Correlation Between Posterior Tibialis Tendon Dysfunction with Ultrasonography and Adult Acquired Flatfoot Deformity with Radiographic X-ray and Feiss line in East Java’s Indonesian Professional Athletes

Background : Adult acquired atfoot deformity (AAFD) is marked with a partial or complete attening of the longitudinal medial arch that developed after maturity. AAFD, secondary to posterior tibialis tendon dysfunction (PTTD), is one of the most frequent foot and ankle pathologies in professional athletes. Different modality and procedures can be used to establish the diagnosis of AAFD and PTTD However, the correlation of these various clinical and imaging measurements with specic injuries of the PTT and supporting medial longitudinal arch structures has not been fully reported. The purpose of this study is to investigate the correlation between PTTD using ultrasonography and AAFD that diagnosed using both radiographic x-ray and feiss line examination. Method : 112 professional athletes with at foot deformity on physical examination, symptom of PTT dysfunction such as medial ankle or foot pain, focal pain along the course of the PTT underwent foot radiographic x-ray using calcaneal inclination angle, ankle ultrasound to see PTT abnormality and feiss line examination using three degree of at foot classication. Result : There were strong association between calcaneal inclination angle and PTTD includes the presence of PT tendon sheath uid as well as tendon sheath thickening with p<0.05 with correlation coecient (r) = 0.921 and 0.892 respectively. Weak association were also found between feiss line result and PT tendon sheath uid as well as tendon sheath thickening with correlation coecient (r) = 0.288 and 0.244. There were non signicant association between calcaneal inclination and partial PT tendon tear as well as calcaneal inclination and feiss line result. Conclusion : A compressive understanding of posterior tibialis tendon dysfunction and atfoot diagnosis will lead to more effective management in reducing the symptom.


Introduction
The foot of human has become exceptionally specialized for the performance of two divergent functionsstatic balance & propulsion. Various arches were the main features to make the series of bones forming to do the balance & propulsion. Flat foot occurs from a partial or complete collapse of the arch Propulsion and static balance were the main functions in human foot that made them unique. 1 Flatfoot cause several complications such as foot pain, knee pain, back pain and postural disturbance. 2 These pains rarely occur on babies and children, but the main cause of pain on runners and increase the risk of sport injury Adult Acquired Flatfoot Deformity may cause some symptoms and complications such as postural disturbance, knee pain and foot pain, all of them were the most common cause of pain on professional athletes in sport injury. 3 Adult acquired atfoot deformity (AAFD) is marked with a partial or complete attening of the longitudinal medial arch that developed after maturity. 4 AAFD, secondary to posterior tibialis tendon dysfunction (PTTD), is one of the most frequent foot and ankle pathologies in professional athletes and also approximately 5 million adults in America. 5 The disorder is initiated most commonly by dysfunction of the posterior tibialis tendon (PTT), which normally functions to maintain the talonavicular joint at the apex of the three arches of the foot. There are several causes of AAFD, such as PTTD, trauma, neuroathropathy, neuromuscular disease, in amamatory arthritis and the most common is PTTD. 4;6 The overuse injury in professional athletes with AAFD is one of the cause of PTT degeneration. 7;8 PTT degeneration encompasses tenosynovitis, tendinosis, tendon elongation, and tendon tearing. The malaligned foot is initially exible but becomes rigid and constant as the disorder progresses. 4 Different modality and procedures can be used to establish the diagnosis of AAFD and PTTD such as clinical diagnosis as well as imaging diagnosis include radiographic x-ray, ultrasound and MRI. 9 The gold standard for the evaluation of adult acquired atfoot is weight-bearing radiographs. Radiographs are necessary in the anteroposterior, lateral, and hindfoot views. These views will assess the degree of arch collapse, particularly by measuring the calcaneal inclination and lateral rst tarsometatarsal angle. 10;11 Several studies indicate that ultrasound may be a useful modality in assessing the posterior tibial tendon when compared to the more time consuming and costly MRI. Results from an ultrasonographic evaluation of the posterior tibial tendon were equivalent to MRI in 87% to 94% of patients. 11;12 However, correlation of these various clinical and imaging measurements with speci c injuries of the PTT and supporting medial longitudinal arch structures has not been fully reported. Multimodality evaluation using radiographic x-ray, ultrasonography and feiss line examination in professional athletes that examine the correlation between PTTD and AAFD has not been widely studied yet. Through this study, sports science can be applied in the process of seeding athletes since a comprehensive approaches include promotion, preventative, curative as well as rehabilitative management will enhance the long-term athletic performance. The aims of this study was to investigate the correlation between PTTD using ultrasonography and AAFD that diagnosed using both radiographic x-ray and feiss line examination.

