Record of archaeal activity at the serpentinite-hosted Lost City Hydrothermal Field

Samples of young, outer surfaces of brucite-carbonate deposits from the ultramafic-hosted Lost City hydrothermal field were analyzed for DNA and lipid biomarker distributions and for carbon and hydrogen stable isotope compositions of the lipids. Methane-cycling archaeal communities, notably the Lost City Methanosarcinales (LCMS) phylotype, are specifically addressed. Lost City is unlike all other hydrothermal systems known to date and is characterized by metal- and CO2 -poor, high pH fluids with high H2 and CH4 contents resulting from serpentinization processes at depth. The archaeal fraction of the microbial community varies widely within the Lost City chimneys, from 1-81% and covaries with concentrations of hydrogen within the fluids. Archaeal lipids include isoprenoid glycerol di- and tetraethers and C25 and C30 isoprenoid hydrocarbons (pentamethylicosane derivatives - PMIs - and squalenoids). In particular, unsaturated PMIs and squalenoids, attributed to the LCMS archaea, were identified for the first time in the carbonate deposits at Lost City and probably record processes exclusively occurring at the surface of the chimneys. The carbon isotope compositions of PMIs and squalenoids are remarkably heterogeneous across samples and show highly (13) C-enriched signatures reaching δ(13) C values of up to +24.6‰. Unlike other environments in which similar structural and isotopic lipid heterogeneity has been observed and attributed to diversity in the archaeal assemblage, the lipids here appear to be synthesized solely by the LCMS. Some of the variations in lipid isotope signatures may, in part, be due to unusual isotopic fractionation during biosynthesis under extreme conditions. However, we argue that the diversity in archaeal abundances, lipid structure and carbon isotope composition rather reflects the ability of the LCMS archaeal biofilms to adapt to chemical gradients in the hydrothermal chimneys and possibly to perform either methanotrophy or methanogenesis using dissolved inorganic carbon, methane or formate as a function of the prevailing environmental conditions.

Minimally invasive fixation of type B and C interprosthetic femoral fractures

INTRODUCTION

Interprosthetic femoral fractures are rare and raise unresolved treatment issues such as the length of the fixation material that best prevents secondary fractures. Awareness of the advantages of locked-plate fixation via a minimally invasive approach remains limited, despite the potential of this method for improving success rates.

HYPOTHESIS

Femur-spanning (from the trochanters to the condyles) locked-plate fixation via a minimally invasive approach provides high healing rates with no secondary fractures.

MATERIALS AND METHODS

From January 2004 to May 2011, all eight patients seen for interprosthetic fractures were treated with minimally invasive locked-plate fixation. Mean time since hip arthroplasty was 47.5 months and mean time since knee arthroplasty was 72.6 months. There were 12 standard primary prostheses and four revision prostheses; 11 prostheses were cemented and a single prosthesis showed femoral loosening. Classification about the hip prostheses was Vancouver B in one patient and Vancouver C in seven patients; about the knee prosthesis, the fracture was SoFCOT B in three patients and SOFCOT C in five patients, and a single fracture was SoFCOT D. Minimally invasive locking-plate fixation was performed in all eight patients, with installation on a traction table in seven patients.

RESULTS

Healing was obtained in all eight patients, after a mean of 14 weeks (range, 12-16 weeks). One patient had malalignment with more than 5° of varus. There were no general or infectious complications. One patient died, 32 months after surgery. The mean Parker-Palmer mobility score decreased from 6.2 pre-operatively to 2.5 at last follow-up. Early construct failure after 3 weeks in one patient required surgical revision. There was no change in implant fixation at last follow-up. No secondary fractures were recorded.

DISCUSSION

In patients with type B or C interprosthetic fractures, femur-spanning fixation not only avoids complications related to altered bone stock and presence of prosthetic material, but also decreases the risk of secondary fractures by eliminating stress riser zones. The minimally invasive option enhances healing by preserving the fracture haematoma. Thus, healing was obtained consistently in our patients, with no secondary fractures, although the construct failed in one patient.

LEVEL OF EVIDENCE

Level IV.

