An attachment-based description of the medial collateral and spring ligament complexes

Deltoid ligament injuries: A review of the anatomy, diagnosis and treatments

PURPOSE

Ankle sprains remain the most common soft tissue injury presenting to Emergency Departments. Recently, there has been increased awareness and reporting of deltoid ligament injuries in association with injuries to the lateral ligament complex as well as with fibula fractures. This article reviews the currently available literature on the anatomy of the deltoid ligament, clinical and radiological diagnosis of injuries to the deltoid ligament and treatment recommendations.

METHODS

A literature review was conducted for keywords associated with deltoid ligament injuries. MEDLINE, PubMed and Embase databases were utilised for this search. Articles were included if involving an adult population, were English-language, were related to deltoid ligament injuries (with or without associated injuries) and reported on patho-anatomy, clinical or radiological diagnosis or treatment methods.

RESULTS

A total of 93 articles were assessed for relevance from the database search, and 47 were included after the removal of irrelevant articles and duplicates. Several studies reported on the clinical findings of deltoid ligament injury, as well as the radiographic analysis. Arthroscopy was considered the gold standard of diagnosis, with authors reporting on the potential benefit of performing arthroscopic repair or reconstruction at the same time. There were no studies that provided a system for the classification of deltoid ligament injury or larger studies of treatment pathways. Long-term studies of the incidence of instability in deltoid ligament injuries were not available.

CONCLUSION

There is limited evidence available regarding deltoid ligament injuries, particularly in terms of treatment options, either in isolation or with concomitant injuries. Long-term follow-up studies are needed to obtain more accurate data on the number of complications.

LEVEL OF EVIDENCE

Level IV.

The deltoid ligament is constantly formed by four fascicles reaching the navicular, spring ligament complex, calcaneus and talus

PURPOSE

The medial collateral ligament of the ankle, or deltoid ligament, can be injured in up to 40% of patients who sustain an ankle inversion sprain. Reporting injuries of the deltoid ligament is not easy due to confusion in the current anatomical descriptions, with up to 16 fascicles described, with variable frequencies. The purpose of this study was to clarify the anatomy of the deltoid ligament.

METHODS

Thirty-two fresh-frozen ankle specimens were used for this study. Careful dissection was undergone until full visualization of the deltoid ligament was achieved and measurements taken.

RESULTS

The deltoid ligament was found to have four constant fascicles in two layers. The superficial layer consists of the tibionavicular, tibiospring and tibiocalcaneal fascicles, while the deep layer consists of the tibiotalar fascicle. Measurements of these fascicles are given in detail. The tibiotalar fascicle and the anterior part of the tibionavicular fascicle were found to be intra-articular structures.

CONCLUSION

The deltoid ligament has a constant number of fascicles divided into a superficial and a deep layer. This clarification of the anatomy and terminology of the deltoid ligament and its fascicles will help clinical view, diagnosis and (interdoctor)communication and treatment. The ligamentous fibres of the deep layer, as well as the anterior fibres of the superficial layer (tibionavicular fascicle) are intra-articular, which could negatively impact its healing capacity, explaining chronicity of these types of injuries.

LEVEL OF EVIDENCE

Not applicable (cadaveric study).

Investigation into the effect of deltoid ligament injury on rotational ankle instability using a three-dimensional ankle finite element model

Background

Injury to the lateral collateral ligament of the ankle may cause ankle instability and, when combined with deltoid ligament (DL) injury, may lead to a more complex situation known as rotational ankle instability (RAI). It is unclear how DL rupture interferes with the mechanical function of an ankle joint with RAI.

Purpose

To study the influence of DL injury on the biomechanical function of the ankle joint.

Methods

A comprehensive finite element model of an ankle joint, incorporating detailed ligaments, was developed from MRI scans of an adult female. A range of ligament injury scenarios were simulated in the ankle joint model, which was then subjected to a static standing load of 300 N and a 1.5 Nm internal and external rotation torque. The analysis focused on comparing the distribution and peak values of von Mises stress in the articular cartilages of both the tibia and talus and measuring the talus rotation angle and contact area of the talocrural joint.

