(see also: Pyknodyostosis) Discussion disease characterized by failure of maturation and organization of collagen fibers; defect in collagen (procollagen to type I collagen sequence and abnormal cross linking) leading to decreased collagen secretion, bone fragility; there may be an inability to form normal bone due to a defect in osteoblastic function; with the formation of … Read more
– Discussion: – see: homeobox genes database – history: discovered by Marshall Urist in the early 1960s; – currently sixteen different proteins (BMP-1 through BMP-16) have been identified; – these proteins can now be produced by recombinant DNA technology and are further purified by column chromatography; … Read more
– See: Bone Tumor Menu – Discussion: – benign osseous tumor usually less than 1.5 cm in diameter, comprising 11% of all benign bone tumors; – no cases of malignant transformation has been reported; – occurs primarily in adolescents and less often in children; … Read more
– See: Osteochondral Lesions of the Adult Knee – Discussion: – term OCD is a defect in the subchondral region with partial or compete separation of the bone fragment; – most often seen on the postero-lateral aspect of the medial femoral condyle (about 80% of cases), and less often seen in … Read more
– Discussion: – a developmental dysplasia of peripheral growth plate which forms a cartilage capped projection of bone found near metaphyses of long bones; – peripheral chondroblast grows outward from the metaphysis, acting as an ectopic growth plate, which ceases growth at skeletal maturation; … Read more
– See: – Osteoarthritis Menu: – predisposing conditions – pathology and histology – clinical features – Discussion: – biomechanical considerations: (see kinematics and anatomy of knee – thick cartilaginous surfaces of … Read more
– Bone Tumor Menu – Discussion: – unusual benign osseous tumor; – it resembles osteoid osteoma in some respects buts is larger ( >2 cm); – unlike osteoid osteoma: – occurs in older adolescents and young adults; – osteoblastoma … Read more
– Discussion: – see: osteocytes and osteoclasts – arise from marrow stroma cells, and are found on the surfaces where bone is being formed; – may require bone morphogenic proteins for induction into osteoblasts; – generally regarded as bone forming cells; – … Read more
– See: – Diff Dx: Hypercalcemia – Diff Dx: HyperPhosphatemia – Approaches To Differential Diagnosis In Musculoskeletal Imaging: Soft Tissue Calcifications – Discussion: – calcium hydroxyapatite can be deposited in periarticular soft tissues or within joints; – in either event the disease may be monoarticular or polyarticular; … Read more
– Discussion: – results from failure of an anterior acromial ossification center to fuse to the acromial process; – caused by failure of one of three ossification centers; – ossification centers appear at age 15 and should fuse by age 22-25; – subtypes: (from … Read more