It is a randomized, prospective, single-blind study of two treatment techniques for rhizarthrosis. The patients are divided into two groups: one in which a Maia trapeziometacarpal prosthesis is implanted, and the other in which the standard technique of trapeziectomy and tenosuspension plasty is performed according to the Burton-Pellegrini technique.The follow-up of the patients is one year, and functionality (measured with the Quick Dash test) and pain (measured with the VAS scale) are compared throughout this period.This study has a sample size of 62 patients, 31 per group. Other secondary variables are also evaluated, such as strength and mobility of the thumb trapeziometacarpal joint (measured with the Kapandji index).