A biosemiotic interpretation of certain genital morphological structures in the spiders Dysdera erythrina and Dysdera crocata (Araneae: Dysderidae)

A biosemiotic approach to the interpretation of morphological data is apt to highlight morphological traits that have hitherto gone unnoticed for their crucial roles in intraspecific sign interpretation and communication processes. Examples of such traits include specific genital structures found in the haplogyne spiders Dysdera erythrina (Walckenaer 1802) and Dysdera crocata (Koch 1838). In both D. erythrina and D. crocata, the distal sclerite of the male bulb and the anterior diverticulum of the female endogyne exhibit a striking, previously unreported correspondence in size and shape, allowing for a precise match between these structures during copulation. In D. erythrina, the sclerite at the tip of the bulb and the anterior diverticulum are semi-circular in shape, whereas in D. crocata they are rectangular. From the perspective of biosemiotics, which studies the production and interpretation of signs and codes in living systems, these structures are considered the morphological zones of an intraspecific sign interpretation process. This process constitutes one of the necessary prerequisites for sperm transfer and the achievement of fertilization. Therefore, these morphological elements deserve particular attention as they hold higher taxonomic value compared to morphological traits of the bulb for which a relevant role in mating and fertilization has not been proven. Thus, an approach to species delimitation based on biosemiotics, with its specific evaluation of morphological structures, provides new insights for the multidisciplinary endeavour of modern integrative taxonomy.

Zebrafish as model system for the biological characterization of CK1 inhibitors

Introduction: The CK1 family is involved in a variety of physiological processes by regulating different signaling pathways, including the Wnt/β-catenin, the Hedgehog and the p53 signaling pathways. Mutations or dysregulation of kinases in general and of CK1 in particular are known to promote the development of cancer, neurodegenerative diseases and inflammation. There is increasing evidence that CK1 isoform specific small molecule inhibitors, including CK1δ- and CK1ε-specific inhibitors of Wnt production (IWP)-based small molecules with structural similarity to benzimidazole compounds, have promising therapeutic potential. Methods: In this study, we investigated the suitability of the zebrafish model system for the evaluation of such CK1 inhibitors. To this end, the kinetic parameters of human CK1 isoforms were compared with those of zebrafish orthologues. Furthermore, the effects of selective CK1δ inhibition during zebrafish embryonic development were analyzed in vivo. Results: The results revealed that zebrafish CK1δA and CK1δB were inhibited as effectively as human CK1δ by compounds G2-2 with IC50 values of 345 and 270 nM for CK1δA and CK1δB versus 503 nM for human CK1δ and G2-3 exhibiting IC50 values of 514 and 561 nM for zebrafish CK1δA and B, and 562 nM for human CK1δ. Furthermore, the effects of selective CK1δ inhibition on zebrafish embryonic development in vivo revealed phenotypic abnormalities indicative of downregulation of CK1δ. Treatment of zebrafish embryos with selected inhibitors resulted in marked phenotypic changes including blood stasis, heart failure, and tail malformations. Conclusion: The results suggest that the zebrafish is a suitable in vivo assay model system for initial studies of the biological relevance of CK1δ inhibition.

C5-Iminosugar modification of casein kinase 1δ lead 3-(4-fluorophenyl)-5-isopropyl-4-(pyridin-4-yl)isoxazole promotes enhanced inhibitor affinity and selectivity

The quest for isoform-selective and specific ATP-competitive protein kinase inhibitors is of great interest, as inhibitors with these qualities will come with reduced toxicity and improved efficacy. However, creating such inhibitors is very challenging due to the high molecular similarity of kinases ATP active sites. To achieve selectivity for our casein kinase (CK) 1 inhibitor series, we elected to endow our previous CK1δ-hit, 3-(4-fluorophenyl)-5-isopropyl-4-(pyridin-4-yl)isoxazole (1), with chiral iminosugar scaffolds. These scaffolds were attached to C5 of the isoxazole ring, a position deemed favorable to facilitate binding interactions with the ribose pocket/solvent-open area of the ATP binding pocket of CK1δ. Here, we describe the synthesis of analogs of 1 ((-)-/(+)-34, (-)-/(+)-48), which were prepared in 13 steps from enantiomerically pure ethyl (3R,4S)- and ethyl (3S,4R)-1-benzyl-4-[(tert-butyldimethylsilyl)oxy]-5-oxopyrrolidine-3-carboxylate ((-)-11 and (+)-11), respectively. The synthesis involved the coupling of Weinreb amide-activated chiral pyrrolidine scaffolds with 4- and 2-fluoro-4-picoline and reaction of the resulting 4-picolyl ketone intermediates ((-)-/(+)-40 and (-)-/(+)-44) with 4-fluoro-N-hydroxybenzenecarboximidoyl chloride to form the desired isoxazole ring. The activity of the compounds against human CK1δ, -ε, and -α was assessed in recently optimized in vitro assays. Compound (-)-34 was the most active compound with IC₅₀ values (CK1δ/ε) of 1/8 µM and displayed enhanced selectivity toward CK1δ.

