Accessory talar facet impingement in pathologic conditions of the peritalar region in adults

Non-osseous coalition of accessory anterolateral talar facet-A case series

The accessory anterolateral talar facet (AALTF) is an anatomical variation that broadens the apex of the lateral talar process. Studies have associated it with other tarsal coalitions as a cause of rigid painful flatfoot. However, a coalition of an AALTF has never been described before. With the advent of MRI, there has been an increase in the detection of these accessory facets. Nevertheless, owing to its small size and unfamiliarity, it is not easily identified. Proper assessment of imaging findings and associated conditions is needed to confirm the diagnosis. Imaging findings in a series of four patients with painful rigid flatfoot revealed the presence of an AALTF with adjacent marrow edema and reduced joint space. This was associated with hindfoot valgus and subfibular impingement. Radiographic suspicion of a non-osseous coalition of AALTF was raised, which was confirmed intraoperatively in one of the patients and demonstrated on CT and MR images in the other patients. This case series presents rare cases of non-osseous coalition of AALTF with a new radiographic sign, the 'reverse tip of the iceberg sign'.

The Evolution of Sinus Tarsi Syndrome-What Is the Underlying Pathology?-A Critical Review

Background and Objectives: Sinus tarsi syndrome (STS) is defined as pain located at the lateral opening of the tarsal sinus. The exact etiology of sinus tarsi syndrome is not completely understood. Some do not believe it to be a true pathology. This review aims to clarify the definition of sinus tarsi syndrome to better understand the underlying pathologies. We further propose an algorithm to evaluate sinus tarsi pain and provide advice for consecutive treatment options. Design: This is a narrative review. By searching PubMed, the available current literature was reviewed. Articles were critically analyzed to determine the pathoanatomy, biomechanics, and etiology of sinus tarsi pain. Algorithms for clinical evaluation, diagnosis, and treatment were also recorded. Finally, the authors approach to evaluating and treating sinus tarsi pain was included in this review. Results: Reviewing the available literature, STS seems to be a catch-all phrase used to describe any pain in this anatomic region. Many causes of sinus tarsi pain were listed, including impingement, subtalar instability, and many other pathologies around the ankle. Conclusions: A thorough evaluation of patients presenting with pain in the sinus tarsi or instability of the hindfoot is essential to determining the underlying cause. When the cause of pain is still not clear after clinical exam and radiologic assessment, subtalar arthroscopy can be helpful as both a diagnostic and treatment tool. We propose that the term of STS should be avoided and that a more accurate diagnosis be used when possible. Once a diagnosis is made, appropriate treatment can be initiated.

Sinus tarsi and sinus tarsi syndrome: An imaging review

The sinus tarsi is a funnel-shaped region at the junction of mid-foot and hind-foot which contains fat, vessels, nerves and ligaments. The ligaments help stabilise the subtalar joint and maintain the longitudinal arch of the foot. The nerve endings contain proprioceptive fibres indicating a role for the sinus tarsi in movement of the foot. Sinus tarsi syndrome is a clinical entity characterised by lateral hind-foot pain with worsening on palpation and weight-bearing, and perceived instability. It is associated with both traumatic and non-traumatic causes. Magnetic resonance imaging is the imaging modality of choice for assessment of the sinus tarsi and sinus tarsi syndrome. In this review article, we review the anatomy and various aetiologies of sinus tarsi syndrome, along with the imaging appearances.