Surface plasmon resonance optical cavity enhanced refractive index sensing

We report on a method for surface plasmon resonance (SPR) refractive index sensing based on direct time-domain measurements. An optical resonator is built around an SPR sensor, and its photon lifetime is measured as a function of loss induced by refractive index variations. The method does not rely on any spectroscopic analysis or direct intensity measurement. Time-domain measurements are practically immune to light intensity fluctuations and thus lead to high resolution. A proof of concept experiment is carried out in which a sensor response to liquid samples of different refractive indices is measured. A refractive index resolution of the current system, extrapolated from the reproducibility of cavity-decay time determinations over 133 s, is found to be about 10(-5) RIU. The possibility of long-term averaging suggests that measurements with a resolution better than 10(-7) RIU/√Hz are within reach.

Impact of clinical and health services research projects on decision-making: a qualitative study

Background

This article reports on the impact assessment experience of a funding program of non-commercial clinical and health services research. The aim was to assess the level of implementation of results from a subgroup of research projects (on respiratory diseases), and to detect barriers (or facilitators) in the translation of new knowledge to informed decision-making.

Methods

A qualitative study was performed. The sample consisted of six projects on respiratory diseases funded by the Agency for Health Quality and Assessment of Catalonia between 1996 and 2004. Semi-structured interviews to key informants including researchers and healthcare decision-makers were carried out. Interviews were recorded, transcribed verbatim and analysed on an individual (key informant) and group (project) basis. In addition, the differences between achieved and expected impacts were described.

Results

Twenty-three semi-structured interviews were conducted. Most participants indicated changes in health services or clinical practice had resulted from research. The channels used to transfer new knowledge were mainly conventional ones, but also in less explicit ways, such as with the involvement of local scientific societies, or via debates and discussions with colleagues and local leaders. The barriers and facilitators identified were mostly organizational (in research management, and clinical and healthcare practice), although there were also some related to the nature of the research as well as personal factors. Both the expected and achieved impacts enabled the identification of the gaps between what is expected and what is truly achieved.

Conclusions

In this study and according to key informants, the impact of these research projects on decision-making can be direct (the application of a finding or innovation) or indirect, contributing to a more complex change in clinical practice and healthcare organization, both having other contextual factors. The channels used to transfer this new knowledge to clinical practice are complex. Local scientific societies and the relationships between researchers and decision-makers can play a very important role. Specifically, the relationships between managers and research teams and the mutual knowledge of their activity have shown to be effective in applying research funding to practice and decision-making. Finally the facilitating factors and barriers identified by the respondents are closely related to the idiosyncrasy of the human relations between the different stakeholders involved.

Distal femur fractures. Surgical techniques and a review of the literature

Fractures of the distal femur are rare and severe. The estimated frequency is 0.4% with an epidemiology that varies: there is a classic bimodal distribution, with a frequency peak for men in their 30s and a peak for elderly women; however, at present it is found predominantly in women and in the elderly with more than 50% of patients who are over 65. The most common mechanism is an indirect trauma on a bent knee, and more rarely direct trauma by crushing. The anatomy of the distal femur explains the three major types of fracture. Because of the anatomy of the distal femur, only surgical treatment is indicated to stabilize the fracture. A non-surgical treatment is a rare option. The aim of this report was to provide an update on the existing surgical solutions for the management of these fractures and describe details of the surgical technique applicable to these injuries. Recent radiological, clinical and biomechanical data published in the literature are reported to compare different surgical options.

Treatment of distal humerus fractures with LCP DHP™ locking plates in patients older than 65 years

INTRODUCTION

Fractures of the distal humerus are often complex and therefore challenging to treat. In elderly patients with decreased bone strength due to osteoporosis, strong fixation is crucial to allow resuming early motion that guarantees a good functional outcome as well as minimising mechanical complications. Locked implants meet these requirements. Here, we report outcomes in a uniform series of patients older than 65 years with distal humerus fractures managed with LCP DHP(®) (Synthès) fixation. Our objective was to evaluate the efficacy and limitations of this technique.

HYPOTHESIS

LCP DHP provides strong fixation of osteoporotic bone and leads to good clinical and radiological outcomes.

MATERIALS AND METHODS

We retrospectively studied 46 consecutive patients (2004-2010) with a mean age of 80 years including 15 with extra-articular and 31 with articular distal humerus fractures. At presentation, 11 complications were noted in nine patients (compound fractures and trauma-related nerve injuries). The transolecranon approach was used in 31 patients. Mean duration of immobilisation was 2.7 weeks in 33 patients.

