Foreign body reaction to a bioabsorbable interference screw after anterior cruciate ligament reconstruction

Bioabsorbable interference screws have been effective for graft fixation in anterior cruciate ligament (ACL) reconstruction. The overall complication rate associated with the use of these screws is low but some unique problems have been reported in the literature. We present a case of unusual tissue reaction to a bioabsorbable interference screw following ACL reconstruction.A young male underwent ACL reconstruction, during which a bioabsorbable interference screw was used for graft fixation at the tibial end. The patient presented with a pretibial swelling at 30 months after the operation. Exploration revealed chalky white remnants of the bioabsorbable screw with no evidence of infection. Histological studies confirmed a foreign body reaction against screw remnants with the presence of multinucleated giant cells.The patient had a full recovery with no compromise to graft stability. Bioabsorbable interference screws are usually inert but can initiate a tissue reaction. The presentation can be as late as 2-3 years postoperatively and may mimic an infection. Satisfactory results can be achieved by proper exploration and debridement.