[Clinical multicenter investigation and analysis of the adverse events after primary anterior cruciate ligament reconstruction using the ligament advanced reinforcement system].

Objective: To investigate the postoperative adverse events after primary anterior cruciate ligament reconstruction (ACLR) using the ligament advanced reinforcement system (LARS) for establishing grounds to standardize the clinical use of artificial ligaments. Methods: The China Artificial Ligament Study Group (CALSG) was organized to follow up the cases of ACLR using the LARS(LARS-ACLR) at 20 orthopedic sports medicine centers in China between July 1, 2004 and December 31, 2010. Adverse events, including cumulative failures and complications, were identified through follow-up study and case screening. The cumulative failure was classified as graft rupture and clinical failure, with graft rupture confirmed by arthroscopy and clinical failure confirmed by either limited knee range of motion (>5° in extension and/or >15° in flexion, contralateral knee as control) or joint laxity (Lachman test ≥Ⅱ, pivot shift test ≥Ⅱ, side-to-side difference>5 mm). The demographic information and clinical data of cumulative failure cases were collected, and the cumulative failure rate, the complication rate, the composition ratio of different degrees of joint symptoms among cumulative failure cases, and the composition ratio of failure causes were statistically analyzed. Results: A total of 1 705 cases of LARS-ACLR were collected at 20 centers, of which 1 393 met the inclusion criteria of the study. Of the included cases, 1 146 completed the follow-up, with a follow-up rate of 83.3% (1 146/1 393) and a median follow-up time [M (Q1, Q3)] of 87.1 (68.2, 116.0) months. Ninety-eight adverse events were identified, including 51 cumulative failures and 47 complications, with a cumulative failure rate of 4.5% (51/1 146) and a complication rate of 4.1% (47/1 146). The median cumulative failure time [M (Q1, Q3)] was 12 (7, 24) months after surgery, with 44 patients (86.3%, 44/51) presenting with joint instability, 39 patients (76.5%, 39/51) with joint pain, 31 patients (60.8%, 31/51) with joint swelling, 25 patients (49.0%, 25/51) feeling knee catching and locking, 10 patients with flexion restriction greater than 15° (19.6%, 10/51), and 1 patients with extension restriction greater than 10° (2.0%, 1/51). The incorrect bone tunnel position were confirmed in 32 patients (62.7%, 32/51) and reinjury in 25 patients (49.0%, 25/51). The graft rupture was confirmed under arthroscopy in 21 patients (41.2%, 21/51) and screw loosening occurred in 8 patients(15.7%, 8/51). Complications were detected in 47 patients, with screw-related problems confirmed in 20 patients (1.7%, 20/1 146), synovitis in 18 patients (1.6%, 18/1 146), stiffness in 6 patients (0.5%, 6/1 146), and infection in 3 patients (0.3%, 3/1 146). Conclusions: The long-term cumulative failure rate is 4.5% and the complication rate is 4.1% after LARS-ACLR. Joint instability and pain are the main joint symptoms in cumulative failure cases of LARS-ACLR. Incorrect bone tunnel positioning is the primary cause of failure and should be of great concern to clinicians.