Primary ACL reconstruction using the LARS device is associated with a high failure rate at minimum of 6-year follow-up

Abstract

PurposeThe Ligament Augmentation and Reconstruction System (LARS®) is a synthetic ligament consisting of fibres made of polyethylene terephthalate. Despite the LARS being used as an anterior cruciate ligament (ACL) device for nearly 30 years and the well‐documented complications from earlier synthetic ligament designs, there is a paucity of published medium‐ to long‐term results. The aim of this study is to report the clinical and functional outcomes after ACL reconstruction using the LARS at a minimum follow‐up of 6 years. MethodsResults of a single surgeon’s entire cohort of 55 patients who underwent primary LARS ACL surgery were reviewed at a median of 7.8 years (6.0–9.4). Patient‐reported outcome measures including the International Knee Documentation Committee (IKDC) score and 36‐Item Short Form Health Survey (SF‐36) were collected and clinical assessment consisted of range of motion (ROM) and the KT‐1000 arthrometer to assess the side–side difference in the operative and non‐operative knee. Mechanical failures of the graft were confirmed at revision surgery and a survivorship analysis was performed using the Kaplan–Meier method. ResultsThe overall mechanical failure rate was 17/51 (33.3%) with ruptures occurring at a median 3.9 years (0.6–8.8 years) following primary LARS ACL surgery. Secondary operative procedures were performed in 39.2% of patients. For intact grafts, there was no statistically significant difference is side‐to‐side ROM or anterior knee laxity and subjective scores revealed a median IKDC subjective score of 85.1 (26.4–100) and SF‐36 physical component score of 94.1. ConclusionThe rates of LARS ACL construct failure (33.3%) in this cohort are high and based on these results the LARS should not be considered as a graft option for primary ACL reconstruction. Level of evidenceIII, cohort study.

Long-term outcomes of surgery using the Ligament Advanced Reinforcement System as treatment for anterior cruciate ligament tears

“…43 At latest functional follow-up, all norm-based SF-36 items were at or above the general population-based comparator, in the present study cohort. At the same interval, overall median IKDC was 89.7 points, being comparable to the median 85.1 IKDC points observed by Tulloch et al, 29 and higher than the mean 76.6 points observed by Tiefenboeck et al 26 Similar to the study by Tiefenboeck et al, 26 we likewise observed significantly poorer IKDC scores in patients with any previous complications, indicating that outcome is impaired by sequelae of screw loosening, graft failure, and synovitis in the long term. Of note, our observed overall discrepancy in subjective and objective outcome has already been observed by Ventura et al 40 for three different, polyethylene terephthalatebased synthetic ACL devices (i.e.…”

“…Median symptom duration prior to surgery in our study was 12 days. One further report with a comparable delay of less than two weeks has been published thus far, 26 while most studies reported on symptoms lasting for several months 1,[27][28][29] to over one year 30 until ACL reconstruction with the LARS device.…”

Acceleration of ligamentization and osseointegration processes after anterior cruciate ligament reconstruction with autologous tissue-engineered polyethylene terephthalate graft

“…It consists of fibers made of polyethylene terephthalate (PET) (7). Despite the advantages of high tensile strength for rapid return to sports and early rehabilitation postoperatively, LARS leads to a relatively high rate of graft failure in the medium-and long-term follow-up (8). Recently, studies showed that the failure rate of ACL reconstruction with LARS was 33.3% at a mean follow-up of 3.9 years and 31% at a mean follow-up of 9.5 years (8,9).…”

“…There are also mechanical factors, including inadequate fiber abrasion resistance or flexural and rotational fatigue (10). In addition, biological factors, such as foreign body synovitis or poor biological integration, may account for the high failure rates (8). Among these reasons, poor biological integration in the bone tunnels and articular cavity is thought to be the primary issue (11).…”

Differences in artificial ligament graft osseointegration of the anterior cruciate ligament in a sheep model: a comparison between interference screw and cortical suspensory fixation

“…Synthetic ligaments have emerged as substitute materials for allografts or autografts in surgical anterior cruciate ligament reconstruction (ACLR). The benefits of synthetic ligaments are the elimination of donor-site morbidity and postoperative early rehabilitation (1)(2)(3)(4). Most clinical studies have demonstrated satisfying long-term outcomes after ACLR using synthetic grafts (5)(6)(7)(8).…”