Outcome of cranial cruciate ligament replacement with an enhanced polyethylene terephthalate implant in the dog: A pilot clinical trial

Objective To assess the 6-month outcome and survival of enhanced polyethylene terephthalate (PET) implants as a replacement for the cranial cruciate ligament (CCL) in dogs with spontaneous CCL disease (CCLD). Study design Pilot, prospective case series. Animals Ten client-owned large breed dogs with unilateral spontaneous CCLD. Methods Dogs were evaluated before and 6 months after intra-articular placement of a PET implant with the Liverpool Osteoarthritis in Dogs questionnaire and force platform gait analysis. Arthroscopy was performed 6 months after surgery to visually assess implant integrity. Results Scores on owner questionnaires and limb asymmetry improved in all dogs that reached the 6-month time point, by 51.7% (p = .008) and 86% (p = .002), respectively. The PET implant appeared intact and functioning in two stifles, partially intact and functioning in four stifles and completely torn in three stifles. One dog had an implant infection and was removed from the study. Evidence of deterioration and tearing occurred in the midbody of the implant. Conclusion Although function improved over the course of this study, only 2/10 implants appeared intact 6 months after placement. Clinical significance Implant survivability prohibits further clinical investigation using this implant.