Management of Acute Hematogenous Infection Following Total Knee Arthroplasty: A Case Series of 11 Patients.

OBJECTIVE: Acute hematogenous infection is a devastating complication that can occur after total knee arthroplasty (TKA). The best strategies for management of this infection remain controversial. Two-stage revision has been well described as the gold standard for the management of chronic late infections. However, there is a paucity of information presently available on the management and outcomes of patients treated for acute hematogenous infections. The purpose of the present study was to report the outcome of acute hematogenous infections following TKA with the treatment of irrigation, debridement, and retention of the prosthetic components.

METHODS: Eleven patients who had been diagnosed with acute hematogenous infection of the knee following TKA underwent irrigation and debridement between 2002 and 2012. To improve the efficiency of irrigation, a vacuum constriction device was used and the most sensitive antibiotics were injected into the irrigation saline. The mean age of the 11 patients was 56.3 ± 11.8 years (range, 35-73 years), with 2 male patients (18.2%) and 9 female patients (81.8%). The diagnosis at primary operation was osteoarthritis in three cases, rheumatoid arthritis in seven and osteoarthritis (OA) secondary to fracture in 1. They had pain and swell with the acute onset of pain after a previously well-functioning TKA, and met the Musculoskeletal Infection Society (MSIS) criteria for prosthetic joint infection. Before the onset of symptoms in the operated knees, patients had a history of bacteriaemia, and blood culture was consistent with the culture result of local infection. Failure was defined as: (i) death before the end of antibiotic treatment; (ii) a further surgical intervention for treatment of infection was needed; and (iii) life-long antibiotic treatment, or chronic infection. The prosthesis survivorship, Knee Society Score (KSS) and the factors that may lead to the infection recurrence, such as type of bacteria, age, sex, rheumatoid arthritis, history of diabetes, and interval surgery time, were analyzed.

RESULTS: Among the 11 patients, the most common infecting organisms were staphylococcal and streptococcus species. The 2 staphylococcal species cases included: Staphylococcus epidermidis (1) and Staphylococcus aureus (1); The 7 Streptococcus species cases included: Streptococcus agalactiae (1), β-Hemolytic Streptococcus (1), Streptococcus pneumonia (3), Streptococcus dysgalactiae (1), Viridans streptococci (1) and Enterobacter cloacae (1). The survivorship at the endpoint was 9 in 2 years. The survival rate for patients with a staphylococcal infection was 0%, and 100% for patients infected with non-staphylococcus species, with a mean KSS of 72.6 points. The duration of symptoms prior to operation and the type of pathogen affected the outcome (P = 0.00).

CONCLUSIONS: Patients who developed an acute hematogenous infection with non-staphylococcus species following operative debridement and continuous irrigation with prosthetic retention had satisfactory outcomes, but patients infected with staphylococcal had poor results. To improve the success rate of treatment, patients should be treated as soon as possible and individually according to the bacterial culture results.