Humoral and cellular immune response to tick-borne-encephalitis (TBE) vaccination depends on booster doses in patients with Juvenile Idiopathic Arthritis (JIA)

Juvenile Idiopathic Arthritis (JIA) patients living in areas with high prevalence of tick-borne-encephalitis-virus-(TBEV)-infection are recommended for administration of inactivated TBE-vaccination. However, there are serious concerns regarding protective vaccine-induced immune responses against TBEV in immunocompromised patients. The present study aimed to analyze the humoral and cellular immune response to TBE-vaccination in previously TBE-vaccinated JIA patients compared to healthy controls (HC) including investigation of IgG-anti-TBEV avidity, neutralization capacity, cellular reactivity by IFNgamma-ELISPOT and cytokine secretion assays. Similar IgG-anti-TBEV antibody concentrations, neutralization titers and cellular reactivity were found between JIA and HC. The number and the early timing of booster vaccinations after primary vaccination had the most prominent effect on neutralizing antibodies in JIA and on IgG-anti-TBEV concentrations in both JIA and HC. Administration of booster vaccinations made it more likely for JIA patients to have IgG-anti-TBEV concentrations ≥165 VIEU/ml and avidities >60%. TNF-alpha inhibitors had a positive and MTX administration a negative effect on humoral immune responses. In conclusion, irrespective of having JIA or not, vaccinated children showed similar humoral and cellular immunity against TBEV several years after primary TBE-vaccination. However, in JIA, booster vaccinations mounted a significantly higher humoral immune response than in JIA without boosters. Our results highlight the need for timely administration of boosters particularly in JIA. Although immunosuppressive treatment at vaccinations in diagnosed JIA had a negative effect mainly on TBEV-specific cellular immunity, most JIA patients mounted a favorable humoral immune response which was maintained over time. Thus, successful TBE-vaccination seems highly feasible in JIA patients with immunosuppressive regimens.

Continuous Plankton Recorder in the omics era: from marine microbiome to global ocean observations

First routinely deployed in 1931 the Continuous Plankton Recorder (CPR) technology has established the most extensive, marine biological sampling programme in the world. With more than 90 years of sampling, over a total of 8 million nautical miles covered and 500 000 curated samples, the CPR survey provides a gold mine of information available to marine researchers. Such information is likely to exponentially increase thanks to new cutting-edge molecular technologies that are beginning to be applied on CPR samples. In this review we aim to address the exciting developments that the genomic revolution is having on ​CPR applications from the study of marine microbiome to ocean plankton communities leading to ​a new 'digital era' of the global ocean CPR observation programme.

Parasites, pathogens, and other symbionts of copepods

There is a large diversity of eukaryotic symbionts of copepods, dominated by epizootic protists such as ciliates, and metazoan parasites. Eukaryotic endoparasites, copepod-associated bacteria, and viruses are less well known, partly due to technical limitations. However, new molecular techniques, combined with a range of other approaches, provide a complementary toolkit for understanding the complete symbiome of copepods and how the symbiome relates to their ecological roles, relationships with other biota, and responses to environmental change. In this review we provide the most complete overview of the copepod symbiome to date, including microeukaryotes, metazoan parasites, bacteria, and viruses, and provide extensive literature databases to inform future studies.

Aquatic reservoir of Vibrio cholerae in an African Great Lake assessed by large scale plankton sampling and ultrasensitive molecular methods

The significance of large tropical lakes as environmental reservoirs of Vibrio cholerae in cholera endemic countries has yet to be established. By combining large scale plankton sampling, microbial culture and ultrasensitive molecular methods, namely Droplet Digital PCR (ddPCR) and targeted genomics, the presence of Vibrio cholerae was investigated in a 96,600 L volume of surface water collected on a 322 nautical mile (596 km) transect in Lake Tanganyika. V. cholerae was detected and identified in a large area of the lake. In contrast, toxigenic strains of V. cholerae O1 or O139 were not detected in plankton samples possibly in relation to environmental conditions of the lake ecosystem, namely very low salinity compared to marine brackish and coastal environments. This represents to our knowledge, the largest environmental study to determine the role of tropical lakes as a reservoir of V. cholerae.

