Evaluation of the Foot Arch in Partial Weightbearing Conditions. (January 2022)

• Record Type: Journal Article
• Authors: Kimura, Tadashi; Thorhauer, Eric D.; Kindig, Matthew W.; Sangeorzan, Bruce J.; Ledoux, William R.
• Is Part Of: Foot & ankle international. Volume 43:Number 1(2022)
• Page Start: 113
• Page End: 122
• Publication Date: 2022-01
• Subjects: weightbearing CT -- plain radiograph -- foot alignment -- arch -- flat foot -- high arched foot; Foot -- Abnormalities -- Periodicals; Ankle -- Abnormalities -- Periodicals; Orthopedics -- Periodicals; 617.585
• DOI: 10.1177/10711007211034804
• Languages: English
• ISSNs: 1071-1007

Abstract

Background: Weightbearing plain radiography or computed tomography (CT) is used for diagnosis or treatment selection in foot disorders. This study compared foot alignment between full weightbearing (50% body weight [BW] per foot) plain radiography and nonweightbearing (0% BW) or partial weightbearing (10% BW per foot) CT scans. Methods: Subjects had both full (50% BW per foot) weightbearing plain radiographs and either a nonweightbearing (0% BW) or a partial weightbearing (20% BW or 10% BW per foot) CT scan. Feet (n = 89) had been previously classified as pes cavus (n = 14/17 [subjects/feet]), neutrally aligned (NA; 20/30), asymptomatic pes planus (APP; 18/24), and symptomatic pes planus (SPP; 15/18). Lateral talometatarsal angle (LTMA) and calcaneal pitch angle were compared between weightbearing radiography and maximum-intensity projection images generated from CT. Results: Significant differences in LTMA were found between nonweightbearing CT scans and full (50% BW per foot) weightbearing plain radiographs: the mean difference was 6.6 degrees in NA, 9.2 degrees in APP, and 11.3 degrees in SPP ( P < .0001); no significant difference in LTMA was found for pes cavus. Although the interaction of foot type ( P = .084) approached statistical significance, pairwise differences between 10% weightbearing and 50% weightbearing images by foot type were significant but small. The 50% weightbearing condition resulted in calcaneal pitch angles the same or slightly lower or higher than those of the 10% weightbearing and nonweightbearing images. LTMA and calcaneal pitch angle measurements made on full (50% BW per foot) weightbearing plain radiographs and non- (0%) or partial (10% BW per foot) weightbearing angles from CT scans were strongly correlated. Conclusion: Different foot types have similar 2-dimensional sagittal plane morphologies with partial weightbearing (10% BW per foot) CT scans and, to a lesser degree, nonweightbearing (0%) neutral-position CT scans when compared to full weightbearing (50% BW per foot) plain radiographs. Level of Evidence: Level III, retrospective case control study.