Results

The dimensions and location of insertion points of ligaments in the finite element ankle model were adopted from previous anatomical research and dissection studies. The anterior drawer distance in the finite element model was within 6.5% of the anatomical range, and the talus tilt angle was within 3% of anatomical results. During static standing, a combined rupture of the anterior talofibular ligament (ATFL) and anterior tibiotalar ligament (ATTL) generates new stress concentrations on the talus cartilage, which markedly increases the joint contact area and stress on the cartilage. During static standing with external rotation, the anterior talofibular ligament and anterior tibiotalar ligament ruptured the ankle's rotational angle by 21.8% compared to an intact joint. In contrast, static standing with internal rotation led to a similar increase in stress and a nearly 2.5 times increase in the talus rotational angle.

Conclusion

Injury to the DL altered the stress distribution in the tibiotalar joint and increased the talus rotation angle when subjected to a rotational torque, which may increase the risk of RAI. When treating RAI, it is essential to address not only multi-band DL injuries but also single-band deep DL injuries, especially those affecting the ATTL.

Biomechanical Effects of Subtalar Joint Fusion and Medial Ligament Reconstruction in Simulated Progressive Collapsing Foot Deformity

BACKGROUND

The purpose of this study is to investigate the biomechanical effect of medial displacement calcaneal osteotomy (MDCO), subtalar joint fusion (SF), and medial ligament reconstruction (MLR: deltoid-spring ligament) in a severe flatfoot model. We hypothesized that (1) combination of MDCO and SF improves the tibiotalar and foot alignment in severe progressive collapsing foot deformity (PCFD) cadaver model. (2) However, if a residual valgus heel alignment remains after MCDO and SF, it can lead to increased medial ligament strain, foot malalignment, and tibiotalar valgus tilt, which will be mitigated by the addition of MLR.

METHODS

Ten fresh-frozen cadaveric foot specimens were used to create a severe flatfoot model. The foot alignment changes, including the talo-first metatarsal angle in the axial and sagittal planes, subtalar angle, and tibiotalar angle in the coronal plane, were measured. The angles were measured at the initial condition, after creating the severe flatfoot model, and after each successive reconstructive procedure in the following order: (1) MDCO, (2) SF, and (3) MLR.

RESULTS

Tibiotalar valgus tilt was decreased with the MDCO procedure: 4.4 vs 1.0 degrees (P = .04). Adding in situ SF to the MDCO led to increased tibiotalar tilt to 2.5 degrees was different from the initial condition (P = .01). Although the tibiotalar valgus tilt was significantly decreased after adding the MLR to the MDCO/SF procedure compared with the severe flatfoot model (0.8 vs 4.4 degrees, P = .03), no significant difference in the tibiotalar valgus tilt was observed between MDCO/SF and MDCO/SF with MLR.

CONCLUSION

Our results demonstrated that MDCO significantly improved forefoot abduction and medial arch alignment, with no significant additional improvement observed with addition of SF. Following SF, a residual valgus heel alignment can contribute to subsequent tibiotalar valgus tilt. The addition of MLR did not show significantly decreased tibiotalar valgus tilt following SF.

CLINICAL RELEVANCE

Residual valgus heel alignment after subtalar joint fusion in the surgical treatment of PCFD can lead to increased medial ligament strain. Although MLR might be considered for providing medial stability, it may not necessarily prevent the development of tibiotalar valgus tilt.

[Ligamentous injuries of the ankle joint : Importance of radiological imaging procedures]

Injuries of the ankle joint show lesions of the lateral ligamentous apparatus with an incidence of 1 in 1000 cases. With a range of 0.3-0.7 in 1000 cases, injuries of the medial ligamentous apparatus occur more frequently than previously thought and are often overlooked. Correct imaging diagnostics of the ankle ligaments are mandatory for the prognosis and treatment planning. In cases of clinically strong suspicion of ligamentous injury or osteochondral lesions of the ankle joint, after primary radiographic evaluation magnetic resonance imaging (MRI) is primarily recommended for a more precise assessment. Additionally, the sensitivity for assessment of the ligaments with ultrasonography is good (91% vs. 97% with MRI) but its specificity is inferior compared to MRI (63% vs. 93% with MRI). Supination trauma is the most common ankle injury and attention should be paid to the anterior tibiofibular ligament and calcaneofibular ligament. In approximately 50%, injuries to the superficial layer of the medial collateral ligament complex are associated with lesions of the posterior tibiotalar ligament.

