The Morphology of an Ideal Trapezial Implant for Base of Thumb Arthritis GANHEWAAPARNA DASUNMALEE 2019 Base of thumb arthritis is a common problem in our population. There are many operations that can be done to treat base of thumb arthritis. These operations all have advantages and disadvantages. Operations done using an implant carry higher complications. We propose that the best way to treat pain, improve thumb function and reduce complications is by using an implant shaped like the original trapezium bone at the base of the thumb.