In Tape Locking Screw (TLS^®) ligamentoplasty, transplant bone fixation uses polyethylene terephthalate (PET). We report two cases of aseptic arthritis following anterior cruciate ligament (ACL) reconstruction using this material. Diagnosis was founded on negative sampling and complete cure following arthroscopic lavage and synovectomy without curative antibiotherapy. This complication was also described with other synthetic materials used in this indication (Dacron, PFTE, carbon), and with PET as transplant material but never as bone fixation material. The physiopathological hypothesis is in terms of PET particle release in the suprapatellar bursa; sinking the strips into the bone as fully as possible on implantation could avoid impingement. Longer TLS^® ligamentoplasty series with adequate follow-up will be needed in order to estimate the true incidence of this complication.