Spring Ligament Reconstruction for Progressive Collapsing Foot Deformity: Contemporary Review

The spring ligament is one of the main stabilizers of the medial arch of the foot and the primary static supporter of the talonavicular joint. Attenuation or rupture of this ligament is thought to play a central role in the pathophysiology of progressive collapsing foot deformity. Traditional correction of flexible flatfoot consists of posterior tibial tendon augmentation along with various osteotomies or hindfoot fusions. Repair or reconstruction of the spring ligament has not been as widely pursued. In recent years, newer techniques have been explored and may improve outcomes of traditional procedures, or possibly entirely replace some osteotomies. Combined spring-deltoid ligament reconstruction is also gaining traction as a viable technique, particularly as the ankle begins to deform into valgus. This review summarizes the variety of nonanatomic and anatomic reconstruction techniques that have been described, including autologous tendon transfers, allografts, and synthetic augmentation. Although many have only been characterized in biomechanical cadaver studies, this article reviews preliminary clinical studies that have shown promising results. There is a need for more high-quality studies evaluating the clinical, radiographic, and patient-reported outcomes following spring ligament reconstruction.

[Ligamentous injuries of the ankle joint : Importance of radiological imaging procedures]

Injuries of the ankle joint show lesions of the lateral ligamentous apparatus with an incidence of 1 in 1000 cases. With a range of 0.3-0.7 in 1000 cases, injuries of the medial ligamentous apparatus occur more frequently than previously thought and are often overlooked. Correct imaging diagnostics of the ankle ligaments are mandatory for the prognosis and treatment planning. In cases of clinically strong suspicion of ligamentous injury or osteochondral lesions of the ankle joint, after primary radiographic evaluation magnetic resonance imaging (MRI) is primarily recommended for a more precise assessment. Additionally, the sensitivity for assessment of the ligaments with ultrasonography is good (91% vs. 97% with MRI) but its specificity is inferior compared to MRI (63% vs. 93% with MRI). Supination trauma is the most common ankle injury and attention should be paid to the anterior tibiofibular ligament and calcaneofibular ligament. In approximately 50%, injuries to the superficial layer of the medial collateral ligament complex are associated with lesions of the posterior tibiotalar ligament.

Ligament Ruptures in Ankle Fractures-Was Lauge-Hansen Right?

The contribution of Lauge-Hansen to the understanding and treatment of ankle fractures cannot be underestimated, an unquestionable merit being the analysis of the ligamentous component of these injuries that are considered as equivalent to the respective malleolar fractures. In numerous clinical and biomechanical studies, the lateral ankle ligaments are ruptured either together with or instead of the syndesmotic ligaments, as predicted by the Lauge-Hansen stages. A ligament-based view on malleolar fractures may deepen the understanding of the mechanism of injury and lead to a stability-based evaluation and treatment of the 4 osteoligamentous pillars (malleoli) at the ankle.

Medium- to Long-term Results of Nonanatomic Spring Ligament Reconstruction Using an Allograft Tendon in Progressive Collapsing Foot Deformity With Severe Abduction Deformity

BACKGROUND

Spring ligament reconstruction (SLR) has been suggested as an adjunct to other reconstructive procedures to potentially avoid talonavicular joint fusion in progressive collapsing foot deformity (PCFD) with severe abduction deformity. Most clinical reports present short-term follow-up data and a small number of patients. The purpose of this study was to examine the medium- to long-term outcomes of an SLR using allograft tendon augmentation as part of PCFD surgical reconstruction. This study to our knowledge represents the largest number of patients and the longest follow-up to date.

