Anterior cruciate ligament reconstruction with six and eight-strand hamstring tendon autografts produces adequate graft dimensions and functional outcomes: A systematic review

Purpose: This study aims to summarize the graft dimensions, failure rates, return-to-sport rates and patient-reported outcome measures (PROMs) following anterior cruciate ligament reconstruction (ACLR) with six or eight-strand hamstring tendon autografts (6SHG or 8SHG). Methods: Three databases were searched from inception to 12 February 2024. The authors adhered to PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. All clinical studies reporting patient demographics, objective clinical outcomes and PROMs following ACLR with 6SHG or 8SHG were included for data synthesis. PROMs included the International Knee Documentation Committee (IKDC), Lysholm and Tegner scores. Results: Thirteen studies comprising 1103 patients were included (mean age: 30.6 years). The transtibial technique was used in all studies, except one study using anatomic ACLR (n = 38), and one study using transtibial and all-inside ACLR (n = 41). Eight studies comprising 512 patients used 6SHG, four studies comprising 507 patients 8SHG and two studies comprising 97 patients used either. Mean graft diameters ranged from 8.0 to 9.2 mm (6SHG) and 9.1 to 9.9 mm (8SHG). Mean graft lengths for 49 6SHG patients ranged from 60.0 to 83.3 mm. The failure rate for 817 patients (6SHG or 8SHG) was 4.8% (0.0%-20.0%). The return-to-sport rate for 112 patients (6SHG or 8SHG) was 75.9% (69.7%-100.0%). Mean IKDC, Lysholm and Tegner scores for 6SHG or 8SHG were 88.4 (86.1-96.3), 91.7 (90.4-96.5) and 6.9 (6.5-7.3), respectively. Conclusions: Both 6SHG and 8SHG produced graft diameters <8 mm. Data regarding PROMs suggested good patient satisfaction based on established criteria. Re-rupture and return-to-sport rates were 4.8% and 75.9%, respectively.