Impact du confinement sur le suivi des immunothérapies orales alimentaires : étude multicentrique dans 3 centres d’Île-de-France

But de l’étude

Plusieurs études ont confirmé l’impact du confinement sur la population, entraînant une rupture de soins, des effets somatiques et psychologiques. Notre étude s’intéresse aux effets indésirables et aux problèmes d’observance au cours d’immunothérapie orale (ITO) alimentaires pendant le confinement.

Patients et méthodes

Au total, 132 patients, majoritairement des enfants (95 %), avec un antécédent atopique (60 %) suivis pour une ITO ont été inclus dans 3 centres d’allergologie en Île-de-France, pendant le confinement lié à la pandémie SARS-Cov-2 du 16/03 au 11/05/20. Les aliments des ITO étaient principalement l’arachide (38 %), le lait de vache (24 %), la noisette (14 %), l’œuf (9 %), la noix de cajou et la pistache (8 %).

Résultats

Des effets indésirables ont été retrouvés chez 13 patients soit 10 % des cas. Ces réactions étaient principalement de grade 1 et 2 selon la classification de Ring et Messmer. Trois patients ont présenté des réactions de grade 3 et six patients ont utilisé l’adrénaline au domicile. L’observance était correcte dans 81 % des cas sans aucun oubli. Trois patients ont augmenté leur dose quotidienne sans avis médical. Nous n’avons pas retrouvé de différence significative dans l’analyse en sous-groupe comparant des enfants appariés en âge suivis en ITO en 2019 et en 2020 sur la même période dans le même hôpital.

Conclusion

Il n’y a pas eu d’augmentation des effets indésirables au cours d’ITO pendant la période du confinement. L’éducation thérapeutique au cours de l’ITO est primordiale et participe à réduire la survenue d’effets indésirables.

Quantification of hyaluronan in human fasciae: variations with function and anatomical site

Recently, alterations in fascial gliding-like movement have been invoked as critical in the etiology of myofascial pain. Various methods have been attempted for the relief of this major and debilitating clinical problem. Paramount have been attempts to restore correct gliding between fascial layers and the movement over bone, joint, and muscular structures. One of the key elements that underlies such fascial movement is hyaluronan. However, until now, the precise content of hyaluronan within fasciae has been unknown. This study quantifies for the first time the hyaluronan content of human fascial samples obtained from a variety of anatomic sites. Here, we demonstrate that the average amount varies according to anatomic site, and according to the different kinds of sliding properties of the particular fascia. For example, the fascia lata has 35 μg of hyaluronan per gram of tissue, similar to that of the rectus sheath (29 μg g^-1 ). However, the types of fascia adherent to muscle contain far less hyaluronan: 6 μg g^-1 in the fascia overlying the trapezius and deltoid muscles. In the fascia that surrounds joints, the hyaluronan increases to 90 μg g^-1 , such as in the retinacula of the ankle, where greater degrees of movement occur. Surprisingly, no significant differences were detected at any site as a function of age or sex (P-value > 0.05, t-test) with the sole exception of the plantar fascia. This work can provide a better understanding of the role of hyaluronan in fascia. It will facilitate a better comprehension of the modulation of the hyaluronan-rich layer that occurs in relation to the various conditions that affect fascia, and the diverse factors that underlie the attendant pathologies.

On the in Vivo Clearance of Thrombin

The turnover of labeled bovine thrombin was studied in heparinized dogs. The results of these studies indicate that

1. thrombin is rapidly removed from the blood, clearance takes place predominantly by the liver ;

2. the uptake occurs by the Kupffer cells ;

3. after its uptake the thrombin is rapidly broken down ;

4. in the absence of the liver thrombin is slowly cleared by extrahepatic phagocytes ;

5. the rate of thrombin clearance is so rapid and its critical dose so small that this protein can be used to study hepatic blood flow and Kupffer cell clearance function.

Hawkins' type-II talar fracture with subtalar dislocation: A very unusual combination

We report the unusual case of a 16-year-old young man who sustained a rare association of a Hawkins' type-II talar neck fracture with a complete medial subtalar dislocation (Hawkins type-IIB) that occurred as an isolated injury after indirect trauma during a soccer game. Following closed reduction of the subtalar dislocation, standard radiographs and computed tomography (CT) demonstrated a comminuted fracture of the talus involving the base of the talar neck. Open reduction was performed and the fracture was stabilized by ORIF. At 1-year follow-up, functional and radiographic outcomes were graded as excellent, with no radiographic evidence of talar osteonecrosis.

