Rifampin combination therapy in staphylococcal prosthetic joint infections: a randomized controlled trial.

BACKGROUND: The evidence supporting rifampin combination therapy in prosthetic joint infections (PJI) is limited due to the lack of controlled studies. The aim of this study is to evaluate the effect of adding rifampin to conventional antimicrobial therapy in early staphylococcal PJIs treated with debridement and retention of the implant (DAIR). METHODS: In this multicenter randomized controlled trial, 99 patients with PJI after hip and knee arthroplasties were enrolled. They were randomly assigned to receive rifampin or not in addition to standard antimicrobial treatment with cloxacillin or vancomycin in case of methicillin resistance. The primary endpoint was no signs of infection after 2 years of follow-up. RESULTS: Forty-eight patients were included in the final analyses. There were no differences in patient characteristics or comorbidities between the two groups. There was no significant difference in remission rate between the rifampin combination group (17 of 23 (74%)) and the monotherapy group (18 of 25 (72%), relative risk 1.03, 95% confidence interval 0.73 to 1.45, p = 0.88). CONCLUSION: This trial has not proven a statistically significant advantage by adding rifampin to standard antibiotic treatment in acute staphylococcal PJIs. TRIAL REGISTRATION: The Regional Ethics Committee and the Norwegian Medicines Agency approved the study (EudraCT 2005-005494-29), and the study was registered at ClinicalTrials.gov at Jan 18, 2007 ( NCT00423982 ).

Infection after Constrained Condylar Knee Arthroplasty: Incidence and microbiological findings in 100 consecutive complex primary and revision total knee arthroplasties.

Background: To report incidence, microbiological findings, and treatment outcome of prosthetic joint infection (PJI) after constrained condylar knee arthroplasty. Methods: Retrospective study of 100 consecutive complex primary and revision total knee arthroplasties operated with constrained condylar knee arthroplasties between February 2006 and October 2015 at a single institution. Demographic and surgical data were registered, as well as data regarding infection, microbiology and treatment. Follow-up median 43 months; SD 32. Results: The overall incidence of acute postoperative PJI was low (3/100). 1/33 (3%), 1/ 45 (2%), and 1/22 (5%), following primary complex TKA, aseptic revisions, and septic revisions, respectively. The incidence of late acute hematogenous PJI was 5/100. 1/33 (3%),1/45 (2%), and 3/22 (14%) following primary complex TKA, aseptic revisions, and septic revisions, respectively. Late acute hematogenous infections were associated with a lower success rate of treatment with debridement and implant retention compared with acute postoperative PJIs, 1/5 versus 2/3. Conclusion: The risk of late acute hematogenous infections seems increased. Multiple previous surgery, poor soft tissue, and large metal implants may contribute to an increased lifelong susceptibility for bacteremias to cause PJIs.

Effectiveness of gentamicin-containing collagen sponges for prevention of surgical site infection after hip arthroplasty: a multicenter randomized trial.

BACKGROUND: Surgical site infection (SSI) is a feared complication in hip arthroplasty, especially following femoral neck fracture in the elderly, associated with substantially increased morbidity, mortality, and costs. Gentamicin-containing collagen sponges are widely used for prevention of SSIs, but their effectiveness in joint replacement surgery remains unclear. METHODS: We performed a multicenter, randomized trial between February 2011 and July 2013. Eligible patients with femoral neck fracture undergoing hemiarthroplasty were randomly assigned to receive either intravenous antimicrobial prophylaxis alone or with the addition of 2 gentamicin-containing collagen sponges into the hip joint perioperatively. The primary end point was SSI according to the Centers for Disease Control and Prevention criteria within 30 days after surgery. RESULTS: Seven hundred thirty-nine patients were randomly assigned, 684 of whom were included in the modified intention-to-treat analysis. There was no statistical significant difference in SSI between the gentamicin-collagen group (16 of 329 patients [4.9%]) and the control group (19 of 355 patients [5.4%]) (relative risk [RR], 0.91 [95% confidence interval, .48-1.79]; P = .77). No significant differences were observed between the groups in superficial SSI (2 of 329 [0.6%] vs 3 of 355 [0.8%]; P = .99) and deep SSI (14 of 329 [4.3%] vs 16 of 355 [4.5%]; P = .87). There were no significant differences between the groups regarding type of bacteria isolated. CONCLUSIONS: Locally administered gentamicin-collagen sponges did not reduce the incidence of SSI in elderly patients treated with a hemiarthroplasty because of femoral neck fracture. CLINICAL TRIALS REGISTRATION: NCT01287780.

