Hip joint function and reconstruction of the anterior femoral offset in patients with short stem vs. conventional THA.

In cases where mobility and joint function are impaired after implantation of a THA, weakening of hip movement in both extension/flexion and adduction/abduction may play a role due to shortening of the physiological lever arm of the hip muscles. Mechanical factors of influence include the lateral femoral offset, which affects the lever arm, and the antetorsion angle of the hip prosthesis, which affects the anterior femoral offset. This study aimed to investigate the effect of an altered antetorsion angle of the implant on the hip moments and gait patterns of the patient. For this study, 13 patients with a conventional stem on one side and a calcar-guided short stem implanted on the contralateral side were included. To determine the maximum hip moment, tests were performed on a dynamometer in extension/flexion and adduction/abduction in addition to gait analysis. As a control, a comparison was made with data from a reference group of 30 healthy subjects. Both implants showed similar symmetry indices. There was a significant difference between the implants for adduction moments (p < 0.001). The ratios between the directions of moments showed no significant differences. The joint function measured by isokinetic measurements and gait analysis remains comparable to the healthy control group after short stem arthroplasty, but shows slight changes after conventional stem arthroplasty.

Kinetic investigation of para-nitrophenol reduction with photodeposited platinum nanoparticles onto tunicate cellulose.

Photodeposition is a specific method for depositing metallic co-catalysts onto photocatalysts and was applied for immobilizing platinum nanoparticles onto cellulose, a photocatalytically inactive biopolymer. The obtained Pt@cellulose catalysts show narrow and well-dispersed nanoparticles with average sizes between 2 and 5 nm, whereby loading, size and distribution depend on the preparation conditions. The catalysts were investigated for the hydrogenation of para-nitrophenol via transfer hydrogenation using sodium borohydride as the hydrogen source, and the reaction rate constant was determined using the pseudo-first-order reaction rate law. The Pt@cellulose catalysts are catalytically active with rate constant values k from 0.09 × 10-3 to 0.43 × 10-3 min-1, which were higher than the rate constant of a commercial Pt@Al2O3 catalyst (k = 0.09 × 10-3 min-1). Additionally, the Pt@cellulose catalyst can be used for electrochemical hydrogenation of para-nitrophenol where the hydrogen is electrocatalytically formed. The electrochemical hydrogenation is faster compared to the transfer hydrogenation (k = 0.11 min-1).

Pediatric back pain-Diagnostic algorithm.

BACKGROUND: Back pain in the pediatric population is common. History and a thorough physical examination and a systematic work-up approach are key components to guide the physician in evaluating the possible causes of pain and providing appropriate treatment. OBJECTIVE: The main aim of this review was to develop an algorithmic approach to assist physicians in the assessment of pediatric back pain. A comprehensive review of prevalence, differential diagnoses and proper management of pediatric back pain are also presented. MATERIAL AND METHODS: An extensive literature search was performed in PubMed to gather articles on the prevalence, risk factors, diagnostic tools, differential diagnoses and appropriate management of pediatric back pain. RESULTS: Available literature revealed that pediatric back pain is a common complaint. Although most cases are non-specific and self-limiting, there is a wide differential that should be considered including inflammatory, neoplastic, infectious and mechanical causes. Sedentary lifestyle, obesity and vigorous physical activity have been shown to increase the likelihood of developing back pain. We proposed an algorithm to guide the physician's decision about the next step in the diagnostic process. CONCLUSION: A well-defined strategy in the diagnostic process is needed in approaching children/adolescents with back pain. This would have the benefit of minimizing costs, unnecessary tests and child/family anxiety as well as increasing the likelihood of early diagnosis and proper treatment.

Do biomarkers allow a differentiation between osteonecrosis of the femoral head and osteoarthritis of the hip? - a biochemical, histological and gene expression analysis.

