Functional Dependence of IM and HV Angle in Hallux Valgus Deformity before and after Operative

Hallux valgus is a relatively common and multifaceted complex deformity of the front part of the foot. It is the result of multiple effects of innate (endogenous) and exogenous etiological factors with different degrees of influence. The degree of hallux valgus deformity is usually assessed by radiological values of hallux valgus (HV) and intermetatarsal (IM) angles. The aim of the paper is to justify the definition of hallux valgus deformity as a function of one angle, (HVA or IMA), and then to determine the functional connection and the most suitable function equalizing the values of the angles IMA and HVA. As hallux valgus is a double angulation deformity, the analytically determined connection between the HVA and IMA angles reduces the study of the deformity to the study of function with one argument, and makes the analysis of deformity changes before and after operative treatment simpler. For the determined connections between the angles, the values of linear proportionality coefficients and regression coefficients of corresponding linear functions of analytical equalization of the value of the IM angle and the degree of deformity for a given value of the HV angle were experimentally determined. The obtained results were checked on a sample of 396 operatively treated hallux valgus deformities. The presented analytical approach and the obtained functional links of IMA and HVA enable quantitative observation of the change in the degree of deformity based on the radiologically determined value of these angles, and the established nonlinear function will be useful for evaluating the expected value of the IM angle and the degree of deformity based only on the measured value of the HV angle. .

Classification of Hallux Valgus Using Conjugated Deformity

Hallux valgus is a complex deformity of the forefoot. It is the result of multiple effects of endogenous and exogenous etiological factors with different degrees of influence. The degree of hallux valgus deformity was assessed by radiological values of hallux valgus (HVA) and intermetatarsal (IMA) angle. Thus, each hallux valgus deformity corresponds to a pair (HVA, IMA) of hallux valgus angle (HVA) and intermetatarsal angle (IMA) values in the plane of the deformity. The intensity of the point position vector S (HVA, IMA) in the deformation plane determined by the relation represents the absolute (conjugate) value of the power deformities. The goal of the article is to explain the advantage of the definition of the degree of hallux valgus deformity using its absolute (conjugate) value, and then to show that the degree of deformity defined in this way enables a better classification of deformities for all values of the HVA and IMA angles. Furthermore, in this article, applying the definition of conjugate deformity, analytical expressions were constructed for the assessment of the average value of deformity correction after operative treatment, as well as the error assessment of deformity correction after operative treatment. All obtained results were checked on a sample of 396 operatively treated feet.