Posterior ankle labral changes at MRI: A preliminary study

Prevalence and clinical aspects of os trigonum: a meta-analysis

Os trigonum (OT) is one of the most common accessory ossicles in the foot and ankle region. It is believed that OT was first described by Rosenmuller in 1804, but von Bardeleben is the one who coined the nomenclature for this anatomical variation in 1883. The literature indicates that OT is extremely variable in prevalence, with reported rates ranging from 1.7% to 32.5%. In clinical practice, OT is a considerable factor that may predispose patients to posterior ankle impingement syndrome (PAIS). The aim of this study was to provide comprehensive data on the prevalence and anatomical characteristics of OT. We conducted a comprehensive search of the main electronic databases to find the relevant research. Information concerning geographical origin, prevalence, gender distribution, imaging modality, and morphometry of OT was extracted. The PRISMA guidelines were strictly followed throughout the study. The reliability of the included studies was assessed using the AQUA tool. A total of 41 studies (n = 36,612 feet) were included in this meta-analysis. This meta-analysis showed that OT was present in 9.0% (95% CI: 7.4-10.8) of the feet, and was present bilaterally in 32.7% (95% CI: 23.3-43.7) of cases. Regarding the types of imaging modality used in the evaluation of OT by the included studies, prevalence assessed by X-rays was 8.2% (95% CI: 6.8-9.9), MRI was 24.2% (95% CI: 14.6-37.3), CT was 21.0% (95% CI: 12.8-32.5), and cadaveric dissection was 5.0% (95% CI: 3.4-7.4). OT was most commonly found in East Asia (11.0%, 95% CI: 7.1-16.8). Two studies provided enough data to calculate the odds ratio linking PAIS with OT. The analysis showed that patients with PAIS are almost 16 times more likely to have OT compared to those without PAIS (OR = 15.98, 95% CI = 0.255-1002.8). OT is a very common accessory ossicle and is present in nearly one in 10 feet. The highest prevalence is noted in the East Asian population. MRI and CT show the highest prevalence of OT. It is important to keep in mind the possible presence of OT when a patient is diagnosed with PAIS.

Posterior Ankle Impingement Syndrome Clinical Features Are Not Associated With Imaging Findings in Elite Ballet Dancers and Athletes

OBJECTIVE

To assess the association between clinical features and magnetic resonance imaging (MRI) findings in posterior ankle impingement syndrome (PAIS) and to compare the prevalence of imaging findings between participants with and without a clinical diagnosis of PAIS.

DESIGN

Case-control study.

SETTING

Elite ballet and sport.

PARTICIPANTS

Eighty-two male (54%) and female participants comprising ballet dancers (n = 43), cricket fast bowlers (n = 24), and football (soccer) players (n = 15).

INDEPENDENT VARIABLES

Clinical: posterior ankle pain on body chart, passive plantarflexion pain provocation test. Patient-reported outcome measures: Oslo Sports Trauma Research Center Overuse Injury Questionnaire, Foot and Ankle Ability Measure Sports subscale.

MAIN OUTCOME MEASURES

Imaging findings including posterior ankle bone marrow edema, os trigonum (± bone marrow edema, and increased signal at synchondrosis), Stieda process (± bone marrow edema), talocrural and subtalar joint effusion-synovitis size, flexor hallucis longus tendinopathy, and tenosynovitis identified as present or absent on 3.0-Tesla MRI.

RESULTS

Imaging findings were not associated with posterior ankle pain or a positive ankle plantarflexion pain provocation test. Imaging findings were not associated with patient-reported outcome measures. Imaging findings did not differ between PAIS-positive and PAIS-negative groups. Os trigonum and Stieda process were prevalent despite clinical status.

CONCLUSIONS

The lack of association between imaging findings and clinical features questions the role of imaging in PAIS. Clinicians should rely primarily on clinical assessment in the diagnosis and management of patients with PAIS.

The prevalence of posterior inferior tibiofibular ligament and inferior tibiofibular transverse ligament injuries in syndesmosis-injured ankles evaluated by oblique axial magnetic resonance imaging: a retrospective study

Background

Transverse ligament and posterior inferior tibiofibular ligament injuries have not been investigated till date because these are difficult to evaluate using standard magnetic resonance imaging. This study aimed to investigate the prevalence of transverse ligament and posterior inferior tibiofibular ligament injuries in syndesmosis-injured ankles using oblique axial magnetic resonance imaging.

Methods

The patients who were diagnosed with syndesmosis injury using magnetic resonance imaging (MRI) within 7 days of the trauma were included. Patients with concomitant fractures were excluded. A total of 34 patients (1 woman and 33 men) with an average age of 22 years (range, 14–64 years) were included. The anterior inferior tibiofibular, interosseous, transverse, and posterior inferior tibiofibular ligaments were classified as intact, partial tear, or complete tear using usual axial and oblique axial MRIs.

Results

There were 8 (23.5%) ankles with an intact, 21 (61.8%) ankles with a partially torn, and 5 (14.7%) ankles with a complete tear of transverse ligament. There were 20 (58.8%) ankles with an intact, 12 (35.3%) ankles with a partially torn, and 2 (5.9%) ankles with a complete tear of posterior inferior tibiofibular ligament. Overall, 50% of the transverse ligament injuries occurred without posterior inferior tibiofibular ligament involvement.

Conclusions

The oblique axial magnetic resonance imaging scan revealed that the prevalence of transverse ligament and posterior inferior tibiofibular ligament injuries in syndesmosis-injured ankles were 76.5 and 41.2%, respectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05220-0.