OBJECTIVE: Osteonecrosis of the femoral head (ONFH) is a devastating disease of the hip joint. Its early diagnosis is crucial to increase the chances of joint preserving, yet difficult due to similarities with osteoarthritis (OA) of the hip in its clinical appearance. The purpose of this study was to enhance the understanding of ONFH and its pathologic processes in contrast to OA and to identify serum biomarkers helping to improve the diagnosis of the disease. DESIGN: Bone and bone marrow samples were collected from 24 patients diagnosed with OA and 25 patients with ONFH during total hip replacement surgery. RNA was isolated, histological examination, determination of free reactive oxygen species as well as gene expression and biomarker analysis were performed. RESULTS: Histological analysis revealed differences in the structural and cellular pattern between the groups. Gene expression analysis revealed a significant upregulation for the genes ASPN, COL1A1, COL2A1 and IL6 and a significant downregulation for HIF1A in ONFH compared to OA group. Analysis of serum biomarkers showed significant differences between the groups for asporin and adiponectin. A final logistical regression model including the parameters adiponectin, asporin and HIF 1α was overall significant, explained 34.5 % of variance and classified 74.5 % of the cases correctly. CONCLUSION: The combination of adiponectin, asporin and HIF 1α as serum biomarkers revealed a classification accuracy of 74.5 %. The information provided in this study may help to enhance the understanding of pathologic processes in ONFH and to elaborate further aspects of prediction and treatment.

Constrained tripolar liner in patients with high risk of dislocation - Analysis of incidence and risk of failure.

INTRODUCTION: The aim of this study was to determine number and type of failures and revisions after usage of a constrained tripolar acetabular liner in patients with high risk of dislocation. Potential correlations between these failures and the factors included were analyzed. MATERIALS AND METHODS: In this retrospective study 55 participants in 68 cases were included after treatment with constrained tripolar acetabular liner. Patient specific data as well as surgery and implant specific data were collected. Radiological images were assessed. Furthermore, the gluteal function was analyzed. The parameters were statistically verified with regard to their influence on the failure of the constrained tripolar liner. RESULTS: This study included 16 cases (in nine participants) of postoperative failure. This results in a survival rate of 76.5% regarding the number of cases after 17 months. The statistical analysis of the different parameters considered that the number of previous surgeries has a significant (p = 0.027) influence on the failure. CONCLUSIONS: This retrospective study shows that treatment with constrained tripolar acetabular liners is a satisfactory method of treatment in cases with a high risk of dislocation. However, in cases with an increasing number of previous surgeries, an increased risk of failure was found. Therefore, in such cases, this type of supply treatment should be treated critically.

[Disease-related knowledge acquisition through structured patient information in rheumatoid arthritis (StruPI-RA) : First results of the StruPI-RA study in Germany]. / Krankheitsbezogener Wissenserwerb durch strukturierte Patienteninformation bei Rheumatoider Arthritis (StruPI-RA) : Erste Ergebnisse der StruPI-RA-Studie in Deutschland.

BACKGROUND/OBJECTIVE: The structured patient information for rheumatoid arthritis (StruPi-RA) program was the first standardized outpatient education program in rheumatoid arthritis (RA) in Germany. The main objective of the study was to determine the efficacy of the StruPi-RA program concerning disease-specific knowledge acquisition in patients with early stage RA or after changing the treatment regimen. METHODS: A total of 61 patients were included in a control group design, 32 in the intervention group (IG) and 29 in the control group (CG). Patients of the IG attended 3 modules of 90 min in a structured patient information program (StruPI-RA) including the topics of diagnostics, treatment and living with RA. Patients in the CG only received information material from the German Rheumatism League. The primary target criterion was the disease-related acquisition of knowledge, measured with the patient knowledge questionnaire (PKQ). Data were collected before and after participation in StruPI-RA. RESULTS: The improvement in knowledge in the IG attending the StruPI-RA compared to the CG was significant in time and group comparisons. No influence of disease duration or educational level was observed. The subscale treatment alone showed a significant difference in the group and time comparison. CONCLUSION: Participation in the StruPI-RA program in early RA was associated with a significant increase in disease-specific knowledge compared to the control group of patients. This leads to better decision-making in terms of treatment, a more beneficial doctor-patient communication and better self-management. In the long term an improvement in treatment adherence and quality of life is expected.

