A common finding in progressive osteoarthritis of the carpometacarpal joint of the thumb is ligamentous laxity. In patients with Ehlers-Danlos syndrome, which is a disorder characterized by generalized ligamentous laxity, splinting and arthrodesis have been recommended because of the random results achieved by other reconstructive procedures. We report a patient with thumb carpometacarpal joint osteoarthritis secondary to Ehlers-Danlos syndrome who was treated with bilateral arthroscopic tendon interposition arthroplasty.