Self-reported outcomes are associated with knee strength and functional symmetry in individuals who have undergone anterior cruciate ligament reconstruction with hamstring tendon autograft

Abstract

Background: The aim of this study was to investigate the relationship between self-reported knee outcomes and limb symmetry indices (LSIs) for hip and knee strength, postural control and single leg hop distance in individuals who had undergone an ACL reconstruction with hamstring tendon autograft (HTG).
Methods: A total of 72 participants with a history of unilateral ACL reconstruction with HTG (Mean ± SD age, 28.0 ± 7.6 years; height, 178.4 ± 6.7 cm; mass, 76.9 ± 14.9 kg) were included. IKDC, Lysholm, KOOS and TAMPA scores were used to evaluate self-reported outcomes. Concentric and eccentric knee extensor and flexor strength, and hip abductor strength were measured with an isokinetic dynamometer. Postural control was assessed using the modified star excursion balance test and hop performance using the single leg hop test. The relationships between the LSI scores and the performance measures were explored using the Pearson correlation coefficient.
Results: The IKDC, Lysholm and KOOS scores were positively correlated with knee extensor and flexor strength LSIs (p<0.05, r=0.34 to r=0.50), and the TAMPA score was negatively correlated with eccentric extensor LSI (p=0.02, r=-0.34). Single leg hop distance LSI was correlated with IKDC and Lysholm scores (p=0.003, r=0.50; p=0.04, r=0.29) respectively, while postural control was only correlated with the KOOS scores (p<0.001, r=0.51 to r=0.52). No correlation was observed between self-reported outcomes and hip abductor strength (p>0.05).
Conclusions: Self-reported scores were correlated with knee extensor and flexor strength, postural control and hop performance in individuals who have undergone ACLR with HTG. Compared to Lysholm and TAMPA scores, KOOS and IKDC scores were more likely to be correlated with performance-based outcomes. Therefore, KOOS
and IKDC scores may help clinicians in RTS decision making when there is a limited time to perform extensive evaluations or access equipment.