To prevent the mechanical consequences of trapeziectomy, interposition devices are promoted, such a Dacron spacer. We report three cases of osteolysis and synovitis related to the use of such a device. This phenomenon occurred 4 months after insertion and required revision surgery after 9 months of follow-up because of pain and extensive osteolysis of the carpal bones. Revision consisted of an extended synovectomy, removal of the broken Dacron followed by a ligamentoplasty using the Flexor Carpi Radialis. Two years after revision surgery the result was satisfactory, with no recurrence of pain or osteolysis. The Dacron device did not demonstrate improvement in clinical results after short-term follow-up when compared to conventional ligamentoplasty. We recommend cautious use of the Dacron device at trapeziectomy and attention must be paid to follow up of the patient.