The Anatomical Variations of the Posterolateral Tubercle of Talus in Patients with Posterior Ankle Impingement Syndrome

Abstract Background: The most important anatomical variations of the posterolateral talar tubercle that can predispose patients to development of posterior ankle impingement syndrome (PAIS) are an os trigonum and Stieda process. The aim of this study was to elucidate the prevalence of different anatomical variants of posterolateral talar tubercle on CT imaging, their prevalence in patients with PAIS, and to evaluate the risk posed by these anatomical variants to PAIS. Methods: 1478 ankle CT scans were retrospectively reviewed for the different anatomical variants of the lateral talar tubercle, the type and size of os trigonum. In addition, these anatomical differences were assessed in a subgroup of patients with PAIS. Results: Normal sized lateral tubercle was found in 46.1%, Stieda’s process in 26.1%, os trigonum in 20.5% and almost absent tubercle in 7.3%. A statistically higher prevalence of Stieda’s process was found in males while os trigonum was higher in females (p<0.05). In patients with PAIS, the most common variant was os trigonum (48.8%), followed by Stieda process (34.1%). Patients with Stieda process were 1.5 times more likely to have PAIS, and patients with os trigonum were 4.4 times more likely to have PAIS. PAIS was observed in 20.8% of patients with os trigonum. Fused forms of os trigonum (by cartilage) and sizes larger than 1cm were associated with a higher risk of occurrence of PAIS (OR 2.10 and OR 1.96 respectively)(p<0.05). Conclusion: Patients with os trigonum, followed by Stieda process were more likely to have PAIS compared to other anatomical variants of lateral talar tubercle.

Download Full-text

A comprehensive study of the anatomical variations of the posterolateral tubercle of talus

10.21203/rs.3.rs-140532/v2 ◽

2021 ◽

Author(s):

Heba Kalbouneh ◽

Mohammad Alsalem ◽

Maysoon Bani Hani ◽

Hamzeh Alhusamiah ◽

Yazan Momani ◽

...

Keyword(s):

Anatomical Variations ◽

Ct Imaging ◽

Ct Scans ◽

Os Trigonum ◽

Anatomical Variants ◽

Different Types ◽

Accessory Ossicle ◽

Clinical Problems ◽

Comprehensive Study

Abstract The aim of our study was to establish the prevalence of the different anatomical variants of the posterolateral tubercle of talus on CT imaging. 1478 ankle CT scans were retrospectively reviewed for the different anatomical variants of the posterolateral tubercle of talus, the type and size of os trigonum. Normal sized lateral tubercle was found in 46.1%, an enlarged posterolateral tubercle (Stieda’s process) in 26.1%, os trigonum in 20.5% and almost absent tubercle in 7.3%. A statistically higher prevalence of Stieda’s process was found in males while os trigonum was higher in females (p<0.05). Among feet with os trigonum, 25.7% were non-articulating and identified as a separate bone located posterior to the posterolateral tubercle of talus and 74.3% of os trigonum were identified as fused to the posterolateral tubercle by synchondrosis or syndesmosis. Additionally, 17.5% of os trigonum were associated with intact lateral tubercle, 53.5% were considered as part of the lateral tubercle and 29.0% were without a lateral tubercle. According to its size, 22.8 % of os trigonum were smaller than 0.5 cm, 55.4% were between 0.5 and 1cm, and 21.8% were larger than 1 cm. No significant differences were found between the different types/sizes of os trigonum according to gender (p>0.05). The posterolateral tubercle of talus and its accessory ossicle, the os trigonum, could vary morphologically. The data of this study could be helpful in understanding the clinical problems that could be associated with some of these variants.

Download Full-text

Endoscopic versus open excision of os trigonum for the treatment of posterior ankle impingement syndrome (PAIS)

Foot and Ankle Surgery ◽

10.1016/j.fas.2017.07.296 ◽

2017 ◽

Vol 23 ◽

pp. 69

Author(s):

D. Georgiannos ◽

I. Bisbinas

Keyword(s):

Impingement Syndrome ◽

Os Trigonum ◽

Ankle Impingement ◽

Posterior Ankle Impingement ◽

Open Excision

Download Full-text

Endoscopic Repair of Posterior Ankle Impingement Syndrome Due to Os Trigonum in Soccer Players

Foot & Ankle International ◽

10.1177/1071100714552078 ◽

2014 ◽

Vol 36 (1) ◽

pp. 70-74 ◽

Cited By ~ 18

Author(s):

Víctor López Valerio ◽

Roberto Seijas ◽

Pedro Alvarez ◽

Oscar Ares ◽

Gilbert Steinbacher ◽

...