Field-stepped broadband NMR in pulsed magnets and application to SrCu2(BO3)2 at 54T

Pulsed magnets generate the highest magnetic fields as brief transients during which the observation of NMR is difficult, however, this is the only route to unique insight into material properties up to the regime of 100T. Here, it is shown how rather broad NMR spectra can be assembled in a pulsed magnet during a single field pulse by using the inherent time dependence of the field for the recording of field-stepped free induction decays that cover a broad frequency range. The technique is then applied to (11)B NMR of the spin-dimer system SrCu2(BO3)2, a magnetic insulator known to undergo a series of field-driven changes of the magnetic ground state. At peak fields of about 54T at the Dresden High Magnetic Field Laboratory, (11)B NMR spectra spanning a total of about 9MHz width are reconstructed. The results are in good accordance with a change from a high-temperature paramagnetic state to a low-temperature commensurate superstructure of field-induced spin-dimer triplets.

Radiographic evaluation of posttraumatic osteoarthritis of the ankle: the Kellgren-Lawrence scale is reliable and correlates with clinical symptoms

OBJECTIVE

To assess reliability and construct validity of the Kellgren-Lawrence (K&L) scale in posttraumatic ankle osteoarthritis (OA); additionally evaluate the validity of including tibiotalar tilting in the scale.

METHOD

One-hundred and fifty ankle radiographs (75 patients, unilateral malleolar fractures) evaluated at average of 18 years after surgery. American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot (HF) score and pain (visual analog scale) were recorded. Grading of OA according to K&L criteria and identification of OA features was performed on standardized radiographs by four physicians. Minimal joint space width, sclerosis, and talar tilt angle were quantified by digital measurements. A modified K&L scale including talar tilting is presented. Validity of original and modified scale was evaluated and expressed as ability to (1) Identify those with clinical symptoms of ankle OA; and (2) Distinguish between different degrees of fracture severity.

RESULTS

Inter- and intra-observer reliability of OA assessment according to K&L were good (ICC 0.61 and 0.75). Original and modified K&L grades significantly increased with decreasing AOFAS ankle-HF scores and greater pain. A talar-tilt angle > 2° compared with ≤ 2° in grade 3 was associated with significantly higher pain levels (VAS pain 4.2 vs 1.4, respectively; mean difference 2.8, 95% CI 0.5-5.1). More severe fracture patterns at time of surgery were more often in patients with the highest K&L grades.

CONCLUSIONS

The K&L scale is a valid and reliable radiographic grading system for assessment of ankle OA. Inclusion of the talar tilt angle might allow for better differentiation with respect to clinical outcomes.

Absence of skin rash in Goodpasture's syndrome: the hyaluronan effect

Goodpasture's syndrome is a rare disease that involves rapidly progressive kidney failure as well as hemorrhagic lung disease. It is a form of autoimmune disorder with unusual features; marked male preponderance, in contrast with other autoimmune disease in which females are at far greater risk. The autoantibodies are directed again the carboxy-extension non-collagenous (NC1) portion of one of the basement membrane-specific collagen IV alpha 3 chains. Basal laminas throughout the body share this structure, including those in kidney, lung and skin. But curiously, skin is rarely involved in Goodpasture's syndrome. Hyaluronan is a large extracellular matrix carbohydrate polymer. Half of total body hyaluronan occurs in skin. High molecular weight hyaluronan, a potent immunosuppressive polymer, might be functioning as an immune shield for skin in Goodpasture's syndrome, and be the basis for the anomaly. A summary of this putative effect is described, including possible molecular mechanisms involved, and suggestions for testing this hypothesis.