The synthesis of brominated-boron-doped PAHs by alkyne 1,1-bromoboration: mechanistic and functionalisation studies

The synthesis of a range of brominated-B n -containing (n = 1, 2) polycyclic aromatic hydrocarbons (PAHs) is achieved simply by reacting BBr3 with appropriately substituted alkynes via a bromoboration/electrophilic C-H borylation sequence. The brominated-B n -PAHs were isolated as either the borinic acids or B-mesityl-protected derivatives, with the latter having extremely deep LUMOs for the B2-doped PAHs (with one example having a reduction potential of E 1/2 = -0.96 V versus Fc+/Fc, Fc = ferrocene). Mechanistic studies revealed the reaction sequence proceeds by initial alkyne 1,1-bromoboration. 1,1-Bromoboration also was applied to access a number of unprecedented 1-bromo-2,2-diaryl substituted vinylboronate esters directly from internal alkynes. Bromoboration/C-H borylation installs useful C-Br units onto the B n -PAHs, which were utilised in Negishi coupling reactions, including for the installation of two triarylamine donor (D) groups onto a B2-PAH. The resultant D-A-D molecule has a low optical gap with an absorption onset at 750 nm and emission centered at 810 nm in the solid state.

[Validity and Reliability of the German Version of the HSS Expectation Questionnaire on Hip Joint Replacement]

Background: Total hip arthroplasty is one of the most successful operations in medicine. The clinical result after surgery and compliance during rehabilitation are influenced by the patient's expectations. There is a lack of a validated German instrument to record these expectations in a standardised manner. Patients: 193 patients from the Dresden Hip Register with osteoarthritis of the hip were surveyed with respect to their expectations before the operation. The study sample consists of 108 women and 85 men. The average age of the patients was 59.7 years, with a standard deviation of 12.2 years. Methods: The Hospital for Special Patient Expectations Survey was translated into German and culturally adapted. In addition, the RKI demographic core data set, the HADS-D, LOT-R and the SCL-(K-)9 were collected to validate the instrument. In the statistical analysis, four main factors could be distinguished. These were "everyday activities", "pain relief and improvement in function", "medication and social participation" and "gait improvement". Results: Patients were predominantly married. 20 % of the women were widowed. 20 % had received higher education. Almost half of the patients were retired, 30 % were employed, 15.1 % self-employed and 7.3 % were unemployed. For most of the items, patients expected major improvements up to normalisation of their health. There were many different answers to several items, such as the question on occupation. For sporting and sexual activities no high expectations were given. The average expectation of the whole sample shows major differences to individual expectations. Men showed higher expectations for medication, social participation and gait improvement than did women. There were lower expectations for everyday activities, medication and social participation and gait improvement for older patients. Summary: The German version of the HSS patients expectation survey was validated. The instrument is useful in the preoperative setting to give the surgeon a first impression on the patient's expectations.

[Evidence-based trauma and orthopedic surgery : 20 years after Sackett]

The article "Evidence based medicine: what it is and what it isn't" published in the BMJ in 1996, is regarded as the foundation of the evidence-based medicine (EbM) movement. Approximately 5 years later David L. Sackett, one of the leaders of the movement, requested all experts to voluntarily abandon their position to make way for young researchers and fresh ideas. Since the term was first coined and the establishment of organizations and platforms fostering the idea, EbM has polarized clinicians and scientists around the world. Clinical and methodological developments during recent years have, however, overtaken the original principles of EbM. This review highlights the core concepts of EbM which have remained unchanged and valid for the current practice of trauma and orthopedic surgery and where revision is needed.

Similar stability and range of motion between cruciate-retaining and cruciate-substituting ultracongruent insert total knee arthroplasty

PURPOSE

The use of an ultracongruent (UC) insert with a standard femoral component for substitution of the posterior cruciate ligament (PCL) is a bone-preserving and therefore interesting alternative to the established box and cam mechanism of posterior-stabilized total knee arthroplasty (TKA). Despite the regular use of these UC inserts, there is little evidence about stability and range of motion (ROM).

METHODS

The aim of this study was to evaluate the stability and ROM in standard cruciate-retaining (CR) and cruciate-substituting UC inserts of the same TKA. In 39 patients, intraoperative measurements of stability and ROM were taken (1) before soft tissue release and bone cuts, (2) after implantation of a CR TKA and (3) after resection of the PCL and substitution with an UC insert. All measurements were taken using a navigation system.

RESULTS

Stability measurements demonstrated no differences between CR (PCL intact) and UC TKA (PCL resected), but significantly increased anteroposterior translation at 60° and 90° of knee flexion compared with the preoperative condition. ROM measurements demonstrated improvement of knee flexion from preoperatively mean 105° (SD 14.1°) to intraoperative 120.2° (SD 6.7°) with the CR and 121.0° (SD 7.5°) with the UC insert and 113.5° (SD 14.0°) at the 1-year follow-up.

CONCLUSION

This study demonstrates similar stability of an UC insert compared with a standard CR insert. UC inserts are therefore a bone-preserving solution if the PCL needs to be substituted. ROM was not improved after resection of the PCL and substitution with the UC insert.

LEVEL OF EVIDENCE

II.

[Complications of metal-on-metal tribological pairing]

BACKGROUND

Metal-on-metal (MoM) tribological pairing results in less volumetric abrasion than pairing with the conventionally used polyethylene and is associated with a lower risk of material failure compared to other hard-hard pairings. An increased frequency of problem cases in recent years has led to a great increase in uncertainty. Against this background in this article the current aspects of epidemiology, etiology, diagnostics and treatment of complications in MoM hip joint endoprostheses will be discussed.

EPIDEMIOLOGY AND ETIOLOGY

Based on the results from national endoprosthesis registers and selected clinical studies an evaluation of the rate of local complications from MoM tribological pairings was undertaken. A differentiation was made between MoM pairings in pedicled small head prostheses (≤ 32 mm), large head (> 32 mm) and surface replacement (OFE) endoprostheses. Each year MoM endoprostheses release on average 10(12)-10(14) cobalt (Co) and chromium (Cr) nanoparticles per patient. This release of metal ions and particles can lead to a variety of tissue reactions.