Hindfoot Fractures: Injury Patterns and Relevant Imaging Findings

The hindfoot consists of the talus and calcaneus, spans the tibiotalar to transverse tarsal joints, and is critical for support of body weight and absorption and transfer of physiologic loads during bipedal movements. Hindfoot fractures account for approximately 17% of foot and ankle fractures, with calcaneal fractures being more common than talar fractures. Hindfoot fractures are usually caused by high-impact axial loads such as falls from heights and motor vehicle accidents, and understandably, they are often seen in patients with polytrauma. Long term, these fractures have implications in development of posttraumatic osteoarthrosis with associated pain and stiffness, affecting daily living activities. An overview of the talus and calcaneus is presented, with emphasis on fractures with articular involvement-namely, the tibiotalar and subtalar joints. Articular talar and calcaneal injuries can also alter hindfoot alignment, causing ankle and foot function abnormalities. Optimal treatment-that is, restoration of articular surfaces and hindfoot alignment followed by rigid fixation until fracture union-is dependent on an accurate understanding of the injury that is well depicted with imaging, radiography and CT in particular. The discussion of talar and calcaneal fractures includes a review of the normal anatomy, epidemiologic factors, classification systems, and imaging and pathologic-anatomic features of common injury patterns. This review is intended to aid surgical management and restoration of articular and hindfoot alignment for optimal ankle and foot function, thereby reducing patient morbidity in these often devastating injuries. ^©RSNA, 2022.

Accessory Talar Facet Impingement and Sinus Tarsi Pain Associated With Accessory Anterolateral Talar Facet

BACKGROUND

Sinus tarsi pain caused by accessory talar facet impingement (ATFI) owing to accessory anterolateral talar facet (AALTF) is not well documented. We evaluated prevalence of AALTF and differences of magnetic resonance imaging (MRI) findings between persons with and without sinus tarsi pain, and investigated the relevant association between MRI findings and sinus tarsi pain in persons with AALTF.

METHODS

We performed a case-control study on 120 ankles with sinus tarsi pain and 120 age- and gender-matched ankles without sinus tarsi pain. As MRI findings, bone marrow edema (BME), sinus tarsi fat obliteration (STFO), calcaneal cyst, talocalcaneal coalition, Gissane angle, talar inferolateral surface (TILS) angle, and calcaneal cortical thickness (CCT) were evaluated. The MRI findings were compared between persons with and without sinus tarsi pain, and between persons with and without AALTF. Among persons with AALTF, MRI findings were compared between those with and without sinus tarsi pain. Relevant association was evaluated between MRI findings and sinus tarsi pain in persons with AALTF.

RESULTS

Presence of AALTF, BME, and STFO were significantly higher in the group with sinus tarsi pain. The Gissane angle was significantly smaller, and the TILS angle and CCT were significantly larger in the group with sinus tarsi pain. The BME (OR 7.571, CI 1.453-39.446) and small Gissane angle (OR 0.891, CI 0.804-0.986) were significantly associated with sinus tarsi pain in persons with the AALTF.

CONCLUSION

The study provides evidence for ATFI related to impingement of an AALTF associated with talocalcaneal BME.

LEVEL OF EVIDENCE

Level III, case-control study.

Accessory Anterolateral Talar Facet Syndrome After Treatment of Neglected Fracture of the Lateral Process of the Talus: A Case Report

Fracture of the lateral process of the talus has often been missed or confused with lateral ankle sprain, and this can lead to long-term untreated cases of nonunion, malunion, and subtalar joint osteoarthritis. In a review of the published data, accessory anterolateral talar facet syndrome was not found after treatment of nonunion of the lateral process of the talus fracture. This report presents the case of a 40-year-old male snowboard instructor who suffered from a neglected fracture of the lateral process of the talus and was treated with open reduction using an iliac autogenous bone graft. Subsequently, partial resection of the anterior aspect of the process was required to treat the impingement syndrome that developed secondary to the united but enlarged lateral process. The patient resumed his activities a year after the second operation. We describe the consequences of misdiagnosis of the lateral process of the talus and its management.

