conservative treatment and in histologic sec-tions of the excised facet specimens [8]. Re-section of the facet from patients with acces-sory anterolateral talar facet impingement has been reported to relieve pain and reduce or eliminate focal subjacent bone marrow edema–like changes on MR images [7, 8].
To our knowledge, there has been no report of the prevalence of accessory anterolateral talar facet in a living population. The aim of this study was to determine the prevalence of accessory anterolateral talar facet and the rel-evant associated findings during ankle MRI of populations with and without symptoms. Subjects and Methods
Study Population
This prospective case-control study encom-passed MRI of 110 ankles with symptoms in 100
Accessory Anterolateral Talar Facet
in Populations With and Without
Symptoms: Prevalence and Relevant
Associated Ankle MRI Findings
Üstün Aydıngöz
1Osman Melih Topcuoğlu
1Aysegül Görmez
1Tijen Cankurtaran
1Elif Dilara Topcuoğlu
2Fatma Bilge Ergen
1Aydıngöz Ü, Topcuoğlu OM, Görmez A, Cankurtaran T, Topcuoğlu ED, Ergen FB
1Department of Radiology, Hacettepe University School of Medicine, Sihhiye, 06100 Ankara, Turkey. Address correspondence to Ü. Aydıngöz (ustunaydingoz@yahoo.com).
2Department of Radiology, Ufuk University School of Medicine, Ankara, Turkey.
AJR 2016; 207:846–851
0361–803X/16/2074–846 © American Roentgen Ray Society
F
irst described by Sewell in 1904 as facies externa accessoria cor-poris tali [1], accessory antero-lateral talar facet (Fig. 1) is an anatomic variation of the talocalcaneal artic-ulation. Originally reported to be present in 10.2% of 1006 tali in a study conducted in Egypt [1], this facet was found in 25–34% of cadaveric specimens in later studies [2–5]. The accessory anterolateral talar facet has been implicated as an etiologic factor in pain-ful talocalcaneal impingement in rigid flat-foot during adolescence [6, 7] and adulthood [8]. CT and MRI were used to identify the ac-cessory anterolateral talar facet in several clinical studies [6–8]. A layer of articular car-tilage covering the facet and spreading from the facet was identified during arthroscopy of patients with sinus tarsi pain refractory toKeywords: ankle, MRI, sinus tarsi, talocalcaneal articulation
DOI:10.2214/AJR.16.16056
Received January 2, 2016; accepted after revision March 14, 2016.
OBJECTIVE. The purpose of this study was to determine the prevalence of and relevant findings associated with the accessory anterolateral talar facet, which may have a role in ta-localcaneal impingement and sinus tarsi syndrome, on ankle MR images of persons with and those without symptoms.
SUBJECTS AND METHODS. In this case-control study, three observers independently reviewed 1.5-T or 3-T MR images of 110 ankles with symptoms in 100 consecutively registered patients (age range, 16–79 years; mean, 41.5 years) and limited 1.5-T MR images of 104 age-, sex-, and side-matched ankles in 104 volunteers without symptoms for the presence of an ac-cessory anterolateral talar facet, calcaneal cortical thickness, subjacent talar or calcaneal cystic and bone marrow edema–like changes at the angle of Gissane, and sinus tarsi fat obliteration.
RESULTS. An accessory anterolateral talar facet was present in 36 (32.7%) ankles with symptoms versus 27 (26.0%) symptom-free ankles (p = 0.297). Interobserver agreement was almost perfect (κ = 0.851; 95% CI, 0.772–0.929) for the detection of accessory anterolateral talar facet and substantial for the detection of sinus tarsi fat obliteration (κ = 0.671; 95% CI, 0.427–0.915). The angle of Gissane was significantly smaller in persons with an accessory anterolateral talar facet, either with or without symptoms (p < 0.0001). Subjacent talar (p = 0.003) and calcaneal (p = 0.033) bone marrow edema–like change and sinus tarsi fat oblit-eration (p = 0.034) were significantly more frequent in persons with accessory anterolateral talar facet, but chronic reactive osseous changes at the angle of Gissane were not (p > 0.05).
CONCLUSION. The higher prevalence of the MRI finding of an accessory anterolat-eral talar facet in ankles with and without symptoms is not statistically significant. This facet may be associated with subjacent talar bone marrow edema–like change on MR images of individuals with and those without symptoms and with sinus tarsi fat obliteration in individu-als with symptoms.