DIAGNOSTICS

A differentiation must be made between regular routine diagnostics within the framework of implant follow-up screening and specific investigations due to the occurrence of complaints. The diagnostics for patients treated with MoM hip endoprostheses consists of a standardized step-wise approach considering possible differential diagnoses and the utilization of modern laboratory chemical and radiological methods. When problems occur, a differentiation should preferentially be made between complaints not caused by metal and mechanical problems (e.g. prosthesis loosening and impingement) and symptoms due to periprosthetic infections.

THERAPY OF COMPLICATIONS

The normal standards for hip endoprosthetics are also valid for periprosthetic infections, fractures and other general complications. Specific measures are, however, necessary for complications due to metal-specific risks.

[Endoprosthetic treatment of osteoporosis-related coxarthrosis : aspects of safe patient treatment]

BACKGROUND

With increasing life expectancy the prevalence of osteoarthritis is also substantially rising. Patients aged between 65 and 75 years scheduled for total joint arthroplasty suffer from undetected osteoporosis in 20-25% of cases.

OBJECTIVES

How to determine osteoporosis during preoperative workup? Which conclusions can be drawn for the operation treatment and the postoperative course?

METHODS

The literature dealing with the prevalence of osteoporosis, perioperative complications of total hip arthroplasty, selected register informations, guidelines for diagnostics and treatment of osteoporosis and for the postoperative treatment are summarized and discussed.

RESULTS

The fracture risk is determined according to the guidelines of the Dachverband Osteologie (DVO, Governing Body on Osteology). The implant and the anchorage are selected based on the risk of suffering from osteoporosis. An intraoperative fracture and early aseptic loosening are the main operative risk factors. For the postoperative course in addition to education about arthroplasty, adequate support for prevention of falls is mandatory. Continuous physiotherapy with muscular strengthening is advisable. The long-term medication should be checked for risks in the PRISCUS list of potentially inappropriate medication in the elderly and non-steroidal anti-inflammatory drugs (NSAIDs) should not be prescribed in patients with cardiac comorbidities. Patients with confirmed osteoporosis should be treated with antiresorptive agents.

[Minimally invasive surgery for knee total arthroplasty - evidence-based advantages?]

The impact of minimally invasive surgical techniques for implantation of a total knee arthroplasty is evaluated according to evidence-based medicine criteria. The patient-relevant clinical question can be formulated as: Is the rehabilitation of osteoarthritis patients with minimally invasive implantation of total knee arthroplasty faster compared to those with the conventional approach. The available literature is sorted and critically appraised with regard to methodological quality and risk of bias. Following the results of the meta-analyses the clinical question can be positively answered. Following the aspect of a structured evolution for surgical techniques, the meaning of a minimally invasive technique for total knee arthroplasty cannot be answered finally. Under the impression of more frequent surgical complications, the rating of the procedure is conservative. A general advantage is not apparent. Further studies investigating surgical learning curves, proper patient selection and the selection of the patient for such techniques are required, before the final judgement on the use of this technique can be formed.

[Re-evaluation of the AOK hospital navigator with a focus on total knee replacement]

BACKGROUND

One of the biggest health insurance companies in Germany (AOK, Allgemeine Ortskrankenkasse) has published new results focussing on process quality of total knee replacement in 2010. These results were published in the online portal "Weiße Liste", which is based on health insurance routine data. The German Association of Orthopeadic Surgery questions the credibility of the rating system of the "Weiße Liste". To prove the system an interdisciplinary task force was created.

MATERIAL AND METHODS

The task force identified patient-specific parameters, which influence the outcome of total knee replacement based on the literature and expert opinions. Out of 907 orthopaedic departments, 4 above average and four below average were identified. The AOK was asked to provide 80 data sets for each department. These anonymised data sets could be converted into patient-specific data sets in the identified departments. Statistical analysis was performed to answer the question of whether there are differences between the below and the above average groups.

RESULTS

625 cases could be investigated. We found an increased rate of postoperative complications in the below average group. There are differences between both groups in terms of factors influencing the procedure. In the below average group an increased rate of patients with one or more comorbidities and a preoperative extension lag of over 10° was found. The above average group has a higher rate of operations before the knee replacement.

CONCLUSION

The results need to be proven on a larger scale. Further, prospective investigations are planned.

[Femoral nerve palsy as delayed complication after total hip replacement: delayed hematoma formation in unexpected screw malpositioning]

Nerve injury after total hip replacement is a rare but severe complication. If the nerve lesion becomes evident in the early postoperative phase the lesion is often due to an incorrect implant position, direct nerve injury or vascular injury with manifestation of a hematoma which results in nerve compression. Secondary nerve lesions are more often due to a chronic hematoma with nerve compression. Secondary nerve lesions in particular are often a diagnostic challenge and should lead to an early revision after comprehensive imaging diagnostics.

Clinical benefit and cost effectiveness of total knee arthroplasty in the older patient

Purpose

Total knee arthroplasty (TKA) is an effective, but also cost-intensive health care procedure for the elderly. Furthermore, bearing demographic changes in Western Europe in mind, TKA-associated financial investment for health care insurers will increase notably and thereby catalyze discussions on ressource allocation to Orthopedic surgery. To derive a quantitative rationale for such discussions within Western Europe's health care systems, a prospective assessment of both the benefit of TKA from a patient's perspective as well as its cost effectiveness from a health care insurer's perspective was implemented.

