Radiographic analysis of lower limb alignment in professional football players

Abstract

Introduction: To radiographically analyze lower limb alignment in adult asymptomatic professional football players and to correlate these values to clinical measurements.

Materials and methods: Twenty-four asymptomatic players [24.2 (3.6) years] were enrolled. Standard bilateral lower limb anteroposterior weight-bearing radiographs were acquired and clinical measurement of intercondylar/intermalleolar (ICD/IMD) distance was performed. Coronal plane mechanical alignment was assessed by five angles: leg mechanical axis (LMA), lateral proximal femoral angle (LPFA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and lateral distal tibial angle (LDTA). Their values were compared to the reference values for adult population. An inter-individual comparison between right/left and dominant/non-dominant leg was added. The sum of bilateral LMA was correlated against ICD/IMD and against ICD/IMD adjusted for body height.

Results: Football players presented with ICD/IMD of 46.5 (19.8) mm. Two, out of five, lower leg coronal angles showed significant differences (p < 0.001) compared to reference data from literature: LMA 5.8 (3.0)º vs.1.2 (2.2)º and MPTA 83.5 (2.6)º vs. 87.2 (1.5)º. No significant differences between left/right leg and dominant/non-dominant leg were established. Summed up bilateral LMA showed a high correlation to IMD/ICD (r = 0.8395; R² = 0.7048), and even higher to ICD/IMD adjusted for body height (r = 0.8543; R² = 0.7298).

Conclusions: This study was radiographically confirming increased varus of elite football players toward general population. Apex of the varus deformity was located in the proximal tibia. Clinical measurement of ICD/IMD adjusted for body height highly correlated with the radiographic values of coronal alignment; therefore, it may be used in population studies.

Keywords: Alignment; Bowlegs; Coronal plane; Deformity; Football; Lower limb; Mechanical axis.