[2 cases of early "siliconitis" (silicone synovitis)].

Two cases of early silicone synovitis, 12 and 18 months after surgery for partial scaphoid implant arthroplasty (Swanson design) are reported. None of the implants had been fixed by Kirschner wire or sutured to the radius or an other carpal bone. Both implants had been immobilized for six weeks. Initially the result in both cases was good. Pain and loss of range of movement gradually increased, and a large erosive osteolytic defect of the radius was seen on the X-ray after 12 months for the first case and 18 months for the second one. Surgical revision consisted of implant removal, synovectomy with a proximal row carpectomy in the first case and a soft tissue interposition arthroplasty for the second one. The histologic examination showed a foreign body reaction with birefringent material in multinucleated giant cells. All reports about this type of silicone implant complication emphasises the role of compression forces and micro-fragmentation of the silicone. Should we continue to perform partial scaphoid implant arthroplasty from whom microparticles are creating a severe foreign body reaction?