Abstract
Background
Septic knee arthritis is one of the most serious complications after total knee arthroplasty (TKA), and the effectiveness of its treatment affects the patient's quality of life. In our super-aging society, the frequency of TKA in the elderly, often combined with various comorbidities, is increasing. Careful management should be considerd during the management of septic arthritis after TKA in these patients.
Purpose
To analyze the clinical features and outcomes of septic arthritis after TKA in our institution.
Materials and Methods
Between April 1999 and March 2014, 534 TKAs (osteoarthritis [OA]; 381, rheumatoid arthritis [RA]; 154) were performed. Of these patients, 8 with post-operative infected TKA were retrospectively surveyed.
Results
The TKA-associated infection rates were 0.83% (0.35%, OA; 1.7%, RA) during the study period. Five male and 3 female patients were included, with a mean age of 68 years (range, 39–88 years) and primary diagnoses of OA (5) and RA (3). Malignant rheumatoid arthritis (MRA) was present in 1 patient. The infection was affected by a comorbidity in 2 (diabetes mellitus and mixed connective tissue disease). Microorganisms were detectable in 7 patients (methicillin-resistant Staphylococcus aureus [MRSA], 1; methicillin-sensitive Staphylococcus aureus, 2; Streptococcus pyogens, 1; Streptococcus oralis, 1; Escherichia coli, 1; Staphylococcus epidermidis, 1; and unknown, 1) (Fig. 1). The use of the Segawa/Leone classification resulted in 5 patients with type III (acute hematogenous) and 3 with type IV (late) infections. Four patients with type III (80%) infection underwent open debridement, continuous irrigation, and successful implant retention (Fig. 2). The MRA patient had type III infection and an MRSA infection that was treated with two-stage revision, but the infection recurred. We could not perform a re-implantation, and resection arthroplasty was needed. Arthroscopic irrigation in 1 patient with type III infection ended in failure, and open debridement was required. We attempted to retain the implant in 1 patient with type IV infection, but implant removal was required. Three patients with type IV infection underwent two-stage revision successfully.
Discussion
The post-TKA infection rate was 0.83% in our institution. Of the implants, 50% (type III, 80%; type IV, 0%) were successfully retained. Early open debridement and irrigation are important for implant retention in patients with infected TKAs, while arthroscopic debridement does not appear to be effective for infected TKA. Implant retention was difficult in the presence of resistant microorganisms. Two-stage revision was required in patients with type IV infection, with a success rate of 75%.
