Sagittal plane translation during level walking in poor-functioning and well-functioning patients with anterior cruciate ligament deficiency

Background: Some patients with anterior cruciate ligament deficiency can function well and participate in high-level sports, whereas others have functional limitations even during activities of daily living. Hypothesis: Patients who function well after an anterior cruciate ligament injury can stabilize the knee joint during gait by an anterior positioning of the tibia. Study Design: Controlled laboratory study. Methods: Sagittal tibial translation was registered with the CA-4000 electrogoniometer, during the Lachman test and walking, in 20 patients with a unilateral anterior cruciate ligament injury. Eleven patients functioned well (Lysholm score greater than or equal to84), and 9 patients had poor knee function (Lysholm score <84). Results: During gait, the well-functioning group had 24% greater anterior translation in the injured leg compared to the noninjured leg. In the poor-functioning group, the anterior translation in the injured leg was 16% smaller compared to the noninjured leg (P = .0003). Tibial translation during the Lachman test was similar in the injured leg in the 2 groups. Conclusion: Patients who function well position their tibiae near the anterior border of the joint play. This position may encourage functional stability. Clinical Relevance: Rehabilitation that emphasizes training to stabilize the tibia in an anterior position may improve functional stability of the anterior cruciate ligament-deficient knee.