Comparison of planned and achieved implant position in total knee arthroplasty with patient-specific positioning guides.

BACKGROUND AND PURPOSE: Intraoperatively, patient-specific positioning guides (PSPGs) represent the preoperatively planned alignment. We investigated the degree of correlation between preoperative planning and the alignment achieved postoperatively with the PSPG technique. PATIENTS AND METHODS: TKAs performed with the PSPG technique between 2009 and 2011 were included. 39 patients (42 TKAs) volunteered for a postoperative CT scan. 2 independent observers performed the postoperative CT measurements. Preoperative component angles (target angles) in the coronal and axial planes were defined as 0 degrees, and in the sagittal plane on average 2.8 degrees for the femoral component and 3 degrees for the tibial component. A postoperative full-length standing anteroposterior radiograph was carried out in 41 TKAs. RESULTS: The femoral component was on average 1.2 (SD 1.5) degrees in varus, 4.4 (SD 4.0) degrees in flexion, and 0.5 (SD 1.4) degrees in external rotation. The tibial component was on average 0.4 (SD 2.5) degrees in varus and 3.7 (SD 2.3) degrees in flexion. A statistically significant difference between the target (preoperative software plan) and postoperative CT measurement was found for the femoral component angle in the frontal plane (p < 0.001; CI: 0.8-1.7), the sagittal plane (p = 0.01; CI -5.6 to -3.1), and the axial plane (p = 0.03; CI: 0.04-0.88). HKA angles were greater than 3 degrees from the neutral axis in 10 of the 41 cases. INTERPRETATION: We found our postoperative component alignment angles to be close to the software plan, especially for the tibial component. However, we found outliers in all planes and we cannot therefore conclude that the PSPG technique is a method that reproduces preoperatively planned alignment in a consistent manner.

Early prosthetic joint infections treated with debridement and implant retention: 38 primary hip arthroplasties prospectively recorded and followed for median 4 years.

BACKGROUND AND PURPOSE: Debridement and retention of the prosthesis is often attempted to treat early prosthetic joint infection (PJI). However, previous studies have found inconsistent results, with success rates ranging from 21% to 100%, and little has been written in the literature about hip function. We have therefore analyzed the clinical and functional outcome of early PJIs treated with this procedure. PATIENTS AND METHODS: 38 patients with early PJI after primary hip arthroplasty who were treated with debridement and retention of the implant between 1998 and 2005 were studied prospectively, with a median follow-up time of 4 (0.8-10) years. Early infection was defined as that which occurred within 4 weeks of index arthroplasty. The primary outcome measure was infection control. Functional outcome was assessed with the Harris hip score. RESULTS: 27 of 38 patients were successfully treated, with no signs of infection or continued antibiotic treatment at the latest follow-up. Median Harris hip score was 86 (47-100) points. In 9 of the 11 patients for whom treatment failed, infection was successfully treated with 1-stage or 2-stage reimplantation or resection. Intraoperative cultures were positive in 36 hips, and the most frequently isolated organisms were Staphylococcus aureus and coagulase-negative staphylococci (CoNS). 15 infections were polymicrobial, and only 8 of them were successfully treated with debridement and retention of the implant. INTERPRETATION: Our data suggest that debridement and retention of the prosthesis is a reasonable treatment option in early PJI after primary hip arthroplasty, with satisfactory functional results.

Ultralok uncemented femoral prostheses: 12 to 15 year follow-up evaluation.

The results of total hip arthroplasty (THA) in young patients with osteoarthritis have been discouraging. In this prospective study, 78 patients (89 THA) were consecutively included and followed for 12 to 15 years (mean, 12.2 years) after the index surgery with the uncemented Ultralok femoral prosthesis (Zimmer, Wiltshire, UK). Age at surgery was 59.8 years (40 to 76). The follow-up process included an in-office clinical evaluation and a radiographic evaluation. A cumulative survival of 96.6% (with the end point defined as revision of the femoral component because of mechanical or radiographic loosening) was found for the femoral component after13 years, and all unrevised components were radiographically fixed by bony ingrowth. Twenty-three well-fixed stems had to be removed for femoral head damage at the time of the acetabular revision. The results of this comparatively large series show that good fixation has been achieved with a proximal titanium mesh and grit-blasted titanium alloy stem.