Aydıngöz et al.
MRI of Accessory Anterolateral Talar Facet Musculoskeletal Imaging
Original Research
consecutively registered patients with ankle pain and 104 age-, sex-, and side-matched ankles in 104 volunteers without symptoms at a university hospital (Table 1). The body mass index (BMI) of study participants was calculated; however, no at-tempt was made to match the BMIs of the groups with and without symptoms. All patients with an-kle pain who gave informed consent were eligible for participating in the study. Volunteers included only those who did not have ankle or foot pain or had not sustained an ankle sprain during the last month. Patients and volunteers with a history of surgery or fracture at the ankle or midfoot were excluded from the study. The study received insti-tutional review board approval, and informed con-sent was obtained from all patients and volunteers. MRI Protocols and Observation Settings
Ankle MRI examinations were performed with any of three 1.5-T scanners in our department (SymphonyTim, Siemens Healthcare; Achieva, Philips Healthcare; Signa HDxt, GE Healthcare) and with dedicated coils. Subjects were in su-pine position with foot relaxed and toes pointing up. Our routine ankle MRI protocol consisted of the following sequences: coronal, sagittal, and transverse fat-saturated T2-weighted spin-echo (TR/TE, 2500–4470/60–71; matrix, 256–512 × 256–512; number of signals acquired, 1–6; FOV side range 16–20 cm; slice thickness, 3.0–3.5 mm; interslice gap, 3.1–4.5 mm) and sagittal and transverse T1-weighted spin-echo (TR/TE, 507– 580/10–20; matrix, 256–320 × 256–320; number of signals acquired, 1–3; FOV side range 16–20 cm; slice thickness, 3.0–3.5 mm; interslice gap, 3.1–4.5 mm). The patients in the study underwent
routine ankle MRI, but the symptom-free volun-teers underwent a limited MRI protocol consist-ing of sagittal T1-weighted and T2-weighted fat-saturated sequences. Sagittal MR images of both patients and volunteers were aligned parallel to the longitudinal axis of the talus.
MRI evaluations in this study were indepen-dently performed on sagittal T1-weighted and T2-weighted fat-saturated images by three radi-ologists (two with 19 and 8 years of experience in musculoskeletal imaging and one junior radi-ologist who had just finished a 4-year residency) using the viewer of a PACS (Centricity RA1000, GE Healthcare) on medical diagnostic display monitors. In an attempt to standardize the im-age reviewing conditions, radiologists turned on the 2× magnification setting of the PACS viewer at the start of their MRI evaluation of each
pa-tient or volunteer. Observers were not blinded to the symptomatic or asymptomatic background of study participants.
Quantitative and Qualitative MRI Assessments Quantitative assessment—The accessory
an-terolateral talar facet was defined on sagittal MR images as contiguous spread of the posterior talo-calcaneal facet articulation of the talus anterior to the lateral process of the talus [8]. To set an objec-tive criterion for deciding on the presence of the accessory anterolateral talar facet for two inde-pendent observers (i.e., the senior musculoskeletal radiologist and the junior radiologist), we defined the following measurements either on the sagittal T1-weighted MR image that showed the medial aspect of the fibula along with the tibia or on the image just medial to that one. We first measured the critical angle of Gissane (formed between the lines along the superior margin of the anterior pro-cess of the calcaneus and along the posterior cal-caneal facet of the subtalar joint) and then divided it by two; the accessory anterolateral talar facet was present if the resulting bisecting line (drawn by actual measurement) crossed an anterior bony protuberance at the anterolateral aspect of the ta-lus (Fig. 2). Ten routine ankle MRI examinations of patients not in the study group but who met the same inclusion criteria were randomly select-ed for a test session precselect-eding the evaluation of the study groups. In the first five cases, the senior musculoskeletal radiologist identified the acces-sory anterolateral talar facet by using the angu-lar measurement method described to the junior radiologist, who thereafter performed the mea-surements in the other five cases under the senior radiologist’s supervision before starting to inde-pendently review the images of the study group. Interobserver agreement analysis was made with independent observer decisions regarding the TABLE 1: Characteristics of Study Group and of Accessory Anterolateral
Talar Facet on MR Images
Characteristic Patients With Symptoms (n = 100) Volunteers Without Symptoms (n = 104) p
Ankles studied with MRI 110a 104 NA
Age (y) 41.5 (16–79) 40.3 (18–80) 0.571
Sex 1.000
Women 54 (54.0) 56 (53.8)
Men 46 (46.0) 48 (46.2)
Body mass index 26.8 (17.2–38.1) 25.5 (18.1–34.8) 0.085
Ankle sidea 1.000
Right 61 (55.5) 57 (54.8)
Left 49 (44.5) 47 (45.2)
Accessory anterolateral talar facet 36b (32.7) 27 (26.0) 0.297 Note—Data are mean with range in parentheses or number with percentage within the group in parentheses.