RESULTS

Forty-three patients were re-evaluated after a mean follow-up of 25 months (range, 10-64 months); two patients died and one was lost to follow-up. Flexion was 127° and loss of extension was 23°, producing an average range of motion of 104°. Functional recovery was highly satisfactory with a Mayo Clinic Performance Score of 87 (70-100) and 95% of good and very good results. Postoperative complications consisted of infection (n=3), metaphyseal non-union (n=2), ulnar nerve injury (n=6), transient radial nerve palsy (n=1), and peri-articular ossification (n=4). Compound fracture and worse AO fracture type were associated with worse functional outcomes.

DISCUSSION

Despite the high complication rate, functional recovery was similar to that reported in previous case series, including after arthroplasty. Furthermore, the rate of mechanical complications was lower. Thus, our working hypothesis was confirmed.

LEVEL OF EVIDENCE

Level IV retrospective non-comparative study.

Characteristics of Spanish articles of "scientific quality" cited in clinical practice guidelines on mental health

INTRODUCTION

The study aims to illustrate the impact of Spanish research in clinical decision making. To this end, we analysed the characteristics of the most significant Spanish publications cited in clinical practice guidelines (CPG) on mental health.

MATERIAL AND METHODS

We conducted a descriptive qualitative study on the characteristics of ten articles cited in Spanish CPG on mental health, and selected for their "scientific quality". We analysed the content of the articles on the basis of the following characteristics: topics, study design, research centres, scientific and practical relevance, type of funding, and area or influence of the reference to the content of the guidelines.

RESULTS

Among the noteworthy studies, some basic science studies, which have examined the establishment of genetic associations in the pathogenesis of mental illness are included, and others on the effectiveness of educational interventions. The content of those latter had more influence on the GPC, because they were cited in the summary of the scientific evidence or in the recommendations. Some of the outstanding features in the selected articles are the sophisticated designs (experimental or analytical), and the number of study centres, especially in international collaborations. Debate or refutation of previous findings on controversial issues may have also contributed to the extensive citation of work.

CONCLUSIONS

The inclusion of studies in the CPG is not a sufficient condition of "quality", but their description can be instructive for the design of future research or publications.

Survivin in adrenocortical tumors - pathophysiological implications and therapeutic potential

Treatment options for adrenocortical carcinoma (ACC) are very limited. In other solid tumors, small vaccination trials targeting the anti-apoptotic molecule survivin suggested immunological and clinical benefit in selected patients. Therefore, we investigated whether survivin might be a suitable target for immunotherapy in ACC. Survivin mRNA and protein expression was assessed in adrenal tissue specimens [by real-time-PCR in 29 ACC, 24 adrenocortical adenomas (ACA) and 12 normal adrenal glands; by immunohistochemistry in 167 ACCs, 15 ACA, and 5 normal adrenal glands]. Expression was correlated with clinical outcome using Kaplan-Meier and Cox regression analyses. The anti-apoptotic role of survivin was investigated in the SW13 ACC cell line using survivin siRNA. The presence of spontaneous survivin specific T-cells in peripheral blood was assessed by FACS dextramere staining in 29 ACC patients in comparison to healthy controls. Survivin mRNA in ACC was significantly overexpressed when compared with ACA or normal adrenal glands. Immunohistochemistry confirmed survivin protein expression in 97% of the ACCs. In 83% of samples, staining was moderate or high and clinical outcome in this subgroup showed a trend towards poorer prognosis [hazard ratio for death 2.28 (95% CI 0.99-5.28); p=0.053]. Survivin knockdown in SW-13 cell significantly increased the rate of apoptosis. Finally, spontaneous survivin-reactive T cells were detectable in 3 of 29 ACC patients. In conclusion, our data suggest that survivin could play an important role in the anti-apoptotic mechanisms in ACC and provide first hints that targeting survivin might be an interesting new therapeutic approach in this rare disease.

Complex fractures of the distal humerus in the elderly: is primary total elbow arthroplasty a valid treatment alternative? A series of 20 cases

INTRODUCTION

Distal humerus fractures are fairly rare. But as our population ages, these fractures become more complex and the choice of treatment more delicate. Poor bone quality results in many technical problems and the fixation hardware stability remains at risk. The goal of this study was to evaluate the functional recovery and morbidity of complex distal humerus fractures in elderly patients when treated with elbow prosthesis.

