Load to failure of common meniscal repair techniques: Effects of suture technique and suture material

Success of meniscal repair with early or immediate motion depends on the ability of the suture fixation to withstand the loads applied. Vertical and horizontal mattress suture techniques were tested using 2-0 Ethibond, and 0-PDS and 1-PDS sutures (Ethicon, Somerville, NJ). Mulberry knot technique was tested with 0-PDS and 1-PDS sutures. Twenty menisci (60 sutures) were tested for each suture material. Sutures were placed 3 to 4 mm from the peripheral edge of the meniscus with double barreled cannulas for vertical and horizontal mattress techniques or a spinal needle for the mulberry knot technique, reproducing clinical techniques of meniscal repair. Mechanical testing of suture fixation was performed to failure at a rate of 10 mm/min on a MTS material testing system (MTS Systems Corp. Minneapolis, MN). Suture pullouts were reported as the load displacement to failure from the inner fragment only, because clinical failure would ensue should a suture pull through the inner fragment of a tear. Vertical mattress technique with 1-PDS suture had significantly greater load to failure than any other combination (P < .05). Analysis of variance showed that the vertical mattress technique had statistically superior pullout strength (P < .0001) compared with the horizontal mattress and mulberry knot techniques, which were statistically similar. There were significant differences (P < .0001) between suture types, with 1-PDS proving best compared with 0-PDS, which was stronger than 2-0 Ethibond. Selection of suture material had the greatest impact on vertical mattress load to failure and was not important to the strength of the other techniques.     

Reoperation for prosthetic heart valve replacement

From 1974 to 1984, 847 heart valve replacement operations were performed with 1005 prosthetic valves. Thirty-nine (4.6%) were reoperations with 43 prosthetic valve replacements (PVR), on 38 patients. Thirty-three patients had received their initial valve replacement in our hospital and 5 elsewhere. Twenty additional cardiac procedures were required, concomitantly with the prosthesis replacement. Twenty-three patients underwent replacement of a mechanical prosthesis (61%) an average of 4.3 years after initial implantation and 15 patients a bioprosthesis (39%) after 2.8 years. Indications for PVR were endocarditis in 15 patients (39%), prosthesis failure in 13 (34%), periprosthetic leak in 7 (18%), thrombosis in 2 (5%), and a left ventricle subannular aneurysm in 1 (3%). Preoperatively 4 patients were in NYHA functional class II (11%), 15 in class III (39%) and 19 in class IV (50%). Six patients died early postoperatively (15.8%) Various risk factors were analyzed. The early mortality rate was 22% for mechanical prosthesis replacement and 7% for bioprosthesis; 11% for aortic position, 13% for mitral position and 50% to 100% for double valve replacement; 23% for non-elective and 6% for elective operations; 10% for patients with only an initial valve replacement and 43% with additional previous valve operations; 18% for active endocarditis, 15% for prosthesis failure, 14% for periprosthetic leak, 0% for thrombosis and 100% for subannular aneurysm; 0% for patients in class II, 7% in class III and 26% in class IV; 6% in patients with an aortic cross-clamp time less than 2 hours and 24% with more; 27% prior to 1981 and 9% during the last 4 years; and finally 50% in patients over the age of 60.(ABSTRACT TRUNCATED AT 250 WORDS)     

Regional anaesthesia in ambulatory surgery

Regional anaesthesia provides many advantages and can be practised safely in ambulatory surgery. It provides better postoperative pain control, avoids many complications associated with general anaesthesia and shortens recovery time. However, extra time required, associated complications and acceptance of patients are the factors of concern in practising regional anaesthesia in an ambulatory setting. This review will discuss various regional anaesthesia techniques suitable for outpatients.     

Potential risk factors for infection with Candida spp. in critically ill patients

The incidence, risk factors and prognostic factors for candidal infection were determined in a prospective study of 280 infected patients. Thirty-one (11%) patients were infected with Candida spp., sub-divided into 18 (58%) with C. albicans, and 13 (42%) with non-albicans spp. (six C. glabrata, three C. parapsilosis, and one each of C. krusei, C. tropicalis, C. guilliermondii and C. lusitaniae). Infection with Candida spp. was always associated with concurrent bacterial infection. By univariate logistic regression analysis, the degree of morbidity and the duration of mechanical ventilation were independent predictive factors for death, but infection with Candida spp., was not. Factors associated with Candida spp. infection were the degree of morbidity, intensive care unit length of stay, alterations of immune response, and the number of medical devices involved. By multivariate logistic regression analysis, the only independent risk factor for candidal infection was intensive care unit length of stay.     