Subjects
Approval from institiuional review board from Ethics Committee of Soetomo General Academic Hospital, Surabaya (2043/118/KEPK/III/2020) had been obtained. The inclusion sample consisted of 112 athletes with at foot deformity on physical examination, symptom of PTT dysfunction such as medial ankle or foot pain, focal pain along the course of the PTT who underwent ankle ultrasound, radiographic x-ray, and feiss line examination in Sport Clinic of Soetomo General Academic Hospital Surabaya on March 2020. Athlete who had history of ankle or pedis trauma, previous intensive treatment for atfoot were excluded from the sample.
This study is an observational analytic using a cross-sectional study design that assesses the correlation of the thickness of the uid around the PTT, the thickness of the PTT tendon sheath, the degree of uid area around the PTT, and the tearing of the PTT were diagnosed from the ultrasound with the calcaneal inclination angle of the radiographic x-ray lateral pedis as well as feiss line examination.

Radiography x-ray and Ultrasonography
Weight-bearing radiography x-rays of the foot and ankle lateral projection remained the gold standard for the diagnosis of adult-acquired atfoot deformity. 11;13 X-ray machine unit of DRGEM Stationary X-ray System GXR-C52SD was used for examination. Standing anterosuperior (AP) and lateral views of the foot were obtained for athletes ( Figure.1). All radiographs were obtained in a weight-bearing position with standardized technique using the same digital radiography system. The digital x-ray detector ( lm) and the x-ray tube (source) are 35-40 inchies apart in both the AP and lateral views of foot. When the AP view of the foot is taken, the xray tube source was angled at 10 o . Calcaneal inclination angle is one of the most common measurement to make the diagnosis for atfoot deformity ( Figure.2). 4 The calcaneal inclination angle was measured by the angle between the line that paralells to plantar calcaneal surface and the horizontal plane. Alignment angle (degrees) <18° is categorized as pes planus. Schematic anatomy of posterior tibial tendon is seen in Figure 3.
The PTT is well assessed with US. We used GE Logiq P9 ultrasound machine in scanning of the PTT.
Tranducer positioning of posterior tibialis tendon for ultrasound scanning is very important so we can get the correct results. It is scanned in both longitudinal and transverse position ( Figure 4). Posterior tibialis dysfunction appeared as tenosynovitis, tear or tendinosis. Free uid collection that made hypoechoic lesion around posterior tibialis tendon and a sheath size of greater than 7 mm was tenosynovitis (hyperechoic central structure with a hypoechoic halo) on the ultrasound transverse position. Posterior tibialis tendon tear or rupture appeared from ultrasound as an empty tibial groove and have a gap intermuscular of posterior tibialis tendon. Tendinosis results in thickening, with heterogeneous hypoechoic regions replacing the normal brillar architecture. 4;10;15 All of the radiograph measurement and US examination were performed by a senior musculokeletal radiology consultant with more than 10 years of experience.

The Feiss Line Test
The feiss line test used to measure the degree of fall or fall of the navicular in standing. It is possible to quantify the medial longitudinal arch using a simple setup, without the need for identi cation of subtalar neutral position. The Feiss line is de ned as an imaginary straight line from the medial malleolus through the navicular bone to the center of the head of the rst metatarsal. 17 Patient is asked to sit on a chair with feet on the oor. The navicular tubercle is marked while sitting, again the patient is asked to stand up, then the navicular tubercle is marked again and observe if the navicular falls while standing ( Figure 7). If the tubercle falls 1/3 of the distance to the oor, it represents a level leg of 1 degree; if it falls 2/3 of the distance to the oor, it is level 2; if attached to the oor, it represents a 3 degree atfoot. 18

Statistical Analysis
We use SPSS 24 software (IBM, Armonk, New York, United States) for statistical analysis. Data from ultrasonography, radiographic x-ray, and The Feiss Line Test were arranged in table and analyzed.

