Second-look arthroscopic findings and clinical results after polyethylene terephthalate augmented anterior cruciate ligament reconstruction

Abstract

Purpose Based on the revival of artificial ligaments containing polyethylene terephthalate, this study aimed to evaluate objective intra-articular findings within scheduled secondlook arthroscopy, patient-reported clinical outcome and stability after isolated augmented ACL reconstruction with polyethylene terephthalate (Trevira®) augmented patella-bonetendon-bone graft. Methods In a retrospective analysis of our institutional database, we found 126 patients with polyethylene terephthalate (Trevira®) augmented ACL reconstruction. All these patients underwent standardised second-look arthroscopic evaluation when removal of the augmentation became necessary. These second-look arthroscopic analyses focused on graft integration and remodelling in line with the polyethylene terephthalate augmentation. Arthroscopic re-examination comprised a graft evaluation including a structural and functional classification according to the Marburger Arthroscopy Score (MAS).Additional clinical evaluation was performed via the IKDC score and the scores of Tegner and Lysholm. Instrumental anterior laxity testing was carried out with a KT-1000™ arthrometer. Furthermore, a correlation analysis between the clinical parameters, the instrumental stability assessment and the corresponding arthroscopic graft condition was performed.Results The arthroscopic evaluation showed rupture of 87 (69 %) of 126 augmentation devices. In 27 (31 %) of these 87 cases, synovial reactions were found particularly in the anterior compartment. An intact synthetic augmentation with signs of graft integration with intact synovial coating was only found in 30 %. Evaluation according to the MAS showed good to excellent structural and functional characteristics in 88 % of patients. Presence of a type III graft (MAS) was found in an additional 11 %. A rudimentary (type IV) graft was only detected once. Eighty-five percent of patients were graded A or B according to IKDC score. The Lysholm score was 92.4± 4.8. Correlation analysis demonstrated a significant relationship between clinical outcome according to the IKDC score (p<0.05), instrumental stability performance according to the KT-1000™ assessment (p<0.05) and the corresponding arthroscopic graft evaluation according to the MAS. Conclusion Graft integration and remodelling has complex and multi-factorial origins, particularly with artificial augmentation. Correlation analysis showed a significant relation between clinical condition, instrumental stability performance and arthroscopic graft constitution. The release of polyethylene terephthalate fibres caused inflammation of synovial tissue of the knee. Characteristic sub-clinical graft changes of structural, morphological and functional qualities of the inserted graft appear on second-look arthroscopy despite good clinical results.

Anterior cruciate ligament reconstruction with LARS™ artificial ligament results at a mean follow-up of eight years

“…During the last 15 years, the development of mainly biocompatible materials and a better understanding of the knee's kinematics has led to the development of a new generation of synthetic graft [5,10]. No abstract The LARS™ ligament consists of fibres made of polyethylene terephthalate (PET) composed of two parts: an intra-osseous segment composed of longitudinal fibres bound together by a transverse knitted structure and an intra-articular segment composed of parallel longitudinal free fibres twisted at 90°.…”

Primary ankle ligament augmentation versus modified Brostrom-Gould procedure: a 2-year randomized controlled trial

“…Synthetic grafts, such as the ligament augmentation reconstruction system (LARS), may be used in an extra‐articular location to augment a primary repair, without the risks of polyethylene synovitis seen with their use inside joints, such as the knee …”

Biomedical coatings on polyethylene terephthalate artificial ligaments

“…However, there were also several reports of graft rupture cases in the intra‐articular portion of PET ligaments longer after implantation . Inferior healing was observed in the intra‐articular part, with foreign body granulomatous reaction and synovial reaction around the graft . Thick fibrous scar tissue was around the graft and poorly organized fibrous scar tissue infiltrated into the graft fibres, which might result in the loss of the ligament structural integrity and eventual graft rupture …”

“…15,16 Inferior healing was observed in the intra-articular part, with foreign body granulomatous reaction and synovial reaction around the graft. 3,17,18 Thick fibrous scar tissue was around the graft and poorly organized fibrous scar tissue infiltrated into the graft fibres, which might result in the loss of the ligament structural integrity and eventual graft rupture. 15 The main disadvantage of PET ligament is the hydrophobic property.…”