Anatomy of the Tarsal Canal and Sinus in Relation to the Subtalar Joint Capsule

Benign incidental lesion of the calcaneus: the calcaneal vascular remnant

BACKGROUND

The calcaneal vascular remnant, first described by Fleming et al. in 2005, is a benign intramedullary lesion of the calcaneus with a vascular origin.

PURPOSE

To determine the prevalence and magnetic resonance imaging (MRI) characteristics of incidental calcaneal vascular remnant on routine ankle MRI.

MATERIAL AND METHODS

We retrospectively reviewed 457 ankle MRI scans for the presence of calcaneal vascular remnant. MRI was considered positive when a focal cyst-like area was seen on a T2-weighted sequence, and a low signal intensity was identified on a T1-weighted image beneath the calcaneal sulcus. Patients with calcaneal vascular remnants were further evaluated for age, gender, right or left foot location, size, and lesion characteristics.

RESULTS

The prevalence of incidental calcaneal vascular remnant was 21.7% on our consecutive ankle MR examinations. The average lesion size was 5.5 mm. No statistically significant difference was noted in the frequency of lesion detection between gender, age, and side of the lesions (P > 0.05). Multilobulated lesions were detected predominantly in women (P = 0.013) and classic type lesions were detected predominantly in men (P = 0.036).

CONCLUSION

This report is the first to determine the prevalence and MRI characteristics of calcaneal vascular remnants. Detecting and reporting this lesion on routine MRI is essential to avoid confusion with other pathologic entities.

Talus bone: normal anatomy, anatomical variations and clinical correlations

Talus is a pivotal bone that assists in easy and correct locomotion and transfers body weight from the shin to the foot. Despite its small size, it is implicated in many clinical disorders. Familiarity with the anatomy of the talus and its anatomical variations is essential for the diagnosis of any disorder related to these variations. Furthermore, orthopedic surgeons must be fully aware by this anatomy during podiatry procedures. In this review, we attempt to present its anatomy in a simple, updated and comprehensive manner. We have also added the anatomical variations and some clinical points relevant to the unique and complex anatomy of talus. The talus has no muscle attachment. However, it does have many ligaments attached to it and others around it to keep it in place. Moreover, the bone plays a pig role in movements due to its involvement in many joints. Most of its surface is covered with articular cartilage. Therefore, its blood supply is relatively poor. This puts the talus at greater risk for poor healing as well as more complications in the event of injury than any other bone. We hope this review will make it easier for clinicians to pursue and understand the updated essential knowledge of one of the most complex bone anatomies that they need in their clinical practice.

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.

Effect of Ligament Mapping from Different Magnetic Resonance Image Quality on Joint Stability in a Personalized Dynamic Model of the Human Ankle Complex

Background. Mechanical models of the human ankle complex are used to study the stabilizing role of ligaments. Identification of ligament function may be improved via image-based personalized approach. The aim of this study is to compare the effect of the ligament origin and insertion site definitions obtained with different magnetic resonance imaging (MRI) modalities on the mechanical behaviour of a dynamic model of the ankle complex. Methods. MRI scans, both via 1.5 T and 3.0 T, were performed on a lower-limb specimen, free from anatomical defects, to obtain morphological information on ligament-to-bone attachment sites. This specimen was used previously to develop the dynamic model. A third ligament attachment site mapping scheme was based on anatomical dissection of the scanned specimen. Following morphological comparison of the ligament attachment sites, their effect on the mechanical behaviour of the ankle complex, expressed by three-dimensional load–displacement properties, was assessed through the model. Results. Large differences were observed in the subtalar ligament attachment sites between those obtained through the two MRI scanning modalities. The 3.0 T MRI mapping was more consistent with dissection than the 1.5 T MRI. Load–displacement curves showed similar mechanical behaviours between the three mappings in the frontal plane, but those obtained from the 3.0 T MRI mapping were closer to those obtained from dissection. Conclusions. The state-of-the-art 3.0 T MRI image analysis resulted in more realistic mapping of ligament fibre origin and insertion site definitions; corresponding load–displacement predictions from a subject-specific model of the ankle complex showed a mechanical behaviour more similar to that using direct ligament attachment observations.

