transforming-growth-factor-beta and Bone-Demineralization--Pathologic

In normal life on earth, the locomotor system is exposed to two types of stimulation: gravity (passive stimulation) and motion (active stimulation). Both permanently combine, and the interactions between locomotion and gravity induce an overall recruitment which is repeated daily and maintains the bone tissue structure within the range of constraints to which it is adapted. This range is one of the basic hypotheses underlying the mechanical concepts of bone structure control, and it has been considered as logical to assume that weightlessness of spaceflight should produce bone loss since astronauts are outside of the terrestrial gravitational field of forces, no longer relying on muscular work to change positions or move. But, thirty years after the first changes in phospho-calcium metabolism were observed in astronauts after spaceflight, current knowledge does not provide a full understanding of this pathogeny, and prove the G-factor is now considered as an essential component of the experimental tools available to study bone physiology. The study of the physiology of bone tissue usually consists in the investigation of its two fundamental roles, i.e. reservoir of inorganic elements (calcium, phosphorus, magnesium) and mechanical support for soft tissues. Together with the combined action of muscles, tendons, and ligaments, this support permits motion and locomotion. These two functions rely on a sophisticated bone tissue architecture, and on the adaptability of this structure, with modeling and remodeling processes, themselves associated with the coupled activity of specialized bone cell populations.

Topics: Animals; Bone and Bones; Bone Demineralization, Pathologic; Calcium; Hindlimb Suspension; Humans; Insulin-Like Growth Factor I; Osteoblasts; Osteoporosis; Rats; Space Flight; Transforming Growth Factor beta; Weightlessness

Seroma formation following posterior cervical laminectomy and fusion is now recognized as a rare but significant risk. Previous reports have attributed the development of postoperative seromas to the use of recombinant bone morphogenetic protein-2 (rhBMP-2). Here the authors present the case of a 78-year-old female with a history of osteoporosis who developed delayed postoperative neck and shoulder pain following posterior cervical laminectomy and fusion utilizing only autograft bone and demineralized bone matrix (DBM) allograft. Postoperative MRI demonstrated normal hardware placement and a large epidural fluid collection that extended from C-4 to C-6. The patient underwent decompression and drainage of her sterile postoperative seroma. To the authors' knowledge, no case of seroma formation with the use of DBM has been previously reported. This case suggests that although rhBMP-2 is involved in the majority of postoperative seroma developments, other osteoinductive agents such as DBM can contribute to the development of a symptomatic seroma. This report presents an illustrative case study and reviews the current understanding of the development of and treatment for cervical seroma following posterior cervical laminectomy and fusion.

Topics: Aged; Bone Demineralization, Pathologic; Bone Morphogenetic Protein 2; Bone Transplantation; Cervical Vertebrae; Female; Humans; Laminectomy; Postoperative Complications; Recombinant Proteins; Seroma; Spinal Fusion; Transforming Growth Factor beta; Treatment Outcome