Objective: We analyzed the treatment and outcomes for patients with surgical site infections (SSIs) after total knee arthroplasty (TKA) in our hospital. We also present a discussion of the current literature.
Methods: From 2002 to 2017 inclusive, TKA was performed in 1,672 patients at our hospital and SSI occurred in seven knees in seven patients, respectively. We also treated three cases of SSI in three knees after TKA was performed at another hospital. All 10 cases (2 males and 8 females) were originally treated for osteoarthritis. The average age was 71.6 years (range: 62-85 years). The therapy for SSI, Segawa classification, outcomes, cement mold placement time, and Japan Orthopaedic Association (JOA) scores were analyzed in these patients.
Results: With respect to the Segawa classification, the SSI cases encompassed type 2 (early postoperative infection, n=1), type 3 (acute hematogenous infection, n=7), and type 4 (n=2), respectively. Isolated bacteria included Pseudomonas aeruginosa (n=2), Escherichia coli (n=2), hemolytic streptococci (n=2), Staphylococcus epidermidis (n=1), coagulase-negative staphylococci (n=1), Streptococcus pneumoniae (n=1), and methicillin-susceptible Staphylococcus aureus (n=1). There were no cases with methicillin-resistant Staphylococcus aureus.
One case was treated with irrigation, debridement and removal of the polyethylene implant, which resulted in the elimination of infection. The other nine cases underwent two-stage revision TKA with initial placement of a cement mold once (n=7) or twice (n=2), respectively. The median implantation time of the cement mold was 2.3 months (range: 8-32 months). Reimplantation was performed at a mean period after initial surgery of 64.1 months (2-185 months). Seven cases had no subsequent infection. The mean JOA scores in the 10 patients were 29 points preoperatively and 69 points at the last follow-up.
Conclusion: SSI occurred in 10 TKA cases. The time to the start of therapy from onset of infection was linked to retention of the prosthesis. A good clinical outcome was obtained using a two-stage TKA with an articulating spacer.
