Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

Pattern Recognition and Machine Learning

结节病易误诊,据王洪武等~([1])收集国内18篇关于此病误诊的文献,误诊率高达63.2%,当然有误诊就会有误治,如孙永昌等~([2])报道26例结节病在影像学检查诊断的第一印象中拟诊结核5例,其中就有2例完成规范的抗结核治疗,为此应引起临床对本病诊治的重视。

Sarcoidosis

Articular cartilage was predicted to be one of the first tissues to successfully be regenerated, but this proved incorrect In contrast, bone (but also vasculature and cardiac tissues) has seen numerous successful reparative approaches, despite consisting of multiple cell and tissue types and, thus, possessing more complex design requirements Here, we use bone-regeneration successes to highlight cartilage-regeneration challenges: such as selecting appropriate cell sources and scaffolds, creating biomechanically suitable tissues, and integrating to native tissue We also discuss technologies that can address the hurdles of engineering a tissue possessing mechanical properties that are unmatched in human-made materials and functioning in environments unfavorable to neotissue growth

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Unlike Bone, Cartilage Regeneration Remains Elusive

This review analyzes the literature of bone grafts and introduces tissue engineering as a strategy in this field of orthopedic surgery. We evaluated articles concerning bone grafts; analyzed characteristics, advantages, and limitations of the grafts; and provided explanations about bone-tissue engineering technologies. Many bone grafting materials are available to enhance bone healing and regeneration, from bone autografts to graft substitutes; they can be used alone or in combination. Autografts are the gold standard for this purpose, since they provide osteogenic cells, osteoinductive growth factors, and an osteoconductive scaffold, all essential for new bone growth. Autografts carry the limitations of morbidity at the harvesting site and limited availability. Allografts and xenografts carry the risk of disease transmission and rejection. Tissue engineering is a new and developing option that had been introduced to reduce limitations of bone grafts and improve the healing processes of the bone fractures and defects. The combined use of scaffolds, healing promoting factors, together with gene therapy, and, more recently, three-dimensional printing of tissue-engineered constructs may open new insights in the near future.

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Bone regenerative medicine: classic options, novel strategies, and future directions

Ca(2+) is an essential ion in all organisms, where it plays a crucial role in processes ranging from the formation and maintenance of the skeleton to the temporal and spatial regulation of neuronal function. The Ca(2+) balance is maintained by the concerted action of three organ systems, including the gastrointestinal tract, bone, and kidney. An adult ingests on average 1 g Ca(2+) daily from which 0.35 g is absorbed in the small intestine by a mechanism that is controlled primarily by the calciotropic hormones. To maintain the Ca(2+) balance, the kidney must excrete the same amount of Ca(2+) that the small intestine absorbs. This is accomplished by a combination of filtration of Ca(2+) across the glomeruli and subsequent reabsorption of the filtered Ca(2+) along the renal tubules. Bone turnover is a continuous process involving both resorption of existing bone and deposition of new bone. The above-mentioned Ca(2+) fluxes are stimulated by the synergistic actions of active vitamin D (1,25-dihydroxyvitamin D(3)) and parathyroid hormone. Until recently, the mechanism by which Ca(2+) enter the absorptive epithelia was unknown. A major breakthrough in completing the molecular details of these pathways was the identification of the epithelial Ca(2+) channel family consisting of two members: TRPV5 and TRPV6. Functional analysis indicated that these Ca(2+) channels constitute the rate-limiting step in Ca(2+)-transporting epithelia. They form the prime target for hormonal control of the active Ca(2+) flux from the intestinal lumen or urine space to the blood compartment. This review describes the characteristics of epithelial Ca(2+) transport in general and highlights in particular the distinctive features and the physiological relevance of the new epithelial Ca(2+) channels accumulating in a comprehensive model for epithelial Ca(2+) absorption.

https://www.physiology.org/doi/pdf/10.1152/physrev.00003.2004

Calcium Absorption Across Epithelia

The objective of this study was to show model-based economic consequences of minimal invasive surgery total hip arthroplasty (MIS THA). The model is based on hospital and rehabilitation costs and lowering of loss of productivity. This study used conventional THA data from Switzerland and cost-effectiveness MIS THA analysis from the United States. According to our model, a total of 42.1 70.1 million can be saved annually in Switzerland when using MIS THA instead of conventional THA. Annual savings of 7,8 12,9 million result from the significantly shorter hospital stay. The savings potential for rehabilitation costs is 10,5 17,5 million annually. In addition, the productivity loss for the economy is lowered by 23.8 39.7 million annually. According to this economic study we recommend the introduction of MIS techniques in THA. MIS THA surgical techniques may allow the reduction of healthcare costs. Despite the promising economic advantages of MIS THA, clinical studies are necessary to prove long-term benefits.

Cost-benefit analysis of MIS THA: Model-based analysis of the consequences for Switzerland.

