Bioscrew degradation without osseous replacement but with large pretibial cystic formation following anterior cruciate ligament reconstruction: A report of two cases and a literature review

The formation of a pretibial cyst out of the tibial tunnel associated with bioscrew fixation of the hamstring tendon following anterior cruciate ligament reconstruction is a rare condition. In the cases presented here, bioscrew degradation without osseous tissue replacement but with cyst formation and foreign body reaction was shown pathologically. Curettage and bone substitute grafting provided a good result in both cases.