NA = not applicable.
aBilateral in six female and four male patients with symptoms. bBilateral in four patients with symptoms.
A
Fig. 1—Accessory anterolateral talar facet.
A and B, Schematics of ankle viewed from lateral side show talus (green) without (A) and with (B) accessory
anterolateral talar facet (circle, B). Light gray indicates articular surfaces. (Adapted from Essential Anatomy 5 App with permission of 3D4Medical.com)
B
presence of an accessory anterolateral talar facet based on their measurements. In cases of conflict between observers, the final decision was reached by consensus. We also measured the calcaneal cortical thickness, including subchondral sclero-sis when present, at the apex of the angle of Gis-sane on T1-weighted MR images.
Qualitative assessment—The senior
muscu-loskeletal radiologist identified cystic changes within the calcaneus at the angle of Gissane on MR images. Such changes were characterized as well-defined structures of vessellike, tubular, fusi-form, globular, or lobulated fluid signal intensity of any size within the calcaneus bone marrow sub-jacent to the angle of Gissane that might or might not have disrupted the bone cortex on MR imag-es. The senior musculoskeletal radiologist and the ju-nior radiologist independently noted talar or calcane-al subcorticcalcane-al bone marrow edema–like changes at the angle of Gissane and elsewhere in tarsal bones on MR images. Bone marrow edema–like change was described as ill-defined fluid signal in-tensity in the bone marrow subjacent to the talar or calcaneal cortex at the angle of Gissane. Final-ly, the two musculoskeletal radiologists used vi-sual estimation to independently identify persons with more than 50% sinus tarsi fat obliteration on T1-weighted MR images. Interobserver agreement analysis was made by independent observation. In cases in which there was conflict between observ-ers, the final decision was reached by consensus. Statistical Analysis
Data analysis was performed with Microsoft Ex-cel 2010 for Windows and free online resources at the GraphPad Software website. Continuous vari-ables were recorded as mean ± SD unless otherwise noted. Although the differences between groups
were compared by Fisher exact test and t test, the re-lation between continuous variables was evaluated by Spearman correlation test. A value of p < 0.05 was considered statistically significant. Interobserv-er agreement was assessed with kappa statistics [9]. Results
Study Population
There was no statistically significant differ-ence between patients and volunteers with re-spect to age, sex, ankle side, or BMI (Table 1). Quantitative and Qualitative MRI Assessments Quantitative assessment—An accesso-ry anterolateral talar facet was present in 36 ankles with symptoms (32.7%; 24 wom-en, 12 men) and 27 ankles without symp-toms (26.0%; 15 women, 12 men) (p = 0.297) (Table 1). No sex or side predominance was identified for the presence of an accessory anterolateral talar facet in either population. Of the 10 patients who underwent bilateral ankle MRI studies, six had an accessory an-terolateral talar facet, and of those, four had bilateral facets (all subjects without symp-toms underwent unilateral ankle MRI). In-terobserver agreement was almost perfect (κ = 0.851; 95% CI, 0.772–0.929) for the de-tection of accessory anterolateral talar fac-et [9]. The observers agreed on the presence or absence of an accessory anterolateral ta-lar facet in 201 of 214 ankles. There was no significant difference in mean BMI of per-sons with or without an accessory antero-lateral talar facet in either the group with symptoms (p = 0.290) or the group without symptoms (p = 0.704). The angle of Gissane ranged between 94° and 128° (mean, 113.7°)
in patients with symptoms and between 95° and 129° (mean, 113.6°) in volunteers without symptoms. The difference was not significantly different between the groups with and without symptoms (p = 0.888), but a significantly smaller angle was found in persons with an accessory anterolateral ta-lar facet in both populations (Table 2). Mean calcaneal cortical thickness (including sub-chondral sclerosis when present) at the apex of angle of Gissane was significantly great-er at 2.4 ± 1.0 mm (range, 0.9–5.2 mm) in ankles with symptoms versus 1.9 ± 1.0 mm (range, 0.6–7.7 mm) ankles without symp-toms (p = 0.0005); however, this thickness was not significantly different between per-sons with and those without an accessory an-terolateral talar facet (Table 2).
