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Weightbearing conventional radiographs provide limited, sectorized, and biased information regarding the complex and 3-dimensional nature of hallux valgus (HV) deformity, leading to potential misinterpretation and poor understanding.
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Cone beam weightbearing computed tomography (WBCT) allows multiplanar 3-dimensional standing weightbearing imaging and a detailed evaluation of HV deformity.
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WBCT allowed demonstration that the hypermobility of the first tarsometatarsal (TMT) joint occurs not only in
Use of Advanced Weightbearing Imaging in Evaluation of Hallux Valgus
Section snippets
Key points
Hallux Valgus Angle
HV angle describes the amount of transverse plane valgus deviation of the proximal phalanx (PP) of the first toe over the head of the first metatarsal (M1), measured on AP views of weightbearing conventional radiographs (Fig. 1). Represented by the angle between the axis of the M1 and the PP of the first toe, it is considered normal if less than 15° of valgus angulation.5 It takes part of the staging system of the severity of the pathology in mild, moderate, and severe deformities. It is
Limitations of conventional radiographs and the rise of 3-dimensional multiplanar weightbearing imaging
Even though conventional radiographs have proven since x-rays were discovered by Wilhelm Conrad Roentgen in 1895, the 2-dimensional nature of this imaging modality in the characterization of complex 3-dimensional deformities is insufficient. Conventional radiographs provide sectorized and limited information of the HV deformity in the different planes, with well-known limitations regarding superimposition of structures, image magnification, x-ray source and patient positioning misalignment, and
Weightbearing cone beam computed tomography and hallux valgus deformity
Collan and colleagues54 were the first to report on the use of standing CB WBCT in the assessment of HV patients. They evaluated 10 patients with HV deformity and 5 controls. Patients underwent resting NWB and standing WB CBCT. They measured 2-dimensional and 3-dimensional HVA and IMA, as well as the rotational status of the M1 and PP of the first toe, using coronal plane images. They found that, when compared with controls, patients with HV deformity demonstrated significantly increased HVA
Weightbearing computed tomography artificial intelligence and automatic measurements: the next step
The recently published literature demonstrates that WBCT measurements provide a complete analysis of all 3-dimensional components of the HV deformity. However, the amount of data acquired during the examination is vast and can represent a burden, needing a critical amount of time and effort for adequate interpretation. The more accurate 3-dimensional measurements usually include the need for a manual or semiautomatic segmentation of each tarsal bone involved in the measure, using different
Summary and future perspectives
The pieces of evidence in the orthopedic literature supporting the use of CB WBCT imaging in the assessment of different complex deformities of the foot and ankle has been growing consistently.44, 45, 46, 47,59, 60, 61, 62, 63 It is the author’s opinion that standing CB WBCT will soon represent the gold standard imaging evaluation of foot and ankle pathologies, replacing WBCR. It is clear that the WBCR assessment of multiplanar pathologies is limited by multiple biases related to acquisition
Disclosure
Dr C. de Cesar Netto reports paid consultancy and share options for CurveBeam LLC, as well as paid consultancy for Ossio LTD. Dr C. de Cesar Netto is also a board member of the International Weight-Bearing CT Society. Dr M. Richter reports paid consultancy for CurveBeam LLC, Ossio LTD, Geistlich, and Intercus. He is also proprietor of R-Innovation and the current president of the International Weight-Bearing CT Society.
References (67)
- et al.
A radiographic analysis of the contribution of hallux valgus interphalangeus to the total valgus deformity of the hallux
Foot Ankle Surg
(2017) Hallux valgus: a review of etiologic factors
Orthop Clin North Am
(1974)- et al.
PedCAT for 3D-imaging in standing position allows for more accurate bone position (angle) measurement than radiographs or CT
Foot Ankle Surg
(2014) - et al.
Influence of lower limb rotation on hindfoot alignment using a conventional two-dimensional radiographic technique
Foot Ankle Surg
(2017) - et al.
Combination of pedCAT(R) for 3D imaging in standing position with pedography shows no statistical correlation of bone position with force/pressure distribution
J Foot Ankle Surg
(2016) - et al.
Evaluation of peritalar subluxation in adult acquired flatfoot deformity using computed tomography and weightbearing multiplanar imaging
Foot Ankle Surg
(2018) - et al.
Weightbearing CT in normal hindfoot alignment - Presence of a constitutional valgus?
Foot Ankle Surg
(2018) - et al.
Influence of investigator experience on reliability of adult acquired flatfoot deformity measurements using weightbearing computed tomography
Foot Ankle Surg
(2019) - et al.
The biomechanics of the first metatarsal bone in hallux valgus: a preliminary study utilizing a weight bearing extremity CT
Foot Ankle Surg
(2013) - et al.
