Foot Alignment in Symptomatic National Basketball Association Players Using Weightbearing Cone Beam Computed Tomography

Abstract

Background: Weightbearing cone beam computed tomography (WB CBCT) allows detailed 3-dimensional imaging of the foot and ankle in a weightbearing state and provides improved accuracy and reliability of foot alignment measures, especially when compared with conventional radiographic views. Purpose: To describe the foot alignment in National Basketball Association (NBA) players with different symptomatic foot and ankle injuries using WB CBCT and to determine if any predominant morphotype would be identified. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 45 active NBA players (mean age, 24.4 years [range, 20-34 years]; N = 54 feet [29 right, 25 left]) were assessed using WB CBCT. Measurements included the following: (1) foot and ankle offset (FAO), (2) calcaneal offset (CO), (3) hindfoot alignment angle (HAA), (4) angle between the inferior and superior facets of the talus (Inftal-Suptal), (5) angle between the inferior facet of the talus and the horizontal floor line (Inftal-Hor), (6) forefoot arch angle (FAA), (7) navicular-to-floor distance, and (8) medial cuneiform–to-floor distance. Measurements were then compared with values available in the literature for a “normal” foot morphotype. Results: Among the 54 feet, the mean FAO was 0.48% (95% CI, –0.25% to 1.21%), the mean CO was 1.18 mm (95% CI, –0.50 to 2.87 mm), and the mean HAA was 1.42° (95% CI, –0.80° to 3.65°). The mean Inftal-Suptal angle was 5.31° (95% CI, 3.50°-7.12°), while the mean Inftal-Hor angle was 4.04° (95% CI, 2.56°-5.51°). The mean FAA was 15.84° (95% CI, 14.73°-16.92°), the mean navicular-to-floor distance was 38.30 mm (95% CI, 36.19-40.42 mm), and the mean medial cuneiform–to-floor distance was 26.79 mm (95% CI, 25.30-28.28 mm). None of these values were found to be significantly different when comparing forwards, guards, and centers. Conclusion: NBA players presenting with symptomatic foot and ankle injuries had a fairly “normal” foot morphology, with a tendency toward a varus hindfoot and a high-arched morphotype. No significant differences were found between players based on their position on the court. WB CBCT may help to shed light on anatomic risk factors for common injuries in professional players and may aid in the planning of specific prevention programs.