A novel rRNA hybridization-based approach to rapid, accurate Candida identification directly from blood culture.

Invasive fungal infections are increasingly common and carry high morbidity and mortality, yet fungal diagnostics lag behind bacterial diagnostics in rapidly identifying the causal pathogen. We previously devised a fluorescent hybridization-based assay to identify bacteria within hours directly from blood culture bottles without subculture, called phylogeny-informed rRNA-based strain identification (Phirst-ID). Here, we adapt this approach to unambiguously identify 11 common pathogenic Candida species, including C. auris, with 100% accuracy from laboratory culture (33 of 33 strains in a reference panel, plus 33 of 33 additional isolates tested in a validation panel). In a pilot study on 62 consecutive positive clinical blood cultures from two hospitals that showed yeast on Gram stain, Candida Phirst-ID matched the clinical laboratory result for 58 of 59 specimens represented in the 11-species reference panel, without misclassifying the 3 off-panel species. It also detected mixed Candida species in 2 of these 62 specimens, including the one discordant classification, that were not identified by standard clinical microbiology workflows; in each case the presence of both species was validated by both clinical and experimental data. Finally, in three specimens that grew both bacteria and yeast, we paired our prior bacterial probeset with this new Candida probeset to detect both pathogen types using Phirst-ID. This simple, robust assay can provide accurate Candida identification within hours directly from blood culture bottles, and the conceptual approach holds promise for pan-microbial identification in a single workflow. LAY SUMMARY: Candida bloodstream infections cause considerable morbidity and mortality, yet slow diagnostics delay recognition, worsening patient outcomes. We develop and validate a novel molecular approach to accurately identify Candida species directly from blood culture one day faster than standard workflows.

Delayed flap reconstruction with vacuum-assisted closure management of the open IIIB tibial fracture.

OBJECTIVE: Vacuum-assisted closure (VAC) therapy has been shown to be effective at reducing bacterial counts in wounds until definitive bony coverage. However, there is continued debate over timing and type of definitive wound coverage even with VAC therapy application. METHODS: From 2004 to 2009, 32 patients with Gustilo type IIIB open tibia fractures were initially treated with VAC therapy were included. The number of debridements, length of treatment with VAC dressing, definitive wound coverage management, and length of hospital stay, flap-related complications, and time to radiographic fracture healing were recorded. RESULTS: The mean Injury Severity Score was 17.3 ± 2.0. All wounds closed after being treated with the primary VAC closure. The mean interval between the initial injury and definitive intervention was 10.9 days ± 0.3 days. Twenty of 27 patients (74%) underwent rotational muscle flaps; four received free muscle flaps and three only with split-thickness skin grafts for definitive wound coverage. Nine of 32 patients (28%) underwent below knee amputation, five without flap coverage after several VAC sessions and four after definitive flap coverage. The average time to union was 10.0 months ± 2.0 months. Eight patients developed nonunion and 11 patients developed infections. The average follow-up time is 2.4 years ± 0.2 years. Patients were divided into two groups for analysis according to the interval time. The rate of infection was significantly increased in patients who had an interval of more than 7 days from the time of injury to flap coverage. CONCLUSIONS: The VAC therapy may help to reduce the flap size and need for a flap transfer for type IIIB open tibial fractures. However, prolonged periods of VAC usage, greater than 7 days, should be avoided to reduce higher infection and amputation risks.

Treatment of interprosthetic fractures of the femur.

BACKGROUND: The treatment of interprosthetic femoral fractures is challenging because of several factors. Poor bone stock, advanced age, potential prosthetic instability, and limited fracture fixation options both proximally and distally can complicate standard femur fracture treatment procedures. The purpose of this report was to describe our experience treating interprosthetic femoral fractures, providing an emphasis on treatment principles and specific intraoperative management. METHODS: All patients with fractures occurring between ipsilateral hip and knee prostheses between 2004 and 2010 were identified from a comprehensive database and included in this study. Patients had been treated using principles adapted from two isolated periprosthetic fracture classification systems, the Vancouver and Su classifications. The electronic medical record (including inpatient medical records, operative notes, outpatient medical records, and all radiographs) was reviewed for each patient and demographic and treatment-related variables as well as complications and outcomes were recorded. RESULTS: Thirteen consecutive patients with interprosthetic fractures were included. Four fractures occurred around a clearly loose prosthesis, which were subsequently treated with long-stemmed revisions. The remaining 12 fractures were treated with a locked-plate construct. Two of nine patients (22.2%) died before fracture union. Follow-up averaged 28 months ± 4 months, with fracture union achieved at an average of 4.7 months ± 0.3 months. All patients returned to their self-reported preoperative ambulatory status except one who developed a loose hip prosthesis at 3-year follow-up after fracture union. CONCLUSIONS: The principles for treatment of isolated periprosthetic fractures are useful to guide the fixation of interprosthetic fractures. Locked plating is an effective method for the treatment of interprosthetic femoral fractures. Bypassing the adjacent prosthesis by a minimum of two femoral diameters is a necessary technique to prevent a stress riser.

Treatment of pertrochanteric fractures (OTA 31-A1 and A2): long versus short cephalomedullary nailing.