HYPOTHESIS

Good functional recovery can be achieved with a total joint replacement.

PATIENTS AND METHODS

This series consisted of 20 patients (18 women and two men) having an average age of 80years (range 65-93, median 80). Based on the AO classification, there were two Type A2 fractures, two Type B fractures, 15 Type C fractures and one fracture that could not be classified because of previous rheumatoid disease history at this elbow. Two fractures were open. In two cases, the olecranon was also fractured. Treatment consisted of the implantation of a Coonrad-Morrey, hinge-type total elbow prosthesis (Zimmer(®), Warsaw, IN, USA). The Mayo Clinic surgical approach was used 17 times and the transolecranon approach was used three times. Primary arthroplasty was performed in 19 cases and the surgery was performed after six weeks of conservative treatment (diagnostic delay) in one case. Unrestricted motion was allowed after surgery, but a maximum of 0.5kg could be carried during the first 3months; this was subsequently increased to 2.5kg.

RESULTS

Fifteen of the 20 patients were available for reevaluation with an average follow-up of 3.6years (range 1.7-5.5, median 3.4). Four patients had died and one was lost to follow-up. The average range of motion was 97° (range 60-130°), comprising an average flexion of 130° (range 110-140°) and average loss of extension of 33° (range 0-80°). Pronation and supination were normal. The average Mayo Elbow Performance Score (MEPS) was 83 (range 60-100, median 80). X-rays revealed seven cases of radiolucent lines, with two being progressive. There was no visible wear of the polyethylene bushings at the hinge. Six patients had moderate periarticular heterotopic ossification. The two cases of olecranon osteotomy and one case of olecranon fracture had healed. There were no surgical site infections but two cases of ulnar compression, one of which required neurolysis. There was one case of humeral component loosening after 6years, but the implant was not changed.

DISCUSSION

The clinical range of motion results were comparable to published data. The functional scores were slightly lower, mainly because of the pain factor. The initial results were encouraging and consistent with published data as long as the indications were well-chosen. Based on this retrospective study, total elbow arthroplasty can be a valid alternative in the surgeon's treatment armamentarium for complex distal humerus fractures in elderly patients who have moderate functional demands. Our results support our hypothesis, since we found good functional recovery without associated morbidity.

LEVEL OF EVIDENCE

Level IV retrospective study without comparator.

Early surgical site infection in adult appendicular skeleton trauma surgery: a multicenter prospective series

INTRODUCTION

Surgical site infections (SSI) studies rely on an imprecise and debatable definition. The term "wound healing problems" (WHP), not necessarily septic, is also frequently cited. This study had the objectives of determining the frequency of early SSIs in traumatology, these terms eventual correlation, and the factors influencing onset.

PATIENTS AND METHODS

A multicenter prospective observational study was conducted in 12 centers. The exclusion criteria were open lesions as well as multiple injuries and multiple fractures (more than two fractures treated surgically). All patients were followed for the first three postoperative months until there was clinical certainty of healing and absence of infection. The presence of any WHP or SSI required a minimum follow-up of 1 year. WHP and SSI risk factors were determined using logistical regression adjusted on the centers.

RESULTS

Out of 1617 cases, 103 were complicated by a WHP and 22 by a SSI. The SSIs were mainly secondary to Staphylococcus infections. The factors predisposing the patients to WHP and SSI (p≤0.05) were age; the NNIS, ASA, and Parker scores; alcoholism; antiaggregant use; and the locoregional aspect at the time of injury. The 522 subcutaneous osteosyntheses "near the skin" resulted in 58 WHPs (11%) and 14 SSIs (2.7%); 13 of the 58 WHPs (22%) resulted in one SSI. Out of 707 deep osteosyntheses, 24 (3.4%) presented a WHP and seven (1%) a SSI; Four SSIs originated from a WHP. The 352 fractures of the trochanter were complicated by a WHP in 15 cases (5.5%) and a SSI in one case (0.4%) after interlocked nailing and two WHPs and two SSIs (2.5%) after screw and plate fixation. Of the 388 first-line arthroplasties, only the prostheses implanted for a proximal femur fracture presented complications: 21 WHPs (6%) and one SSI (0.02%). Of the 103 WHPs of the entire series, 18 became SSIs. In absence of WHP, the SSI rate was 0.2%, whereas the probability of a WHP evolving toward a SSI was 100 times higher. The only factor significantly associated with a WHP becoming a SSI was osteosynthesis material exposure.

