The Role of Weightbearing Computed Tomography Scan in Hallux Valgus.
Publication/Presentation Date
3-1-2021
Abstract
BACKGROUND: Hyperpronation of the first metatarsal in hallux valgus (HV) is poorly understood by conventional weightbearing radiography. We aimed to evaluate this parameter using weightbearing computed tomography (WBCT) and to understand its association with other standard measurements.
METHODS: Retrospective evaluation of WBCT and weightbearing radiographs (WBXRs) was performed for 20 patients with HV feet and 20 controls with no such deformity. Axial computed tomography images of both groups were compared for the first metatarsal pronation angle (alpha angle) and tibial sesamoid subluxation (TSS) grades. The HV angle (HVA), first-second intermetatarsal angle (IMA), first metatarsal-medial cuneiform angle (MMCA), Meary's angle, and calcaneal pitch (CP) angle of the study and control groups were compared on both WBXR and the corresponding 2-dimensional images of WBCT. All measurements were independently performed by 1 musculoskeletal radiology fellow and 1 foot and ankle surgical fellow. Measurements were averaged and interobserver reliability was calculated.
RESULTS: The HV group demonstrated significantly higher values for TSS grade (
CONCLUSION: The alpha angle, a measure of abnormal hyperpronation of the first metatarsal, was an independent factor that may coexist with other parameters in HV, but in isolation had limited diagnostic utility. "Abnormal" alpha angles were even observed in individuals without HV. Increases in IMA and MMCA were not necessarily associated with similar increases in alpha angle, despite moderate correlations with TSS grade and HVA on WBXR. Nevertheless, the WBCT was a useful method for assessing hyperpronation and guiding surgical management in individual cases.
LEVEL OF EVIDENCE: Level III, retrospective comparative study.
Volume
42
Issue
3
First Page
287
Last Page
293
ISSN
1944-7876
Published In/Presented At
Mahmoud, K., Metikala, S., Mehta, S. D., Fryhofer, G. W., Farber, D. C., & Prat, D. (2021). The Role of Weightbearing Computed Tomography Scan in Hallux Valgus. Foot & ankle international, 42(3), 287–293. https://doi.org/10.1177/1071100720962398
Disciplines
Medicine and Health Sciences
PubMedID
33148045
Department(s)
Department of Surgery
Document Type
Article
