Translation, cross-cultural adaptation, and clinimetric properties evaluation of the Danish version of the Anterior Cruciate Ligament - Return to Sport after Injury scale (ACL-RSI)

PURPOSE: To translate and cross-cultural adapt the Anterior Cruciate Ligament-Return To Sport After Injury (ACL-RSI) questionnaire into Danish (ACL-RSI-DK) and evaluate the psychometric properties with the purpose to identify the psychological readiness on returning to sport (RTS).

METHODS: The ACL-RSI-DK followed a six-step translation and cultural-adaptation process. Statistical analysis included correlation for construct validity of the ACL-R-DK with the Lysholm, KOOS and K-SES. Moreover, we assessed reliability using Cronbach's alpha and ICC and used Bland Atman methods to assess bias between test and re-test. An exploratory factor-analysis was used for the dimensionality of ACL-RSI-DK.

RESULTS: 102 Danish individuals (Female 49%, age 27.7 ± 7.3 years), 51.2 (±15.5) weeks post-op from anterior cruciate ligament reconstruction (ACLR) were included. The ACL-RSI-DK showed excellent internal consistency (Cronbach's alpha 0.957) and test-retest reliability (ICC = 0.96), with no floor or ceiling effects. The Bland Atman analysis showed no systematic bias. The mean score was 48 ± 23 out of 100 points. The SEM was calculated to be 5/10 points and the MDC95 was 13/100. The construct validity evaluation presented strong correlation between ACL-RSI-DK, K-SES (ρ = 0.63) and KOOS-Sport (ρ = -0.63), whereas a moderate correlation was found with Lysholm (ρ = 0.48) and KOOS (ρ = -0.58) and its subscales KOOS-Symptoms (ρ = -0.27), KOOS-Pain (ρ = -0.43), KOOS-ADL (ρ = -0.47) and KOOS-QoL (ρ = -0.59. ACL-RSI-DK was found to be an unidimensional scale with a total variance explained of 68.5%.

CONCLUSION: The ACL-RSI was successfully translated and cross-cultural adapted into Danish and displayed good psychometric properties. The ACL-RSI-DK is a valid and reliable tool to investigate the psychological readiness on RTS.