A Novel SAT-Based Approach to Model Based Diagnosis

This paper introduces a novel encoding of Model Based Diagnosis (MBD) to Boolean Satisfaction (SAT) focusing on minimal cardinality diagnosis. The encoding is based on a combination of sophisticated MBD preprocessing algorithms and the application of a SAT compiler which optimizes the encoding to provide more succinct CNF representations than obtained with previous works. Experimental evidence indicates that our approach is superior to all published algorithms for minimal cardinality MBD. In particular, we can determine, for the first time, minimal cardinality diagnoses for the entire standard ISCAS-85 and 74XXX benchmarks. Our results open the way to improve the state-of-the-art on a range of similar MBD problems.

A comparative assessment of small-head metal-on-metal and ceramic-on-polyethylene total hip replacement

Large-head metal-on-metal (MoM) total hip replacements (THR) have given rise to concern. Comparative studies of small-head MoM THRs over a longer follow-up period are lacking. Our objective was to compare the incidence of complications such as infection, dislocation, revision, adverse local tissue reactions, mortality and radiological and clinical outcomes in small-head (28 mm) MoM and ceramic-on-polyethylene (CoP) THRs up to 12 years post-operatively. A prospective cohort study included 3341 THRs in 2714 patients. The mean age was 69.1 years (range 24 to 98) and 1848 (55.3%) were performed in women, with a mean follow-up of 115 months (18 to 201). There were 883 MoM and 2458 CoP bearings. Crude incidence rates (cases/1000 person-years) were: infection 1.3 vs 0.8; dislocation 3.3 vs 3.1 and all-cause revision 4.3 vs 2.2, respectively. There was a significantly higher revision rate after ten years (adjusted hazard ratio 9.4; 95% CI 2.6 to 33.6) in the MoM group, and ten of 26 patients presented with an adverse local tissue reaction at revision. No differences in mortality, osteolysis or clinical outcome were seen. In conclusion, we found similar results for small-head MoM and CoP bearings up to ten years post-operatively, but after ten years MoM THRs had a higher risk of all-cause revision. Furthermore, the presence of an adverse response to metal debris seen in the small-head MOM group at revision is a cause for concern.

Enhanced Partial Expansion A*

When solving instances of problem domains that feature a large branching factor, A* may generate a large number of nodes whose cost is greater than the cost of the optimal solution. We designate such nodes as surplus. Generating surplus nodes and adding them to the OPEN list may dominate both time and memory of the search. A recently introduced variant of A* called Partial Expansion A* (PEA*) deals with the memory aspect of this problem. When expanding a node n, PEA* generates all of its children and puts into OPEN only the children with f = f (n). n is re-inserted in the OPEN list with the f -cost of the best discarded child. This guarantees that surplus nodes are not inserted into OPEN. In this paper, we present a novel variant of A* called Enhanced Partial Expansion A* (EPEA*) that advances the idea of PEA* to address the time aspect. Given a priori domain- and heuristic- specific knowledge, EPEA* generates only the nodes with f = f(n). Although EPEA* is not always applicable or practical, we study several variants of EPEA*, which make it applicable to a large number of domains and heuristics. In particular, the ideas of EPEA* are applicable to IDA* and to the domains where pattern databases are traditionally used. Experimental studies show significant improvements in run-time and memory performance for several standard benchmark applications. We provide several theoretical studies to facilitate an understanding of the new algorithm.

Is there any benefit in pre-operative urinary analysis before elective total joint replacement?

Whether patients with asymptomatic bacteriuria should be investigated and treated before elective hip and knee replacement is controversial, although it is a widespread practice. We conducted a prospective observational cohort study with urine analyses before surgery and three days post-operatively. Patients with symptomatic urinary infections or an indwelling catheter were excluded. Post-discharge surveillance included questionnaires to patients and general practitioners at three months. Among 510 patients (309 women and 201 men), with a median age of 69 years (16 to 97) undergoing lower limb joint replacements (290 hips and 220 knees), 182 (36%) had pre-operative asymptomatic bacteriuria, mostly due to Escherichia coli, and 181 (35%) had white cells in the urine. Most patients (95%) received a single intravenous peri-operative dose (1.5 g) of cefuroxime as prophylaxis. On the third post-operative day urinary analysis identified white cells in 99 samples (19%) and bacteriuria in 208 (41%). Pathogens in the cultures on the third post-operative day were different from those in the pre-operative samples in 260 patients (51%). Only 25 patients (5%) developed a symptomatic urinary infection during their stay or in a subsequent three-month follow-up period, and two thirds of organisms identified were unrelated to those found during the admission. All symptomatic infections were successfully treated with oral antibiotics with no perceived effect on the joint replacement.