The immune response of Drosophila melanogaster

Summary:  The response of the fruit fly Drosophila melanogaster to various microorganism infections relies on a multilayered defense. The epithelia constitute a first and efficient barrier. Innate immunity is activated when microorganisms succeed in entering the body cavity of the fly. Invading microorganisms are killed by the combined action of cellular and humoral processes. They are phagocytosed by specialized blood cells, surrounded by toxic melanin, or lysed by antibacterial peptides secreted into the hemolymph by fat body cells. During the last few years, research has focused on the mechanisms of microbial recognition by various pattern recognition receptors and of the subsequent induction of antimicrobial peptide expression. The cellular arm of the Drosophila innate immune system, which was somehow neglected, now constitutes the new frontier.     

Efficacy and safety of xaliproden in amyotrophic lateral sclerosis: results of two phase III trials.

Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive and fatal motor neuron disease. We carried out two randomized, double-blind, placebo-controlled, multi-centre, multi-national studies with xaliproden (a drug with neurotrophic effect) to assess drug efficacy and safety at two doses. Patients with clinically probable or definite ALS of more than 6 months and less than 5 years duration were randomly assigned to placebo, 1 mg or 2 mg xaliproden orally once daily as monotherapy in Study 1 (n=867); or to the same regimen with addition of riluzole 50 mg bid background therapy in Study 2 (n=1210 patients). The two primary endpoints were defined as: 1. Time to death, tracheostomy, or permanent assisted ventilation (DTP), and 2. Time to vital capacity (VC)<50% or DTP before (log-rank test) and after adjustment using a Cox proportional hazard model for prespecified prognostic factors. Secondary endpoints were rates of change of various functional measures. In Study 1, primary outcome measures did not reach statistical significance. For the 2 mg group, for time to VC<50% analysis (without DTP) a significant 30% RRR was obtained (95% confidence interval [CI]: 8.46, P=0.009). In Study 2, no significant results were obtained. However, there was a trend in favour of add-on 1 mg dose xaliproden vs. placebo (RRR 15% [-6.31, ns] for time to VC<50%; RRR 12% [CI: -6.27, ns] for time to VC<50% or DTP). Adjusted RR ratios were consistently more favourable for the xaliproden groups. Tolerability was good, and dose-dependent side effects were largely associated with the serotonergic properties of xaliproden. An effect of xaliproden on functional parameters, especially VC, was noted. Although this effect did not reach statistical significance, xaliproden had a small effect on clinically noteworthy aspects of disease progression in ALS.     

Ultrasound of soft tissue abnormalities of the extremities

Ultrasound may be the preferred initial diagnostic modality for the painful swollen extremity, the palpable extremity mass, and the injured extremity. The role of ultrasound in extremity soft tissue abnormalities, including muscle hemorrhage and injury, inflammatory processes, and soft tissue neoplasms, is the subject of this review.     

Monocytes in active multiple sclerosis: intact regulation of HLA-DR density in vitro despite decreased HLA-DR density in vivo

HLA-DR expression on circulating monocytes varies as a function of disease activity in patients with multiple sclerosis (MS), a putative immunopathological demyelinating disorder. Specifically, monocytes isolated from subjects with active MS exhibit reduced HLA-DR antigen density, and immunoregulatory aberrations such as impaired T lymphocyte-mediated suppression correlate strongly with this quantitative defect. To address the mechanism underlying this phenomenon, we compared in vitro regulation of HLA-DR by interferon beta (IFN beta), interferon gamma (IFN gamma), and lipopolysaccharide (LPS) in monocytes from patients with stable and active MS and normal individuals. Interferon-gamma and LPS enhanced monocyte expression of HLA-DR equally in both MS patient groups, suggesting that underexpression of HLA-DR in active MS was not explained by impaired in vivo monocyte responsiveness. Furthermore, interferon regulation of HLA-DR in normals and stable MS subjects was indistinguishable, indicating that aberrant interferon-mediated regulation of class II major histocompatibility complex (MHC) on circulating monocytes does not appear to be a characteristic of the MS disease state.