Stress-vs-time signals allow the prediction of structurally catastrophic events during fracturing of immature cartilage and predetermine the biomechanical, biochemical, and structural impairment

Objective Trauma-associated cartilage fractures occur in children and adolescents with clinically significant incidence. Several studies investigated biomechanical injury by compressive forces but the injury-related stress has not been investigated extensively. In this study, we hypothesized that the biomechanical stress occurring during compressive injury predetermines the biomechanical, biochemical, and structural consequences. We specifically investigated whether the stress-vs-time signal correlated with the injurious damage and may allow prediction of cartilage matrix fracturing. Methods Superficial and deeper zones disks (SZDs, DZDs; immature bovine cartilage) were biomechanically characterized, injured (50% compression, 100%/s strain-rate), and re-characterized. Correlations of the quantified functional, biochemical and histological damage with biomechanical parameters were zonally investigated. Results Injured SZDs exhibited decreased dynamic stiffness (by 93.04 ± 1.72%), unresolvable equilibrium moduli, structural damage (2.0 ± 0.5 on a 5-point-damage-scale), and 1.78-fold increased sGAG loss. DZDs remained intact. Measured stress-vs-time-curves during injury displayed 4 distinct shapes, which correlated with histological damage (p < 0.001), loss of dynamic stiffness and sGAG (p < 0.05). Damage prediction in a blinded experiment using stress-vs-time grades was 100%-correct and sensitive to differentiate single/complex matrix disruptions. Correlations of the dissipated energy and maximum stress rise with the extent of biomechanical and biochemical damage reached significance when SZDs and DZDs were analyzed as zonal composites but not separately. Conclusions The biomechanical stress that occurs during compressive injury predetermines the biomechanical, biochemical, and structural consequences and, thus, the structural and functional damage during cartilage fracturing. A novel biomechanical method based on the interpretation of compressive yielding allows the accurate prediction of the extent of structural damage.National Institutes of Health (U.S.) (Grant R01-AR45779)Deutsche Forschungsgemeinschaft (Grant RO2511/1-1)Deutsche Forschungsgemeinschaft (Grant RO2511/2-1)Germany. Federal Ministry of Education and Research (Grant 01KQ0902B TP2

Does fixed-angle plate osteosynthesis solve the problems of a fractured proximal humerus?: A prospective series of 87 patients

Background and purpose There is considerable controversy about the treatment of complex, displaced proximal humeral fractures. Various types of head-preserving osteosynthesis have been suggested. This prospective case series was designed to evaluate the perioperative and early postoperative complications associated with fixed-angle implants and to record outcome after bone healing

Effects of Antibiotics on the Growth and Physiology of Chlorophytes, Cyanobacteria, and a Diatom

The occurrence of antibiotics in surface waters has been reported worldwide with concentrations ranging from ng L−1 to low µg L−1 levels. During environmental risk assessments, effects of antibiotics on algal species are assessed using standard test protocols (e.g., the OECD 201 guideline), where the cell number endpoint is used as a surrogate for growth. However, the use of photosynthetic related endpoints, such as oxygen evolution rate, and the assessment of effects on algal pigments could help to inform our understanding of the impacts of antibiotics on algal species. This study explored the effects of three major usage antibiotics (tylosin, lincomycin, and trimethoprim) on the growth and physiology of two chlorophytes (Desmodesmus subspicatus and Pseudokirchneriella subcapitata), a cyanobacteria (Anabaena flos-aquae), and a diatom (Navicula pelliculosa) using a battery of parameters, including cell density, oxygen evolution rate, total chlorophyll content, carotenoids, and the irradiance–photosynthesis relationship. The results indicated that photosynthesis of chlorophytes was a more sensitive endpoint than growth (i.e., EC50 derived based on the effects of tylosin on the growth of D. subspicatus was 38.27 µmol L−1 compared with an EC50 of 17.6 µmol L−1 based on photosynthetic rate), but the situation was reversed when testing cyanobacteria and the diatom (i.e., EC50 derived based on the effects of tylosin on the growth of A. flos-aquae was 0.06 µmol L−1; EC50 0.33 µmol L−1 based on photosynthetic rate). The pigment contents of algal cells were affected by the three antibiotics for D. subspicatus. However, in some cases, pigment content was stimulated for P. subcapitata, N. pelliculosa, and A. flos-aquae. The light utilization efficiency of chlorophytes and diatom was decreased markedly in the presence of antibiotics. The results demonstrated that the integration of these additional endpoints into existing standardised protocols could provide useful insights into the impacts of antibiotics on algal species

Inter- and intraobserver reliability of the MTM-classification for proximal humeral fractures: A prospective study

