Clinical applications 2 bone healing

Stmctural load-bearing applications of bone grafts cannot be performed by injection but in situ setting bone graft substitutes can be injected to provide structural support or fixation for metaphyseal and epiphyseal fractures. 

Allograft bone has an unlimited supply, often at significant expense, and is osteoinductive, especially when BMPs in the matrix are exposed through demineralization, but, it carries the risk of transmitting disease (1 1 500000 for human immunodeficiency virus (HIV), 1 100000 for hepatitis B, and 1 60 000 for hepatitis C) [66]. If allograft bone is not completely cleared of cellular components, there is the potential for an immunological response, a clinical problem mostly for composite tissue transplants. 

In spite of obvious potential use, experienee with injection of signaling molecules is aneedotal with insuffieient data to establish efficacy or safety. FDA approved indieations for use are very limited and extreme cost makes off-label use a ehallenge. Clinieal trials, as have been done for BMP 2 and BMP 7, are required to establish indications. 

Human BMP is therapeutically active in milligram doses but is present in cortical bone in the concentration of only 1-2 /xg/kg, making it impractical to extract sufficient quantities for clinical use. Therefore, therapeutic quantities are produced commercially through molecular biology techniques (recombinant BMP - rhBMP). Two are currently available for clinical use rhBMP-2 (Infuse Medtronic Sofamor Danek, Memphis, Tennessee) and rhBMP-7 (OP-1 Stryker, Kalamazoo, Michigan). 

Off-label use is a natural consequence of surgical techniques developing faster than regulatory approval can respond. Currently more BMP2 is being used for non-approved procedures than the approved procedure. Serious complications associated with the use of BMP in anterior cervical spine fusion without improved fusion rates illustrate the need for controlled clinical trials before successful treatment for one condition can be extended to a similar condition [110]. 

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R448 A. S. Patil, R. B. Sable and R. M. Kothari, An Update on Transforming Growth Factor-P (TGF-P) Sources, Types, Functions and Clinical Applicability for Cartilage/Bone Healing , J. Cell. Physiol., 2011, 226, 3084. 

The aim of this paper is to review the application of EIT in monitoring bone healing as studied by Aberbeen s researchers in the late 80s and early 90s and to propose possible applications and upgrades/improvements for clinical applications with the current technology. 

The effects of BMP-2 and BMP-7 on osteoblast differentiation, growth, proliferation, and apoptosis are well documented, and currently are used for clinical applications in the healing bone defects (Hay et al., 2004, Bessa et al., 2008). Of the BMP family, BMP-2, is known as a main factor in osteoblast homeostasis and BMP-7, is regarded as a main factor in chondrocyte function (Yoon and Fisher, 2007). 

Biodegradable internal fixation devices such as screws, pins, and plates are already nsed in clinical applications such as orthopaedic surgery. The advantage of using biodegradable fixation devices instead of metallic counterparts in bone orthopaedic snrgery is obvions - the device simply disappears after the bone heals. Loads... 

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