Treatment of a chronically infected nasal silicone prosthesis with continuous antibiotic irrigation and gentamicin-impregnated polymethylmethacrylate beads

Infected nasal alloplasts in revision rhinoplasty can be a complex problem, as timing between implant removal and reconstruction is the major limiting factor. Delaying reconstruction can result in loss of mechanical support, a constricted nose, and in severe cases, complete nasal airway collapse and respiratory compromise. In this case report, we describe a novel surgical approach for the management of a chronically infected nasal implant combining techniques used to treat biomaterial-associated infections: antibiotic-impregnated polymethymethacrylate beads and a continuous catheter-based antibiotic irrigation system. We report a case of a chronic alloplastic-associated infection following nasal reconstruction using a silicone implant. We utilized a two-staged approach. The involved nasal implant was removed and replaced temporarily with gentamicin-impregnated polymethymethacrylate beads and a continuous closed irrigation and drainage system with local and parenteral delivery of antibiotics. Both modalities allowed for complete eradication of the infection. In addition, the gentamicin beads provided sufficient mechanical support in order to minimize the risk of skin contracture. Twelve days after her initial surgery, nasal reconstruction was performed using a cadaver bone graft. The patient was followed for two years postoperatively and has shown good results with no evidence of skin contracture or recurrent infection. This technique may allow for shorter delay in revision surgery and reduce the risk of long-term complications without compromising functional and aesthetic outcomes

Treatment of a chronically infected nasal silicone prosthesis with continuous antibiotic irrigation and gentamicin-impregnated polymethylmethacrylate beads.

Infected nasal alloplasts in revision rhinoplasty can be a complex problem, as timing between implant removal and reconstruction is the major limiting factor. Delaying reconstruction can result in loss of mechanical support, a constricted nose, and in severe cases, complete nasal airway collapse and respiratory compromise. In this case report, we describe a novel surgical approach for the management of a chronically infected nasal implant combining techniques used to treat biomaterial-associated infections: antibiotic-impregnated polymethymethacrylate beads and a continuous catheter-based antibiotic irrigation system. We report a case of a chronic alloplastic-associated infection following nasal reconstruction using a silicone implant. We utilized a two-staged approach. The involved nasal implant was removed and replaced temporarily with gentamicin-impregnated polymethymethacrylate beads and a continuous closed irrigation and drainage system with local and parenteral delivery of antibiotics. Both modalities allowed for complete eradication of the infection. In addition, the gentamicin beads provided sufficient mechanical support in order to minimize the risk of skin contracture. Twelve days after her initial surgery, nasal reconstruction was performed using a cadaver bone graft. The patient was followed for two years postoperatively and has shown good results with no evidence of skin contracture or recurrent infection. This technique may allow for shorter delay in revision surgery and reduce the risk of long-term complications without compromising functional and aesthetic outcomes

AFAP1 Is a Novel Downstream Mediator of TGF-β1 for CCN2 Induction in Osteoblasts.

BACKGROUND:CCN2 acts as an anabolic growth factor to regulate osteoblast differentiation and function. CCN2 is induced by TGF-β1 and acts as a mediator of TGF-β1 induced matrix production in osteoblasts and Src is required for CCN2 induction by TGF-β1; however, the molecular mechanisms that control CCN2 induction in osteoblasts are poorly understood. AFAP1 binds activated forms of Src and can direct the activation of Src in certain cell types, however a role for AFAP1 downstream of TGF-β1 or in osteoblats is undefined. In this study, we investigated the role of AFAP1 for CCN2 induction by TGF-β1 in primary osteoblasts. RESULTS:We demonstrated that AFAP1 expression in osteoblasts occurs in a biphasic pattern with maximal expression levels occurring during osteoblast proliferation (~day 3), reduced expression during matrix production/maturation (~day 14-21), an a further increase in expression during mineralization (~day 21). AFAP1 expression is induced by TGF-β1 treatment in osteoblasts during days 7, 14 and 21. In osteoblasts, AFAP1 binds to Src and is required for Src activation by TGF-β1 and CCN2 promoter activity and protein induction by TGF-β1 treatment was impaired using AFAP1 siRNA, indicating the requirement of AFAP1 for CCN2 induction by TGF-β1. We also demonstrated that TGF-β1 induction of extracellular matrix protein collagen XIIa occurs in an AFAP1 dependent fashion. CONCLUSIONS:This study demonstrates that AFAP1 is an essential downstream signaling component of TGF-β1 for Src activation, CCN2 induction and collagen XIIa in osteoblasts