Results
In this study (Table 1), a sample of athletes from various sports with the highest number of atfoots was obtained is wrestling (30.4%) and the lowest number is gymnastic (3.6%). From wrestling atheles group, we also found the highest number of PTTD (tenosynovitis and tear) and at foot incidence of 21,4% among other sports. From all atheles, 43% showed normal PTT ultrasound nding and 33% showed normal calcaneal inclination angles from radiograph From ultrasound nding of this study, the size of the tendon sheath uid thickness around the posterior tibial tendon, the thickness of the posterior tibial tendon sheath, the presence of a tear in the posterior tibial tendon as well as their correlation to the calcaneal inclination angle data from the radiographic examination and feiss line test from clinical ankle-foot examination were analyzed. We found the range of uid thickness of the sample were 0-5.8 cm with a mean value of 2.57 cm and a median value of 2.8 cm. The thickness of the posterior tibial tendon sheath ranges from 5.5-13 cm with a mean value of 8.25 cm and a median value of 8.2 cm. The the posterior tibial tendon tears ranges from 0.12 to 0.27 cm with a mean value of 0.013 cm. The calcaneal inclination angle from x-ray radiographic measurement ranges from 9.5-23.1 with a mean value of 17.2 and a median value of 16.6 ( Table 2). From 112 samples we got 67% had rst degree of atfoot, 20,5% second degree, 1,5% got third degree. Radiographic examination shows similar results approximately 70,5 % were atfoot (Table. 3) Based on the Kolmogorov-Smirnov distribution test, it was found that the PTT thickness was the ratio data that was normally distributed in the group of East Java's Indonesian professional athletes in, the correlation hypothesis test were carried out using the Pearson test. Based on the correlation test, there is a very strong correlation between the thickness of the uid around the posterior tibial tendon and the calcaneal inclination angle with p <α (p = 0.000; α = 0.05) and a correlation coe cient (r) = 0.921. In the other hand, there is a weak correlation between the thickness of the uid around the posterior tibial tendon with feiss line test with p <α (p = 0.003; α = 0.05) and a correlation coe cient (r) = 0.280. A very strong correlation is found between the thickness of the posterior tibial tendon sheath and the calcaneal inclination angle with p<α (p = 0.000; α = 0.05) and a correlation coe cient (r) = 0.892. From the correlation between posterior tibial tendon sheath thickness and feiss line test showed weak correlation with p <α (p = 0.001; α = 0.05) and correlation coe cient (r) = 0.244. Compared to the previous variables, the correlation between tibialis tendon partial tear and calcaneal inclination as well as feiss line test resulted in not signi cant correlation with p <α (p = 0.728; α = 0.05) and a correlation coe cient (r) = 0.033 for calcaneal inclination, while p <α (p = 0.541; α = 0.05) with a correlation coe cient (r) = 0.058 for feiss line test (

