Abstract
Category:
Bunion
Introduction/Purpose:
There is a question as to the relationship of the effect of the arch height on the frontal plane rotation of the 1st metatarsal, and its impact on hallux valgus deformities. We attempt to evaluate this question and offer an answer for discussion.
Methods:
A series of patients who presented to a single orthopedic foot and ankle clinic with a compliant of hallux valgus deformity received a standardized 4 view standing radiograph series. These included the standard weight-bearing anterior- posterior, oblique, and lateral images. The fourth view was an axial sesamoid view to evaluate the frontal plane rotation. The first 50 patients that met our inclusion criteria were used. Inclusion criteria were skeletal maturity, non-traumatic issue, and primary bunion complaint with no complaint related to the arch. Any patients with prior surgery on the 1st metatarsal or arch structure were excluded. The radiographs where then evaluated by 2 fellowship trained foot and ankle specialist with predetermined radiographic parameters. The included measurements regarding the HAV deformity were IM angle, HAV angle, sesamoid position, DMAA, and axial sesamoid rotation. The measurements captured in relation to arch height included Meary’s angle, talonavicular coverage angle, medial cuneiform arch height, navicular height, and lateral talocalcaneal angle.
Results:
The collected information was then initially checked for inter-observer reliability and found to be consistent between the two observers. Collected values allowed the subjects to be placed into 3 initial categories labeled as planus, normal, and cavus based on the arch measurements. The imaging studies related to the HAV deformity was then classed initially as mild, moderate and severe. The HAV deformities were then further classified based on frontal plane rotation deformity and categorized as rotated, rotated and subluxed, subluxed, or no rotation. All of the individual group measurements were determined and quantified using the same radiographic software and uniform points of measurement. The information was then feed into algorithms that included direct comparisons as well as regression analysis of the defined subsets.
Conclusion:
After review of the data it was noted that there was no significant correlation between arch height measurements, HAV deformity and frontal plane rotation of the 1st metatarsal.