I'm going to present our work on morphologic and radiographic alignment features of fate with insertional Achilles tendinopathy. It is a retrospective study. I am Xu Yanli, the corresponding author of this paper, and we have nothing to disclose. Insertional Achilles tendinopathy associated with calcification and degeneration of the insertion of the Achilles is a common disorder. Presently, there is little understanding of the etiology, pathogenesis, and biomechanics of this disease. Although extensive tension at the Achilles insertion associated with calcaneus abnormalities have been considered as contributing factors. In the literature, multiple imaging modalities have been used to investigate a possible correlation between calcaneus morphology and insertional Achilles tendinopathy. However, no prognostic criteria have yet been found. Here is a typical example. This is a 46-year-old male with bilateral changes on the X-ray in the Achilles insertion areas. There are symptoms only on the right side, so why is there only one side symptomatic? Could the alignment features of the hind foot and the mid-foot contribute some of the symptoms? So our purpose of this study was to evaluate the size of the calcified enlargement of the Achilles insertion using a newly developed angular measurement, we call it pathologic Achilles insertion angle, and with PAI in abbreviation, and to investigate features of the hind foot and mid-foot alignment to compare PAI among groups with different hind foot and arch height alignment features. This was a retrospective study with IRB approval. There were 85 patients with symptomatic insertional Achilles tendinopathy, and lateral X-ray images of those patients were revealed. And then the PAI was used for the morphological evaluation. And this parameter is based on mechanism of mapping and curve fitting, and it represents the extent of the enlarged Achilles insertion, and that is how severe the insertional Achilles tendinopathy is. You will see detailed explanation of PAI in figures one and two. And then a lateral view of the subtler joint alignment, which reflects the alignment of the hind foot. The hind foot can be categorized into neutral, valgus, and valgus groups. As well as the calculus pitch angle, and the ratio of the medial cuneiform base hind divided by the cuboid hind, as well as the ratio of the medial cuneiform base hind with the face metatarsal hind were also recorded. The last two arch height ratios reflected the arch height features of the midfoot. And the comparison of PEIA among the three groups of the lateral view-based subtler joint alignment were also evaluated, as well as the correlation between PEIA and arch height ratios were also studied. In this figure, you can see how the parameter PEIA was developed. We used 60 control, this was the result from another study of us. We used a 40 control fit to determine the size, and we put the user box to determine the size of the calcaneus. And then we put dots on the back of the posterior tuberosity of the calcaneus to map the contour of the tuberosity. And after all of this was done, we were able to get the information of the calcaneus dimension and the x and y information of each dot of the posterior tuberosity of the calcaneus. By doing this, we were able to create a standard circle for each individual. You can see here in full figure C, and we are able to work out the standard circle with the x and y information, that is the dimension of the calcaneus. Once we have this, and we are able to know what is the ideal posterior tuberosity of the calcaneus for each individual. And here, we use the same method to map the posterior tuberosity with the calcified, calcified osteophyte, or the insertional Achilles tendinopathy, the osteophyte. With that mapping out, and you can see the green dots shows that is a normal contour of the posterior tuberosity of the patient should be, and the red dots showed how large the calcification is. And by rotating around the weight-bearing point, we are able to bring the red curve to the green curve, that is to bring the diseased contour of the posterior tuberosity to the ideal contour of the posterior tuberosity of the calcaneus. These were all done by math. With this angle developed, and in our retrospective study, we studied 38 males and 47 females with a mean age of 54.49 years old. Those patients all had symptomatic insertional Achilles tendinopathy, and the PNIA angles were between 2.45 to 29 degrees, with 12.56 degrees as the average number. And the pitch angle with this whole cohort was 21.37 degrees in average. And then on the lateral view, the subcutaneous joint assessment showed that 59 patients had a neutral high-foot alignment. It took up about 69.41% of the whole group, and then 14 had a valgus high-foot alignment, and 12 patients had a valgus high-foot alignment. And among these three subgroups, there was a significant difference of the calcaneus pitch angle and the medial cuneiform base height with the cuboid height index between the valgus and the valgus high-foot groups, and the valgus and the neutral high-foot groups. But there was no difference between the valgus and the neutral high-foot groups. And there was no difference was found in the medial cuneiform base height against the face metatarsal height between any two of those three groups. And we also found that the PNIA difference between the neutral and the valgus high-foot groups was significantly larger than the others. And there was no significant correlation between the PNIA and the calcaneus pitch angle, as well as the two arch height indexes. And you can see here all the numbers were shown, the difference between the PNIA angles between different groups. And there was significant statistical significant difference between the neutral and the various high-foot alignment groups. And here, you can see the two different arch height index and the numbers under the PNIA angle in degrees between all the different high-foot alignment groups. Conclusion. This study is the first to include the morphology of the calcaneus, the high-foot and the arch height features of the foot in assessing symptomatic insertional Achilles tendinopathy. In this study, we have found that in this group of patients with a various high-foot had a much smaller calcified enlargement of the Achilles insertion than those with a neutral high-foot. Further investigations with a large sample size to study possible correlations among the clinical symptoms, calcaneus morphology, and alignment of the feet will be helpful to guide both diagnosis and treatment of the insertional Achilles tendinopathy, in particular when the patient has combined malalignment issue in the high-foot and the middle foot. Here is our reference. Thank you.

presentation

retrospective study

morphological features

radiographic alignment

insertional Achilles tendinopathy