Discussion
Acquired adult atfoot is classi ed according to clinical symptoms, the severity of the foot deformity, and whether the deformity is exible or xed. 19;20 The foot was mainly supported by posterior tibialis tendon to maintain medial longitudinal arch and balancing the hindfoot against valgus deformity. Accordingly, adult acquired atfoot deformity can be caused by posterior tibialis tendon dysfunction. Posterior tibialis tendon dysfunction manifestation given an overview in the form of tendinosis, tenosynovitis, and tear.
When the person got posterior tibialis tendon dysfunction, the body weight distribution will be disturbed to the supporting structures, consisting of spring ligamentum complex, sinus tarsi ligament, and deltoid ligament complex. Distribution from this structure can caused atfoot deformity. 19 Classi cation regarding to the severity of atfoot deformity in relation to posterior tibial tendon dysfunction was proposed by Johnson and Strom in 1989 (Wacker J at al., 2003). 21 In athletes, the state of the foot greatly depends on the type of effort and weight of the load carried, which differs in different disciplines, and on the type of surface on which training and competition are carried out. This situation will increase the burden the the foot arch. This study showed that's the majority of athletes have atfoot deformity and posterior tibialis tendon tenosynovitis. These results are correlated with previous studies Lichota et al that the majority of sportsmen especially in athletics have atfoot deformity. Research on the variability of foot-arches among practitioners of different sporting has already been carried out by Nizankowski and Wanke, found that the greatest risk factor for the diagnosis of atfoot and posterior tibial tendon dysfunction occurs in sports athletes. Author also found only very few athletes (6,3%) that have tear at posterior tibialis tendon this have a different result from previous studies by Hsu, T.C., Wang which had (43,75%) from total sample. 15 In this study, a sample of athletes from various sports with the highest number of atfoots was obtained is wrestling. This nding is con with previous research by Mira Saraswati Kumala with the results of the three categories with the most atfoot deformity, include football, takraw, athletics and wrestling. The sport that has the greatest number and greatest percentage of atfoot is wrestling. These nding were similar with previous study by Mira Saraswati Kumala with resulted in the top three largest sport that is related to atfoot deformity including sepak takraw, athletic and wrestling. From the table no 5 and 6 concludes that characteristic of atfoot and tenosynovitis most likely bilateral foot and only very few samples that only had unilateral atfoot or unilateral posterior tibial tenosynovitis. This ndings are concordance with previous study by Mira Saraswati Kumala that only (14,3%) have unilateral atfoot. 3 In this study, we found that there is a statistically signi cant association between calcaneal inclination angle with PT tendon sheath thickening and tendon sheath uid as diagnosed on ultrasound. Our ndings are supported by Karasick and Schweitzer evaluated patients with surgically proven PTT tears and found that 50% of the patients had a decreased calcaneal pitch angle and also by Lin et al that showed signi cant association between some radiograph measurements include calcaneal inclination angle with PTTD diagnosed on MRI. 19;22 On the other hand, a non signicant association is found between feiss line grading system with PT tendon sheath thickening and tendon sheath uid. It assumes that the imaging evaluation using radiograph and ultrasound plays an important role in diagnosing of PTTD and AAFD to con rm the clinical assessment respectively. This is reasonable, because PTTD including tears and diffuse PT tenosynovitis can lead to tendon lengthening due to tendon ber disruption, which will cause the medial longitudinal arch to fail and lead to abnormal radiographic measurements. However, this study also found PTTD in normal calcaneal inclinations. These ndings suggest that in focal PTT tendinosis and isolated tenosynovitis, the tendon although abnormal is structurally intact; thus, the longitudinal medial curvature will be maintained and radiographic measurements will remain within normal limits. 19 The angle of inclination of the calcaneals is well associated with injury to the supporting structures of the medial longitudinal arch. This is indicated by the strong relationship with PTTD found on ultrasound, this may be due to the ease in calculating this measurement. Bone landmarks used to calculate calcaneal pitch angle are often preserved even in cases of severe leg deformity. 19 therefore, precise measurements can still be obtained. Ultrasound has recently become a widely used diagnostic tool for PT tendon lesions in sports injuries, due to its ability to visualize the bers in the desired projection and real-time functional state, as well as to provide a variety of PTTD ndings including tearing, tendon ber thickening, heterogeneity. Thickening of the tendon sheath echogenicity as well as uid of the tendon sheath. 4;15;25 The limitation of the study was the amount of the sample which are only limited variety type of sports. Furthermore, there was no surgical proof since all of our patients were treated conservatively with most ultrasound nding was tendinosis, tenosynovitis as well as partial tendon tear. No tendon rupture is detected on the sample group. We only use calcaneal inclination angle as the radiograph evaluation, so that further study is better considered to perfome using multiparameter radiograph measurements.
As a summary in our study, we could con rm the statistically signi cant relation between PTTD found on the ultrasound in key structures for the stabilization of plantar arch. We have opinion that this study is very useful to make better analyze study to understand more about the risk factor and type of sports that tend to have more predispotition to increase the chance of being atfoot deformity and posterior tibialis tendon dysfunction. The association between these ultrasound-diagnosed structures and signs of radiological at foot and PTTD and its possible physiopathological mechanisms can be especially useful for a precise diagnosis to support a comprehensive management.

Conclusion
Posterior tibialis tendon plays an important role in dynamic support of arch. This study conducted that there is a close relation between posterior tibialis tendon dysfunction, atfoot deformity in professional athletes, that posterior tibialis tendon dysfunction is common cause of acquired atfoot deformity. A compressive understanding of posterior tibialis tendon dysfunction and atfoot diagnosis will lead to more effective management in reducing the symptom Declaration Ethical Clearance  Transducer positioning for posterior tibial tendon ultrasound scanning Figure 5 Transverse sonographic of posterior tibialis tendon with tenosynovitis showed thickening of the tendon ber (A) with uid in the tendon sheath (B) Figure 6 Longitudinal sonographic of posterior tibialis tendon with partial tear Figure 7