Hello, I'm going to present our work on tassel coalition and midfoot and handfoot alignment features. I'm Shuyan Li, the corresponding author of this paper. We have nothing to disclose. Tassel coalition has been historically reported to be associated with a flat foot deformity. There are, however, case reports demonstrating that it can be found in Kiva virus and clubfoot deformities. So the goal of this study was to retrospectively review all weight-bearing CT scans that were taken in one medical center, and to investigate the clinically diagnosed as well as missed cases of tassel coalition. And in the meantime, to determine the height-foot alignment and arch height features of each case. So this was a retrospective study with IRB approval. And we reviewed 800 weight-bearing CT scans separately by two senior fellowship trained foot and ankle surgeons. So the structure of the height-foot and mid-foot were carefully examined in all three views for different types of tassel coalition. For cases that were diagnosed with tassel coalition on weight-bearing CT, their medical charts were then reviewed to determine the original clinical diagnosis. And in the meantime, height-foot alignment and arch height features of the mid-foot were subsequently evaluated on weight-bearing CT scans. So among the 800 weight-bearing CT scans, 41 feet that were diagnosed with tassel coalition radiographically. Among them, there were 19 valgus height-foot, 18 neutral height-foot, and 4 varus height-foot. 15 out of 41 cases were clinically diagnosed with tassel coalition. But 26 out of 61 with symptomatic problems were missed with tassel coalition. So here are the clinical diagnoses. 16 were diagnosed with congenital or acquired flat feet. Three were diagnosed with septal arthritis. One was diagnosed with talar navicular arthritis. One was diagnosed with peroneal tendinopathy plus kivavarus foot deformity. There were two kivavarus foot deformities with mid-foot arthritis. And there were two cases diagnosed with post-traumatic ankle arthritis. And one case was diagnosed with subtalar impingement. And in the mid-foot, 38 feet had a positive distal medial cuneiform and 5th metatarsal arch height index. And 3 feet had a negative index. And all 41 feet had a positive proximal cuneiform against cuboid height index. So here's a typical case. This case with multiple tassel coalition. And on the first side you will see, on the lateral side and from the height foot view, you will see it is kivavarus foot. It's very obvious. And if you look at image C, you will see something is happening in the four corners. You may argue, okay, it might be arthritis. But if you go more medially, you will see clear middle facet coalition. And also there is calcaneus navicular under the cuboid coalition. And this case was missed with tassel coalition and was diagnosed with kivavarus foot. So our conclusion. One should be aware that patients with tassel coalition do not always present with a flat foot and high foot valves. Since many can have a variety of high foot and mid-foot alignment features. There can be a neutral high foot alignment and it can be a kivavarus high foot. In cases presenting with a history of trauma, degenerative arthritis, as well as kivavarus or collapsed foot deformity, tassel coalition can easily be clinically overlooked. So here's our question. Are those clinically missed tassel coalition actively involved in the symptoms of the foot or not? Should they be treated or left alone? And with regards to this, more research needs to be done. Here are our references. Thank you.

Shuyan Li

tarsal coalition

midfoot alignment

handfoot alignment

weight-bearing CT scans