We conclude that testing and treating asymptomatic urinary tract colonisation before joint replacement is unnecessary.

Cite this article: Bone Joint J 2014;96-B:390–4.

Hyaluronan peroxidation is required for normal synovial function: an hypothesis

Despite widespread use of antioxidants, reactive oxygen species have important functions in normal tissues. Herein, we present an example of a physiological role for free radicals, and in particular, reactive oxygen species, that are suppressed by anti-oxidants. Free radicals catalyze the degradation of hyaluronan in synovial fluid, a tissue in which hyaluronidase activity is barely detectable. Articular cartilage requires a low oxygen environment. The process of hyaluronan peroxidation consumes significant amounts of molecular oxygen, thus keeping the tension of oxygen in the joint at a low but physiologically critical level. One concern is the change in physical activity between day and night, with periods of joint hyperemia and ischemia, respectively. Increased oxygen and the resulting oxidative stress would lead to chondrocyte dysfunction and cartilage damage. A mechanism for keeping oxygen levels low is required. We postulate that a mechanism indeed exists for the removal of excess oxygen. High-molar-mass hyaluronan turnover in synovial fluid utilizes peroxidative degradation, during which oxygen is massively consumed. The peroxidation itself may be initiated by hydrogen peroxide, which is produced by chondrocyte mitochondria, that can diffuse into the synovial fluid. The resulting decrease in available oxygen down-regulates hyaluronan peroxidation. This in turn prevents excessive oxygen consumption. It appears that free radicals and reactive oxygen species may be components of normal physiology, particularly in the synovial fluid of joints and articular cartilage. It is suggested therefore that indiscriminate use of anti-oxidants, vigorously promoted currently by health professionals and the health industry, be approached with caution.

Ligulate Desmarestia (Desmarestiales, Phaeophyceae) revisited: D. japonica sp. nov. and D. dudresnayi differ from D. ligulata

The phylogeny of ligulate and sulfuric-acid containing species of Desmarestia, occurring worldwide from polar to temperate regions, was revised using a multigenic and polyphasic approach. Sequence data, gametophyte characteristics, and sporophyte morphology support reducing a total of 16 taxa to four different species. (1) D. herbacea, containing broad-bladed and highly branched forms, has dioecious gametophytes. The three other species have monoecious gametophytes: (2) D. ligulata which is profusely branched and, except for one subspecies, narrow-bladed, (3) Japanese ligulate Desmarestia, here described as D. japonica sp. nov., which is morphologically similar to D. ligulata but genetically distant from all other ligulate taxa. This species may have conserved the morphology of original ligulate Desmarestia. (4) D. dudresnayi, including unbranched or little branched broad-bladed taxa. A figure of the holotype of D. dudresnayi, which was lost for decades, was relocated. The taxonomy is complemented by a comparison of internal transcribed spacer and cytochrome c oxidase subunit I (cox1) as potential barcode loci, with cox1 offering good resolution, reflecting species delimitations within the genus Desmarestia.

Jahn–Teller orbital glass state in the expanded fcc Cs3C60 fulleride

Magic-angle-spinning NMR measurements on fcc Cs₃C₆₀ to cryogenic temperatures reveal freezing-out of the C₆₀^3¬ Jahn–Teller dynamics and emergence of an electronic orbital glass state guided by the C₆₀^3¬ merohedral disorder.

Unstable pelvic ring injury with hemodynamic instability: what seems the best procedure choice and sequence in the initial management?

INTRODUCTION

Most fatalities related to pelvic ring injuries occur early and are caused by massive retroperitoneal bleeding. The objective of our study is to determine the optimal sequence of surgical procedures to restore hemodynamic stability in patients with unstable pelvic ring injuries.

