Objective: The aim of this study was to determine the correlation between 3 different footprint measurement procedures and 3 different radiological assessment methods in the diagnosis of pes planus.

Metarials and Methods: Harris Mat footprints of 338 hospital staff were taken and were evaluated by using 3 different measurement methods: Staheli index (SI), Chippaux-Smirak Index (CSI) and Grivas Classification System (GCS). In 52 patients who were diagnosed with pes planus according to the SI underwent lateral weight-bearing radiogram and calcaneal pitch angles (CPA), talohorizontal angle (THA) and talo-first metatarsal angle (TMA) were evaluated.

Results: Of the 338 patients, 133 (39.4%) were male, and 205 (60.6%) were female. The average age was 38±8,6 years. Pes planus was determined in 118 patients (34.9%) according to the CSI, in 63 (18.6%) according to SI, and in 9 patients (2.6%) according to GCS. There was a strong correlation between the three footprint measurement methods (SI/CSI r: 0.961, p<0.001, SI/GCS r: - 0.876, p<0.001, CSI/GCS r: -0.886, p<0.001). However, when we investigated whether the footprint measurement methods can give the same pes planus diagnosis, we found that the methods are statistically discordant (p>0.05). CPA and TMA had a low correlation with each of three footprint measurement methods. (CPA/SI r: -0.317, p= 0.001, CPA/CSI r: - 0.420, p<0.001, CPA/GCS r:0.462, p<0.001, TMA/SI r: 0.342, p<0.001, TMA/CSI r: 0.332, p=0.001, TMA/GCS r: -0.465, p<0.001). We have not observed a statistically significant correlation between THA and footprint measurement methods.

Conclusion: In the diagnosis of flatfoot, different footprint measurements and radiologic methods give incompatible results even though they may show correlation with each other.