A Comparison of Polyethylene and Tantalum for Cranioplasty

World War II, tantalum, and the evolution of modern cranioplasty technique

Cranioplasty is a unique procedure with a rich history. Since ancient times, a diverse array of materials from coconut shells to gold plates has been used for the repair of cranial defects. More recently, World War II greatly increased the demand for cranioplasty procedures and renewed interest in the search for a suitable synthetic material for cranioprostheses. Experimental evidence revealed that tantalum was biologically inert to acid and oxidative stresses. In fact, the observation that tantalum did not absorb acid resulted in the metal being named after Tantalus, the Greek mythological figure who was condemned to a pool of water in the Underworld that would recede when he tried to take a drink. In clinical use, malleability facilitated a single-stage cosmetic repair of cranial defects. Tantalum became the preferred cranioplasty material for more than 1000 procedures performed during World War II. In fact, its use was rapidly adopted in the civilian population. During World War II and the heyday of tantalum cranioplasty, there was a rapid evolution in prosthesis implantation and fixation techniques significantly shaping how cranioplasties are performed today. Several years after the war, acrylic emerged as the cranioplasty material of choice. It had several clear advantages over its metallic counterparts. Titanium, which was less radiopaque and had a more optimal thermal conductivity profile (less thermally conductive), eventually supplanted tantalum as the most common metallic cranioplasty material. While tantalum cranioplasty was popular for only a decade, it represented a significant breakthrough in synthetic cranioplasty. The experiences of wartime neurosurgeons with tantalum cranioplasty played a pivotal role in the evolution of modern cranioplasty techniques and ultimately led to a heightened understanding of the necessary attributes of an ideal synthetic cranioplasty material. Indeed, the history of tantalum cranioplasty serves as a model for innovative thinking and adaptive technology development.

Skull bone defects. Preliminary results using a new prosthesis

The use of a new prosthetic material (110 DTEX F 33 Propylene and Medical Polyester Torlen 165 DTEX) in the reconstruction of bone defects of the skull, even of large dimension, is described by the authors. The material has good biologic tolerance, is already pre-moulded, can be easily adapted to the exact size of the defect and offers remarkable aesthetic and functional results. EEG, X-ray, MRI and CT can be performed without artefact and interferences.

Polyacryl prosthesis for cranioplasty--their production in silicon rubber casts

The frequently observed osteolysis after reimplantation of deep-frozen skullcap bone have led us to use polyacryl as the material of choice if a secondary covering of a skull bone defect becomes necessary. Polyacryl has an excellent biological compatibility but often yields unsatisfactory cosmetic results when the modelling is done at the site of the intervention, especially in the case of defects in the forehead region. A method is described that allows the preparation of a prosthesis before the actual operation identical with the original bone in every detail. The surgery is then confined to the anchoring of the prosthesis to the bone edges.