https://journal.chestnet.org/article/S0012-3692(12)60124-X/pdf

Prevention of VTE in Nonsurgical Patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

Bone is formed by a series of complex events involving the mineralization of extracellular matrix proteins rigidly orchestrated by cells with specific functions of maintaining the integrity of the bone. Bone, similar to other calcified tissues, is an intimate composite of the organic (collagen and noncollagenous proteins) and inorganic or mineral phases. The bone mineral idealized as calcium hydroxyapatite, Ca10 (PO4)(6)(OH)2, is a carbonatehydroxyapatite, approximated by the formula: (Ca,X)(10)(PO4,HPO4,CO3)(6)(OH,Y)2, where X are cations (magnesium, sodium, strontium ions) that can substitute for the calcium ions, and Y are anions (chloride or fluoride ions) that can substitute for the hydroxyl group. The current author presents a brief review of CaP biomaterials that now are used as grafts for bone repair, augmentation, or substitution. Commercially-available CaP biomaterials differ in origin (natural or synthetic), composition (hydroxyapatite, beta-tricalcium phosphate, and biphasic CaP), or physical forms (particulates, blocks, cements, coatings on metal implants, composites with polymers), and in physicochemical properties. CaP biomaterials have outstanding properties: similarity in composition to bone mineral; bioactivity (ability to form bone apatitelike material or carbonate hydroxyapatite on their surfaces), ability to promote cellular function and expression leading to formation of a uniquely strong bone-CaP biomaterial interface; and osteoconductivity (ability to provide the appropriate scaffold or template for bone formation). In addition, CaP biomaterials with appropriate three-dimensional geometry are able to bind and concentrate endogenous bone morphogenetic proteins in circulation, and may become osteoinductive (capable of osteogenesis), and can be effective carriers of bone cell seeds. Therefore, CaP biomaterials potentially are useful in tissue engineering for regeneration of hard tissues.

Properties of Osteoconductive Biomaterials: Calcium Phosphates

The inorganic part of hard tissues (bones and teeth) of mammals consists of calcium phosphate, mainly of apatitic structure. Similarly, most undesired calcifications (i.e. those appearing as a result of various diseases) of mammals also contain calcium phosphate. For example, atherosclerosis results in blood-vessel blockage caused by a solid composite of cholesterol with calcium phosphate. Dental caries result in a replacement of less soluble and hard apatite by more soluble and softer calcium hydrogenphosphates. Osteoporosis is a demineralization of bone. Therefore, from a chemical point of view, processes of normal (bone and teeth formation and growth) and pathological (atherosclerosis and dental calculus) calcifications are just an in vivo crystallization of calcium phosphate. Similarly, dental caries and osteoporosis can be considered to be in vivo dissolution of calcium phosphates. On the other hand, because of the chemical similarity with biological calcified tissues, all calcium phosphates are remarkably biocompatible. This property is widely used in medicine for biomaterials that are either entirely made of or coated with calcium phosphate. For example, self-setting bone cements made of calcium phosphates are helpful in bone repair and titanium substitutes covered with a surface layer of calcium phosphates are used for hip-joint endoprostheses and tooth substitutes, to facilitate the growth of bone and thereby raise the mechanical stability. Calcium phosphates have a great biological and medical significance and in this review we give an overview of the current knowledge in this subject.

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Biological and medical significance of calcium phosphates.

Prevention of VTE in Orthopedic Surgery Patients

https://www.tpbin.com/Uploads/Subjects/643149a0-8194-4c67-bf05-73fae6f0d14f.pdf

Development of new metallic alloys for biomedical applications

Mechanical strength of calcium phosphate cement in vivo and in vitro.

Prevention of postoperative venous thromboembolism in Japanese patients undergoing total hip or knee arthroplasty: two randomized, double-blind, placebo-controlled studies with three dosage regimens of enoxaparin

A filler for filling in defects or hollow portions of bones to coalesce with the bone tissues is provided which comprises powders of a calcium phosphate compound having the apatite crystalline structure of each crystal grain size of from 50 ∪ to 10 microns and represented by the following general formula of Cam (PO4)n OH (1.33≦m/n≦1.95); and said powders being adapted for filling in a fluidized or plasticized state. A method of treating a bone with the filler is also provided wherein at least a portion of said filler is filled in to reach the bone-marrow cavity of said bone.

Method for filling in defects or hollow portions of bones

A filler for filling in defects or hollow portions of bones to coalesce with the bone tissues is provided which comprises powders of a calcium phosphate compound having the apatite crystalline structure of each crystallite size of 400 Å or larger and of each crystal grain size of 3 μm or smaller, said calcium phosphate compound being represented by the following general formula of Ca m (PO 4 ) n OH (1.33≦m/n≦1.95), and said powders being fluidized or plasticized.

Filler for filling in defects or hollow portions of bones

PROBLEM TO BE SOLVED: To arbitrarily inject bone cement and fully function as a screw without losing its fixed strength by forming a lot of through holes, whose inner end communicates with a hollow hole and outer end is opened to the outside, around the circumferential wall of the screw main body in such a state as being dispersed in the axial and circumferential directions of the screw main body. SOLUTION: A screw main body 1 is provided with a screw part 2 in its tip side, a non-screw part 3 in the base end side, and a head part 4, where the tip of a hexagonal wrench or a screw driver is inserted and engaged, in the other end. A hollow hole 5 penetrating the screw main body in the axial direction (long shaft direction) is formed in the screw main body 1 so that a guide pin can be inserted in the hollow hole 5. The tip of the screw main body 1 is notched into a recessed shape so as to facilitate its insertion into the bone and a plurality of through holes 6 whose inner end communicates with the hollow hole 5 and outer end is opened to outside are formed in an a valley part 2a of the screw part 2 in the circumferential wall of the screw main body 1 in such a state as being dispersed in the axial and circumferential directions of the screw main body 1. COPYRIGHT: (C)1998,JPO

Shigeo Niwa

Papers

Mechanical strength of calcium phosphate cement in vivo and in vitro.

Prevention of postoperative venous thromboembolism in Japanese patients undergoing total hip or knee arthroplasty: two randomized, double-blind, placebo-controlled studies with three dosage regimens of enoxaparin

Method for filling in defects or hollow portions of bones

Filler for filling in defects or hollow portions of bones

Screw for bone joint