Methods

A prospective cost effectiveness trial recruited a total of 65 patients (60% females), who underwent TKA in 2006; median age of patients was 66 years (interquartile range 61 - 74 years). Before and three months after surgery patients were interviewed by means of the EuroQol-5D and the WOMAC questionnaires to assess their individual benefit due to TKA and the subsequent inpatient rehabilitation. Both questionnaires' benefit estimates were transformed into the number of gained quality adjusted life years [QALYs]. Total direct cost estimates for the overall care were based on German DRG and rehabilitation cost rates [€]. The primary clinical endpoint of the investigation was the individual number of QALYs gained by TKA based on the WOMAC interview; the primary health economic endpoint was the marginal cost effectiveness ratio (MCER) relating the costs to the associated gain in quality of life [€/QALY].

Results

Total direct costs for the overall procedure were estimed 9549 € in median. The WOMAC based interview revealed an overall gain of 4.59 QALYs (interquartile range 2.39 - 6.21 QALYs), resulting in marginal costs of 1795 €/QALY (1488 - 3288 €/QALY). The corresponding EuroQol based estimates were 2.93 QALYs (1.75 - 5.59 QALYs) and 3063 €/QALY (1613 - 5291 €/QALY). Logistic regression modelling identified the patients' age as the primary determinant of cost effectiveness (Likelihood Ratio p = 0.006): patients younger than 60 years showed a median gain of 6.45 QALYs and median marginal costs of 1463 €/QALY, patients between 60 - 70 years 5.47 QALYs and 1744 €/QALY, patients older than 70 years 2.76 QALYs and 3186 €/QALY.

Conclusion

TKA was proven to be cost effective from a health care insurer's perspective, although its marginal costs notably increased with increasing age. Note, however, that this age-related gradient in marginal cost effectiveness is of comparable order as the changes in cost effectiveness due to variation of the underlying assessment instrument.

[The EbM Commentary at the Annual Meeting of the German Congress of Orthopaedics and Traumatology (DKOU): background, aims and vision]

The critical appraisal of clinical and scientific work to assure the effectiveness and to balance the risks of treatment are mandatory today. Recent innovations in medicine often lead only to minor improvement in patient benefit. For the better understanding of the presented study results, the EbM commentary was introduced in 2007 at the Annual Meeting of the German Society of Orthopaedics and Traumatology. The EbM commentary was developed within the Swiss Orthopaedic Society and is a vital part of the Annual Meetings. The EbM commentary is a carefully prepared critical appraisal of an orally presented study by a specially trained colleague. The commentary consists of three components and begins with a systematic analysis following the SPION principle. What kind of study was carried out? Which patients were enrolled in the investigation? What kind of interventions were compared? How was the outcome measured? What is the benefit of the study for my own practice and what is the benefit for the patient? The reporting and the evaluation of the patient benefit is of great interest. In the second step the strengths and weaknesses of the study were discussed and the study will be rated for their evidence. For the best case the presented study implies direct changes in the usual treatment of patients. In the worst case no changes are necessary and the study is rated "so what" because of methodological weaknesses making the drawn conclusions invalid. For the audience the EbM commentary may support their rating of the quality of the presented study. The congress team selects interesting presentations for the EbM commentary. The EbM commentators receive the oral presentation and in most cases additional information from the selected studies four weeks in advance of the meeting. The EbM commentary is focused on a precise analysis of the presented data in an open and pleasant discussion. The aim of the EbM commentary is to clearly point out the patient benefit and to disclose the biases and weaknesses. The best studies of the DKOU were awarded following the suggestion of the EbM jury. The experiences have shown some methodological improvement of the presentations. The pragmatic style of the EbM commentary has led to good acceptance at the Annual Meeting of the German Society of Orthopaedics and Traumatology.

[Avoidance, diagnostics and therapy of nerve lesions after total hip arthroplasty]

Nerve palsy following total hip arthroplasty is a rare complication. Developmental dysplasia of the hip, previous fracture treatment and medical comorbidities are characteristic risk factors. By accurate preparation of the patient and a careful operative technique nerve palsy can be avoided in most cases. Nerve palsy following poor patient positioning during the perioperative period should be avoided by close cooperation with anesthesiologists.In cases of postoperative nerve palsy correct diagnostics should be carried out immediately. Further treatment options should be considered to minimize the damage. For patients with definite nerve palsy, devices such as a foot drop splint are often necessary and should be carried out as soon as possible.

[Clinical pathway "total knee arthroplasty"]

Total knee arthroplasty is a standardized intervention in orthopedic departments. Due to the standard character of the procedure it is predestinated to be performed in a clinical pathway. We developed a clinical pathway for total knee arthroplasty and aim to show the details of it and discuss it together with the current literature. Total knee arthroplasty is a standardized procedure and is therefore predestinated to be included in a clinical pathway. The team consists of different groups which are combined in this path to work together in a very structured and standardized manner. We describe and discuss our clinical pathway for total knee arthroplasty and the initial experiences which are very promising.

Social, educational, and occupational predictors of total hip replacement outcome

OBJECTIVE

There is limited evidence on social, educational, and occupational factors as predictors of response to total hip replacement (THR). We aimed to analyze these factors in a large population-based setting.

METHOD

Patients of the Dresden Hip Surgery Registry were recruited and the pre and post (6 months) operative functional status was assessed using the global Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) score (0-100 points). Non-response was defined a gain of <20 points in WOMAC score over a 6 months period and was analyzed with respect to six socioeconomic parameters. Multiple logistic regression modeling was applied to adjust for age, sex, BMI, co-morbidity, and preoperative functional status.

