The Chitranjan Ranawat Award: Mid-Term to Long-Term Followup of Two-stage Reimplantation for Infected Total Knee Arthroplasty

Abstract

94 patients (96 knees) had a two-stage reimplantation for treatment of an infected total knee arthroplasty. All patients were treated with an interval antibiotic-loaded static cement spacer and had antibiotic-loaded bone cement for prosthesis fixation at the time of reimplantation. The purpose of this study was to assess the long-term risk of reinfection and the mechanical durability of these reimplantation arthroplasties. Patients were followed up for a median of 7.2 years (range, 2.5-13.2 years). At final followup, 15 knees (16%) had required reoperation. Nine knees (9%) had component removal for reinfection and six knees (6%) were revised for aseptic loosening. The median time to reoperation for reinfection was 1 year (range, 0.1-9.8 years). The risk of recurrent infection was not correlated with the type of organism, patient demographics, or method of prosthesis fixation at reimplantation. The survivorship free of implant removal for any reason was 90% (confidence intervals, 83.9-96.4%) at 5 years and 77.3% (confidence intervals, 65.5-89.6%) at 10 years. The survivorship free of implant removal for reinfection was 93.5% (confidence intervals, 88.5-98.7%) at 5 years and 85% (confidence intervals, 73.8-96.3%) at 10 years. Survival free of revision for mechanical failure (aseptic loosening or radiographic loosening) was 96.2% (confidence intervals, 92-100%) at 5 years and 91% (confidence intervals, 80.8-98.3%) at 10 years. These results suggest that the high likelihood of early success after two-stage reimplantation of an infected TKA is well maintained throughout long-term followup, with a modest rate of late recurrent infection or mechanical implant failure.A two-stage reimplantation protocol for the treatment of the infected total knee arthroplasty (TKA) originally was proposed by Insall et al. 10 Their report of 11 knees noted initial eradication of infection in all knees, but one knee eventually had reinfection develop with a different organism because of hematogenous spread. For the past two decades, many investigators adopted this two-stage protocol but also augmented this treatment approach with the use of antibiotic-loaded bone cement for delivery of local antibiotics. 1,7,9,14,16 The use of antibiotic-loaded bone cement for prosthesis fixation at the time of reimplantation has been shown to lower considerably the risk of reinfection. 6 In contrast, the use of antibiotic-loaded cement block spacers or the use of antibiotic-loaded mobile articulating spacers has not been shown definitively to reduce the risk of reinfection, but their use does facilitate the ease of the reimplantation procedure. 1,4,6,9 Short-term cure rates of infection associated with modern techniques of reimplantation are approximately 90%. 16 Most reports have focused primarily on the cure rate of infection at short-term followup, but little is known about the long-term reinfection-free survival or the mechanical durability of the reimplanted prostheses. 5 The purpose of the current study was to evaluate the mid-term to long-term res...

Two-stage Exchange Knee Arthroplasty: Does Resistance of the Infecting Organism Influence the Outcome?

“…We believe the need for further surgery and administration of prolonged therapeutic or suppressive antibiotics should be considered a failure. Our time to reinfection (66 weeks), reinfection with a methicillin-resistant organism (50%), and reinfection with the same organism as the index infection (56%) are consistent with data from other studies [5,6,8,16]. These findings suggest our higher reinfection rate is unlikely the result of intraoperative or early postoperative management of the patients as we did not see a rise in acute infections and were similarly competent at controlling the index organism.…”

“…However, we believe our findings provide valuable information to patients in making informed decisions about their healthcare, help physicians in appropriate patient selection and through further research create opportunities to develop tailored protocols for these patients. Our reinfection rate (27%) after two-stage exchange arthroplasty is on the high end of what is reported in the literature (Table 8) [5,6,8,16]. This may be explained by our study representing a worst-case scenario: although only 19 of the 26 patients who were classified as reinfected underwent subsequent resection arthroplasty, any additional surgery after the initial reimplantation, even if the prosthesis was retained, was considered a failure.…”

“…Previous studies [6,8,11,12,16] have demonstrated lower satisfaction ratings among patients, increased number of surgical procedures (3.9 per patient) and lower rates of controlling infections (18-76%) in the setting of methicillin-resistant organism infections after primary TKA. The largest published study [6], 96 knees in 94 patients, did not find methicillin-resistant organism infections to be associated with failure of two-stage exchange but suggested this likely represented a Type II statistical error. Our findings serve to confirm what has long been presumed by the orthopaedic community, highlight the need for close followup of these patients for signs of recurrent infection, and expose the possibility that our current treatment strategies may be inadequate when dealing with more virulent organisms.…”

“…This is concerning to the orthopaedic community as multiple studies have reported lower success rates (18-76%) in treating resistant organism PJI [6,8,12,16]. However, it is unclear whether the increased failure rate after two-stage exchange arthroplasty is associated with the virulence of the infecting organism.…”

Novel Biomarkers to Detect Infection in Revision Hip and Knee Arthroplasties

“…Periprosthetic joint infections occur commonly; in some series, infection complicates revision arthroplasty in as many as 10% to 20% of patients [9,15,17,36]. The clinical picture often is ambiguous [9], and although biomarkers like C-reactive protein (CRP) or leukocyte levels [4, 7, 9-11, 28, 34] are helpful, they can be misleading in patients with chronic inflammatory diseases, obesity, metabolic syndrome, and insulin resistance, and in smokers [3,4,27] and patients with postoperative hematomas [11,22].…”