8/13/2023 0 Comments Marta dubois feet soles![]() ![]() A laser-assisted measure has been recently proposed 36, but this is still based on a qualitative observation of the external aspect of the back of the ankle. Classical assessments in this condition were based on standard goniometers 32, 33, but this was shown to be unreliable 34, frequently underestimating the valgus deformity when compared to radiographical assessments 35. ![]() in single- or double-leg upright posture 25. HAA should be measured in weight-bearing, i.e. HAA, also called the varus/valgus of the calcaneus or the heel valgus or the hindfoot coronal alignment, has been largely used to characterize deformities flatfoot patients. 3D measurements of hindfoot alignments in weight-bearing added considerably to standard clinical evaluations 28 and showed that traditional bi-dimensional measurements from radiographs significantly underestimated the severity of the flatfoot deformity 29– 31. Another advantage of the CBCT-based analyses is the weight-bearing condition, as demonstrated recently in flatfoot patients 14. 3D measurements from CBCT are no longer affected by manual digitisation and confounding projections associated with foot malposition or severe deformities. This finally overcomes the traditional bi-dimensional angular measurements from radiographs 6, 26 and enables more comprehensive representations of foot bone alignments in 3D 6, 8, 9. Bone alignments and orientation angles are calculated by reference frames or anatomical axes embedded into these 3D bone models. segmentation 27, in the final format of digital mesh. Starting from CBCT scans, quantitative analysis of the foot’s overall skeletal geometry requires 3D reconstruction of the bone external shape, i.e. CBCT scans are proving to be very valuable in many different clinical contexts 1, 5, 7, 12, 14– 18, 21– 23, 25, 26, but the assessment of hindfoot alignment angle (HAA) in severely deformed feet can be among the areas of most considerable benefit. These modern devices provide valuable 3D scans of the foot and ankle with subjects in one- or two-leg stance 15– 19, with low radiation doses, high spatial resolution, convenient ergonomy and suitable post-processing 7, 20– 24. Nowadays, 3D scans of the foot in weight-bearing conditions are possible using the cone beam technology (CBCT) 7, 14. Unfortunately, simple foot bone alignments in weight-bearing are usually assessed based on X-ray pictures with the subject in upright postures 6, 12, thus missing essential 3D observations and suffering of bones’ superimposition and reproducibility, particularly for the analysis of the subtalar joint 13. In support to the standard clinical assessments 1, 5, accurate measurements on foot bones should be established 6– 11 to evaluate the severity of the deformities, to plan for possible correction procedures and to assess the outcomes. It is recommended to be aware of the anatomical and functional concepts behind these techniques before clinical and surgical conclusions.Īcquired adult flatfoot, more recently defined as ‘progressive collapsing foot deformity’ 1, implies multiple, complex and combined three-dimensional (3D) deformities, including flattening of the medial longitudinal arch, abduction of the forefoot and, in particular, valgus of the hindfoot 1– 4. Measurements from the different available techniques do not compare well, as they are based on very different approaches. CBCT finally allows 3D assessment of foot deformities in weight-bearing. The assessment of the pre-operative valgus deformity and of the corresponding post-operative correction varied considerably. Most of them were very different from the traditional clinical measures. According to these techniques, and starting from a careful 3D reconstruction of the relevant foot skeletal structures, a large spectrum of measurements was found to represent the same hindfoot alignment angle. ![]() Standard clinical measurements by goniometers were taken for comparison. the inclination of the hindfoot in the frontal plane of the shank. Six different techniques from the literature were used to calculate the varus/valgus deformity, i.e. Corresponding 3D shape of each bone of the distal shank and hindfoot were defined (Materialise, Belgium). Ten patients with severe acquired adult flatfoot and indication for surgery underwent CBCT scans (Carestream, USA) while standing on that leg, before and after surgical correction. This study aims to analyze and to compare these measurements from CBCT scans in a real clinical population with large such deformity. Among the most common skeletal deformities, the varus/valgus of the hindfoot is the most complex to be represented, and a number of measure proposals have been published. Cone-beam CT (CBCT) scans now enable accurate measurements on foot skeletal structures with the advantage of observing these in 3D and in weight-bearing. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |