[Development and evaluation of a German version of the Lysholm score for measuring outcome after anterior cruciate ligament injuries]

Abstract

Background: The Lysholm score is a questionnaire that assesses knee function after conservatively or operatively treated anterior cruciate ligament (ACL) injuries. Its original version is in English and consists of eight items (limping, support, locking, instability, pain, swelling, stair-climbing, squatting). The aim of this study was to translate the Lysholm score in the German language, to test discriminative validity and reliability of this German version and, thus, to provide a validated German version of the Lysholm score to be applied in further studies.

Methods: The cross-cultural adaptation to the German language was performed according to recommended guidelines in the literature. Validity and reliability of the German version were tested in two patient groups in the acute (< 3 months post incident/operation; n = 12) and late rehabilitation phase after ACL injury (3 - 12 months post incident/operation, n = 16), respectively as well as in a control group without any knee problems (n = 22). The subjects filled in the questionnaire twice within three days.

Results: With respect to validity, the control group (total score 96.8 ± 5.1 points) differed significantly from the total patient group (p < 0.001) as well as from the patient group in the acute (75.3 ± 16.8 points) (p < 0.001) and the late (82.7 ± 12.8 Punkte) (p < 0.001) rehabilitation phase, respectively. Test-retest reliability of the total Lysholm score was good for the total patient group (intraclass correlation coefficient (ICC) = 0.82) as well as for the patients in the acute (ICC = 0.82) and in the late (ICC = 0.84) rehabilitation phase, respectively. The Cronbachs Alpha was 0.73.

Conclusion: The psychometric properties of the German version of the Lysholm score are comparable to the English version. It is a valid and reliable instrument for the objective assessment of rehabilitation outcome after ACL injury at least in the German speaking part of Switzerland. Based on these first results, its application for further research projects in all German speaking countries is recommended.