MRI of lateral hindfoot impingement

Lateral hindfoot impingement (LHI) is a subtype of ankle impingement syndrome with classic MRI findings. Biomechanically, LHI is the sequela of lateral transfer of weight bearing from the central talar dome to the lateral talus and fibula. The transfer occurs due to collapse of the medial arch of the foot, most commonly from posterior tibial tendon (PTT) and spring ligament (SL) insufficiency. Clinical features include lateral hindfoot pain, deformity, and overpronation on gait analysis. MRI changes continuously reflect the altered biomechanics as the syndrome progresses over time, including typical and often sequential changes of PTT and SL failure, increasing heel valgus, talocalcaneal and subfibular impingement, and finally lateral soft tissue entrapment. In addition to diagnosis, MRI is a useful adjunct to plan surgical treatment.

Correlation between the accessory anterolateral talar facet, bone marrow edema, and tarsal coalitions

OBJECTIVE

The purposes of this study was to determine the prevalence of the accessory anterolateral talar facet (AALTF); to evaluate the relationship between AALTF, focal abutting bone marrow edema (FABME), and sinus tarsi edema; and to study the prevalence of tarsal coalitions in patients with the AALTF utilizing ankle MR images.

MATERIALS AND METHODS

5-T ankle MR images were reviewed for the presence of AALTF, FABME, sinus tarsi edema, tarsal coalition, and location and type of coalition (cartilaginous, fibrous, and osseous). Multivariate analysis was performed to examine the correlation between AALTF and the other variables.

RESULTS

Three hundred ninety-one consecutive patients were included (age range 5-86 years; mean age 45 years). An AALTF was present in 3.6% (14/391) of patients. The AALTF prevalence was 2% in women and 6.6% in men. There was a significantly association between AALTF and FABME (9/14, p < 0.05), sinus tarsi edema (13/14, p < 0.05), and tarsal coalition (4/14, p < 0.05).

CONCLUSION

AALTF is relatively often detected on MRI of the ankle and significantly associated with BME, sinus tarsi edema, and subtalar coalition. Patients with a tarsal coalition should be evaluated for the concurrent presence of an AALTF.

Accessory anterolateral talar facet associated with tarsal coalition: prevalence and cross-sectional characterization

OBJECTIVE

The accessory anterolateral talar facet (AALTF) is a developmental entity described as a potential cause for rigid, painful flat foot. This study evaluates the possible association between the AALTF and other flat foot etiologies, specifically different types of tarsal coalitions.

MATERIALS AND METHODS

We evaluated patients with tarsal coalition or sinus tarsi syndrome for an AALTF on CT and MRI. Exclusion criteria included acute ankle trauma, recent surgery, motion or metal artifacts. We evaluated the AALTF length and height, and the lateral talocalcaneal structures for associated findings. The presence of calcaneonavicular (CNC), intra-articular middle facet talocalcaneal (MFTCC), posterior facet talocalcaneal (PFTCC), extra-articular posteromedial talocalcaneal (EATCC) and other rare coalitions were also evaluated.

RESULTS

One hundred eighty-seven patients were included (age range 14-91 years; mean ± SD; 50 ± 17 years). The AALTF prevalence in the study population was 31.55% (59/187), 40.91% in men, and 23.23% in women. The AALTF average length was 4.5 ± 1.1 mm, and average height was 8.9 ± 3.4 mm. The AALTF was found to be significantly associated with lateral talocalcaneal osseous changes such as cortical thickening and cystic changes (34/59 and 24/59 respectively, P < 0.01). The AALTF was also found to be significantly associated with sinus tarsi edema on MRI (45/52, P < 0.05). The AALTF was also significantly associated with EATCC (19/59, P < 0.01) and MFTCC (7/59, P < 0.05). No significant association was found with CNC, PFTCC or other rare coalitions.

CONCLUSION

The AALTF is common and significantly associated with some tarsal coalitions, specifically EATCC and MFTCC. When an AALTF or coalition is identified, special attention should be made to evaluate for other associated pathologies, as this could potentially affect management.

Accessory anterolateral talar facet: analysis of the morphologic features on MRI

PURPOSE

To analyze the morphologic features of accessory anterolateral talar facet (AALTF) on MRI that can assist in detecting this entity, identify any associated structural changes and also define its MRI prevalence.