DISCUSSION

This prospective study can be criticized on several points: the deliberately limited inclusion criteria, the short follow-up, and the possible subjectivity of the data collection. The SSI rates reported are for the most part in agreement with the literature. This study is innovative in traumatology given the large number of patients and the notion of WHP that was preferred over superficial infection. It demonstrates the relations between WHP and SSI, in particular for osteosyntheses near the skin.

LEVEL OF EVIDENCE

Level III.

Advantage and limitations of a minimally-invasive approach and early weight bearing in the treatment of tibial shaft fractures with locking plates

OBJECTIVES

Intramedullary nailing is a common method of treating tibial shaft fractures. However, precise control of reduction at the proximal and distal quarters is difficult to achieve. The purpose of this study was to assess the results of plating using locking screws and the feasibility of a minimally-invasive approach.

PATIENTS/PARTICIPANTS

All patients with tibial shaft fracture treated by means of locking plates from January 2004 to October 2006. Thirty-two fractures were treated in 32 patients with a mean age of 43.8 years.

INTERVENTION

Internal fixation with a locking plate and screw construct, using a minimally-invasive or standard approach.

MAIN OUTCOME MEASUREMENTS

Surgical approach, time to weight bearing, complications and their type, time to bone union, alignment in the frontal and sagittal planes on anteroposterior and lateral radiographs.

RESULTS

The minimally-invasive approach was performed in 28 cases and immediate full weight bearing allowed in 25 cases. At a mean follow-up of 27 months, two patients had died and two patients were lost to follow-up. The mean time to bone union was 9.1 weeks. Four cases had a complicated course: one infection, one compartment syndrome, one hardware breakage and one pseudarthrosis. Six cases ended up with valgus malunion exceeding 5° in the frontal plane, already present at the time of surgery.

CONCLUSION

Where a minimally-invasive approach can be performed, immediate pain-free weight bearing can be allowed without further displacement at follow-up. The observed rate of malunion underlines the need for adequate reduction and shows that the rationale for success does not solely depend on the plate anatomic design but also on the skills of the operating surgeon.

SETTING

Level I university regional hospital Cohort study.

Dual mobility cups hip arthroplasty as a treatment for displaced fracture of the femoral neck in the elderly. A prospective, systematic, multicenter study with specific focus on postoperative dislocation

INTRODUCTION

Displaced fractures of the femoral neck in the elderly are best treated with arthroplasty. The type of arthroplasty to be used, either hemi- or total hip arthroplasty, remains controversial as total hip replacements potentially have a higher rate of dislocation.

HYPOTHESIS

Dual mobility cups have a low dislocation rate when used to manage acute fractures of the femoral neck.

PATIENTS AND METHODS

In a multicenter prospective study conducted in France over an inclusion time of 3 months, all displaced fractures of the femoral neck treated with arthroplasty were operated on with insertion of a dual mobility cup. Patients had clinical and radiological assessment at 3, 6, and 9 months postoperative.

RESULTS

Two hundred and fourteen hips in 214 patients with a mean age of 83 years (range, 70-103 years) were included. None of the patients was lost to follow-up. The mortality rate after 9 months was 19%. Two patients (1%) had early postoperative infection successfully treated with lavage and antibiotics. Three patients (1.4%), operated through a posterior approach, presented one postoperative dislocation, all of which were posterior. Reduction was performed through closed external manipulation under general anesthesia. There was no recurrence of dislocation.

DISCUSSION

This low rate of dislocation after acute total hip replacement using dual mobility design cups favorably compares with hemiarthroplasties. Dual mobility cups might therefore be considered a valuable option to prevent postoperative dislocation when treating displaced intracapsular fractures of the proximal femur in elderly patients if a total hip replacement is recommended. Further study is needed before extending the indications for total hip arthroplasty following a fracture of the femoral neck, to assess the potential cost and complications of a longer procedure with its potential acetabular complication, and weigh them against the potential benefits.

Reliability of locked plating in tibial plateau fractures with a medial component

BACKGROUND

Tibial plateau fractures are notoriously difficult to manage, particularly when there is a medial or posteromedial component. We report a retrospective analysis of our experience with consecutive tibial plateau fractures including a medial component that were managed using a single lateral locking plate.

