Serial assessments to determine normalization of gait following anterior cruciate ligament reconstruction

Abstract

There is an increased emphasis to identify clinically applicable methods that quantify gait deficits following anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to perform serial gait assessments in a clinical setting to determine whether and when clinical gait parameters normalize in patients following ACLR. The hypothesis was that a clinically available gait treadmill would quantify gait deficits measured at 4 weeks post-reconstruction. The secondary hypothesis was that patients would demonstrate incremental improvements in these gait parameters measured at each interval up to 12 weeks post-reconstruction, and that the objectively measured improvements would correlate to the patient's subjective rating of function. Fifteen subjects, five male and 10 female, who had initial unilateral anterior cruciate ligament injury were selected for this study on the basis of operative data. All subjects were evaluated in a physical therapy clinic within 3 days following ACLR and were enrolled in a standardized rehabilitation program. The dependent gait variables of step length, stance time and gait velocity were measured at 4, 6, 8 and 12 weeks post-ACLR on a commercially available gait treadmill. A 2 x 4 multivariate analysis of variance (2 within factors) with measures for limb involvement (uninvolved and involved) and repeated measures for time (4, 6, 8 and 12 weeks) was used to assess the interactions and the main effects on the gait variables of stance time and step length. The results of this study supported the hypothesis that gait deficits and serial improvements can be objectively quantified in a clinical setting (P<0.001). Specifically, stance time, step length and gait velocity deficits evaluated at 4 weeks showed significant improvements at the measured intervals. Step length normalized at week 8. Stance time and gait velocity reached normal levels at the 12-week time interval. Subjective activity of daily living scores (ADLS) also improved following the 12-week rehabilitation, from 53+/-17% to a mean score of 88+/-11% (P<0.001). ADLS scores significantly correlated to step length (R=0.63) and stance time (R=0.53) in the involved limb. Self-selected gait velocity also correlated to ADLS scores and significantly predicted 49% of the variance in the subjective outcome measure. A clinically available gait treadmill can be used to quantify gait deficits and improvements following ACLR. Serial assessments of walking gait may aid clinicians to identify and target deficits in their patients during rehabilitation.