RESULTS

Data from 1007 patients (mean age 61 years, STD 13; 55% women) were included. The average preoperative WOMAC score was 45.8 which increased to 84.4 after surgery. 38.2%, 36.6%, and 25.3% of the patients attended school for 8, 9, and 12 years, respectively. 54.1% were retired, 26.9% worked full time, and 6.7% received a disability pension. A 14.8% of the patients did not achieve a gain of > or =20 points in WOMAC score and were classified as non-responders. After control for confounders, significantly increased risks of non-response were found for widowed patients compared to singles [odds ratio (OR) 4.30, 1.45-12.71], those who lived alone (OR 1.70, 1.02-2.85), and patients with a disability pension compared to those who worked full time (OR 5.81, 2.33-14.46). The risk of non-response decreased with increasing length of school education (12 vs 8 years: OR 0.49, 0.27-0.89). Compared to workers, employees (OR 0.55, 0.33-0.90) and self-employed patients (OR 0.41, 0.18-0.94) showed significantly decreased risks of non-response.

CONCLUSION

Socioeconomic parameters are independent predictors of response to THR. This can help to improve the health service by identifying subgroups which need special attention in order to increase the response rate.

Precision of navigated and conventional open-wedge high tibial osteotomy in a cadaver study

High tibial osteotomy (HTO) is an established treatment option for isolated medial osteoarthritis in young and active patients. One important factor for success of this procedure is the degree of correction of the weight-bearing line. Computer-assisted navigation systems are believed to improve the precision of axis correction through intraoperative real-time monitoring. This study investigates the precision of correction of the weight-bearing line in open-wedge HTO with and without a navigation system.

Nineteen legs of well-preserved human cadaver were randomly assigned to navigated (n = 10) or conventional (n = 9) HTO. In order to achieve a sufficient amount of correction in all legs the weight-bearing line was aimed at 80 percent of the width of the tibial plateau.

The mean deviation of the weight-bearing line from the desired 80 percent was 1 percent in the navigated and 8.6 percent in the conventional operated legs (p = 0.002). The weight-bearing line of all navigated but only 5 of the 9 conventional operated legs was within a ± 5 percent tolerance level (p = 0.33).

Navigated open-wedge HTO achieved better correction of the weight-bearing line than the conventional method in human cadaver legs. Future studies have to prove this advantage in a clinical setting and it's effect on patient outcome.

Reliability of limb alignment measurement for high tibial osteotomy with a navigation system

Objective

High tibial osteotomy (HTO) is one treatment option for young and active patients with unicompartmental osteoarthritis. The success of this procedure substantially depends on the degree of correction of the mechanical axis. Computer-assisted navigation systems are believed to improve the precision of axis correction through intraoperative real-time monitoring. This study investigates the accuracy of limb alignment measurements with a navigation system on a cadaver specimen.

Materials and methods

The measurements were performed on a well-preserved cadaver specimen with a mechanical leg axis of 4° varus. Data was collected during the HTO workflow. Repeated serial measurements were undertaken by four different surgeons. After these measurements, different landmarks were deliberately set at the wrong place to examine the influence of mistakes during registration.

Results

There was a high intra-and interobserver reliability with a mean mechanical leg axis of 3.9° ± 0.7° and a mean error of 0.6°. The grossly incorrect placement of landmarks for knee and ankle center resulted in an incorrect mechanical leg axis of 1° valgus up to 10° varus.

Conclusion

The computer-assisted navigation system provided precise information about the mechanical leg axis, irrespective of the observer's experience.

EULAR evidence-based recommendations for the diagnosis of knee osteoarthritis

Objective

To develop evidence-based recommendations for the diagnosis of knee osteoarthritis (OA).

Methods

The multidisciplinary guideline development group, representing 12 European countries, generated 10 key propositions regarding diagnosis using a Delphi consensus approach. For each recommendation, research evidence was searched systematically. Whenever possible, the sensitivity, specificity and likelihood ratio were calculated for individual diagnostic indicators and a diagnostic ladder was developed using Bayes' method. Secondary analyses were undertaken to test directly the recommendations using multiple predictive models in two populations from the UK and the Netherlands. Strength of recommendation was assessed by the EULAR visual analogue scale.

Results

Recommendations covered the definition of knee OA and its risk factors, subsets, typical symptoms and signs, the use of imaging and laboratory tests and differential diagnosis. Three symptoms (persistent knee pain, limited morning stiffness and reduced function) and three signs (crepitus, restricted movement and bony enlargement) appeared to be the most useful. Assuming a 12.5% background prevalence of knee OA in adults aged ≥45 years, the estimated probability of having radiographic knee OA increased with increasing number of positive features, to 99% when all six symptoms and signs were present. The performance of the recommendations in the study populations varied according to the definition of knee OA, background risk and number of tests applied.

Conclusion

10 key recommendations for diagnosis of knee OA were developed using both research evidence and expert consensus. Although there is no agreed reference standard, thorough clinical assessment alone can provide a confident rule-in diagnosis.

[Implementation of standardized postoperative pain therapy for orthopaedic patients. Comparison between unsystematic and standardized pain therapy]

BACKGROUND

The painless clinic and postoperative pain therapy are currently major issues in the management of surgical procedures. The aim of this study was to evaluate the benefit of a standardized pain therapy on the postoperative pain level after orthopaedic procedures.

PATIENTS AND METHODS

We investigated two different groups of patients who underwent an orthopaedic surgical procedure. Group 1 (n = 249) received a pain therapy which was based on an individual and surgery-dependent concept whereas group 2 (n = 243) was treated with a standardized pain therapy concept. The effect of the treatment was monitored with a VAS-based protocol.

RESULTS

Up to day 9 after surgery there was a significant difference between the two groups in regard to the postoperative pain. The patients of group 2 had less pain but had more unwanted side effects caused by the pain therapy during the first 3 days after surgery. Mobility and mental disposition were positively affected.

