Bending and abrasion fatigue of common suture materials used in arthroscopic and open orthopedic surgery

In orthopedic surgery, the reattachment of tendon to bone requires suture materials that have stable and durable properties to allow time for healing at the tendon–bone interface. The suture, not rigidly restrained within the anchor eyelet, is free to move during surgery and potentially after surgery with limb motion. During such movement, the suture is subjected to bending and frictional forces that can lead to fatigue‐induced failure. We investigated some common contemporary commercial number‐two‐grade suture materials and evaluated their resistance to bending abrasion fatigue and the consequent failure. Sutures were oscillated over a stainless steel wire at low frequency under load. Number of abrasion cycles to failure, changes in suture morphology, and fatigue‐failure method was recorded for each material. Suture structure had a significant effect on abrasion resistance, with braided sutures containing large numbers of fine high tenacity core filaments performing15–20 times better than other braided suture structures. Ultra high molecular weight polyethylene (UHMWPE) core filaments resisted bending abrasion failure better than other core materials due to the load spreading and abrasion resistance of these filaments. Sutures with UHMWPE cores also had high resistance to tensile failure. Limited correlation was observed between tensile strength and abrasion resistance. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:132–138, 2012     

An update on modifiable factors to reduce the risk of surgical site infections

Background contextDespite an increase in physician and public awareness and advances in infection control practices, surgical site infection (SSI) remains to be one of the most common complications after an operation. Surgical site infections have been shown to decrease health-related quality of life, double the risk of readmission, prolong the length of hospital stay, and increase hospital costs.PurposeTo critically evaluate the literature and identify modifiable factors to reduce the risk of SSI.Study design/settingSystematic review of the literature.MethodsA critical review of the literature was performed using OVID, Pubmed, and the Cochrane database and focused on eight identifiable factors: preoperative screening and decolonization of methicillin-sensitive Staphylococcus aureus and methicillin-resistant S. aureus protocols, antiseptic showers, antiseptic cloths, perioperative skin preparation, surgeon hand hygiene, antibiotic irrigation and/or use of vancomycin powder, closed suction drains, and antibiotic suture.ResultsScreening protocols have shown that 18% to 25% of patients undergoing elective orthopedic surgery are nasal carriers of S. aureus and that carriers are more likely to have a nosocomial infection and SSI. The evidence suggests that an institutionalized prescreening program, followed by an appropriate eradication using mupirocin ointment and chlorhexidine soap/shower, will lower the rate of nosocomial S. aureus infections. Based on the current literature, definitive conclusions cannot be made on whether preoperative antiseptic showers effectively reduce the incidence of postoperative infection. The use of a chlorhexidine bathing cloth before surgery may decrease the risk of SSI. There is no definitive clinical evidence that one skin preparation solution effectively lowers the rate of postoperative infection compared with another. The use of dilute betadine irrigation or vancomycin powder in the wound before closure likely decreases the incidence of SSI.ConclusionsThere is strong evidence in the literature that optimizing specific preoperative, intraoperative, and postoperative variables can significantly lower the risk of developing an SSI.     

Oral aphthous-like ulceration due to tiotropium bromide

Unwanted side-effects of a drug therapy are well known to oral medicine specialists and other colleagues. Usually they manifest itself as dry mouth, taste disturbances, various allergic or toxic reactions on the lips and/or in the oral cavity. However, the list of the drugs which might induce unwanted reactions is everyday becoming longer as more and more drugs are introduced on the market. Certain problems when diagnosing and reporting unwanted side effects of the drugs exist as only accurate method of diagnosis is repeated drug use in controlled clinical setting where fatal consequences due to the anaphilactic shock could be avoided. We report a side effect reaction to tiotropium bromide (Spiriva) cap used with HandiHaler manifesting itself as an oral ulceration in a 65 yrs old male. On the third day of drug intake the patient developed oral ulceration two times in a period of few months. Other medications he has been using for several years. To our knowledge this is a first report as an oral side-effect of this drug used for treatment of chronic obstructive pulmonary disease (COPD).     

The Niemann-Pick type C2 protein loads isoglobotrihexosylceramide onto CD1d molecules and contributes to the thymic selection of NKT cells

The Niemann-Pick type C2 (NPC2) protein is a small, soluble, lysosomal protein important for cholesterol and sphingolipid transport in the lysosome. The immunological phenotype of NPC2-deficient mice was limited to an impaired thymic selection of Valpha14 natural killer T cells (NKT cells) and a subsequent reduction of NKT cells in the periphery. The remaining NKT cells failed to produce measurable quantities of interferon-gamma in vivo and in vitro after activation with alpha-galactosylceramide. In addition, thymocytes and splenocytes from NPC2-deficient mice were poor presenters of endogenous and exogenous lipids to CD1d-restricted Valpha14 hybridoma cells. Importantly, we determined that similar to saposins, recombinant NPC2 was able to unload lipids from and load lipids into CD1d. This transfer activity was associated with a dimeric form of NPC2, suggesting a unique mechanism of glycosphingolipid transfer by NPC2. Similar to saposin B, NPC2 dimers were able to load isoglobotrihexosylceramide (iGb3), the natural selecting ligand of NKT cells in the thymus, into CD1d. These observations strongly suggested that the phenotype observed in NPC2-deficient animals was directly linked to the efficiency of the loading of iGb3 into CD1d molecules expressed by thymocytes. This conclusion was supported by the rescue of endogenous and exogenous iGb3 presentation by recombinant NPC2. Thus, the loading of endogenous and exogenous lipids and glycolipids onto CD1d is dependent on various small, soluble lipid transfer proteins present in the lysosome.     

Abnormal linear growth in paediatric adrenal diseases: Pathogenesis,prevalence and management

Abnormal adrenal function can interfere with linear growth, potentially causing either acceleration or impairment of growth in paediatric patients. These abnormalities can be caused by direct effects of adrenal hormones, particularly glucocorticoids and sex steroids, or be mediated by indirect mechanisms such as the disturbance of the growth hormone-insulin-like growth factor-1 axis and aromatization of androgens to oestrogens. The early diagnosis and optimal treatment of adrenal disorders can prevent or minimize growth disturbance and facilitate improved height gain. Mechanisms of growth disturbance in the following abnormal states will be discussed; hypercortisolaemia, hyperandrogenaemia and obesity. Prevalence and features of growth disturbance will be discussed in ACTH-dependent and ACTH-independent Cushing's syndrome, adrenocortical tumours, premature adrenarche, congenital adrenal hyperplasia and adrenal insufficiency disorders. Recommendations for management have been included.