Reliability of different smartphones measuring the hallux valgus parameters in a new rapid method: a follow-up study

Abstract

Objective This study aimed to further compare the abilities to measure hallux valgus parameters in different smartphones using the intrinsic photograph-editing function. Methods We retrospectively reviewed 61 patients (100 feet) of hallux valgus without medical or surgical interventions at our department. The radiographic parameters were assessed and measured via the Picture archiving and communication systems (PACS), iPhone, and Android. The accuracy, reliability, and the time-taken were compared and analyzed between each two methods. Results The mean value of measured hallux valgus parameters were as follow: hallux valgus angle (HVA): 33.71 ± 7.25°; the first and second intermetatarsal angle (IMA): 12.84 ± 3.62° in PACS; HVA: 33.59 ± 7.18° and IMA: 12.80 ± 3.65° in Android; HVA: 33.63 ± 7.23° and IMA: 12.87 ± 3.60° in iPhone. No significant difference was found among the average results measured by PACS, Android and iPhone (F = 0.008, P = 0.992 in HVA; F = 0.009, P = 0.991 in IMA). For measurements by PACS, Android smartphone, and iPhone, the variability of HVA (F = 0.061, P = 1.000) and IMA (F = 0.133, P = 1.000) was similar. The intraclass correlation coefficients (ICCs) of the mean results of four times measurements of HVA and IMA as follows: PACS vs Android: 0.995 (0.993–0.997) and 0.982 (0.973–0.988); PACS vs iPhone:0.997 (0.995–0.998) and 0.974 (0.962–0.982); Android vs iPhone:0.997 (0.995–0.998) and 0.981 (0.971–0.987). The interobserver and intraobserver reliability was very good for Android smartphones and iPhone in measuring hallux valgus parameters. The mean time of measurement by PACS, Android smartphone, and iPhone were 25.34 ± 1.18 s, 20.10 ± 0.92 s, and 19.92 ± 0.99 s respectively. The measurement time of smartphones is significantly faster than that of PACS by about 5 seconds (P = 0.000). The measurement time of iPhone was slightly faster than that of Android smartphone, while no significant difference was found (P = 0.24). Conclusion It is more convenient and faster to use smartphones when compared with PACS, at the same level of accuracy. Furthermore, the abilities of different smartphone platforms are proven to be of no significant difference.

Rapid measurement of thoracolumbar kyphosis with the integrated inclinometer of a smartphone: a validity and reliability study

“…Because the inclinometer function is built into the smartphone, this novel method avoids the aforementioned problems with downloaded apps. It does not need to be updated or maintained, always responds quickly without bugs, and is included with the phone at no additional charge 18 . The purpose and the spirit of the measurement have not been changed even though the method has changed; a new tool has been developed, but the general principles of the kyphotic measurement process remain 19 .…”

Validity and reliability of a novel iPhone method to rapidly measure cervical sagittal parameters

“…In this study, the photos were taken on a vertical computer screen, and it is reasonable to speculate that photos taken with films located in a vertical film viewer machine could also use this novel measuring method. It is important to note that the radiographic film should be kept parallel to the camera when taking the photos in case of parallax error 18 . The radiographic films included in this study were legible in terms of anatomical structures such as the endplate of the vertebral body, the upper end of the sternum and the hard palate.…”