Treatment Outcomes in Gram Negative Periprosthetic Joint Infection

Introduction: Outcomes associated with periprosthetic joint infection (PJI) involving Gram negative (GN) organisms are poorly understood. While prevailing beliefs indicate that GN PJI cases have poorer prognoses than Gram positive (GP) cases, the current literature is sparse and inconsistent. Objective: The purpose of this study is to systematically compare the treatment outcomes for GN PJI versus GP PJI. Methods: A retrospective review of 1189 PJI cases between 2007 and 2017 was performed using an institutional PJI database. Treatment failure defined by the Delphi criteria was compared between cases with only GN organisms (n=45) and only GP organisms (n=663). Cox multivariate regression was used to predict time to failure. Results: GN status did not have significantly higher rates of treatment failure compared to GP PJI (OR=1.021, p=.375) in the multivariate analysis. After sub-analysis of only two-stage exchange procedures, GN cases were significantly less likely to reach reimplantation than GP cases (OR=.182, p\u3c.0001). Patients with GN infections were older (p=.041) and had more comorbidities (p\u3c.0001) than GP patients. Conclusions: While there was no observed difference in the overall Delphi failure rates between GN and GP PJI cases, GN patients were significantly less likely to reach reimplantation. We hypothesize this is largely a result of the GN patients being older and more comorbid hosts. This data increases insight into the risk factors and outcomes of GN PJI. Further research is needed to investigate the utility of alternate procedures to the two-stage exchange in older or immunocompromised patients

Direct Anterior Approach Utilizing a Bikini Incision has Less Wound Related Complications in Patients with High BMI

Introduction: Direct anterior approach (DAA) total hip arthroplasty (THA) can be performed through a traditional vertical skin incision, situating the proximal incision at the hip flexion crease, or a horizontal (bikini) skin incision, situating the incision slightly distal and parallel to the hip flexion crease. The dissection beyond the subcutaneous layer is identical for both methods. Objective: The purpose of this study was to compare these approaches, performed by an experienced single surgeon, in terms of overall wound complications and patient-reported esthetics 6-months post-operatively. It was hypothesized that the bikini incision would result in less wound complications and improved cosmesis due to decreased applied tension from the hip flexion crease. Methods: A case-control retrospective study was conducted and 86 bikini DAA patients were matched 3:1 to 230 conventional DAA patients for gender, age, body mass index (BMI), and American Society of Anesthesiologists score. The outcomes evaluated included wound complications, acute periprosthetic joint infection, transfusion, length of surgery, and dysesthesia with an additional subset analysis for obese patients (BMI \u3e30kg/m2). Patients rated incision cosmesis 6 months post-operatively using a Patient Scar Assessment Scale and the Vancouver scar assessment scale. Results: Bikini patients had lower rates of delayed wound healing compared to conventional incision (2.3% vs. 6.1%; p=0.087). This difference was statistically significant (0% vs. 16.6%; p\u3c0.05) in obese patients with no difference in incision cosmesis in either analysis. Discussion: The bikini incision could offer safety benefits in selected patients (BMI \u3e30kg/m2) undergoing DAA THA by decreasing wound complications while preserving cosmesis