Evaluation of the 1st metatarso-sesamoid joint using standing CT - The Stanmore classification
Foot Ankle Surg
(2018)
Analysis of surface-to-surface distance mapping during three-dimensional motion at the ankle and subtalar joints
J Biomech
First ray instability in hallux valgus deformity: a radiokinematic and pedobarographic analysis
Foot Ankle Int
Manual examination technique to assess dorsal instability of the first ray
Foot Ankle Int
The pathogenesis of hallux valgus
J Bone Joint Surg Am
Hallux valgus--etiology, anatomy, treatment and surgical considerations
Clin Orthop Relat Res
Observations on hallux valgus; based on a controlled series
J Bone Joint Surg Br
Goniometric versus computerized angle measurement in assessing hallux valgus
Foot Ankle Int
Metatarsophalangeal and intermetatarsal angle: different values and interpretation of postoperative results dependent on the technique of measurement
Foot Ankle Int
Disorders of the First Metatarsophalangeal Joint
J Am Acad Orthop Surg
Hallux valgus interphalangeus: reliability of radiological assessment
Foot Ankle Surg
Roger A. Mann Award. The reliability of angular measurements in hallux valgus deformities
Foot Ankle Int
The first intermetatarsal angle in hallux valgus: an analysis of measurement reliability and the error involved
Foot Ankle Int
A Chevron-Akin double osteotomy for correction of hallux valgus
Foot Ankle
Validity and reliability of the first distal metatarsal articular angle
Foot Ankle Int
Variation of the distal metatarsal articular angle with axial rotation and inclination of the first metatarsal
Foot Ankle Int
Intra- and inter-observer reliability of the distal metatarsal articular angle in adult hallux valgus
Foot Ankle Int
Comparison of radiographic and anatomic distal metatarsal articular angle in cadaver feet
Foot Ankle Int
Assessing sesamoid subluxation: how good is the AP radiograph?
Foot Ankle Int
Hallux valgus assessment: report of research committee of American Orthopaedic Foot and Ankle Society
Foot Ankle
Effect of metatarsophalangeal joint position on the reliability of the tangential sesamoid view in determining sesamoid position
Foot Ankle Int
Reliability of standard foot radiographic measurements
Foot Ankle Int
New radiographic analysis of sesamoid rotation in hallux valgus: comparison with conventional evaluation methods
Foot Ankle Int
The mechanics of the foot. I. The joints
J Anat
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A New Paradigm in Foot and Ankle Outcomes?: Away From Radiographs and Toward Patient-Centered Outcomes
2024, Clinics in Podiatric Medicine and SurgeryIntra‑ and Interobserver Reliability of Yamaguchi's Method for the Assessment of First Metatarsal Pronation in Hallux Valgus Deformity
2023, Journal of Foot and Ankle SurgeryCitation Excerpt :According to some authors, WBCR provides scant data on the HV deformity in the different planes, with well-known boundaries regarding the overlaying of structures, radiograph source and patient positioning misalignment, and poor evaluation of rotational deformities, among other limitations (34). Recently, WBCT was shown to be a good option for studying complex 3D deformities (34,35). Two comparative studies showed that indirect signs of metatarsal pronation (based on the head round sign) correlate weakly with the α angle measured in WBCT (4).
Pronation on weightbearing radiographs does not correlate with pronation from weightbearing CT scans
2022, Foot and Ankle SurgeryComparison between Weightbearing-CT semiautomatic and manual measurements in Hallux Valgus
2022, Foot and Ankle SurgeryCitation Excerpt :A possible explanation for this, according to the authors, is that the third dimension might impact how the bone axes are reconstructed, potentially affecting absolute measurements and possibly explaining differences between 3D and 2D measurements. These studies and others [5,37,39,43] confirmed that the semi-automatic 3D measurements used in the WBCT are reliable for measuring angles, and their datasets showed excellent intra- and inter-observer reliability for evaluating pathologies of forefoot and hindfoot. As well as other studies that proposed to dissect this theme, our study has some limitations: First, it was a retrospective study.
Relationship Between Plantar Callosity and Foot Deformity in Hallux Valgus Using Weightbearing Computed Tomography
2021, Journal of Foot and Ankle SurgeryIs Advanced Imaging a Must in the Assessment of Progressive Collapsing Foot Deformity?
2021, Foot and Ankle ClinicsCitation Excerpt :It is technologically a conventional, low-dose imaging (it is a radiographic beam source that revolves around an object) that is paving the way for advanced computer sciences techniques, such as deep learning and artificial intelligence. de Cesar Netto and Richter3 did use the term "advanced" with weight-bearing imaging in a recent publication reporting the use of cone-beam WBCT in hallux valgus in a historic publication reporting the first ever fully automatic 3-dimensional (3D) measurement (of the M1-M2 angle). Advanced imaging is sometimes criticized for being costly, time-consuming, and unnecessary4; however, this is more generally true of any new technology before it becomes mainstream.