<p>Abstract</p> <p>Background</p> <p>A precise modular topographic-morphological (MTM) classification for proximal humeral fractures may address current classification problems. The classification was developed to evaluate whether a very detailed classification exceeding the analysis of fractured parts may be a valuable tool.</p> <p>Methods</p> <p>Three observers classified plain radiographs of 22 fractures using both a simple version (fracture displacement, number of parts) and an extensive version (individual topographic fracture type and morphology) of the MTM classification. Kappa-statistics were used to determine reliability.</p> <p>Results</p> <p>An acceptable reliability was found for the simple version classifying fracture displacement and fractured main parts. Fair interobserver agreement was found for the extensive version with individual topographic fracture type and morphology.</p> <p>Conclusion</p> <p>Although the MTM-classification covers a wide spectrum of fracture types, our results indicate that the precise topographic and morphological description is not delivering reproducible results. Therefore, simplicity in fracture classification may be more useful than extensive approaches, which are not adequately reliable to address current classification problems.</p

Hemiarthroplasty versus angle-stable locking compression plate osteosynthesis in the treatment of three- and four-part fractures of the proximal humerus in the elderly: design of a randomized controlled trial

ABSTRACT: BACKGROUND: The optimal surgical management of dislocated three- and four-part fractures of the proximal humerus in elderly patients remains unclear. Most used techniques are hemiarthroplasty and angle-stable locking compression plate osteosynthesis. In the current literature there is no evidence available presenting superior results between hemiarthroplasty and angle-stable locking compression plate osteosynthesis in terms of speed of recovery, pain, patient satisfaction, functional outcome, quality of life or complications. METHODS/DESIGN: A randomized controlled multicenter trial will be conducted. Patients older than 60 years of age with a dislocated three- or four-part fracture of the proximal humerus as diagnosed by X-rays and CT-scans will be included. Exclusion criteria are a fracture older than 14 days, multiple comorbidity, multitrauma, a pathological fracture, previous surgery on the injured shoulder, severely deranged function caused by a previous disease, "head-split" proximal humerus fracture and unwillingness or inability to follow instructions. Participants will be randomized between surgical treatment with hemiarthroplasty and angle-stable locking compression plate osteosynthesis. Measurements will take place preoperatively and 3 months, 6 months, 9 months, 12 months and 24 months postoperatively. Primary outcome measure is speed of recovery of functional capacity of the affected upper limb using the Disabilities of Arm, Shoulder and Hand score (DASH). Secondary outcome measures are pain, patient satisfaction, shoulder function, quality of life, radiological evaluation and complications. Data will be analyzed on an intention-to-treat basis, using univariate and multivariate analyses. DISCUSSION: Both hemiarthroplasty and angle-stable locking compression plate osteosynthesis are used in the current treatment of dislocated three-and four-part fractures of the proximal humerus. There is a lack of level-1 studies comparing these two most-used surgical treatment options. This randomized controlled multicenter trial has been designed to determine which surgical treatment option provides the fastest recovery of functional capacity of the affected upper limb, and will provide better outcomes in pain, satisfaction, shoulder function, quality of life, radiological evaluation and complications. TRIAL REGISTRATION NUMBER: The trial is registered in the Netherlands Trial Registry (NTR2461)

Homeopathic treatment of patients with chronic sinusitis: A prospective observational study with 8 years follow-up

<p>Abstract</p> <p>Background</p> <p>An evaluation of homeopathic treatment and the outcomes in patients suffering from sinusitis for ≥12 weeks in a usual care situation.</p> <p>Methods</p> <p>Subgroup analysis including all patients with chronic sinusitis (ICD-9: 473.9; ≥12 weeks duration) of a large prospective multicentre observational study population. Consecutive patients presenting for homeopathic treatment were followed-up for 2 years, and complaint severity, health-related quality of life (QoL), and medication use were regularly recorded. We also present here patient-reported health status 8 years post initial treatment.</p> <p>Results</p> <p>The study included 134 adults (mean age 39.8 ± 10.4 years, 76.1% women), treated by 62 physicians. Patients had suffered from chronic sinusitis for 10.7 ± 9.8 years. Almost all patients (97.0%) had previously been treated with conventional medicine. For sinusitis, effect size (effect divided by standard deviation at baseline) of complaint severity was 1.58 (95% CI 1.77; 1.40), 2.15 (2.38; 1.92), and 2.43 (2.68; 2.18) at 3, 12, and 24 months respectively. QoL improved accordingly, with SF-36 changes in physical component score 0.27 (0.15; 0.39), 0.35 (0.19; 0.52), 0.44 (0.23; 0.65) and mental component score 0.66 (0.49; 0.84), 0.71 (0.50; 0.92), 0.65 (0.39; 0.92), 0.74 (0.49; 1.00) at these points. The effects were still present after 8 years with SF-36 physical component score 0.38 (0.10; 0.65) and mental component score 0.74 (0.49; 1.00).</p> <p>Conclusion</p> <p>This observational study showed relevant improvements that persisted for 8 years in patients seeking homeopathic treatment because of sinusitis. The extent to which the observed effects are due to the life-style regulation and placebo or context effects associated with the treatment needs clarification in future explanatory studies.</p