**1. Introduction**

Bone grafting is a standard orthopedic procedure performed in clinical practice. Autogenous graft is the gold standard and the preferred graft used. However, allograft bone continues to play an important role in many orthopedic reconstructive procedures. One has to resort to the allogenic sources especially in filling up of large or multiple containable cavitary lesions, structural intercalary reconstruction of large circumferential osteoperiosteal defects, extensive

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

spinal fusion for gross deformities or severe instabilities especially in children, and repeat surgeries after total joint replacements. These procedures demand an abundant quantity of bone which the recipient's body cannot supply without significant morbidity and risks. At present popularly allogenic bone is preserved by deep-freezing or freeze-drying or by radiation for long-term preservation. These techniques have been shown to maintain sterility, reduce immunogenicity, and provide adequate structural integrity; however, such procedures also reduce the bone-forming biological activity and are expensive (**Table 1**). Autoclaving and radiation completely destroy bone inductive principles.

or posterolateral spinal fusion. Minimum follow-up for declaring "success" or "failure" of the grafting procedures was 2 years after implantation. We prefer to use the expression of "decal-

Allogenic Decal-Bone Grafts: A Viable Option in Clinical Orthopedics

http://dx.doi.org/10.5772/intechopen.80877

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Human bones were obtained from freshly (posttraumatic) amputated extremities, under strict aseptic operation theater conditions. Soft tissues and periosteum were removed from the bones using sharp instruments. After a minimum of three washings with normal saline, the bones were placed and immersed in 0.6 M HCI solution for 3–5 days in a domestic refrigerator. The solution was changed every 24 hours. The partially decalcified bone was washed with normal saline to remove any traces of acid, sealed in 80–90% ethanol, and kept in a domestic refrigerator at about 4–6°C (**Figures 1** and **2**). The stored bone was used between 1 and 12 months of preservation. Osteoporotic bone from old persons would be ready by the third day; however, fully mineralized bone from athletic or healthy persons may take 5 days for achieving 50–40% decalcification. Bone obtained from total knee replacements in the oper-

When required for implantation, the preserved bone was washed thoroughly with normal saline. The superficial surface of graft was pared using a sharp scalpel, and it was cut to the required size to give a snug fit in the host bed for structural grafting, generally fixing to the host bone using an intramedullary nail. For filling large cystic cavities of bone, the decal-bone was cut like matchstick silvers with thickness and width of 4–6 mm and washed with normal saline. The cavities after thorough curettage were compactly packed with the

For spinal fusions the recipient bed was decorticated, and abundant graft was placed oriented along the long axis of the spine. In cases with gross mechanical instability, a suitable implant with multi-segmental fixation was employed as an adjunct. Standard operative principles for such extensive procedures were followed with modifications to suit individual requirements. For giant cell tumors of bone (GCT) prior to 1986, en bloc resection and structural reconstruction was performed as a standard procedure. We had an opportunity to observe the behavior of large allogenic segmental graft used for such patients. Global observation however advised

Currently for all containable cystic lesions including GTC, we use and recommend the follow-

**III.** Fill up the cavity with hydrogen peroxide for 3 minutes, and clean the cavity with nor-

less aggressive joint-sparing intralesional procedures since approximately 1987.

**I.** Perform thorough intralesional curettage through an adequate window.

**IV.** Fill the cavity with absolute ethanol (80–90%) for 3 minutes.

**V.** Remove ethanol and wash with normal saline.

bone" because the whole process of decalcification is performed in vitro.

**2. Preparation of allogenic "decal-bone" graft**

ating rooms was another material processed for use as decal-bone.

matchstick graft.

ing steps for grafting:

mal saline.

**II.** Aspirate the debris completely.

One of the most exciting works during the latter half of the twentieth century (1965–1994) has been the clinical translation of the basic research performed by marshal Urist [1, 2].

After extensive experimental work [3, 4], we have been using partially demineralized allogenic bone (decal-bone) as grafts in clinical cases. For preparation and preservation of allogenic bone graft, we used the techniques described by Urist (1965–1987). We aimed at removal of approximately 50% of mineral from the graft, thus retaining adequate structural integrity (**Table 2**). We used this material since 1978, and we closely observed the clinical results on long-term bases in 67 benign cystic lesions, 32 wide-gap graftings, and 11 posterior


Frozen grafts require thawing, freeze-dried grafts require hydration before implantation, and the unused graft cannot be re-preserved.

**Table 1.** Commonly used bone grafts in clinical orthopedics.


**Table 2.** Processing of allogenic decal-bone.

or posterolateral spinal fusion. Minimum follow-up for declaring "success" or "failure" of the grafting procedures was 2 years after implantation. We prefer to use the expression of "decalbone" because the whole process of decalcification is performed in vitro.
