Covering of wound infection in hip arthroplasty with local cutaneous flaps.

Total hip arthroplasty is a very common procedure to treat osteoarthritis. One of the complication is the infection which occurs in about 1% of the cases. The manifestation of infection can be poor wound healing with dehiscence and exposition of bone or prosthetic components. Hip arthroplasty infections are difficult to treat. It required an associated multidisciplinary approach with infectiology, orthopedic and plastic surgeries. The study included five patients with hip wound dehiscence after total hip arthroplasty. Coverage after orthopedic surgery was provided by local cutaneous flap. These cutaneous flaps were either a deep inferior epigastric perforator flap (DIEP) or a transposition flap. The orthopedic and the plastic treatment were done at the same time. Two deep inferior epigastric flaps were performed for patients with a deep defect with bone or prosthesis exposure. Four transposition flaps were done in three patients with wound dehiscence but without direct contact with the prosthesis. Three transposition flaps were done from the abdominal wall and one from the posterior thigh. The mean follow up was 18 months, ranging from 10 to 24months. After healing, there was no recurrence of the infection. In all cases, the coverage was obtained. The prosthesis was salvage and the gait was possible. Cutaneous flaps are easy and safe to cover the hip. They are reliable flaps even in patients with multiple co-morbidities. They do not cause sequelae on the recipient site. This study is the first about cutaneous flap for covering hip defects in hip arthroplasty infections.

[A pedicled deep inferior epigastric flap to cover a hip arthroplasty infection]. / Couverture d'une prothèse de hanche infectée par un lambeau perforant épigastique inférieur profond pédiculé.

The deep inferior epigastric perforator (DIEP) flap is a reliable flap mostly used in skin resurfacing after signifiant resection for sarcoma or correction contour deformities. This case is about a pedicled DIEP flap covering the trochanteric region after a total hip arthroplasty infection. A 62years old woman with a BMI at 42kg/m2 presents an infected total hip arthroplasty with a cutaneous defect. The hip prosthesis is changed and covered with a pedicled DIEP flap. This original case reports the used of pedicled DIEP flap in hip coverage. This local fasciocutaneous flap covered the hip osteoarticular infection. The limb is salved and the patient can walked again. The success of this surgery is the collaboration between infectious disease specialist, orthopedic surgeon and plastic surgeon.

Efficacy of indefinite chronic oral antimicrobial suppression for prosthetic joint infection in the elderly: a comparative study.

BACKGROUND: During prosthetic joint infection (PJI), surgical management is sometimes impossible and indefinite chronic oral antimicrobial suppression (ICOAS) may be the only option. The outcomes of elderly patients who benefited from ICOAS with strictly palliative intent were evaluated. METHODS: A national retrospective cohort study was performed in France, involving patients aged >75 years with a PJI who were managed with planned life-long ICOAS from 2009 to 2014. Patients who experienced an event were compared to those who did not. An event was defined as a composite outcome in patients undergoing ICOAS, including local or systemic progression of the infection, death, or discontinuation of antimicrobial therapy because of an adverse drug reaction. RESULTS: Twenty-one patients were included, with a median age of 85 years (interquartile range 81-88 years). Eight of the 21 patients experienced an event: one had an adverse drug reaction, three had systemic progression of sepsis, and two had local progression. Two of the 21 patients died. No death was related to ICOAS or infection. There was no significant difference between the population with an event and the population free of an event with regard to demographic, clinical, and microbiological characteristics (p>0.05). CONCLUSIONS: ICOAS appeared to be an effective and safe option in this cohort.

Prolonged suppressive antibiotic therapy for prosthetic joint infection in the elderly: a national multicentre cohort study.

During prosthetic joint infection (PJI), optimal surgical management with exchange of the device is sometimes impossible, especially in the elderly population. Thus, prolonged suppressive antibiotic therapy (PSAT) is the only option to prevent acute sepsis, but little is known about this strategy. We aimed to describe the characteristics, outcome and tolerance of PSAT in elderly patients with PJI. We performed a national cross-sectional cohort study of patients >75 years old and treated with PSAT for PJI. We evaluated the occurrence of events, which were defined as: (i) local or systemic progression of the infection (failure), (ii) death and (iii) discontinuation or switch of PSAT. A total of 136 patients were included, with a median age of 83 years [interquartile range (IQR) 81-88]. The predominant pathogen involved was Staphylococcus (62.1%) (Staphylococcus aureus in 41.7%). A single antimicrobial drug was prescribed in 96 cases (70.6%). There were 46 (33.8%) patients with an event: 25 (18%) with an adverse drug reaction leading to definitive discontinuation or switch of PSAT, 8 (5.9%) with progression of sepsis and 13 died (9.6%). Among patients under follow-up, the survival rate without an event at 2 years was 61% [95% confidence interval (CI): 51;74]. In the multivariate Cox analysis, patients with higher World Health Organization (WHO) score had an increased risk of an event [hazard ratio (HR) = 1.5, p = 0.014], whereas patients treated with beta-lactams are associated with less risk of events occurring (HR = 0.5, p = 0.048). In our cohort, PSAT could be an effective and safe option for PJI in the elderly.

