Vacuum-Sealed Hot Water Bath Immersion for the Preparation of Anatomical and Surgical Cadaveric Bone Models

This method produces accurate anatomical bone models that depicts the native anatomy that helps to guide researchers, clinicians, and surgeons on the surgical approach and implant placement, amongst other benefits. This method produces clean and hygienic anatomical bone models, which is important, considering having these models at the bedside or in the surgical theater, for example. Compared to 3D-printed anatomical bone models, our models are low cost, safe, and effective to produce, and also compared to those 3D models, the architecture of the bone and the native anatomy is better represented by these surgical bone models.

The technique described is to produce accurate anatomical bone models for the spine, but the technique could be easily extrapolated to other osseous structures of the body. The method better informs surgeons, researchers, and clinicians on how to plan and execute surgical techniques, and also informs them of what normal osseous anatomy is that will then help them to recognize pathology. But the technique could be easily extrapolated to a range of other osseous structures from a range of different species.

To begin, manually remove soft tissue, such as muscle, connective tissue, fat, et cetera, using a sharp dissection tool from the bone sample, and seal the sample in a heat-safe sealable plastic bag after removing the air. Completely submerged the sealed sample in a 70-degree Celsius water bath for 24 hours, and then remove the bag from the bath, open the bag, and allow the sample to cool until handleable. Remove as much soft tissue from the bone as possible using a sharp scalpel and running water as needed.

To disarticulate any joints to expose the cartilaginous tissue, keep the disarticulated pieces in situ using materials such as orthopedic wire or cable ties to maintain the anatomical position. Seal the sample in a vacuum bag along with 10 milliliters of dishwashing detergent and 10 milliliters of tap water, and submerge the sealed sample in a 70-degree Celsius water bath for 24 hours. After removing the bag from the bath, repeat the steps shown earlier to remove as much soft tissue as possible until the bone is free of soft tissue material.

Finally, allow the sample to dry for approximately 48 hours. A qualitative comparison between 3D-printed and cadaveric bone models is presented here. These images show that the 3D-printed model does not accurately detail fine osseous detail of the cadaveric specimens, with a loss of finer details, such as contours of the bone, especially on the transverse processes.

Sheep lumbar spine models processed with and without detergent at the same step of the processing are shown here. From these two images, a clear difference in color and texture can be noted. To reproduce this method, the individual or research group does need access to anatomical specimens, a hot water bath, and vacuum-sealing equipment.

The dissection of soft tissues pre and post-hot water bath is not technically demanding, but it does require some fine motor skills and some experience using sharp dissection equipment and other surgical equipment.