# Correlation of Posterior Tibial Tendon Ultrasound with Calcaneal Inclination Angle in Indonesian Professional Athletes with Medial Ankle Pain

## TL;DR

This study finds a strong negative correlation between ultrasound measurements of the posterior tibialis tendon and the calcaneal inclination angle in athletes with medial ankle pain.

## Contribution

The study is the first to investigate the correlation between PTT ultrasound findings and CIA in Indonesian professional athletes with medial ankle pain.

## Key findings

- Fluid thickness around the posterior tibialis tendon negatively correlates with calcaneal inclination angle (r = -0.921).
- Posterior tibialis tendon thickness also shows a strong negative correlation with calcaneal inclination angle (r = -0.892).
- No significant correlation was found between tendon tear and calcaneal inclination angle.

## Abstract

Background: Adult-acquired flatfoot deformity (AAFD) is characterized by partial or complete flattening of the longitudinal medial arch, which develops after maturity. AAFD secondary to posterior tibialis tendon dysfunction (PTTD) is one of professional athletes' most common foot and ankle pathologies. Different modalities and procedures can be used to establish the diagnosis of AAFD and PTTD. However, imaging measurements such as the calcaneal inclination index and ultrasonography (US) of the posterior tibialis tendon (PTT) in professional athletes with medial ankle and focal pain along the PTT have yet to be widely studied. This study investigates the correlation of PTT ultrasound for evaluating PTTD with calcaneal inclination angle (CIA) for evaluating AAFD in professional athletes with medial ankle and focal pain along the PTT. Through this study, clinicians and radiologists may benefit from considering AAFD in athletes with PTTD.

Methods: 112 Indonesian professional athletes with medial ankle or foot pain and focal pain along the direction of the PTT underwent foot radiography using the CIA and ankle ultrasound to observe PTT abnormalities.

Results: A negative correlation between fluid thickness surrounding the PTT and the CIA (p<0.001; 95% CI - 0.945, - 0.885), as well as a negative correlation between PTT thickness and CIA (p<0.001, 95% CI - 0.926, - 0.845), with a correlation coefficient (r) of - 0.921 and - 0.892, respectively. No significant correlation was found between PTT tear and CIA (p = 0.728; 95% CI -0.223, - 0.159; r - 0.033).

Conclusion: This study showed a negative correlation between PTTD and AAFD via ultrasound and CIA in professional athletes with medial ankle and focal pain along the PTT. A better understanding of PTTD and AAFD imaging will lead to more effective management and prompt treatment.