Qualitative assessment—Subjacent ta-lar bone marrow edema–like change was significantly more frequent in both ankles with (p = 0.0003) and those without (p = 0.016) symptoms in which accessory antero-lateral talar facet was present (Table 2, Figs. 3 and 4), whereas such calcaneal change was significantly more frequent only in ankles with symptoms and an accessory antero-lateral talar facet (p = 0.033) (Table 2, Fig. 4). Further questioning of volunteers with-out symptoms who had such bone marrow changes did not disclose any traumatic inju-ry to the ankle in the last 6 months (i.e., even beyond the eligibility criterion of 1 month). Interobserver agreement for the identifica-tion of alteraidentifica-tions in bone marrow signal in-tensity at the angle of Gissane was perfect for the talar side (κ = 1.000; 95% CI, 1.000– 1.000) and substantial for the calcaneal side TABLE 2: MRI Findings
Parameter
Ankles With Symptoms (n = 110) Ankles Without Symptoms (n = 104) With Accessory Anterolateral Talar Facet (n = 36) Without Accessory Anterolateral Talar Facet (n = 74) p With Accessory Anterolateral Talar Facet (n = 27) Without Accessory Anterolateral Talar Facet (n = 77) p Angle of Gissane (°) 109.7 ± 1.1 115.6 ± 0.7 < 0.0001 108.7 ± 1.1 115.2 ± 0.8 < 0.0001 Measurements and observations at angle of Gissane
Calcaneal cortical thickness (mm) 2.4 ± 0.2 2.4 ± 0.1 1.000 2.0 ± 0.2 1.9 ± 0.1 0.629
Calcaneal cystic changes 17 (47.2) 51 (68.9) 0.037 20 (74.1) 47 (61.0) 0.252
Bone marrow edema–like change
Talar 7 (19.4) 0 0.0003 3 (11.1) 0 0.016
Calcaneala 3 (8.3) 0 0.033 0 0 NA
Sinus tarsi fat obliteration 7 (19.4) 3 (4.1) 0.034 0 0 NA
Note—Data are mean ± standard error of the mean in parentheses or number with percentage within the subgroup with or without accessory anterolateral talar facet in parentheses. NA = not applicable.
aAll three ankles with calcaneal bone marrow edema–like change also had talar bone marrow edema–like change at angle of Gissane.
(κ = 0.662; 95% CI, 0.222–1.000) [9]. In sub-jects without symptoms who had an acces-sory anterolateral talar facet, mean BMI was not significantly different between those with subjacent talar bone marrow edema–like changes and those without them (p = 0.867). In subjects with symptoms and an accessory anterolateral talar facet, however, mean BMI was significantly greater in those with subja-cent bone marrow edema–like change on the talar side (p = 0.016) but was not significant-ly different on the calcaneal side (p = 0.295). Calcaneal cystic changes at the angle of Gissane were identified in 61.8% of ankles with symptoms and 64.4% of ankles without symptoms (p = 0.777). More than 50% oblit-eration of the sinus tarsi fat was significant-ly more frequent in persons with an accessory anterolateral talar facet (p = 0.034). No volun-teers without symptoms had greater than 50% obliteration of the sinus tarsi fat. Interobserver agreement was substantial (κ = 0.671; 95% CI, 0.427–0.915) for the identification of greater than 50% sinus tarsi fat obliteration [9].
Correlation between the presence of an accessory anterolateral talar facet and bone marrow edema–like change on the talar side of the angle of Gissane was weak (r = 0.34, p < 0.001) and on the calcaneal side was very weak (r = 0.18, p < 0.001). Correlation be-tween the presence of an accessory
antero-lateral talar facet and greater than 50% sinus tarsi fat obliteration in the population with symptoms was weak (r = 0.25, p < 0.001).
