Test-retest reliability of knee rating scales and functional hop tests one year following anterior cruciate ligament reconstruction

Objectives: The aim of this study was to examine the test-retest reliability of the Cincinnati Knee Rating System and analogue scale, and four hop tests in subjects following anterior cruciate ligament (ACL) reconstruction, and to describe knee function one year following surgery. Design: Within-subject quasi-experimental design for test-retest reliability. Setting: A university rehabilitation laboratory. Participants: Nineteen subjects presenting at 12 months post ACL reconstruction were recruited from two orthopaedic surgeons. Main outcome measures: Knee rating scores, raw performance scores for the 6 m timed hop, cross over hop, stair hop and vertical hop, and hop test limb symmetry indices (LSI) were compared on two testing occasions, performed one week apart. Results: Intraclass correlation coefficients (ICC) indicated high test-retest reliability for all measured parameters (0.81-0.98). No significant difference between test occasions was observed for the knee rating scales and vertical hop raw scores. Significant differences were noted for raw scores in the remaining hop tests (P < 0.01). The LSI scores for all hop tests were not significantly different between the two occasions. Mean values ranged from 88.8% to 96.6%. Conclusions: The knee rating scales and functional hop tests showed high test-retest reliability in an ACL-reconstructed population, supporting their use for evaluating this specific patient group over different sessions. Reconstructed limb functional performances were within normal limb symmetry values one year following surgery. (C) 2002 Harcourt Publishers Ltd.