered.9,11

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Nov 28, 2021 | Posted by in ORTHOPEDIC | Comments Off on Management of the Infected Total Knee Arthroplasty
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