Tracking Patient Outcomes after Anterior Cruciate Ligament Reconstruction

Purpose: To model how patients' knee range of motion (ROM), pain, and self-reported lower-extremity (LE) functional status change over the first 26 weeks following anterior cruciate ligament (ACL) reconstruction and to estimate the test-retest reliability of these measurements. Methods: Patients were assessed weekly over 26 weeks following ACL reconstruction. Outcomes were knee ROM, LE functional status measured by the Lower Extremity Functional Scale (LEFS), and pain measured by the 4-item pain intensity measure (P4). A nonlinear model was applied to describe change for each outcome. Intra-class correlation coefficients and standard errors of measurement were applied to estimate test-retest reliability and minimal detectable change. Results: A nonlinear model provided the following model fit values (R-2): P4 = 0.71, extension ROM = 0.51, flexion ROM = 0.99, LEFS = 0.97. For pain and ROM, the limit values were reached by approximately 12 weeks after reconstruction; LEFS values continued to increase up to 26 weeks. Test-retest reliability coefficients varied from 0.85 to 0.95. Conclusions: The greatest improvement occurred in the first 8 weeks after surgery. Recovery was nearly complete by 12 weeks with respect to pain and ROM, although LE functional status continued to improve throughout the study period. Scores on all measures demonstrated reliability, which supports their use with individual patients.