HYPOTHESIS

Tibial plateau fractures with a medial component can be effectively managed using a single lateral locking plate.

MATERIALS AND METHODS

From January 2005 to December 2008, 20 patients (ten women and ten men, mean age 47 years) were managed for tibial plateau fractures having a medial component, including five Schatzker IV, five Schatzker V, and ten Schatzker VI. One patient had an open fracture. A single lateral anatomically contoured locking compression plate (LCP™) was used with or without additional isolated screws. Mobilization was started immediately after the procedure, and non-weight-bearing was maintained for at least 6 weeks.

RESULTS

All patients were followed until healing. A final evaluation was available for 13 patients after a mean of 39.1 months (12-72); five patients were lost to follow-up and two died. Early revision was needed in one patient for 20° malreduction within the fracture site. We recorded one case each of deep vein thrombosis, superficial infection, knee stiffness, and spontaneously regressive common fibular nerve dysfunction. At final evaluation (n=13), mean range of motion was 0°/2°/130° with a mean Lysholm score of 94.1 (73-100) and a mean HSS score of 93.6 (74-99). All previously employed patients returned to work at the same level after a mean of 4.5 months. Mean healing time (n=20) was 10 weeks (6-12). Initially, articular step-offs greater than 2mm were noted in five patients. At healing, no further displacements or aggravation of articular step-offs were recorded. The reductions remained stable over time. At final evaluation (n=13), mean tibiofemoral mechanical angle was 179.7° (176-184) and no patients had evidence of osteoarthritis.

DISCUSSION

The radiological and clinical outcomes in our patients were satisfactory. A single lateral locked plate ensured stable reduction of tibial plateau fractures with a medial component. Biomechanical studies of these fractures have provided conflicting data on the stability of reduction using single plate systems. However, previously reported clinical outcomes are similar to those found in our study and support the effectiveness of favouring the use of single locking plate fixation.

LEVEL OF EVIDENCE

Level IV, noncomparative retrospective study.

Periprosthetic femoral fractures treated by locked plating: feasibility assessment of the mini-invasive surgical option. A prospective series of 36 fractures

INTRODUCTION

The treatment of periprosthetic femoral fractures by conventional plating is associated with problems related to fracture union and eventual refracture. Additionally, locking nailing cannot be used in all cases because of the risk of malunion. To resolve these issues, locking plates have been proposed to combine the advantages of closed reduction and internal fixation while achieving a higher quality reduction with plate fixation.

HYPOTHESIS

Locking plates put into place by a mini-invasive surgical approach result in fixation without substantial misalignment or non-union.

PATIENTS AND METHODS

From June 2002 to December 2007 we prospectively treated 35 patients (one bilateral), 28 women and seven men with a fracture around the hip implant (21), around the knee (8), between the hip implant and the knee (2), between a trochanteric internal fixation device and the knee implant (5). The mean age was 76, (39-93). Internal fixation was always attempted by mini-invasive surgery using locking plate system with locking screws (Synthès™). Rehabilitation included immediate weight bearing with as much weight as the patient would tolerate. The preoperative Parker score was 5.25 (0-9).

RESULTS

There was one patient lost to follow-up, one early failure, and seven deaths (four of whom were included in the study group since their follow-up was at least 24 months) for a total of 31 fractures (30 patients), the mean follow-up for the series was 26 months (6-67). Twenty-six fixations were performed by mini-invasive approach and 10 through a conventional open surgery. Patients applied full weight (n=20), partial weight (n=3) or no weight for 6 weeks (n=13). Infections developed in two patients and there were three cases of mechanical failure. Fracture union was achieved in 35 out of 36 cases. More than 5° of misalignment was observed in five patients. Loosening of the implant did not occur in any patients during follow-up. The Parker score in patients seen at follow up was 4.3 (0-9).

DISCUSSION-CONCLUSION

Locking compression plates associated with a mini-invasive surgical approach result in a high rate of union (35/36) with no significant misalignment (only 5/36 cases of misalignment of more than 5°), no refractures (n=0) and a low rate of mechanical failure (3/36) while allowing full weight bearing in most cases (20/36). Locking plates for periprosthetic femoral fractures allow patients to begin walking again, with stable intermediate term results.