METHODS

Two radiologists retrospectively evaluated 140 ankle MRI scans for the presence of AALTF, complimentary anterior calcaneal extension facet and angle of Gissane measurement. One observer evaluated the scans for other structural details including AALTF length, cartilage thickness, bone marrow edema, hind foot coalition and talar beaking.

RESULTS

There was a good inter-observer agreement for the detection of AALTF on MRI (Kappa = 0.64). AALTF was present in 33 out of 140 (23.6%) scans. There was no significant difference in the prevalence of AALTF between male and female subjects (P = 0.71). No significant difference in age between those with and those without AALTF (P = 0.96). Angle of Gissane was significantly smaller in ankles with AALTF (P = 0.0367, observer 1 and 0.0003, observer 2). AALTF had a mean length of 7 mm and was covered with cartilage in 25/33 (75.8%) with mean cartilage thickness of 1.4 mm. Complimentary cartilage covered anterior calcaneal facet was demonstrated in 10/33 (30.3%) and had a mean cartilage thickness of 2.5 mm. Talar beaking was more prevalent in ankles with AALTF showing an anterior calcaneal extension facet than those without the latter feature (P = 0.02).

CONCLUSION

AALTF is a frequently observed feature on ankle MRI, with good inter-observer reliability for its detection. When present, it is often opposed by a cartilage covered anterior calcaneal extension facet, which can be associated with talar beaking.

Accessory anterolateral talar facet impingement with tibialis spastic varus foot

In recent years, some authors have reported accessory anterolateral talar facet impingement with flatfoot including peroneal spastic flatfoot. Conversely, to our knowledge, no case report has been published about accessory anterolateral talar facet impingement with tibialis spastic varus foot. We report the first case in a 22-year-old man with intellectual disability, bilateral cleft hands and type 1 diabetes mellitus. Since spraining his left ankle over a year earlier, he experienced left sinus tarsi pain while standing and walking. Physical examination revealed that his left foot was in the varus position with spasm of the anterior tibial muscle, tenderness in the sinus tarsi and lateral hindfoot pain upon attempted passive hindfoot eversion. He could not stand on his left toes. His pain decreased after lying down and receiving a massage on his anterolateral lower leg at night. Radiographs and computed tomography scans revealed the absence of tarsal coalition and the presence of accessory anterolateral talar facet in both feet. Magnetic resonance imaging demonstrated abutting bone marrow edema between the talus and calcaneus around the accessory anterolateral talar facet. We diagnosed the patient with accessory anterolateral talar facet impingement and tibialis spastic varus foot. After conservative treatment failed, resection of accessory anterolateral talar facet achieved good results with short-term follow-up.

Accessory Anterolateral Talar Facet in Populations With and Without Symptoms: Prevalence and Relevant Associated Ankle MRI Findings

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 talocalcaneal 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 accessory 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 obliteration (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 anterolateral talar facet in ankles with 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 individuals with symptoms.

Arthroscopic Debridement of Pediatric Accessory Anterolateral Talar Facet Causing Impingement

Symptomatic subfibular and/or lateral talocalcaneal impingement in pediatric patients may result from an accessory anterolateral talar facet (AALTF). This impingement may cause pain and disability and may limit athletic performance in high-level athletes. We report the case of a 12-year-old female competitive gymnast who had refractory, lateral-sided right ankle pain for 4 months and underwent right ankle arthroscopic resection of the AALTF causing impingement. Standard medial and anterolateral portals with the addition of an accessory anterolateral-distal portal were used in conjunction with a 30° 2.7-mm-diameter arthroscope. The AALTF was resected with a combination of a shaver and a motorized rasp. Intraoperative fluoroscopy was used to verify successful debridement of the bony facet. This case illustrates that arthroscopic debridement is a technique to treat subfibular and/or talocalcaneal impingement associated with an AALTF.