Objective To remove loosened ankle prosthesis components, perform osseous defect augmentation, and reimplant definitive prosthesis components to preserve ankle range of motion. Indications Aseptic loosening of the tibial and/or talar ankle prosthesis components with substantial bone defect. Contraindications General surgical/anesthesiological risks, infections, critical soft tissue conditions, nonmanageable hindfoot instability, neurovascular impairment of the lower extremity, neuroarthropathy, substantial nonreconstructable osseous defects with or without cysts on the tibial and/or talar side, noncompliance, primary total ankle replacement (TAR) using intramedullary fixation (stem fixation), severely reduced bone quality, insulin-dependent diabetes mellitus, smoking, unrealistic patients' expectations, high activity in sports. Surgical technique Exposure of the ankle joint using the previous incision. Mobilization and removal of loosened prosthesis components. Debridement of bone stock. Assessment and measurement of osseous defects. Harvesting of iliac crest autograft. Screw fixation of iliac crest autograft. Placement of polyethylene inlay as a spacer. Wound closure in layers at the ankle and the iliac crest. Implantation of definitive prosthesis components. Postoperative management A soft wound dressing. Thromboprophylaxis recommended. Mobilization on postoperative day 1 using a stabilizing walking boot/cast for 6 weeks (sole contact but no weight bearing). Clinical and radiographic follow-up 3 months postoperatively including computed tomography to assess osseous consolidation. After the second surgery, patient mobilization on postoperative day 1 with 15 kg partial weight bearing using a stabilizing walking boot/cast for 6 weeks. Following clinical and radiographic follow-up at 6 weeks, full weight bearing is initiated gradually. Results From January 2007 to December 2012, a two-stage revision TAR was performed in 5 patients (46.8 and 71.4 years). The time between the initial TAR and revision was 2.4-11.5 years. No intra-/perioperative complications. Substantial pain relief in all patients. Comparable preoperative and postoperative ankle range of motion.

[Aseptic loosening of total ankle replacement : Two-stage revision with bone augmentation of osseous defects and secondary prosthesis implantation].

Chapter 71 – What Is the Best Treatment for Ankle Osteochondral Lesions?

Die Beurteilung des Ausmases von Bandinstabilitaten des oberen Sprunggelenks (OSG) mittels klinischer und radiologischer Diagnostik fallt oft schwer. Umfang und Haufigkeit insbesondere der medialen Instabilitat werden dabei haufig unterschatzt. Werden bei einer operativen Rekonstruktion nicht alle betroffenen Bander eingeschlossen, konnen Instabilitat und Beschwerden persistieren. In einer konsekutiven Serie von 281 chronisch instabilen Sprunggelenken (188 Frauen, 93 Manner, Alter 35,8 [15–61] Jahre) fand sich in 140 Fallen (50%) eine Verletzung des Lig. deltoideum, und diese war in 103 Fallen (37%) mit einer Verletzung der lateralen Bander kombiniert. Eine isolierte laterale Instabilitat lag in 121 Fallen (43%) und eine isolierte mediale Instabilitat in 38 Fallen (14%) vor. Die praoperative arthroskopische Untersuchung des Sprunggelenks hat sich als hilfreich erwiesen, den Umfang der ligamentaren Insuffizienz sowie begleitende Schaden zu erkennen. Diese Informationen hatten meist auch mit aufwandigen bilddiagnostischen Masnahmen nicht in diesem Ausmas gewonnen werden konnen. Die Erkenntnisse aus der funktionellen Prufung der medialen und lateralen Bandstrukturen erlauben dem Chirurgen, die notwendige operative Rekonstruktion optimal dem Verletzungsmuster anzupassen. Dies ist deshalb so wichtig, weil gezeigt werden konnte, dass die Sprunggelenkinstabilitat nicht einer einzigen Entitat entspricht, sondern eine hohe Variabilitat aufweist. Obschon nicht in einer randomisierten Studie nachgewiesen, sind wir doch der Meinung, dass die praoperative Arthroskopie die Effizienz der operativen Behandlung der symptomatischen, konservativ erfolglos behandelten Instabilitat des Sprunggelenks verbessert. Die arthroskopische Untersuchung wird deshalb dem Patienten Nutzen bringen, aber auch volkswirtschaftlich sinnvoll sein.

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Arthroskopische Befunde bei der chronischen Sprunggelenkinstabilität

Nonunion of hindfoot arthrodesis can be difficult to successfully treat and will often require bone graft techniques. Large amounts of autogenous bone graft can be difficult to procure and will be associated with donor site morbidity. The use of porous metal implants has been shown to satisfactorily bridge segmental bone defects and to work in conjunction with allogeneic bone graft material, without the risks associated with autogenous bone graft donor site morbidity. The purpose of the present report is to describe the use of a perforated, porous metal implant combined with an intramedullary nail for revision surgery of failed subtalar joint fusion in an adult female patient.

Victor Valderrabano

Papers

Cost-benefit analysis of MIS THA: Model-based analysis of the consequences for Switzerland.

[Aseptic loosening of total ankle replacement : Two-stage revision with bone augmentation of osseous defects and secondary prosthesis implantation].

Chapter 71 – What Is the Best Treatment for Ankle Osteochondral Lesions?

Arthroskopische Befunde bei der chronischen Sprunggelenkinstabilität

Revision Subtalar Joint Fusion With a Porous Metal Spacer and an Intramedullary Nail: A Case Report