A complication of Silastic hemiarthroplasty in bunion surgery.

Seven cases of painful reactive synovitis following great toe Silastic hemiarthroplasty have been observed. All cases were treated successfully with synovectomy and removal of the implant. Microscopic examination of the synovium uniformly demonstrated a chronic foreign-body giant-cell reaction with intracellular and extracellular silicone elastomer particles. Gross examination of the implants showed varying degrees of erosion of the articulating surface. Abrasion of a Silastic implant creates free-floating silicone elastomer particles that can precipitate a reactive synovitis. The authors believe an irregular, degenerated first metatarsal head is a contraindication to an interpositional Silastic hemiarthroplasty.