Kengo Harato1, Aiko Sakurai2, Yutaka Kudo2, Takeo Nagura3, Ko Masumoto4, Toshiro Otani5, Yasuo Niki6. 1. Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan. Electronic address: kharatoh@yahoo.co.jp. 2. Department of Physical Therapy, International University of Health and Welfare, Mita Hospital, Tokyo, Japan. 3. Department of Clinical Biomechanics, Keio University School of Medicine, Tokyo, Japan. 4. Masumoto Sports Clinic, Tokyo, Japan. 5. Faculty of Nursing and Medical Care, Keio University, Tokyo, Japan. 6. Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan.
Abstract
BACKGROUND: To date, the knee kinematics of a discoid lateral meniscus (DLM) has not been elucidated. The aim was to investigate the three-dimensional knee kinematics in knees with a DLM using gait analysis. METHODS: Ten patients (mean: 14years) diagnosed with bilateral DLM and unilaterally symptomatic snapping as well as 10 healthy controls (mean: 23years) participated in the study. Each patient with a DLM had unilaterally snapping knee in full extension and deep flexion. The three-dimensional gait analysis was performed with the point cluster technique. All subjects were asked to walk on a level floor at the speed of their choice. In the sagittal plane, knee excursion was separately evaluated during the weight acceptance phase and the mid-stance phase. In the axial plane, knee excursion during the stance phase was assessed. Finally, knee excursion during the whole gait cycle was evaluated in the frontal plane. Statistical comparison was conducted between groups, and between both sides in the DLM group. RESULTS: In the sagittal plane, knee excursions during the weight acceptance phase and the mid-stance phase were significantly smaller in the DLM group than in the control group; in addition, these were smaller on the symptomatic side than on the asymptomatic side in the DLM group. In the axial plane, knee excursion was also significantly smaller on the symptomatic side than on the asymptomatic side in the DLM group, whereas the frontal knee motion did not differ significantly. CONCLUSION: Less knee motion in the sagittal plane may prevent snapping during extension and flexion in patients with a DLM. LEVEL OF EVIDENCE: III.
BACKGROUND: To date, the knee kinematics of a discoid lateral meniscus (DLM) has not been elucidated. The aim was to investigate the three-dimensional knee kinematics in knees with a DLM using gait analysis. METHODS: Ten patients (mean: 14years) diagnosed with bilateral DLM and unilaterally symptomatic snapping as well as 10 healthy controls (mean: 23years) participated in the study. Each patient with a DLM had unilaterally snapping knee in full extension and deep flexion. The three-dimensional gait analysis was performed with the point cluster technique. All subjects were asked to walk on a level floor at the speed of their choice. In the sagittal plane, knee excursion was separately evaluated during the weight acceptance phase and the mid-stance phase. In the axial plane, knee excursion during the stance phase was assessed. Finally, knee excursion during the whole gait cycle was evaluated in the frontal plane. Statistical comparison was conducted between groups, and between both sides in the DLM group. RESULTS: In the sagittal plane, knee excursions during the weight acceptance phase and the mid-stance phase were significantly smaller in the DLM group than in the control group; in addition, these were smaller on the symptomatic side than on the asymptomatic side in the DLM group. In the axial plane, knee excursion was also significantly smaller on the symptomatic side than on the asymptomatic side in the DLM group, whereas the frontal knee motion did not differ significantly. CONCLUSION: Less knee motion in the sagittal plane may prevent snapping during extension and flexion in patients with a DLM. LEVEL OF EVIDENCE: III.