In a society based on the use of everyday tools and objects, the loss of function of one or both thumbs due to Rhizarthrosis can drastically reduce the quality of life. Many patients are refractory to preservative treatments.Therefore, multiple arthroplasty techniques were developed.

Trapeziectomy, with or without tendon interposition, gives very good results in terms of pain, function or force. However, it can result in a reduction of the size of the column of the thumb, therefore leading to a loss of force.

Replacement of the trapezo-metacarpal joint with prosthetic material is also proposed and has the advantage to avoid the reduction of the thumb column. Several models are available, mono or bipolar, with a conical or hemispherical cup. Another option is the placement of implants. They were first used when a partial trapeziectomy was possible to counter the collapse of the column and are made of different materials such as metal, silicone, ceramic, pyrocarbon , and gelfoam.

The bioabsorbable poly-LD-lactide implant (PLDLA) is a relatively new possibility for the reconstruction of small joints. Studies have previously revealed that the PLDLA implant is biocompatible and represents a good alternative to arthroplasty by tendon interposition in the reconstruction of the trapezo-metacarpal articulation with osteoarthritis.

In this study, the investigators will investigate the long term effects (1 year after placement) of the Regjoint, a poly-LD-lactide implant (PLDLA).

Inclusion Criteria:

• Adults> 18 years
• Patients having had a trapeziectomy for more than one year, because of chronic Rhizarthrosis defined by pain and Radiographic Signs, aka articular pinching, bone erosion and potential subluxation of the trapezo-metacarpal joint.

Exclusion Criteria:

• Surgery less than 1 year ago.
• Concomitant pathology of the thumb or wrist (Recent injury or trauma, Quervain tenosynovitis, Carpal tunnel syndrome, Dupuytren, jumping finger).
• Trapeziectomy secondary to distal prosthesis and scaphoidectomy.