CONCLUSION

The implementation of a standardized pain therapy is successful in reducing postoperative pain. Mobility and mental disposition are also influenced positively. As a consequence the incidence of unwanted side effects is rising.

Midterm results following revision surgery in clubfeet

Relapse rates of surgically treated clubfeet are about 25%. We reviewed 43 patients (57 feet) treated for relapsed clubfoot deformity between 1992 and 2001 in our department. The average age of the patients at the time of revision surgery was 5.1 years, the mean follow-up was 6.6 years. Surgical therapy was performed using an algorithm according to age groups. The mean Atar score at follow-up was 77 points, representing a good outcome. Out of 57 feet, 20 (35%) were rated excellent, 24 (42%) good, 5 (9%) fair, and 8 (14%) poor. The number of previous surgical interventions had no influence on the outcome. Using an age related surgical algorithm, good postoperative results could be achieved in most of our patients, thus improving their functional situation. This emphasises the usefulness of the proposed algorithm in the difficult situation of recurrent clubfoot, while thorough analysis of the underlying deformity remains essential.

Fuctional outcome after open and arthroscopic bankart repair for traumatic shoulder instability

Purpose

Both open and arthroscopic Bankart repair are established procedures in the treatment of anterior shoulder instability. While the open procedure is still considered as the "golden standard" functional outcome is supposed to be better in the arthroscopic procedure. The aim of this retrospective study was to compare the functional outcome between open and arthroscopic Bankart repair.

Materials and methods

In 199 patients a Bankart procedure with suture anchors was performed, either arthroscopically in presence of an detached, but not elongated capsulolabral complex (40) or open (159). After a median time of 31 months (12 to 67 months) 174 patients were contacted and agreed to follow-up, 135 after open and 39 after arthroscopic Bankart procedure.

Results

Re-dislocations occurred in 8% after open and 15% after arthroscopic Bankart procedure. After open surgery 4 of the 11 re-dislocations occurred after a new adequate trauma and 1 of the 6 re-dislocations after arthroscopic surgery. Re-dislocations after arthroscopic procedure occured earlier than after open Bankart repair. An external rotation lag of 20° or more was observed more often (16%) after open than after arthroscopic surgery (3%). The Rowe score demonstrated "good" or "excellent" functional results in 87% after open and in 80% patients after arthroscopic treatment.

Conclusion

In this retrospective investigation the open Bankart procedure demonstrated good functional results. The arthroscopic treatment without capsular shift resulted in a better range of motion, but showed a tendency towards more frequently and earlier recurrence of instability. Sensitive patient selection for arthroscopic Bankart repair is recommended especially in patients with more than five dislocations.

Allergenicity of wine containing processing aids: a double-blind, placebo-controlled food challenge

BACKGROUND

The European Union requires allergenic food ingredients to appear on labels in order to protect allergic consumers.

OBJECTIVE

To determine whether traces of egg-, milk-, and fish-derived processing aids used in winemaking might elicit clinical reactions in food-allergic patients.

METHODS

Five German wines were fined with a high dose of egg albumin, lysozyme, milk casein, fish gelatin, or isinglass, and filtered. Fourteen adults with allergy to egg (n = 5), milk (n = 5), or fish (n = 4) were included. Skin prick tests were performed with fining agents, and fined and unfined wines. All patients underwent double-blind placebo-controlled food challenges with fined and unfined wines.

RESULTS

Skin prick tests were positive to hen's egg (n = 5), ovalbumin (n = 5), lysozyme (n = 4), cow's milk (n = 5), casein (n = 4), and cod (n = 3), but not to isinglass or fish gelatin (n = 0). Positive skin prick test results were observed for wines fined with albumin (n = 3), lysozyme (n = 2), casein (n = 1), gelatin (n = 0), and isinglass (n = 3), and for unfined wines (n = 1-2 in each patient group), with no significant differences between groups. Seventy-five percent of skin test-positive patients had specific immunoglobulin E to other allergens present in wine (eg, carbohydrates). The provocation test revealed no reactions to fined or unfined wines.

CONCLUSIONS

Although concentrated fining agents containing ovalbumin, lysozyme, and casein were allergenic in the skin prick test, no patient reacted adversely in the provocation test to fined wine. Wines treated with fining agents at commercial concentrations appear not to present a risk to allergic individuals when filtered,

[A rare coagulation disorder. Diagnostics and management in cases of hereditary dysfibrinogenemia]

Before elective surgery, it is mandatory that a precise history be taken to detect increased hemorrhagic diathesis and that thrombocytes, Quick/INR, and aPTT be determined. If pathological levels are found, further laboratory tests are necessary after frequent causes (e.g., liver cirrhosis) have been excluded. Single-factor analysis for the von Willebrand's factor antigen and if necessary further tests to check for von Willebrand's syndrome (multimeric analysis) as well as platelet function tests should be performed.Dysfibrinogenemia is a rare coagulation disorder, which causes elevated INR. It shows a wide spectrum of clinical manifestations including thrombophilia, excessive bleeding, and even asymptomatic cases. We present a 72-year-old patient with asymptomatic dysfibrinogenemia who needed hip replacement due to arthrosis. Lowered fibrinogen levels were substituted prior to operation and the clinical course afterwards was uneventful under additional prophylactic anticoagulation in order to prevent thrombosis. The case report illustrates the interdisciplinary teamwork which is very important in the management of patients with coagulation disorders.