PATIENTS AND METHODS

This was a retrospective review of all patients with pelvic fractures and hemodynamic instability admitted to our level 1 trauma center between January 1998 and December 2008. We entered into our polytrauma database the following patient characteristics: age, sex, mechanism of injury, Injury Severity Score (ISS), classification of injury, timing of operative intervention, and type of operative procedures. Patients were divided into four groups (according to the sequence of surgical procedures performed within 24 hours following admission), as follows: group 1: patients treated with external fixation only; group 2: patients receiving external fixation followed by angiography; group 3: patients receiving external fixation followed by laparotomy ± angiography; and group 4: patients treated by immediate laparotomy or angiography before skeletal fixation.

RESULTS

Eighty of 136 patients admitted with a pelvic fracture were classified, as unstable AO/OTA type B or C pelvic ring injury, and 70/80 were hemodynamically unstable. Eight patients died shortly after arrival and two remained stable without requiring any early procedure. Sixty patients went immediately to the operating room. Twenty-nine patients were placed in group 1 with 100% survival, 12 in group 2 with 91% survival, 11 in group 3 with 82% survival, and eight patients placed in group 4 with 0% survival (P<0.001).

CONCLUSIONS

The management of hemorrhagic instability linked to pelvic ring disruption involves a sequence of therapeutic events, which is more important than the events themselves. Pelvic bone stabilization by pelvic clamp or external fixator followed by arteriography seems to be the more secure. Angiographic embolization is the method of choice whenever haemodynamic instability coexists with an unstable pelvic disruption. Laparotomy and packing are restricted to extreme severe cases in remote hospitals with skillful surgeons! Actually aortic balloon is a good solution to control uncontrollable bleeding.

LEVEL OF EVIDENCE

Level IV. Retrospective study.

Comparison of the outcome following the fixation of osteotomies or fractures associated with total hip replacement using cables or wires: the results at five years

There are no recent studies comparing cable with wire for the fixation of osteotomies or fractures in total hip replacement (THR). Our objective was to evaluate the five-year clinical and radiological outcomes and complication rates of the two techniques. We undertook a review including all primary and revision THRs performed in one hospital between 1996 and 2005 using cable or wire fixation. Clinical and radiological evaluation was performed five years post-operatively. Cables were used in 51 THRs and wires in 126, and of these, 36 THRs with cable (71%) and 101 with wire (80%) were evaluated at follow-up. The five-year radiographs available for 33 cable and 91 wire THRs revealed rates of breakage of fixation of 12 of 33 (36%) and 42 of 91 (46%), respectively. With cable there was a significantly higher risk of metal debris (68% vs. 9%; adjusted relative risk (RR) 6.6; 95% confidence interval (CI) 3.0 to 14.1), nonunion (36% vs. 21%; adjusted RR 2.0; 95% CI 1.0 to 3.9) and osteolysis around the material, acetabulum or femur (61% vs 19%; adjusted RR 3.9; 95% CI 2.3 to 6.5). Cable breakage increased the risk of osteolysis to 83%. There was a trend towards foreign-body reaction and increased infection with cables. Clinical results did not differ between the groups. In conclusion, we found a higher incidence of complications and a trend towards increased infection and foreign-body reaction with the use of cables.

Changes in position and volume of lung cancer target volumes during stereotactic body radiotherapy (SBRT): is image guidance necessary?

The purpose of this study was to analyze inter- and intra-fractional changes in tumor volume with respect to both spatial and volumetric parameters among patients treated by SBRT for lung cancer. Twelve patients (13 tumors) were treated by SBRT with abdominal compression in 3-5 fractions over a 2 week period to a median dose of 60 Gy (range, 48 to 60 Gy). Kilovoltage cone-beam CT (CBCT) was obtained prior to the delivery of each fraction as well as intra-fractionally yielding a total of 55 CBCT scans. All CBCT scans were registered with the planning CT for target alignment and shifts were recorded and analyzed. Retrospectively, gross tumor volume (GTV) was contoured on all CBCT images and compared to initial planning volumes; positional differences were evaluated utilizing directional and vector analysis. Shifts greater than 5 mm were applied inter-fractionally in 6.8% (lateral), 29.5% (longitudinal), and 6.8% (vertical) of all delivered treatments. Using a 10 mm threshold, the corresponding percentages were 2.3%, 13.6%, and 2.3%, respectively. Across all fractions, the calculated inter-fractional shift vectors ranged from 0 to 31.2 mm, with 40.9%, 15.9%, and 11.4% of all fractions having shift vectors≥5 mm, ≥10 mm, and ≥20 mm, respectively. Intra-fractional shifts were also evaluated and found negligible in a small portion of patients evaluated. The mean overall reduction in GTV was 21.1% during SBRT. Significant changes in both position and volume occur during SBRT for lung cancer. Shifts (particularly in the superior-inferior axis) may exceed applied margins and compromise target coverage. Due to the extreme hypofractionation associated with SBRT, inter-fractional image guidance is necessary.