Minimally-invasive fixation of distal extra-articular femur fractures with locking plates: limitations and failures

Minimally-invasive fixation using a locking plate and early motion is normal practice. However, technical errors and pitfalls are common. This surgery has a set of rules that encompass both the mechanics of the internal fixation system and the implantation itself. If these rules are not strictly followed, alignment defects and/or early failure of the fixation can occur. We analysed four cases of clinical failure that were encountered after minimally-invasive distal femoral extra-articular fixation with locking plates. The following rules must be followed with this technique: extra-articular fracture, minimally-invasive approach, long plate alternating between locking screw and empty hole (five holes on either side of fracture), bi-cortical screws, placement of locking screws near a complex fracture but away from a simple fracture. Osteoporotic bone, obesity that interferes with the instrumentation, articular fracture, horizontal fracture line and surgeon experience are all limitations of this minimally-invasive technique.

[Recurrent pericardial effusion as first manifestation of Erdheim-Chester disease]

HISTORY AND ADMISSION FINDINGS

A 65-year-old woman presented with reduced general condition and dyspnoea that was progressive over the last months. Clinical findings revealed an exophthalmus on the right, xanthelasm and mild peripheral oedema. Previously, a pericardiocentesis had been performed due to a large pericardial effusion. A previous CT scan showed a mass attached to the pericardium extending through the atrio-ventricular groove and a thickened aorta. In addition, a retroperitoneal fibrosis and an occlusion of both Aa. iliacae internae were found.

INVESTIGATIONS

The ECG showed sinus rhythm. Laboratory findings demonstrated a microcytic anemia and a renal failure. Chest radiography showed a large cardiac silhouette, while the transthoracic echocardiography revealed a recurrent large pericardial effusion. A PET/CT scan of the chest and abdomen showed a tissue infiltration of the retroperitoneal structures, a mass surrounding the right coronary artery and the right orbita. Finally, a femur biopsy confirmed the diagnosis of Erdheim-Chester disease.

DIAGNOSIS, TREATMENT AND COURSE

With the diagnosis Erdheim-Chester disease we started a high dose immunsuppressive therapy using glucocorticoids and interferon-a. Tumour size slightly decreased during the following 2 months, however the patient developed a severe urosepsis and died from multiorgan failure.

CONCLUSIONS

We report a case of an Erdheim-Chester disease with cardiovascular involvement primarily diagnosed due to a recurrent large pericardial effusion. In case of cardial tumors with interatrial septum or coronary artery involvement together with cerebral manifestations, an Erdheim-Chester disease should be taken into account.

Reversed anatomic distal femur locking plate for periprosthetic hip fracture fixation

The incidence of femoral fracture on hip prosthesis is increasing. Plate fixation is the method of choice when the prosthesis is stable. In fracture with proximal extension, the quality of the bone fixation is critical and, despite the development of anatomic plates, may be endangered when there are too few proximal screws. To resolve this issue, we recommend using a reversed LCP™ anatomic distal femoral Less Invasive Stabilization System (LISS™) locking plate: e.g., a left distal femoral plate for femoral fracture on right-hip implant. This presents several advantages: minimally invasive surgery, the introduction of the plate being facilitated by the LISS™ ancillary; ease of locking, also thanks to the ancillary; and, above all, multiple proximal trochanteric fixation thanks to the form of this anatomic distal LISS™ plate, improving proximal bone fixation. The present technical note seeks to illustrate the interest of using a "reversed" plate, in terms of simplicity of fitting and quality of reduction and consolidation, while also specifying the associated limitations and tolerance.