Discussion
In this study, we found that the accesso-ry anterolateral talar facet was present at a higher prevalence in a population with symp-toms (32.7%) than in a population without symptoms (26.0%), although not to a statis-tically significant degree. The prevalence of an accessory anterolateral talar facet was originally reported in 1904 to be 10.2% [1]. Our results on the prevalence of the accesso-ry anterolateral talar facet in living subjects are similar to the prevalence found in later studies of cadaveric specimens (25–34%) [2– 5]. The frequency of bilaterality of the fac-et in paired ankles in our study was 66.7%, exactly matching the results of a cadaveric dried-bone study of the accessory anterolat-eral talar facet by Martus et al. [3] in a pedi-atric osteologic collection of 79 specimens. Martus et al. also found a prevalence 34% for presence of the facet, which was associated with male sex, a smaller angle of Gissane, and dorsal talar beaking. In our study, how-ever, the accessory anterolateral talar facet in the population without symptoms (prev-alence, 26%) was not associated with any sex predominance. In the population with symptoms, however, the accessory antero-lateral talar facet (prevalence, 32.7%) was significantly more common in women. A
Fig. 2—Assessment process. Accessory anterolateral talar facet is defined as contiguous spread of posterior
talocalcaneal facet articulation of talus anterior to lateral process of talus. In objective assessment, reviewers first identified angle of Gissane (solid lines) on sagittal T1-weighted MR images showing lateral aspect of talocalcaneal articulation and bisected angle (by actual measurement) into two halves (thick dotted line).
A, 28-year-old man with symptoms. MR image shows accessory anterolateral talar facet (thin dotted line)
indicated by bisecting line crossing anterior bony protuberance at anterolateral aspect of talus.
B, 33-year-old woman with symptoms who does not have accessory anterolateral talar facet.
B
Fig. 3—37-year-old man without symptoms and
body mass index of 23.2. Sagittal fat-saturated T2-weighted MR image shows subcortical bone marrow edema–like lesion subjacent to accessory anterolateral talar facet (arrows).
Fig. 4—76-year-old man with ankle pain. Sagittal
fat-saturated T2-weighted MR image shows talar and calcaneal subcortical bone marrow edema–like lesions subjacent to and surrounding accessory anterolateral talar facet (arrows).
Our findings were similar to those of Mar-tus et al. [3] in that the angle of Gissane was significantly smaller in persons with an ac-cessory anterolateral talar facet, both those with and those without symptoms. The reason for such significant narrowing of the angle of Gissane in persons with an accessory antero-lateral talar facet is not clear. Our results in this regard differ from those of Hirano et al. [5], who reported no significant difference in angle of Gissane in 44 feet obtained from 22 cadavers used for systemic autopsy.
Although talar beaking is reportedly asso-ciated with the presence of an accessory an-terolateral talar facet [3, 6], we did not look into this condition in our study because there is no established criterion for the differentia-tion of a talar beak from other bony excres-cences, such as an osteophyte or enthesophyte in this region [10, 11]. The reports of studies that proposed an association of talar beaking with the accessory anterolateral talar facet [3, 6] do not clearly describe what constitutes a talar beak and how it is differentiated from other bony excrescences, including the dorsal talar ridge with a variable size [10], that are not rare in the dorsal anterior aspect of the ta-lus. Furthermore, in the study by Hirano et al. [5], in which an accessory anterolateral talar facet was identified in 25% of 44 cadaveric feet, dorsal talar beaking was sought and not identified in any specimen (mean age at death of the cadavers, 86.5 years).
Anatomic variants become clinically im-portant when they predispose to pathologic conditions, such as increased wear of or
im-pingement on the adjacent soft tissues or os-seous structures. Type 2 lunate and unfused ossification centers such as os acromiale or a type 2 accessory navicular are among exam-ples of variants associated with such patho-logic conditions. Similarly, the anatomic variant of accessory anterolateral talar fac-et has been implicated in talocalcaneal im-pingement and sinus tarsi syndrome [6–8]. The accessory anterolateral talar facet like-ly contributes to these pathologic conditions by passing along the body weight through a wider area of the talocalcaneal articulation in the presence of increased hindfoot valgus stress, especially in patients with pes planus (Fig. 5), and by narrowing an already con-fined soft-tissue space in sinus tarsi syn-drome, which may actually be a part of the talocalcaneal impingement.