Computer-assisted and conventional total knee replacement: a comparative, prospective, randomised study with radiological and CT evaluation

After obtaining informed consent, 80 patients were randomised to undergo a navigated or conventional total knee replacement. All received a cemented, unconstrained, cruciate-retaining implant with a rotating platform. Full-length standing and lateral radiographs and CT scans of the hip, knee and ankle joint were carried out five to seven days after operation. No notable differences were found between computer-assisted navigation and conventional implantation techniques as regards the rotational alignment of the femoral or tibial components. Although the deviation from the transepicondylar axis was relatively low, there was a considerable range of deviation for the tibial rotational alignment. There was no statistically significant difference regarding the occurrence pattern of outliers in mechanical malalignment but the number of outliers was reduced in the navigated group.

[Clinical pathways. A useful steering instrument or a limitation for medical treatment?]

Clinical pathways can be used to organize the optimal sequence for medical procedures. This process is patient centered and developed through the collaborative work of the participating medical specialties. The goals of clinical pathways are facilitation of outcomes, reduction of variance in patient care and cost containment. Clinical pathways can be used for patient information, internal and external transparency and in total quality management. The management of medical organisations can be supported by introducing the data from clinical pathways into prospective clinical and financial control.

[Necrosis of the femoral head in late pregnancy. Necessity of early diagnosis]

Limping and groin pain can issue diagnostic problems during late pregnancy. Differential diagnosis of two idiopathic syndromes, transient osteoporosis and osteonecrosis of the femoral head, is made possible by MRI in the early stages. This case is reported to demonstrate the need to distinguish between those syndromes early so as to prevent further joint damage.

[Results for endoprosthetic care in patients younger than 50 years]

Arthroplasty has become the most successful surgical procedure in developed countries. Replacement of severely damaged joints results in a substantial relief of pain, as the main symptom of osteoarthritis, in the majority of treated patients. With improved results in endoprosthetic surgery over the last decades, however, patients are increasingly undergoing the procedure to enhance their functional capacity and physical mobility. Especially younger patients, who cannot accept a restriction in their professional or sports activity, have become demanding candidates for surgery. This review summarizes the published results on shoulder, hip, knee, ankle and first metatarsophalangeal joint replacement in patients who are younger than 50 years of age. Mid- and long-term follow-up studies in this age group are evaluated in terms of prosthesis survival as well as functional improvement.

[The value of regional and general anaesthesia in orthopaedic surgery]

Adequate postoperative pain management is of major importance for a short rehabilitation time after painful orthopaedic surgery. Multimodal pathways have been established to achieve a surgical patient free of pain and complications. Peripheral and central nerve blocks are a fundamental part of these interdisciplinary strategies and are already implemented in orthopaedic surgical care. This article summarises the value of special anaesthetic techniques, especially regional anaesthesia, in orthopaedic surgery and discusses their impact on several postoperative outcome goals.

Cementless acetabular reconstruction and structural bone-grafting in dysplastic hips. Surgical technique

BACKGROUND

Studies of acetabular reconstruction with use of cement and bulk bone graft have demonstrated increasing rates of cup failure in patients with dysplastic hips seven years after total hip arthroplasty. Comparable data on the long-term results of bulk bone-grafting done in conjunction with cementless implants are limited. The aim of this study was to review the clinical and radiographic results of autologous bulk bone-grafting in conjunction with a cementless cup.

METHODS

From 1987 to 1992, forty-seven patients (forty women and seven men, with an average age of 50.4 years) who had developmental dysplasia of the hip underwent fifty-six total hip arthroplasties and received a structural graft in combination with a cementless Harris-Galante type-I cup. All patients were followed prospectively. In fifty-five hips, implant migration was measured with single-image radiographic analysis.

RESULTS

After an average duration (and standard deviation) of 10.2 +/- 2.9 years, three patients (four hips) had died. In the surviving patients, four implants had been revised and two had radiographic evidence of loosening. With use of revision and loosening as end points, the eleven-year survival rates were 91.6% and 88.9%, respectively. Of the fifty implants that had no loosening, fourteen had measurable cup migration, thirty-five had no migration, and one implant could not be measured. All migrations but one were progressive. With loosening used as the end point, the survival rate at eleven years was 100% for the implants with no migration; however, the survival rate for the cups that had migrated was 69.3% (p = 0.0012).

CONCLUSIONS

The eleven-year survival rate for the spherical press-fit cups in combination with bulk bone-grafting is satisfactory, given the complexity of these reconstructions. However, the difference between the survival of the implants that had migrated and those that had not was significant. We expect that the thirteen implants with progressive acetabular migration at the time of the latest follow-up are at risk for loosening, which will increase the revision rate for this series in the coming years.

Rotatorenmanschettendefekt - eine Berufserkrankung?

BACKGROUND

In literature there are only few data which describe the influence of occupation on the development of rotator cuff disease.

METHODS

In a retrospective study, 760 open rotator cuff repairs were analysed and related to the profession and occupational load. Exclusion criteria were traumatic tears and sports injuries. All male persons were statistically analysed and the data compared with occupational patterns of the region, obtained from the Federal Statistical State Office.

RESULTS

Rotator cuff repairs were performed in 472 males who had no evidence for a traumatic origin. After statistical analysis (p < 0.001) we found significantly more patients working in agriculture and forestry (6.38% versus 1.07% in Bavaria) and in the building industry (35.11% versus 13.40% in Bavaria).

CONCLUSIONS

Our data suggest that working exposure increases the risk or leads to the clinical manifestation of rotator cuff tears. Although a detailed analysis of individual physical exposure is not available yet, the statistical results indicate that rotator cuff tears must be taken into consideration as a result of ergonomic exposure.

Vergleichende Analyse des patientenzentrierten Outcome nach totalendoprothetischem Ersatz von Hüft- und Kniegelenk

AIM

The aim of the present study was a comparative investigation of the functional improvement reported by patients suffering from primary osteoarthritis of the knee or hip undergoing total joint replacement and assessed at 3 months.

