Bioabsorbable interference screw failure in anterior cruciate ligament reconstruction: A case series and review of the literature

•The rate of bioabsorbable interference screw breakage reported in the literature is ~ 3.2%.•Femoral screw failure occurs more frequently than tibial screw failure.•Deformation of the screwdriver tip can lead to increased torque and screw breakage, a mechanism not previously described in the literature.

BackgroundTo report a case series of failures of bioabsorbable interference screws with possible identification of a novel failure mechanism.MethodsA retrospective review of ACL reconstructions by the senior author utilizing BioComposite™ Interference Screws (Arthrex, Inc., Naples, FL) was performed. Complications related to screw placement, including fracture, breakage or bending were examined. Our rate and methods of failure were compared to those quoted in the current literature.ResultsEighty-seven patients of average age 23.8 years met inclusion criteria. There were eight screw failures in six patients, with femoral failure in seven and tibial failure in one. The femoral screw fractured halfway between the tip and head in five, while the head of the screw broke in one and the screw bent in another. In the case of tibial interference screw fracture, failure occurred halfway between the tip and head. The insertion device that was used was replaced after recognition of material deformation and considered a potential contributor to the breakage risk as no further screw failures have occurred since.ConclusionsWe demonstrate a unique failure mechanism of bio-absorbable interference screws. In each case, the reconstruction was salvaged. Regular inspection of materials and implants can ensure optimal outcomes and decrease complications intra-operatively.