Keisuke Uemura1, Penny R Atkins2, Niccolo M Fiorentino3, Andrew E Anderson4. 1. Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT, 84108, USA. Electronic address: keisuke.uemura@utah.edu. 2. Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT, 84108, USA; Department of Bioengineering, University of Utah, James LeVoy Sorenson Molecular Biotechnology Building, 36 S. Wasatch Drive, Rm. 3100, Salt Lake City, UT 84112 USA. Electronic address: penny.atkins@utah.edu. 3. Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT, 84108, USA; Mechanical Engineering Department, University of Vermont, 33 Colchester Ave, Votey Hall 201A, Burlington, VT 05405, USA. Electronic address: niccolo.fiorentino@uvm.edu. 4. Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT, 84108, USA; Department of Bioengineering, University of Utah, James LeVoy Sorenson Molecular Biotechnology Building, 36 S. Wasatch Drive, Rm. 3100, Salt Lake City, UT 84112 USA; Department of Physical Therapy, University of Utah, 520 Wakara Way, Suite 240, Salt Lake City, UT 84108, USA; Scientific Computing and Imaging Institute, 72 S Central Campus Drive, Room 3750, Salt Lake City, UT 84112, USA. Electronic address: andrew.anderson@hsc.utah.edu.
Abstract
BACKGROUND: Individuals are thought to compensate for femoral anteversion by altering hip rotation. However, the relationship between hip rotation in a neutral position (i.e. static rotation) and dynamic hip rotation is poorly understood, as is the relationship between anteversion and hip rotation. RESEARCH OBJECTIVE: Herein, anteversion and in-vivo hip rotation during standing, walking, and pivoting were measured in eleven asymptomatic, morphologically normal, young adults using three-dimensional computed tomography models and dual fluoroscopy. METHODS: Using correlation analyses, we: 1) determined the relationship between hip rotation in the static position to that measured during dynamic activities, and 2) evaluated the association between femoral anteversion and hip rotation during dynamic activities. Hip rotation was calculated while standing (static-rotation), throughout gait, as a mean during gait (mean gait rotation), and as a mean (mid-pivot rotation), maximum (max-rotation) and minimum (min-rotation) during pivoting. RESULTS: Static-rotation (mean ± standard deviation; 11.3° ± 7.3°) and mean gait rotation (7.8° ± 4.7°) were positively correlated (r = 0.679, p = 0.022). Likewise, static-rotation was strongly correlated with mid-pivot rotation (r = 0.837, p = 0.001), max-rotation (r = 0.754, p = 0.007), and min-rotation (r = 0.835, p = 0.001). Strong positive correlations were found between anteversion and hip internal rotation during all of the stance phase (0-60% gait) and during mid- and terminal-swing (86-100% gait) (all r > 0.607, p < 0.05). CONCLUSIONS: Our results suggest that the static position may be used cautiously to express the neutral rotational position of the femur for dynamic movements. Further, our results indicate that femoral anteversion is compensated for by altering hip rotation. As such, both anteversion and hip rotation may be important to consider when diagnosing hip pathology and planning for surgical procedures.
BACKGROUND: Individuals are thought to compensate for femoral anteversion by altering hip rotation. However, the relationship between hip rotation in a neutral position (i.e. static rotation) and dynamic hip rotation is poorly understood, as is the relationship between anteversion and hip rotation. RESEARCH OBJECTIVE: Herein, anteversion and in-vivo hip rotation during standing, walking, and pivoting were measured in eleven asymptomatic, morphologically normal, young adults using three-dimensional computed tomography models and dual fluoroscopy. METHODS: Using correlation analyses, we: 1) determined the relationship between hip rotation in the static position to that measured during dynamic activities, and 2) evaluated the association between femoral anteversion and hip rotation during dynamic activities. Hip rotation was calculated while standing (static-rotation), throughout gait, as a mean during gait (mean gait rotation), and as a mean (mid-pivot rotation), maximum (max-rotation) and minimum (min-rotation) during pivoting. RESULTS:Static-rotation (mean ± standard deviation; 11.3° ± 7.3°) and mean gait rotation (7.8° ± 4.7°) were positively correlated (r = 0.679, p = 0.022). Likewise, static-rotation was strongly correlated with mid-pivot rotation (r = 0.837, p = 0.001), max-rotation (r = 0.754, p = 0.007), and min-rotation (r = 0.835, p = 0.001). Strong positive correlations were found between anteversion and hip internal rotation during all of the stance phase (0-60% gait) and during mid- and terminal-swing (86-100% gait) (all r > 0.607, p < 0.05). CONCLUSIONS: Our results suggest that the static position may be used cautiously to express the neutral rotational position of the femur for dynamic movements. Further, our results indicate that femoral anteversion is compensated for by altering hip rotation. As such, both anteversion and hip rotation may be important to consider when diagnosing hip pathology and planning for surgical procedures.