Pubic Bone: A bone that forms the lower and anterior part of each side of the hip bone.Pubic Symphysis: A slightly movable cartilaginous joint which occurs between the pubic bones.Osteitis: Inflammation of the bone.Groin: The external junctural region between the lower part of the abdomen and the thigh.Cystostomy: Surgical creation of an opening (stoma) in the URINARY BLADDER for drainage.Sarcoma, Small Cell: A sarcoma characterized by the presence of small cells, cells measuring 9-14 micrometers with a faint or indistinct rim of cytoplasm and an oval-to-elongated nucleus with relatively dense chromatin. (From Segen, Dictionary of Modern Medicine, 1992)Desmoplastic Small Round Cell Tumor: A rare, aggressive soft tissue sarcoma that primarily affects adolescents and young adults. It is most commonly found in the abdomen.Bone and Bones: A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.Pelvis: The space or compartment surrounded by the pelvic girdle (bony pelvis). It is subdivided into the greater pelvis and LESSER PELVIS. The pelvic girdle is formed by the PELVIC BONES and SACRUM.Bone Remodeling: The continuous turnover of BONE MATRIX and mineral that involves first an increase in BONE RESORPTION (osteoclastic activity) and later, reactive BONE FORMATION (osteoblastic activity). The process of bone remodeling takes place in the adult skeleton at discrete foci. The process ensures the mechanical integrity of the skeleton throughout life and plays an important role in calcium HOMEOSTASIS. An imbalance in the regulation of bone remodeling's two contrasting events, bone resorption and bone formation, results in many of the metabolic bone diseases, such as OSTEOPOROSIS.Bone Density: The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.Bone Resorption: Bone loss due to osteoclastic activity.Bone Marrow: The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.