Surgical Case Order Has an Effect on the Risk of Subsequent Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) after total joint arthroplasty (TJA) is a serious complication with multiple etiologies. Prior spine literature has shown that later cases in the day were more likely to develop surgical site infection. However, the effect of case order on PJI after TJA is unknown. This study aims to determine the influence of case order, prior infected case, and terminal cleaning on the risk for a subsequent PJI. METHODS: A retrospective, single-institution study was conducted on 31,499 TJAs performed from 2000 to 2014. Case order was determined by case start times per date within the same operating room. PJI was defined by the Musculoskeletal Infection Society criteria. Logistic regression was used to determine risk factors for a subsequent PJI. RESULTS: Noninfected cases followed an infected case in 92 of 31,499 cases (0.29%) and were more likely to develop PJI (adjusted odds ratio [OR], 2.43; P = .029). However, terminal cleaning after infected cases did not affect the risk for PJI in cases the following morning (OR, 1.42; P = .066). Case order had an OR of 0.98 (P = .655), implying that later cases did not have a higher likelihood of infection. CONCLUSION: Although surgical case order is not an independent risk factor for subsequent PJI, TJA cases following an infected case in the same room on the same day have a higher infection risk. Despite improved sterile technique and clean air operating rooms, the risk of contaminating a TJA with pathogens from a prior infected case appears to be high. Terminal cleaning appears to be effective in reducing the bioburden in the operating room.

Sequential targeted delivery of paclitaxel and camptothecin using a cross-linked "nanosponge" network for lung cancer chemotherapy.

The applicability of a HVGGSSV peptide targeted "nanosponge" drug delivery system for sequential administration of a microtubule inhibitor (paclitaxel) and topoisomerase I inhibitor (camptothecin) was investigated in a lung cancer model. Schedule-dependent combination treatment with nanoparticle paclitaxel (NP PTX) and camptothecin (NP CPT) was studied in vitro using flow cytometry and confocal imaging to analyze changes in cell cycle, microtubule morphology, apoptosis, and cell proliferation. Results showed significant G2/M phase cell cycle arrest, changes in microtubule dynamics that produced increased apoptotic cell death and decreased proliferation with initial exposure to NP PTX, followed by NP CPT in lung cancer cells. In vivo molecular imaging and TEM studies validated HVGGSSV-NP tumor binding at 24 h and confirmed the presence of Nanogold labeled HVGGSSV-NPs in tumor microvascular endothelial cells. Therapeutic efficacy studies conducted with sequential HVGGSSV targeted NP PTX and NP CPT showed 2-fold greater tumor growth delay in combination versus monotherapy treated groups, and 4-fold greater delay compared to untargeted and systemic drug controls. Analytical HPLC/MS methods were used to quantify drug content in tumor tissues at various time points, with significant paclitaxel and camptothecin levels in tumors 2 days postinjection and continued presence of both drugs up to 23 days postinjection. The efficacy of the NP delivery system in sequential treatments was corroborated in both in vitro and in vivo lung cancer models showing increased G2/M phase arrest and microtubule disruption, resulting in enhanced apoptotic cell death, decreased cell proliferation and vascular density.