Influence of the shape of the first metatarsal cuneiform joint on the development of hallux valgus deformity.

OBJECTIVE: To examine the presence of certain shapes of the first metatarsal-cuneiform joint (MTC) joint in feet with hallux valgus (HV) deformity. To determine whether the anatomical orientation of this joint affects the size of the hallux valgus angle (HVA) and the first intermetatarsal angle (IMA) and whether it contributes to the dynamics of the developmental course of HV deformity. METHODS: The shape of the first MTC joint was determined on a sample of 315 feet with HV deformity. The influence of the shape of this joint on the values of HVA and IMA was explored. The relation between the position of the tibial sesamoid and the size of HVA and IMA as well as the dynamics of the development of this deformity depending on the shape of the first MTC joint, was examined. RESULTS: The oblique shape of the first MTC joint was found in 165 (52.4%) feet, the transverse in 145 (46%), and the convex shape was registered in five feet (1.6%). In the oblique shape of this joint, a moderate and severe degree of HV deformity is predominant, while in the transverse shape a mild degree dominates. A statistically significant dependence of HVA on the shape of the first MTC joint was found (Sig. = 0.010), while the dependence of IMA did not show statistical significance (Sig. = 0.105). HVA values follow the position of the tibial sesamoid in both shapes of the MTC joint while the size of the IMA in the transverse shape does not follow the change of the position of this sesamoid. CONCLUSION: The oblique shape of the first MTC joint is associated with the more severe form of HV deformity and its faster developmental course. In the analyzed sample, it was shown that HVA is higher in the oblique shape of the MTC joint and significantly depends on the anatomical orientation of this joint. Furthermore, IMA has a higher value in the oblique shape compared to transverse but this dependence is not statistically significant. The analysis showed that the oblique shape of the first MTC joint contributes to the development of HV deformity.

Influence of the length of the first and second metatarsal bone measured distal from Maestro line upon severity of hallux valgus deformity.

To examine the influence of the configuration of the first and second metatarsal (MT) bones on the development of hallux valgus deformity. To determine the extent to which the difference in the lengths of the first and second MT bones, measured distal to the Maestro line, contribute to the severity of the hallux valgus (HV) deformity defined by the size of the hallux valgus angle (HVA) and inter-metatarsal angle (IMA). On a sample of 319 feet with HV deformity the difference of measured lengths R = d (I MT) - d (II MT) was calculated The influence of differences (R) on the values of IMA and HVA as well as on the severity of deformities according to the formed groups was investigated. The influence of age on the development of deformities was examined separately as well as in conjunction with the determined difference in lengths. In 203 feet or 63.7%, a shorter MT bone was measured, while in 80 feet or 25.1% the first MT bone was longer than second ones and only in 36 feet or 11.3% there is no difference in the length of the 1st and 2ndMT bones distal to the Maestro line. A statistically significant correlation was found between the difference between the measured lengths of 1st and 2nd MT bones and IMA, while this correlation with HVA was not statistically significant. There is no statistically significant correlation or the effect of the difference in measured lengths (R) on the severity of hallux valgus deformity classified into three groups. A statistically significant correlation and impact of the age on the intensity of the deformity are established. A shorter 1st MT bone in correlation to the 2nd MT bone is accompanied by an increase in IMA and this correlation and impact are statistically significant. It was not established that there was a statistically significant influence of the length of the first and second metatarsal bone measured distal from Maestro line upon the values of HVA and severity of HV deformity. Age significantly contributes to the severity of the deformity.