OBJECTIVES: To retrospectively compare the clinical outcomes in patients with pertrochanteric femur fractures without subtrochanteric extension (OTA 31-A1 and A2) after treatment with short or long cephalomedullary nails. DESIGN: Retrospective study. SETTING: Academic level I trauma center. PATIENTS: Two hundred eighty three adult patients presenting with simple or multifragmentary pertrochanteric femur fractures (OTA 31-A1 and A2) between 2004 and 2009 qualified for inclusion in this study. INTERVENTION: One hundred patients were treated with a short cephalomedullary nail and 183 with a long cephalomedullary nail. MAIN OUTCOME MEASUREMENTS: Patient demographics and medical comorbidities were recorded for each patient via an electronic medical record. Treatment-related variables including the American Society of Anesthesiologists (ASA) score, duration of surgery, volume of intraoperative blood loss, need for blood products, treatment-related complications, and mortality were recorded and compared between the short and long nail groups. RESULTS: There were no significant difference between treatment modalities, complication, and reoperation rates for the 2 groups. Treatment with a long nail resulted in subtle increases in procedure time and blood loss. CONCLUSIONS: No differences in the union and complication rates between the 2 groups were identified, suggesting that long nails offer no advantage compared with short nails for stabilizing simple and multifragmentary pertrochanteric femur fractures without subtrochanteric extension (OTA 31-A1 and A2). LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Locked plating of periprosthetic femur fractures above total knee arthroplasty.

BACKGROUND: Fractures of the femur above a total knee arthroplasty (TKA) are becoming increasingly common in the osteoporotic, aging populations of developed countries. Treatment of these fractures is complicated by the presence of a knee prosthesis, frequently limiting the bone available for distal fracture fixation. The recent application of minimally invasive surgical techniques and locked plate technology to this problem offers the promise of stable, fixed-angle fixation of small distal fracture fragments with limited surgical exposure. The purpose of this study is to report the clinical and radiographic outcomes of fracture fixation using this technique in patients with periprosthetic femur fractures above TKA. METHODS: Fifty-three patients presenting with periprosthetic femur fractures above a TKA were treated with osteosynthesis. One patient was lost to follow-up resulting in 52 patients with complete data. Thirty-four patients were treated with plate fixation and 18 patients underwent retrograde intramedullary nail fixation (RIMN). Using a comprehensive electronic medical record, we recorded data regarding patient-related demographics, nature of the fractures, the operative treatment, and clinical and radiographic outcomes for all patients treated with osteosynthesis. RESULTS: Successful fracture healing occurred in 75% of patients (39 of 52). Mean operating time was 91.6 ± 6.8 minutes in the RIMN group and 87.4 ± 6.4 minutes in the locked plating (LP) group (P = 0.46). Mean intraoperative blood loss was 182 ± 31.6 mL in the RIMN group and 177.5 ± 23.4 mL in the LP group (P = 0.91). The mean time to bone union was 3.7 ± 0.30 months in the RIMN group and 4.0 ± 0.27 months in the LP group (P = 0.95). The most common cause of treatment failure was patient death within 6 months (9 patients [17%]); three of 18 were treated with a nail and 6 of 34 with a plate (P = 1.0). In the LP group, three (9%) sustained fracture nonunions, three (9%) sustained fracture malunions, and two (6%) sustained surgical site infections. In the RIMN group, one (6%) failed to unite as a result of infection and two (11%) developed fracture malunions. There were no significant differences between patients treated with LP and those treated with RIMN. CONCLUSIONS: Despite significant advances in surgical technique and implant design, the treatment of periprosthetic femur fractures above a TKA remains a challenge. LP using an indirect reduction technique is applicable to most patients and prosthetic designs and can provide similar favorable results as compared with treatment with a RIMN in periprosthetic femoral fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Association of ghrelin receptor promoter polymorphisms with weight loss following Roux-en-Y gastric bypass surgery.

BACKGROUND: Ghrelin plays a role in appetite and has been hypothesized to play a role in the mechanism of Roux-en-Y gastric bypass (RYGB) surgery. Single nucleotide polymorphisms (SNPs) in the promoter region of its receptor gene (growth hormone secretagogue receptor type 1a--GHSR) have also been associated with weight loss outcomes following long-term dietary intervention in adults with impaired glucose tolerance. Our objectives were to evaluate changes in serum ghrelin levels and determine the effect of GHSR promoter polymorphisms on post-RYGB surgery weight loss. METHODS: Preoperative and 6-month postoperative serum ghrelin levels were measured in 37 patients with extreme obesity undergoing RYGB surgery. Total ghrelin was also measured in liver tissue collected intraoperatively. Association analysis between genotypes for SNPs rs9819506 and rs490683 in the promoter region of the GHSR gene and weight loss outcomes in the 30 months following surgery was performed in over 650 RYGB patients. RESULTS: Serum ghrelin levels increased after RYGB surgery. Weight loss trajectories were significantly different using an additive model for both ghrelin SNPs, with patients homozygous for the rs490683 CC genotype exhibiting the most weight loss. Weight loss trajectories were also different using a dominant model. The rs490683 risk allele demonstrated decreased promoter activity in vitro. CONCLUSIONS: The role of increased ghrelin levels in weight loss outcomes following RYGB surgery may be influenced by variation in the GHSR gene.