Ligament Advanced Reinforcement System (LARS) synthetic graft for complex ligament reconstruction after chronic elbow instability: a randomized controlled trial

Objective: To compare the clinical effectiveness, safety, and cost-effectiveness of the Ligament Advanced Reinforcement System (LARS) synthetic ligament versus autologous tendon graft reconstruction for chronic complex elbow instability (CEI) using the box-loop technique. Design: Single-center, parallel-group randomized controlled trial (RCT). Patients: A total of 193 adult patients with CEI were enrolled from a tertiary orthopedic hospital between September 2019 and October 2023. Patients were randomized into an artificial group (LARS graft, N = 99) and an autograft group (autologous palmaris longus tendon graft, N = 94). Methods: Participants underwent elbow ligament reconstruction using the box-loop surgical technique. The artificial group received LARS synthetic ligaments, while the autograft group received autologous tendon grafts. Outcomes were assessed preoperatively and at 4, 12, and 24 weeks post-surgery. The primary outcome measure was the American Shoulder and Elbow Surgeons (ASES) Elbow Function Subscore at 24 weeks. Secondary outcomes included ASES pain subscores, Disabilities of the Arm, Shoulder and Hand (DASH) scores, elbow range-of-motion (ROM), flexion strength, and quality-of-life measures (EQ-5D-5 L). Cost-effectiveness analysis was conducted. Adverse events were systematically recorded. Results: At 24 weeks, the artificial (LARS) group demonstrated significantly superior ASES Function scores compared to the autograft group (mean difference: 1.242 points, 95% CI: 0.217–2.268, p = 0.018). The artificial group also showed significantly better pain relief at all measured time points (24 weeks: mean difference: -1.532 points, 95% CI: -2.491 to -0.573, p = 0.002) and isometric and dynamic elbow flexion strength improvements. Sensitivity analyses using intention-to-treat confirmed these findings. Total costs per patient were higher for the LARS group (97,234.12 CNY vs. 79,050.79 CNY, p<0.001), predominantly due to higher medication costs. Incremental cost-effectiveness ratios favored the LARS graft for functional and pain outcomes. Adverse events occurred in 28.3% (LARS) and 39.4% (autograft), with serious adverse events similarly rare (2% in both groups). Conclusion: LARS synthetic ligament reconstruction provided superior short-term functional outcomes and pain relief compared to autologous tendon graft reconstruction in patients with chronic complex elbow instability. While initial costs were higher, LARS significantly reduced donor-site morbidity and facilitated earlier recovery. Longer-term follow-up studies are necessary to establish the sustained efficacy and durability of LARS ligament reconstructions.