Femoral Cementation in Knee Arthroplasty-A Comparison of Three Cementing Techniques in a Sawbone Model Using the ATTUNE Knee.

Femoral component loosening is a rare but severe complication in total knee arthroplasty. Former studies have repeatedly demonstrated radiolucent lines behind the ventral and dorsal anchoring shields of the femoral components, which has led us to investigate this matter further. Therefore, three different cementing techniques were tested in a group of nine Sawbone samples each. These differed in the amount of cement applied on the femoral component as well as in the pressure application. Computed tomography was performed to evaluate and classify the cement penetration into the bone adjacent to the prosthesis according to the zones defined by the Knee Society scoring system. The results show significantly deeper cement penetration in all zones when a pressurizer is used. In the other two groups, no significant difference in the dorsal bevel cement penetration was noted. Additionally, no difference in ventral and dorsal cement penetrations (Zones 1 and 4) was delineated. In contrast, there was a significant difference in both the ventral bevel (Zone 2) as well as the distal anchoring surface (Zones 5-7). The use of a pressurizer results in greater cement penetration into all anchoring areas. Completely covering the component back surface results in a significantly higher penetration, which is mainly due to differences in volume. These data show significantly improved cementation results when using a pressurizer. Whether this improves the biomechanical properties and ultimately the revision rate requires further investigation.

[Early assessment of the risk of later implantloosening using Roentgen Sterophotogrammetric Analysis (RSA)]. / Früherkennung des Risikos der späteren Implantatlockerung mittels der Röntgen Stereophotogrammetrischen Analyse (RSA).

BACKGROUND: Aseptic implant loosening is the most common cause of implant revisions in total hip and total knee arthroplasty. Roentgen Stereophotogrammetric Analysis (RSA) represents the current gold standard for the in-vivo assessment of implant fixation. PRESENT SITUATION: Long-term clinical trials have shown that continuous implant migration within the first two postoperative years correlates strongly with a later aseptic loosening. Thus, the implant migration measured with RSA can be regarded as a reliable surrogate marker for later implant loosening. Over the past 40 years, RSA has been continuously further developed, and the model-based RSA approach has reduced the effort involved since markers attached to implant are no longer needed. PERSPECTIVES: The RSA method is gaining importance in the certification process of new orthopaedic implants-for example, the Dutch Orthopedic Society has recommended phased-introduction and RSA studies for new hip implants. Furthermore, in the context of the new EU Medical Device Regulation (MDR), which took effect in May 2017, RSA gained relevance for investigating clinically unproven implants. Critics who associate MDR with hindering innovation can be countered in that the RSA method provides a predictive assessment of implant fixation after only two years of follow-up, which is significantly shorter than standard long-term clinical trials.

A composite of clay, cement, and wood as natural support material for the immobilization of commercial titania (P25, P90, PC500, C-TiO2) towards photocatalytic phenol degradation.

Different types of commercial titania (P25, P90, PC500, and C-TiO2) were immobilized as single or mixed photocatalyst onto the surface of a natural support material made of cement, clay, and wood fibers. The successful immobilization was studied by different techniques showing a composite material with the mechanical properties of the support material and the photocatalytic behavior of the immobilized titania. The supported photocatalyst showed high mechanical stability and was applied to the photocatalytic degradation of phenol as a model pollutant under UV light irradiation. As the most active photocatalytic material, a mixture PC500 and P90 (comp-PC500/P90) was identified with an apparent pseudo first-order kinetic rate constant (kapp) of 0.010 min-1 at a degradation efficiency of 100%. The catalyst was used several times and showed minor loss in activity during four runs due to degradation intermediates adsorbed to the surface, shown by a color change from white to yellow.