Keyword(s):

Impingement Syndrome ◽

Soccer Players ◽

Endoscopic Repair ◽

Os Trigonum ◽

Ankle Impingement ◽

Posterior Ankle Impingement

Download Full-text

Posterior Ankle Impingement Syndrome and Os Trigonum Relationship in Children

Northern Clinics of Istanbul ◽

10.14744/nci.2021.22587 ◽

2021 ◽

Author(s):

Merter Keceli

Keyword(s):

Impingement Syndrome ◽

Os Trigonum ◽

Ankle Impingement ◽

Posterior Ankle Impingement

Download Full-text

Exorotated radiographic views have additional diagnostic value in detecting an osseous impediment in patients with posterior ankle impingement

Journal of ISAKOS Joint Disorders & Orthopaedic Sports Medicine ◽

10.1136/jisakos-2019-000272 ◽

2019 ◽

Vol 4 (4) ◽

pp. 181-187

Author(s):

Ruben Zwiers ◽

Johannes G G Dobbe ◽

Geert J Streekstra ◽

Leendert Blankevoort ◽

Johannes I Wiegerinck ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Interobserver Reliability ◽

Diagnostic Value ◽

Lateral View ◽

Ct Scans ◽

Ankle Pain ◽

Os Trigonum ◽

Ankle Impingement ◽

Posterior Ankle Impingement ◽

Projection Angle

ObjectivesA standard lateral radiograph is the first step in the diagnostic workup in patients with posterior ankle pain. Because of overprojection by other structures at suboptimal radiographic projection angle, often an os trigonum is not discovered or erroneously be mistaken for a hypertrophic posterior talar process. The aim of this study was to identify the projection angles at which a radiograph is optimal for detecting bony impediments in patients suffering from posterior ankle impingement.MethodsUsing ankle CT scans of patients with posterior ankle impingement, digitally reconstructed radiographs (DRRs) simulating 13 different radiographic projection angles were generated. The ankle CT scans served as a reference for the detection of an os trigonum and hypertrophic posterior talar process. Members of the Ankleplatform Study Group were invited to assess the DRRs, for presence or absence of an os trigonum or hypertrophic posterior talar process. Diagnostic accuracy and interobserver reliability were estimated for each projection angle. In addition, the diagnostic accuracy of the standard lateral view in combination with the rotated views was calculated.ResultsHigh sensitivity for detecting an os trigonum was found for +15° (90.3%), +20° (81.7%) and +25° (89.7%) degrees of exorotation. Specificity in this range of projection angles was between 89.6% and 97.8%. Regarding the presence of a hypertrophic posterior talar process, increased sensitivity was found for +15° (65.7%), +20° (61.0%), +25° (60.7%), +30° (56.3%) and +35° (54.5%). Specificity ranged from 78.0% to 94.7%. The combination of the standard lateral view in combination with exorotated views showed higher sensitivity. For detecting an os trigonum, a negative predictive value of 94.6% (+15°), 94.1% (+20°) and 96.1% (+25°) was found.ConclusionThis study underlines the additional diagnostic value of exorotated views instead of, or in addition to the standard lateral view in detecting an osseous impediment. We recommend to use the 25° exorotated view in combination with the routine standard lateral ankle view in the workup of patients with posterior ankle pain.Level of evidenceLevel III

Download Full-text

Prevalence of Os Trigonum on CT Imaging

Foot & Ankle International ◽

10.1177/1071100717740937 ◽

2017 ◽

Vol 39 (3) ◽

pp. 338-342 ◽

Cited By ~ 11

Author(s):

Ruben Zwiers ◽

Thomas P. A. Baltes ◽

Kim T. M. Opdam ◽

Johannes I. Wiegerinck ◽

C. Niek van Dijk

Keyword(s):

Odds Ratio ◽

Adjusted Odds Ratio ◽

Patient Characteristics ◽

Ct Imaging ◽

African Origin ◽

Level Of Evidence ◽

Os Trigonum ◽

Ankle Impingement ◽

Posterior Ankle Impingement ◽

Retrospective Comparative Study

Background: The os trigonum is known as one of the main causes of posterior ankle impingement. In the literature, a wide variation of occurrence has been reported. Methods: All foot and/or ankle computed tomography (CT) scans made between January 2012 and December 2013 were reviewed. CT images were assessed, blinded for patient characteristics, for the presence of an os trigonum, size of the os trigonum, and type of os trigonum. In addition, the shape of the lateral tubercle of the posterior talar process was assessed. Results: A total of 628 patients (1256 ankles) were included. In 32.5% of the patients of the cohort, an os trigonum was present. In 14.3% of these patients, it was present bilaterally. In a subgroup of patients without posterior ankle impingement the prevalence was 30.3%. Of the nonaffected ankles, an os trigonum was present in 23.7%. Patients with posterior ankle impingement were more likely to have an os trigonum (adjusted odds ratio [OR], 1.86). Afro-Caribbean/Surinamese/Central African origin was associated with a lower rate of occurrence of os trigonum (adjusted OR 0.43). In the ankles without an os trigonum, an enlarged lateral tubercle of the posterior talar process was found in 34.9% and 36.5% of the ankles. Conclusion: This study showed that os trigonum is a common accessory bone. With a prevalence of 30.3% in a population of patients with CT imaging of both ankles and 23.7% of the nonaffected ankles, the os trigonum is more common than previously reported. Patients with posterior ankle impingement complaints had a higher prevalence of an os trigonum. In one-third of the patients without an os trigonum, there was an enlarged lateral tubercle of the posterior talar process. Level of Evidence: Level III, retrospective comparative study.

Download Full-text