Survivor of a traumatic atlanto-occipital dislocation

Atlanto-occipital dislocation is a devastating ligamentous injury that most often turns fatal. However, because of on-site resuscitation improvements, the emergency teams are increasingly dealing with this condition. We report a rare case of atlanto-occipital dislocation (AOD) in a surviving patient with more than one-year follow-up. The mechanism of injury appears to be an extreme hyperextension applied to the head. This injury occurs more frequently in children since they are anatomically predisposed (flat articulation between the occiput and the atlas, increased ligamentous laxity). The diagnosis should be suggested by severe neurological injury after high trauma but also post-traumatic cardiorespiratory deficit. There have been reports of atlanto-occipital dilocations without neurologic impairment. A radiographic examination must be performed and lateral cervical radiographs should be acquired. However, additional imaging with CT or MRI may be required to aid diagnosis of AOD in cases in which radiographic findings are equivocal. Once the diagnosis of AOD has been confirmed, an anatomical classification should be made according to the magnitude of displacement. Fatal lesions are of neurological and vascular origin and some authors advocate the systematic use of angiography. Consensus regarding the management of AOD in adults has been achieved. Occipito-cervical arthrodesis is the recommended treatment option. We advocate a two-stage surgery: the patient is initially fitted with a halo vest then occipitocervical fusion is performed. Surgical treatment should be combined with cardiorespiratory management. The emergency teams should get familiar with this injury since they will be increasingly confronted to it. Early recognition and standard appropriate management is essential to avoid delayed treatment and complications.

Minimally-invasive internal fixation of extra-articular distal femur fractures using a locking plate: tricks of the trade

Fractures of the distal femur are rare and occur in two distinct population categories: young patients after high energy traumas and elderly patients who fall from their full height, and often carry severe co-morbidities making especially difficult to manage theses complex injuries. In elderly patients the potential complications are numerous including infection, non-union and frequent function deterioration. We present a technique of minimally invasive internal fixation of the distal extra-articular femur using a locking plate and present the tricks of the trade to obtain successful reduction and achieve union. The hardware used includes plate fixation with a large fragment locking screw. This minimally invasive surgery combines stability of the internal fixation device with the principles of closed surgery, allowing early mobilization and immediate weight bearing to warrant good functional recovery.

[Autoimmune hepatitis: two case reports with different clinical courses - case 3/2011]

HISTORY AND CLINICAL FINDINGS

Case 1: A 46-year old female patient presented with a recently occurred icterus of unknown origin as well as dark urine and decolored stool. No diseases were found in the patient's medical history. Clinical examination showed no other findings exept from the icterus. Case 2: A 48-year old female patient was admitted to hospital with epigastric pain and icterus. Similar symptoms reoccurred regularly since several years. The patient already underwent cholecystectomy and an ERCP (endoscopic retrograde cholangiopancreaticography) that showed no pathological findings. She reported chronic pain in her finger joints and appearance of haematomas without adequate trauma.

CLINICAL INVESTIGATIONS

Case 1: We found highly elevated liver enzymes and bilirubin. Ultrasound examination was unremarkable.The laboratory examination showed a negative serology for hepatitis A, B and C, marked immunoglobulin G (IgG) elevation and hypergammaglobulinaemia. Liver biopsy and analysis of autoimmune antibodies were performed showing high titers of antinuclear antibodies (ANA) and smooth muscle antibodies (SMA). Case 2: We found a considerably reduced liver function with low albumin and prothrombin time, as well as a moderate elevation of liver enzymes and a high bilirubin. Ultrasound examination revealed hepatic parenchymal changes, splenomegaly, and ascites. Oesophagogastroduodenoscopy showed oesophageal varices I°. Serology for hepatitis A, B, and C was negative. Also in this case, a marked IgG elevation and hypergammaglobulinaemia were found. Liver biopsy was performed. Autoimmune antibodies (ANA and SMA) were detectable with high titers.

DIAGNOSIS, TREATMENT AND COURSE

In both cases, we diagnosed an autoimmune hepatitis by means of laboratory values, histological findings and detection of typical autoantibodies. Immediate therapy with high-dose prednisolone therapy was initiated (case 1: 60 mg/day; case 2: 100 mg/day), resulting in improvement of patients' condition, clinical findings and laboratory values in both cases. Case 1: The patient showed fast recovery under prednisolone and the further course was without any complications. Continuous therapy with 15 mg /day and clinical monitoring through day hospital was recommended. Case 2: We saw a slower recovery and prolonged reduced liver function with the necessity to substitute coagulation factors. Furthermore, the therapy of subsequent complications, such as surgical drainage of a haematoma, oedema, wound healing disorder and infections under prednisolone was necessary. Liver transplantation is planned if the disease progresses further.

CONCLUSION

Elevated liver enzymes should always be further investigated. Autoimmune hepatitis is a rare disease. Rapid response to immunosuppressive therapy, such as prednisolone, is characteristic. Early diagnosis and therapy are essential for the patients prognosis. Liver transplantation is indicated in advanced disease.