[Periprosthetic joint infections : Latest developments, strategies and treatment algorithms]. / Periprothetische Früh- und Spätinfektionen : Neuste Entwicklungen, Strategien und Behandlungsalgorithmen.

BACKGROUND: Due to their multidimensional consequences, periprosthetic joint infections are a serious complication in arthroplasty. There are disagreements in the literature regarding their classification. At the same time, a consequence for the practical procedure cannot always be derived. THERAPEUTIC PROCEDURES: In addition to debridement with antibiotics and implant retention, there are options for a one or two-stage change in the therapeutic procedure. Although the preservation of implants is only possible in the case of acute infections with a short duration of symptoms, prosthesis changes are indicated with a longer symptom duration. For both procedures, there are interinstitutional deviating indication criteria, weighing pros and cons. Both have specific problems, such as, in particular, the duration of the antibiotics course, the question of anchoring the prosthesis and, in the case of a two-stage procedure, the shape of the spacer.

[Pain generator sacroiliac joint : Functional anatomy, symptoms and clinical significance]. / Schmerzquelle Iliosakralgelenk : Funktionelle Anatomie, Symptome und klinische Bedeutung.

BACKGROUND: The sacroiliac joint is a common cause of low back pain. Due to variable symptoms, the diagnosis is often very difficult. For diagnosis, systemic disease, as well as pathologies in the hips and lumbar spine must be excluded. OBJECTIVES: To describe anatomy and function of the joint and underlying pathologies. To present the evidence of actual diagnostic and therapeutic options. MATERIALS AND METHODS: An extensive literature research was carried out on PubMed. RESULTS: The sacroiliac joint is an important and biomechanically complex joint. There are many controversial diagnostic tests to identify the sacroiliac joint as a source of pain. The cause of the dysfunction must be identified in order to treat it correctly and to prevent a chronification of the pain. The gold standard is conservative care. CONCLUSION: The sacroiliac joint must be included in the differential diagnosis in patients with low back pain. Diagnostic tests are often insufficient for the diagnosis of sacroiliac joint pain. Many of the current diagnostic and therapeutic options present weak evidence.

[Expert assessment of lower extremity prosthetics]. / Begutachtung von Prothesenversorgungen der unteren Extremität.

Although the number of major amputations is declining throughout Germany, more than 57,000 surgical procedures for amputation still take place. As a consequence of high prosthetic care costs, these often lead to disputes before the social court in which expert medical opinions are required. With knowledge of the legal norms, the remit of the expert opinion can be fulfilled. The expert begins with evaluation of the patient's file and a search of the contested parts. The investigation includes a medical history, in addition to a physical examination, in order to be able to comment on the disputed beneficial use of the therapeutic appliance and respond to questions of proof. Questionnaires may be helpful.

[Insoles, knee braces and ankle-foot orthoses in the treatment of medial gonarthrosis : A literature review]. / Einlagen, Knie- und Unterschenkelorthesen in der Behandlung der medialen Gonarthrose : Eine aktuelle Literaturübersicht.

BACKGROUND: Osteoarthritis is the most common joint disease worldwide and mostly affects the knee joint (gonarthrosis). In treatment algorithms, technical aids in the form of laterally wedged insoles, valgizing knee braces and ankle-foot orthoses have an importance in the treatment of medial unicompartmental knee joint disease. However, national and international guidelines differ in their recommendations. INSOLES: Taking into account a great amount of scientific work, the measurable effect of laterally wedged insoles appears to be low, so that a justifying indication only exists at low gonarthrosis levels. KNEE BRACES: Valgizing knee braces have shown stronger biomechanical and clinical effects, but with a slightly increased complication potential and low compliance. Low to medium-grade arthrosis can be treated. ANKLE-FOOT ORTHOSES: Ankle-foot arthroses have not yet been conclusively examined. Initial work indicates biomechanical and clinical efficacy. The overall effects and indications appear comparable to knee braces, probably with less complication potential.