Calcaneal osteotomy for hindfoot deformity

Calcaneal osteotomy is an extra-articular procedure used for conservative surgical treatment of hindfoot deformity. It has static, architectural and dynamic effects, reorienting the tuberosity action point of the digastric muscle formation of the sural triceps and plantar aponeurosis. Calcaneal osteotomies vary in location, form and displacement, but can be categorized as tuberosity osteotomy, acting on talar position, and cervical osteotomy, acting on Chopart joint-line orientation. We here describe the 3 main calcaneal osteotomies we use for hindfoot deformity: talar varus/valgus, valgus flatfoot, and midfoot abductus/adductus. In each case, we describe our technique, resulting from our responses to the difficulties we have had to deal with: medializing osteotomy: performed percutaneously to limit skin complications, and easily associated to cervical calcaneal osteotomy to manage valgus flatfoot; Hintermann cervical adduction osteotomy: providing excellent angular correction, while conserving a medial cortical hinge; lateralizingosteotomy: performed on a medial approach, to enhance translation capacity and prevent the acute tarsal tunnel syndrome with which we have been otherwise confronted. Correcting foot deformities involves complex, multi-dimensional, multi-tissue surgery that is risky as it concerns a segment with terminal vascularization. The present three techniques need to be mastered, as they are usually associated to other tendon and/or ligament reconstruction procedures, and tourniquet time is limited. LEVEL OF EVIDENCE: V; expert opinion.

Anatomical study of the inferior extensor retinaculum and the oblique superolateral band: implications for the Brostrom-Gould procedure

Purpose

The Brostrom-Gould procedure is currently the gold standard surgical choice for the treatment of chronic ankle instability; it can significantly improve ankle function and stability in patients. However, recent studies have reported doubts regarding the feasibility of the inferior extensor retinaculum (IER) after Brostrom-Gould and therapeutic effects compared with the Brostrom procedure. The purpose of the present study was to observe the anatomical characteristics of the lateral part of the IER using cadaveric bodies in order to guide the surgical operation of chronic ankle instability.

Methods

Twenty-three cadaveric ankles were dissected. The morphology of the IER and its internal structure was observed and recorded for each ankle. The shortest distance between the Stem ligament of the IER and the anterior fibular periosteum (AFP) was measured and recorded, then attempts were made to suture the Stem to the AFP.

Results

Twelve of the cadaveric ankles were observed as having an oblique superolateral band (OSLB) that had a tough texture upward of the lateral IER connecting with SL, as are the characteristics of the oblique superolateral band (OSLB) reported in previous studies. The inner and outer membrane of the OSLB were connected with inner and outer membrane of Stem. The average value of the distance between the Stem and AFP was 11.60 ± 2.71 mm, and the maximum and the minimum distance were 19.04 mm and 6.53 mm, respectively. The P -value (P = 0.2) resulting from a single sample K-S test confirmed that the distribution of distances conformed to normality. None of the SL in the study could be sutured to the AFP.

Conclusion

The OSLB of the IER has a tough texture and connects with the Stem, and has the potential be utilised in the Brostrom-Gould procedure. However, we do not recommend utilization of the Stem in this operation regardless of the distance between the AFP and the Stem. When the Stem cannot be used to enhance repair in this operation, other solutions can be used for strengthening and to protect the repaired ATFL.

Current concepts in sinus tarsi syndrome: A scoping review

INTRODUCTION

Sinus tarsi syndrome is a relatively unknown condition presenting with pain and a feeling of instability. We aim to summarise evidence on the aetiology, diagnosis and treatment of the condition, whilst answering the question of whether the term should be used.

METHODS

Scoping review following the methodological frameworks of Arksey and O'Malley, Levac and Peters. The review protocol is registered with the Open Science Framework: (https://osf.io/wj6ct/?view_only=59445d344ec34b6fab640d2fa7a83943).

RESULTS

In total, 605 studies were identified, 31 of which met selection criteria. Sinus tarsi syndrome is used to describe a range of distinct underlying pathologies. MRI and arthrography show non-specific abnormalities in patients and identifying underlying pathologies is challenging.

DISCUSSION

The distinct range of underlying pathologies makes identifying specific imaging abnormalities and optimal treatments difficult. Further research in determining optimal treatments for specific pathologies and investigating the efficacy of conservative treatment must be conducted, before we can justify a more specific diagnosis.