Medical textiles in orthopedics: An overview

The use of textile in the medical field is not new; this has given rise to a new branch known as medical textiles. These are being used to repair or replace various other musculoskeletal tissues. The most common uses of biomaterials are to create aseptic conditions for protection, general health care, and hygiene including bedding and clothing, surgical gowns, face masks, head and shoe covers, sterilization wraps, suture anchors, fiber cast and braces/orthotics. These are also used as materials for preparation of wipes, swabs, wound dressings, bandages, gauzes, plasters, pressure garments, orthopedic belts and for new applications, such as heart valves, vascular grafts, artificial veins, artificial ligaments, artificial joints, artificial skin, and artificial cartilage. The truth is that nowadays the use of biomedical textiles is more rampant than anyone realizes. Commonly used materials for preparation of biomedical textiles includes Cotton, Nylon, Silk, Ultra-high molecular weight polyethylene, Polyester, Polypropylene, Poly tetra-fluoro ethylene, Polyether ether ketone, and Polyether ketone. These are prepared from various monomers in varying proportions as per the requirement of the material to be used. Various methods are used in their preparation like Braiding, Knitting, and Weaving, which helps in the development of certain kinds of materials with different specificity and character. Other important measures in the preparation of the medical textile include Denier (the filament counts in multifilament fibers), Tenacity (the strength per denier) and Heat shrink (the amount of shrinkage at a particular time and temperature).     

Plasma IL-6 and IL-10 Concentrations Predict AKI and Long-Term Mortality in Adults after Cardiac Surgery

Inflammation has an integral role in the pathophysiology of AKI. We investigated the associations of two biomarkers of inflammation, plasma IL-6 and IL-10, with AKI and mortality in adults undergoing cardiac surgery. Patients were enrolled at six academic centers (n=960). AKI was defined as a ≥50% or ≥0.3-mg/dl increase in serum creatinine from baseline. Pre- and postoperative IL-6 and IL-10 concentrations were categorized into tertiles and evaluated for associations with outcomes of in-hospital AKI or postdischarge all-cause mortality at a median of 3 years after surgery. Preoperative concentrations of IL-6 and IL-10 were not significantly associated with AKI or mortality. Elevated first postoperative IL-6 concentration was significantly associated with higher risk of AKI, and the risk increased in a dose-dependent manner (second tertile adjusted odds ratio [OR], 1.61 [95% confidence interval (95% CI), 1.10 to 2.36]; third tertile adjusted OR, 2.13 [95% CI, 1.45 to 3.13]). First postoperative IL-6 concentration was not associated with risk of mortality; however, the second tertile of peak IL-6 concentration was significantly associated with lower risk of mortality (adjusted hazard ratio, 0.75 [95% CI, 0.57 to 0.99]). Elevated first postoperative IL-10 concentration was significantly associated with higher risk of AKI (adjusted OR, 1.57 [95% CI, 1.04 to 2.38]) and lower risk of mortality (adjusted HR, 0.72 [95% CI, 0.56 to 0.93]). There was a significant interaction between the concentration of neutrophil gelatinase-associated lipocalin, an established AKI biomarker, and the association of IL-10 concentration with mortality (P=0.01). These findings suggest plasma IL-6 and IL-10 may serve as biomarkers for perioperative outcomes.     

AID Biology: A pathological and clinical perspective

Activation-induced cytidine deaminase (AID), primarily expressed in activated mature B lymphocytes in germinal centers, is the key factor in adaptive immune response against foreign antigens. AID is responsible for producing high-affinity and high-specificity antibodies against an infectious agent, through the physiological DNA alteration processes of antibody genes by somatic hypermutation (SHM) and class-switch recombination (CSR) and functions by deaminating deoxycytidines (dC) to deoxyuridines (dU), thereby introducing point mutations and double-stranded chromosomal breaks (DSBs). The beneficial physiological role of AID in antibody diversification is outweighed by its detrimental role in the genesis of several chronic immune diseases, under non-physiological conditions. This review offers a comprehensive and better understanding of AID biology and its pathological aspects, as well as addresses the challenges involved in AID-related cancer therapeutics, based on various recent advances and evidence available in the literature till date. In this article, we discuss ways through which our interpretation of AID biology may reflect upon novel clinical insights, which could be successfully translated into designing clinical trials and improving patient prognosis and disease management.     

Treatment of neglected femoral neck fracture

Intra-capsular femoral neck fractures are seen commonly in elderly people following a low energy trauma. Femoral neck fracture has a devastating effect on the blood supply of the femoral head, which is directly proportional to the severity of trauma and displacement of the fracture. Various authors have described a wide array of options for treatment of neglected/nonunion (NU) femoral neck fracture. There is lack of consensus in general, regarding the best option. This Instructional course article is an analysis of available treatment options used for neglected femoral neck fracture in the literature and attempt to suggest treatment guides for neglected femoral neck fracture. We conducted the “Pubmed” search with the keywords “NU femoral neck fracture and/or neglected femoral neck fracture, muscle-pedicle bone graft in femoral neck fracture, fibular graft in femoral neck fracture and valgus osteotomy in femoral neck fracture.” A total of 203 print articles were obtained as the search result. Thirty three articles were included in the analysis and were categorized into four subgroups based on treatment options. (a) treated by muscle-pedicle bone grafting (MPBG), (b) closed/open reduction internal fixation and fibular grafting (c) open reduction and internal fixation with valgus osteotomy, (d) miscellaneous procedures. The data was pooled from all groups for mean neglect, the type of study (prospective or retrospective), classification used, procedure performed, mean followup available, outcome, complications, and reoperation if any. The outcome of neglected femoral neck fracture depends on the duration of neglect, as the changes occurring in the fracture area and fracture fragments decides the need and type of biological stimulus required for fracture union. In stage I and stage II (Sandhu''s staging) neglected femoral neck fracture osteosynthesis with open reduction and bone grafting with MPBG or Valgus Osteotomy achieves fracture union in almost 90% cases. However, in stage III with or without AVN, the results of osteosynthesis are poor and the choice of treatment is replacement arthroplasty (hemi or total).     

Congenital left ventricular diverticulum repair in an adult with dual patch technique

Rupture of a congenital left ventricular diverticulum (CLVD), a rare anatomical anomaly, is a catastrophic event, with potential fatal consequences. Repair techniques documented in the literature include primary closure and single patch closure. We describe a case of a 57-year-old woman with symptomatic anterolateral CLVD. Our approach involves a linear incision through the epicardial surface of the diverticulum with exclusion of the cavity, and restoration of normal ventricular geometry via a two-patch technique.     

Is it safe to remove an infected cardiac implantable electronic device at the time of heart transplantation? Report of two cases

Cardiac implantable electronic device (CIED) infections are treated with antibiotics and device explantation. Lack of CIED removal is associated with infection recurrence. However, CIED removal can be associated with major complications including death. We reported two patients with advanced heart disease who developed CIED infection due Staphylococcus epidermidis while awaiting for orthotopic heart transplantation (OHT). Both patients were managed with a different approach. They were treated with antibiotic therapy and had their CIED removal postponed until OHT. Both patients were kept on suppressive antibiotic treatment until undergoing simultaneous OHT and removal of infected CIED. None of the patients had infection recurrence. Large studies are needed to assess whether the approach of delaying CIED removal until OHT is safe among carefully selected patients with CIED infection.