METHOD

In a prospective, controlled clinical trial, 56 patients with primary osteoarthritis of the hip and 59 patients with primary osteoarthritis of the knee undergoing total joint replacement were assessed at two measuring times (day of admission = t1 and 3-month follow-up = t2) using the XSMFA-D (Extra Short Musculoskeletal Function Assessment Questionnaire--German version), WOMAC (Western Ontario and McMasters Universities) arthrosis index and FFb-H OA (Function Assessment Questionnaire Hannover Osteoarthritis). The statistical analysis included effect sizes as standardised response mean, t-test and covariance analysis.

RESULTS

Both groups of patients demonstrated significant improvements of the musculoskeletal functions measured. The effect sizes between baseline scores and 3-month follow-up scores range from 0.4 to 2.0 and can be considered as large effects. The covariance analysis showed significant differences between patients with osteoarthritis of the hip and knee for almost every score examined. Patients with hip replacement showed large improvements. A significant influence of the presurgery baseline score on the 3-month score was found consistently. Further analysis showed that patients with medium or strong degrees of disability according to the Function index of the XSMFA-D showed the strongest effects of change at 3 months. However, their scores at t2 were less than the scores of the less disabled patients at t1.

CONCLUSION

We conclude that patients with hip replacement show more improvement 3 months after the surgery than patients with knee replacement. Furthermore, it was seen that patients who were more disabled before surgery achieved more improvement than the less-disabled patients. However, they did not achieve the level of the less disabled patients. Thus, the recommendation that total joint replacement should be performed as late as possible should be reviewed.

Proposal for a histopathological consensus classification of the periprosthetic interface membrane

AIMS

The introduction of clearly defined histopathological criteria for a standardised evaluation of the periprosthetic membrane, which can appear in cases of total joint arthroplasty revision surgery.

METHODS

Based on histomorphological criteria, four types of periprosthetic membrane were defined: wear particle induced type (detection of foreign body particles; macrophages and multinucleated giant cells occupy at least 20% of the area; type I); infectious type (granulation tissue with neutrophilic granulocytes, plasma cells and few, if any, wear particles; type II); combined type (aspects of type I and type II occur simultaneously; type III); and indeterminate type (neither criteria for type I nor type II are fulfilled; type IV). The periprosthetic membranes of 370 patients (217 women, 153 men; mean age 67.6 years, mean period until revision surgery 7.4 years) were analysed according to the defined criteria.

RESULTS

Frequency of histopathological membrane types was: type I 54.3%, type II 19.7%, type III 5.4%, type IV 15.4%, and not assessable 5.1%. The mean period between primary arthroplasty and revision surgery was 10.1 years for type I, 3.2 years for type II, 4.5 years for type III and 5.4 years for type IV. The correlation between histopathological and microbiological diagnosis was high (89.7%), and the inter-observer reproducibility sufficient (85%).

CONCLUSION

The classification proposed enables standardised typing of periprosthetic membranes and may serve as a tool for further research on the pathogenesis of the loosening of total joint replacement. The study highlights the importance of non-infectious, non-particle induced loosening of prosthetic devices in orthopaedic surgery (membrane type IV), which was observed in 15.4% of patients.

[Revision of unicompartmental knee arthroplasty]

Despite the good midterm survivorship reported for unicondylar knee arthroplasty, an increase in revision surgery has to be expected due to increased replacement rates. The reasons for failure as well as distribution are different for unicondylar knee arthroplasty compared to total knee arthroplasty. The main reasons for revision are aseptic loosening and the progression of osteoarthritis. In most cases, unicondylar knee arthroplasty will be revised to total knee arthroplasty. To obtain good revision results, the cause of implant failure has to be analysed carefully. In the case of contained bone defects, the reconstruction can be supported with bone grafting. For those cases with uncontained defects, implants with augmentation and, in some cases, stem extensions are needed. The modularity of the revision implant should cover different intraoperative requirements.

Evaluierung des XSMFA-D an Patienten mit Erkrankungen des Bewegungsapparates und operativer oder konservativer stationärer Therapie

AIM

The present study had the objective of evaluating the psychometric characteristics of the shortened 16-item version of the German Short Musculoskeletal Function Assessment questionnaire (XSMFA-D), which was designed for routine assessment of functional capacity in patients with various orthopaedic disorders treated either surgically or medically.

METHODS

A total of 382 patients from seven different samples with either osteoarthritis of the knee, osteoarthritis of the hip, rheumatoid arthritis or rotator cuff tear treated either in surgical hospitals or rehabilitation settings were assessed both before and after treatment. The XSMFA-D was compared with both questionnaires measuring similar constructs and widely accepted indicators of health status in musculoskeletal disorders. Psychometric characteristics were computed.

RESULTS

The internal consistency (Cronbach's alpha) exceeded 0.90 in most cases for the function index and was between 0.80 and 0.90 in most cases for the bother index of the XSMFA-D. Retest-reliability was between 0.80 and 0.95 for the function index and between 0.60 and 0.92 for the bother index. Correlations between the XSMFA-D subscales and the other questionnaires were substantial, showing construct validity. Criterion validity was also demonstrated as significant relationships with accepted external parameters such as function tests, judgements by physicians, pain self-ratings by patients and disease severity scores were found. Sensitivity to change was as high as for the other assessment instruments used in this study.

CONCLUSIONS

The XSMFA-D, a very short assessment instrument, proved to be practical, reliable, valid and sensitive to change among the various patient samples studied. It may be recommended for the assessment of patients' state as well as the evaluation of treatments.