No need to search for the source of haematogenous arthroplasty infections

QUESTIONS UNDER STUDY/PRINCIPLES

Prosthetic joint infections (PJI) may be a potential sentinel event for an unknown neoplastic or infectious source in elderly patients. However, the value and cost-effectiveness of investigations to determine the origin of these infections is unknown.

METHODS

Retrospective study at Geneva University Hospitals, evaluating associated medical examinations performed in search of the origin of all presumed surgical site and haematogenous arthroplasty infections.

RESULTS

A total of 182 PJI were found in 182 patients (median age 75 years). Seventy PJI (38%) were classified as probably haematogenous, occurring more than 2 years post-implantation, with 27 (15%) due to Gram-negative pathogens. Overall, the origin of PJI was found solely by admission history in 28 cases (15%). Among the remaining 154 cases, no remote origin could be detected despite 17 echocardiograms, 17 other sonograms, 49 chest x-rays, 23 computed tomograms, 107 urinary cultures, 11 endoscopies, 9 scintigraphies and 31 medical specialist consultations. The average cost of these exams was 675 Swiss francs (845 US$) per PJI. At long-term follow-up six patients were found to have developed a neoplasm, of which only one (hepatocellular carcinoma after PJI due to Streptococcus bovis) could eventually be attributed to prior infection.

CONCLUSIONS

From an epidemiologic point of view, patient history is the best way to predict the origin of PJI. Blind additional radiographic or endoscopic exams are costly, inconclusive and do not contribute to the management of these cases.

Hyaluronan within fascia in the etiology of myofascial pain

The layers of loose connective tissue within deep fasciae were studied with particular emphasis on the histochemical distribution of hyaluronan (HA). Samples of deep fascia together with the underlying muscles were taken from neck, abdomen and thigh from three fresh non-embalmed cadavers. Samples were stained with hematoxylin-eosin, Azan-Mallory, Alcian blue and a biotinylated HA-binding protein specific for HA. An ultrasound study was also performed on 22 voluntary subjects to analyze the thickness of these deep fasciae and their sublayers. The deep fascia presented a layer of HA between fascia and the muscle and within the loose connective tissue that divided different fibrous sublayers of the deep fascia. A layer of fibroblast-like cells that stained prominently with Alcian blue stain was observed. It was postulated that these are cells specialized for the biosynthesis of the HA-rich matrix. These cells we have termed "fasciacytes", and may represent a new class of cells not previously recognized. The ultrasound study highlighted a mean thickness of 1.88 mm of the fascia lata, 1.68 mm of the rectus sheath, and 1.73 mm of the sternocleidomastoid fascia. The HA within the deep fascia facilitates the free sliding of two adjacent fibrous fascial layers, thus promoting the normal function associated with the deep fascia. If the HA assumes a more packed conformation, or more generally, if the loose connective tissue inside the fascia alters its density, the behavior of the entire deep fascia and the underlying muscle would be compromised. This, we predict, may be the basis of the common phenomenon known as "myofascial pain."

The effect of collateral ligament release on ankle dorsiflexion: an anatomical study

BACKGROUND

Ankle stiffness is a common complication after ankle fracture, reconstructive surgery or total ankle replacement, and the usual limitation is in dorsiflexion. There are few articles in the literature concerning this frequent problem, and furthermore they are not recent and tend to be controversial. The purpose of this anatomical study was to evaluate and quantify the effect of ankle collateral ligament release on dorsiflexion, specifically the amount of increase in ankle dorsiflexion following section of the two ligaments most often implicated in ankle stiffness: the deep posterior tibiotalar ligament (dPTTaL, or posterior deep deltoid) and the posterior talofibular ligament (PTaFL).