Agreement between pre-operative and intra-operative bacteriological samples in 85 chronic peri-prosthetic infections.

BACKGROUND: Whether pre-operative microbiological sampling contributes to the management of chronic peri-prosthetic infection remains controversial. We assessed agreement between the results of pre-operative and intra-operative samples in patients undergoing single-stage prosthesis exchange to treat chronic peri-prosthetic infection. HYPOTHESIS: Agreement between pre-operative and intra-operative samples exceeds 75% in patients undergoing single-stage exchange of a hip or knee prosthesis to treat chronic peri-prosthetic infection. MATERIAL AND METHODS: This single-centre retrospective study included 85 single-stage prosthesis exchange procedures in 82 patients with chronic peri-prosthetic infection at the hip or knee. Agreement between pre-operative and intra-operative sample results was evaluated. Changes to the initial antibiotic regimen made based on the intra-operative sample results were recorded. RESULTS: Of 149 pre-operative samples, 109 yielded positive cultures, in 75/85 cases. Of 452 intra-operative samples, 354 yielded positive cultures, in 85/85 cases. Agreement was complete in 54 (63%) cases and partial in 9 (11%) cases; there was no agreement in the remaining 22 (26%) cases. The complete agreement rate was significantly lower than 75% (P=0.01). The initial antibiotic regimen was inadequate in a single case. DISCUSSION: Pre-operative sampling may contribute to the diagnosis of peri-prosthetic infection but is neither necessary nor sufficient to confirm the diagnosis and identify the causative agent. The spectrum of the initial antibiotic regimen cannot be safely narrowed based on the pre-operative sample results. We suggest the routine prescription of a probabilistic broad-spectrum antibiotic regimen immediately after the prosthesis exchange, even when a pathogen was identified before surgery. LEVEL OF EVIDENCE: IV, retrospective study.

VISLISI trial, a prospective clinical study allowing identification of a new metalloprotease and putative virulence factor from Staphylococcus lugdunensis.

OBJECTIVE: Staphylococcus lugdunensis is a coagulase-negative staphylococcus that displays an unusually high virulence rate close to that of Staphylococcus aureus. It also shares phenotypic properties with S. aureus and several studies found putative virulence factors. The objective of the study was to describe the clinical manifestations of S. lugdunensis infections and investigate putative virulence factors. METHOD: We conducted a prospective study from November 2013 to March 2016 at the University Hospital of Strasbourg. Putative virulence factors were investigated by clumping factor detection, screening for proteolytic activity, and sequence analysis using tandem nano-liquid chromatography-mass spectrometry. RESULTS: In total, 347 positive samples for S. lugdunensis were collected, of which 129 (37.2%) were from confirmed cases of S. lugdunensis infection. Eighty-one of these 129 patients were included in the study. Bone and prosthetic joints (PJI) were the most frequent sites of infection (n=28; 34.6%) followed by skin and soft tissues (n=23; 28.4%). We identified and purified a novel protease secreted by 50 samples (61.7%), most frequently associated with samples from deep infections and PJI (pr 0.97 and pr 0.91, respectively). Protease peptide sequencing by nano-liquid chromatography-mass spectrometry revealed a novel protease bearing 62.42% identity with ShpI, a metalloprotease secreted by Staphylococcus hyicus. CONCLUSION: This study confirms the pathogenicity of S. lugdunensis, particularly in bone and PJI. We also identified a novel metalloprotease called lugdulysin that may contribute to virulence.

Diagnostic accuracy of intra-articular C-reactive protein assay in periprosthetic knee joint infection--a preliminary study.

BACKGROUND: Periprosthetic joint infection often raises diagnostic challenges, as the published criteria are heterogeneous. New markers for predicting periprosthetic infection have been evaluated. Here, we assessed one of these markers, C-reactive protein (CRP), in joint fluid. HYPOTHESIS: We hypothesised that intra-articular CRP levels would perform better than serum CRP concentrations in diagnosing knee prosthesis infection. PATIENTS AND METHODS: We prospectively included 30 patients including 10 with native-knee effusions, 11 with prosthetic-knee aseptic effusions, and 11 with prosthetic-knee infection defined using 2011 Musculoskeletal Society criteria. Serum CRP was assayed using turbidimetry or nephelometry and intra-articular CRP using nephelometry. Appropriate statistical tests were performed to compare the three groups; P values < 0.05 were considered significant. RESULTS: Serum and intra-articular CRP levels were 5- to 16-fold higher in the group with periprosthetic infection than in the other two groups. Although the areas under the ROC curves were not significantly different, the likelihood ratios associated with the selected cut-offs suggested superiority of intra-articular CRP: a value > 2.78 mg/L suggested possible infection (100% sensitivity and 82% specificity) and a value > 5.37 mg/L probable infection (90% sensitivity and 91% specificity). DISCUSSION: Our findings suggest a possible role for intra-articular CRP assay in diagnosing knee prosthesis infection and perhaps periprosthetic infection at any site. LEVEL OF EVIDENCE: Level III, diagnostic study, development of a diagnostic criterion in consecutive patients comparatively to a reference standard.