In this study, we used the MRI findings of talar or calcaneal bone marrow edema– like signal intensity, calcaneal cystic changes, and calcaneal cortical thickness at the an-gle of Gissane as possible indicators of re-active changes to increased chronic stress at the talocalcaneal articulation. Bone marrow edema–like change at the talus or calcaneus centered at the angle of Gissane in our study did not originate from (or extend) elsewhere in these bones. Likewise, we used the MRI finding of sinus tarsi fat obliteration as an in-dicator of sinus tarsi syndrome [12, 13]. We found that greater than 50% obliteration of sinus tarsi fat was significantly more com-mon in patients with accessory anterolater-al tanterolater-alar facet than in those without a facet.
Interestingly, on MR images of persons with accessory anterolateral talar facet, we did not identify an increased prevalence of cys-tic changes or increased corcys-tical thickness in the calcaneus at the angle of Gissane. Over-all, however, persons with symptoms did have significantly increased cortical thick-ness at the angle of Gissane than did vol-unteers without symptoms, likely reflecting subchondral sclerosis reactive to increased stress at the ankles with symptoms.
Cystic lesions within the midcalcane-al body near the angle of Gissane are fre-quently seen at ankle MRI. Elias et al. [14] found that such cystic lesions were present in 40% of 198 ankles in consecutively regis-tered patients [14]. They also found that the location of cystic foci corresponded to pen-etrating microvessels on contrast-enhanced MR images, suggesting that these foci may represent intraosseous ganglion cysts along-side these vessels. The higher prevalence of such cystic foci in our study (61.8% of an-kles with symptoms, 64.4% of those without symptoms) may be due to the possibility that some of the thin tubules we identified as cys-tic foci were actual vessels. We were not able to make this distinction because our routine ankle MRI protocol does not include IV con-trast administration. An interesting finding in our study was that calcaneal cystic chang-es were significantly lchang-ess frequent in anklchang-es with symptoms and an accessory anterolat-eral talar facet. This may be due to a possibly more marked compressive effect of the facet in ankles with symptoms. This effect
some-A
Fig. 5—12-year-old boy with ankle pain (not study participant).
A, Weight-bearing lateral ankle radiograph shows calcaneal pitch angle of 12°, indicating pes planus. Accessory anterolateral talar facet (asterisk) is evident.
B and C, Sagittal T1-weighted (B) and fat-saturated T2-weighted (C) MR images show talar and calcaneal subcortical bone marrow edema–like lesions subjacent to and
surrounding accessory anterolateral talar facet (asterisks).
C B
what seals off the angle of Gissane and de-creases the possibility of formation of such cystic spaces alongside perforating vessels.
Our study had several limitations. First, our population was somewhat small. How-ever, the populations with and without symp-toms were well matched, and the sizes of the groups rendered statistical analysis pos-sible. In addition, our overall study popula-tion was larger than those in all, to our knowl-edge, cadaveric studies [2–5] conducted after Sewell’s original description [1]. Second, the observers in our study were not blinded to the symptomatic or asymptomatic background of study participants, and this might have result-ed in bias in the evaluation of bone marrow signal intensity and calcaneal cortical thick-ness at the angle of Gissane and in sinus tarsi fat assessment. However, this limitation did not preclude our observers from identify-ing talar bone marrow edema–like signal in-tensity at the angle of Gissane in volunteers without symptoms. Neither of the two mus-culoskeletal radiologists in our study identi-fied sinus tarsi syndrome, a painful condition that has been described as being associated with the MRI finding of sinus tarsi fat oblit-eration [12, 13], in any of the pain-free volun-teers. Third, for ethical reasons, weight-bear-ing foot radiographs were not obtained for the population without symptoms and were avail-able only for some of the patients with symp-toms. Therefore, pes planus and hindfoot valgus could not be factored into the study. Finally, because the control group (volunteers without symptoms) underwent limited MRI, we did not correlate pathologic MRI findings
elsewhere in the ankle with the prevalence of an accessory anterolateral talar facet. Conclusion
The accessory anterolateral talar facet is present on MR images of approximate-ly one-third of ankles with symptoms and one-fourth of ankles without symptoms. The higher prevalence of the MRI finding of an accessory anterolateral talar facet in ankles with symptoms than in those without symp-toms is not statistically significant. The ac-cessory anterolateral talar facet may be as-sociated with the MRI findings of subjacent talar and calcaneal bone marrow edema–like change and sinus tarsi fat obliteration. Acknowledgment
We thank Selda Emre Aydıngöz for help in data interpretation and statistical analysis. References
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