METHODS

We dissected 18 adult fresh cadaveric ankle joints, and with an electronic goniometer combined with an electronic dynamometer measured their mobility in dorsiflexion before and after transection of each ligament separately, and the two ligaments combined.

RESULTS

The results showed a significant difference between the two groups of ankles with section of the dPTTaL resulting in a greater increase in ankle dorsiflexion than section of the PTaFL (mean 7.45° vs. 3.5°, respectively; p<0.001). Combined section of both ligaments improved the gain in ankle dorsiflexion more than isolated section of each ligament, but was not statistically significant (p=0.88).

CONCLUSION

If after gastrocnemius recession or Achilles tendon lengthening persistent restriction remains in ankle dorsiflexion, the results of our study demonstrate that the next step should be release of the dPTTaL.

Prevalence of neurologic lesions after total shoulder arthroplasty

BACKGROUND

Clinically evident neurologic injury of the involved limb after total shoulder arthroplasty is not uncommon, but the subclinical prevalence is unknown. The purposes of this prospective study were to determine the subclinical prevalence of neurologic lesions after reverse shoulder arthroplasty and anatomic shoulder arthroplasty, and to evaluate the correlation of neurologic injury to postoperative lengthening of the arm.

METHODS

All patients undergoing either a reverse or an anatomic shoulder arthroplasty were included during the period studied. This study focused on the clinical, radiographic, and preoperative and postoperative electromyographic evaluation, with measurement of arm lengthening in patients who had reverse shoulder arthroplasty according to a previously validated protocol.

RESULTS

Between November 2007 and February 2009, forty-one patients (forty-two shoulders) underwent reverse shoulder arthroplasty (nineteen shoulders) or anatomic primary shoulder arthroplasty (twenty-three shoulders). The two groups were similar with respect to sex distribution, preoperative neurologic lesions, and Constant score. Electromyography performed at a mean of 3.6 weeks postoperatively in the reverse shoulder arthroplasty group showed subclinical electromyographic changes in nine shoulders, involving mainly the axillary nerve; eight resolved in less than six months. In the anatomic shoulder arthroplasty group, a brachial plexus lesion was evident in one shoulder. The prevalence of acute postoperative nerve injury was significantly more frequent in the reverse shoulder arthroplasty group (p = 0.002), with a 10.9 times higher risk (95% confidence interval, 1.5 to 78.5). Mean lengthening (and standard deviation) of the arm after reverse shoulder arthroplasty was 2.7 ± 1.8 cm (range, 0 to 5.9 cm) compared with the normal, contralateral side.

CONCLUSIONS

The occurrence of peripheral neurologic lesions following reverse shoulder arthroplasty is relatively common, but usually transient. Arm lengthening with a reverse shoulder arthroplasty may be responsible for these nerve injuries.

Influence of patient activity on femoral osteolysis at five and ten years following hybrid total hip replacement

We conducted a longitudinal study including patients with the same type of primary hybrid total hip replacement and evaluated patient activity and femoral osteolysis at either five or ten years post-operatively. Activity was measured using the University of California, Los Angeles scale. The primary outcome was the radiological assessment of femoral osteolysis. Secondary outcomes were revision of the femoral component for aseptic loosening and the patients' quality of life. Of 503 hip replacements in 433 patients with a mean age of 67.7 years (30 to 91), 241 (48%) were seen at five and 262 (52%) at ten years post-operatively. Osteolytic lesions were identified in nine of 166 total hip replacements (5.4%) in patients with low activity, 21 of 279 (7.5%) with moderate activity, and 14 of 58 (24.1%) patients with high activity. The risk of osteolysis increased with participation in a greater number of sporting activities. In multivariate logistic regression adjusting for age, gender, body mass index and the inclination angle of the acetabular component, the adjusted odds ratio for osteolysis comparing high vs moderate activity was 3.6 (95% confidence interval 1.6 to 8.3). Stratification for the cementing technique revealed that lower quality cementing increased the effect of high activity on osteolysis. Revision for aseptic loosening was most frequent with high activity. Patients with the highest activity had the best outcome and highest satisfaction. In conclusion, of patients engaged in high activity, 24% had developed femoral osteolysis five to ten years post-operatively.