An Increase in Same-day Discharge After Total Joint Arthroplasty During the COVID-19 Pandemic Does Not Influence Patient Outcomes: A Retrospective Cohort Analysis

Background: The coronavirus disease 2019 (COVID-19) pandemic caused major transitions in total joint arthroplasty (TJA), notably with the increased utilization of same-day discharge (SDD) pathways. This study assessed the effect of accelerated discharge pathways following the resumption of elective cases during the COVID-19 pandemic on SDD rates, adverse events, and characteristics associated with successful SDD following total hip and total knee arthroplasty. Methods: This retrospective study split patients into cohorts: TJA prior to COVID-19 (pre-COVID, July 2019-December 2019) and TJA following the resumption of elective surgeries (post-COVID, July 2020-December 2020). Patient characteristics such as age, sex, body mass index, American Society of Anesthesiologists score, and pertinent comorbidities were analyzed, and length of stay, 30-day emergency department (ED) visit rates, readmissions, and reoperations were compared. Results: A total of 1333 patients met inclusion criteria that were divided into pre-COVID (692) and post-COVID (641) cohorts. The pre-COVID group had a median age of 69 years (interquartile range 63-76), and the post-COVID group had a median age of 68 years (interquartile range 61-75) (P = .024). SDD increased from 0.1% to 28.9% (P < .001), and length of stay decreased from 1.3 days to 0.89 days (P < .001). There was no change in 30-day ED visits, readmissions, or reoperations (P = .817, P = .470, and P = .643, respectively). There was no difference in ED visits, readmissions, or reoperations in SDD patients. The odds of SDD were associated with age (P < .001, odds ratio [OR] = 0.94), body mass index (P = .006, OR = 0.95), male sex (P < .001, OR = 1.83), and history of tobacco use (P < .001, OR = 1.87). Conclusions: At our institution, the COVID-19 pandemic accelerated the utilization of SDD pathways without increasing ED visits, readmissions, or reoperations

AFAP1 is necessary for TGF-β1 induced Col XIIa.

<p>The data show that blocking AFAP1 expression with siRNA impairs Col XIIa protein expression. Primary osteoblasts were pretreated with AFAP1 siRNA (siRNA) and then treated with TGF-β1 (5ng/ml; 24hrs) (+) or mock treated (-) and Col XIIa, AFAP1, CCN2 and Actin were assessed by Western Blot. Western Blots are representative of triplicate determinations.</p

AFAP1 signaling is necessary for TGF-β1 induced Src activation in osteoblast.

<p>The data show that AFAP1 is required for Src activation by TGF-β1 (A) and that AFAP1 binds Src in osteoblasts in a TGF-β1 inducible manner (B). <u>Methods:</u> (A) Primary osteoblasts were pretreated with AFAP1 siRNA (siRNA) or non-targeting control siRNA (control) and the treated with TGF-β1 (5ng/ml; 2hrs) (+) or mock treated (-) and AFAP1, pTyr416-Src (pSrc) and Actin were assessed by Western blot. (B) Primary osteoblasts were treated with TGF-β1 (5ng/ml; 24hrs) (+) or mock treated (-) and IP with AFAP1 or IgG and blotted with Src or AFAP1 The data show that AFAP1 is required for Src activation by TGF-β1 and that AFAP1 binds Src in osteoblasts in a TGF-β1 inducible manner.</p

AFAP1 is required for CCN2 induction by TGF-β1.

<p>The data show that blocking AFAP1 expression with siRNA impairs CCN2 protein and promoter induction by TGF-β1 in primary osteoblasts. Additionally, CCN2 induction by TGF-β1 is impaired in osteoblasts derived from AFAP1^-/- mice. <u>Methods:</u><b>(A)</b> Primary osteoblasts were pretreated with AFAP1 siRNA (siRNA) or non-targeting control siRNA (control) or transfection reagent only (transfectant only) and then treated with TGF-β1 (5ng/ml; 24hrs) (+) or mock treated (-) and AFAP1, CCN2 and Actin were assessed by Western blot. (<b>B</b>) Primary Osteoblasts were treated as in A, co-transfected with a full length CCN2 proximal promoter reporter, serum starved and then treated with TGF-β1 (5ng/ml) for 24hrs. Luciferase is expressed as a ratio of firefly/renilla. (SEM, n = 6) star symbol = p<0.05 compared to TGF-B1 +, control siRNA sample.</p