gms | German Medical Science

Objectives/Interrogation: Only about 1200 wrist joint replacements are carried out annually in the United States compared approximately 1.2M knee joint replacement and approximately 670K hip replacement surgeries. The simple calculation based on the number of patients with degenerative wrist disease for any reason shows that patients requiring surgical wrist replacement can reach one million per year only in the United States. So, the question is: "What is wrong with the total wrist replacement?" The author of the study assumes that a concept of all existing implants ignores the rules of Nature. According to the new vision and mathematical processing of the anthropometry of the joint may be possible to convert the non-linear biomechanical system to the linear one. That will allow creating a solution for wrist replacement closed to Nature's design.

Methods: Anthropometric measurements of the wrist joint structures made on the base of the PA radiograms 210 healthy wrist joints of the adult patients. Three distances evaluated in the measurements. The first is the distance between the base of the ulnar styloid to the apex of the interfacetal ridge. The second is the distance between the apex of the interfacetal ridge and the base of the radial styloid. The third is the distance between the base of the capitate and the apex of the interfacetal ridge. The ratio between the first and second distances and the ratio of the first plus second distances and third distance were determined.

Results and Conclusions: All determined ratios were measured close to 1.5 and 1.6 with the deviation of ±0.1. The results come very close to the number of Golden Section of Fibonacci (Phi-1.618). The same proportions data accepted on the Leonardo da Vinci paintings of the wrist anatomy. According to the fractals, linear model of the wrist joint was built. Two spirals of Fibonacci were drawing according to the fractals and determined two centers of rotation in the capitate bone.

The wrist joint may be described on the base of the fractals and Fibonacci golden section as are the spiral appearance of the most galaxies and the DNA spirals. Autor finds linearity of the human wrist joint. A new opportunity was opened to explain the biomechanics of the wrist joint. This opportunity logically can be defined as "A fractal theory of the biomechanics of the wrist joint." That conversation will help design and built the optimal and universal wrist joint prosthesis similar to the structure created by Nature.