METHODS

This study retrospectively reviewed 26 patients (27 feet, mean age of 61.4 years) who underwent SLR with allograft tendon as part of PCFD reconstruction. The mean follow-up of the cohort was 8 years (range, 5-13.4). Radiographic evaluation consisted of 5 parameters including talonavicular coverage angle (TNC), with the maintenance of correction being evaluated by comparing parameters from the early postoperative period (mean: 11.6 months, range, 8-17) to final follow-up. Foot and Ankle Outcome Score (FAOS) and patient satisfaction questionnaires were collected at final follow-up. Conversion to talonavicular or subtalar fusion was considered as a failure.

RESULTS

Final radiographs demonstrated successful abduction correction, with the mean TNC improving from 43.7 degrees preoperatively to 14.1 degrees postoperatively (P < .0001). All other radiographic parameters improved significantly and exhibited maintenance of the correction. All FAOS subscales showed significant improvement. Responses to the satisfaction questionnaire were received from all except 1 patient, of whom 88.5% (23/26) were satisfied with the results, 96.2% (25/26) would undergo the surgery again, and 88.5% (23/26) would recommend the surgery. Eight feet (29.6%) required painful hardware removal and 1 (3.7%) developed nonunion of the lateral column lengthening osteotomy. No patient required conversion to talonavicular or subtalar fusion.

CONCLUSION

This study demonstrates favorable medium- to long-term outcomes following PCFD reconstruction including an SLR with allograft tendon augmentation.

LEVEL OF EVIDENCE

Level IV, case series.

The role of medial ligaments and tibialis posterior in stabilising the medial longitudinal foot arch: a cadaveric gait simulator study

BACKGROUND

Debate exists whether adult acquired flatfoot deformity develops secondary to tibialis posterior (TibPost) tendon insufficiency, failure of the ligamentous structures, or a combination of both.

AIM

The aim of this study is to determine the contribution of the different medial ligaments in the development of acquired flatfoot pathology. Also to standardise cadaveric flatfoot models for biomechanical research and orthopaedic training.

METHODS

Five cadaveric feet were tested on a dynamic gait simulator. Following tests on the intact foot, the medial ligaments - fascia plantaris (FP), the spring ligament complex (SLC) and interosseous talocalcaneal ligament (ITCL) - were sectioned sequentially. Joint kinematics were analysed for each condition, with and without force applied to TibPost.

RESULTS

Eliminating TibPost resulted in higher internal rotation of the calcaneus following the sectioning of FP and SLC (d>1.28, p = 0.08), while sectioning ITCL resulted in higher external rotation without TibPost (d = 1.24, p = 0.07). Sequential ligament sectioning induced increased flattening of Meary's angle.

CONCLUSION

Function of TibPost and medial ligaments is not mutually distinctive. The role of ITCL should not be neglected in flatfoot pathology; it is vital to section this ligament to develop flatfoot in cadaveric models.

Injuries to the Spring Ligament: Nonoperative Treatment

The fibrocartilage within the superomedial calcaneonavicular (spring) ligament is part of an interwoven complex of ligaments that span the ankle, subtalar, and talonavicular joints. Acute isolated rupture of the spring ligament has been reported in association with an eversion ankle sprain. Attenuation and failure of the spring ligament causes complex 3D changes called the progressive collapsing foot deformity (PCFD). This deformity is characterized by hindfoot eversion, forefoot supination, collapse of the medial longitudinal arch, and forefoot abduction. Nonoperative treatment of an isolated spring ligament rupture and PCFD using various designs of orthoses have shown promising results.

Operative Management: Spring Ligament

Pes planovalgus is a multiplanar deformity consisting of a combination of hindfoot valgus, collapse of the medial longitudinal arch, forefoot varus, and forefoot abduction. This deformity is often associated with posterior tibial tendon dysfunction. Collapse of the medial longitudinal arch increases stress to the static stabilizers of the medial column including the deltoid ligament, spring ligament, plantar fascia, plantar and talocalcaneal interosseous ligaments, as well as the talonavicular and naviculocuneiform capsules. There is a higher incidence of concomitant spring ligament pathology in pes planovalgus deformity and posterior tibial tendon dysfunction based on magnetic resonance imaging and intraoperative observation than in other static stabilizers.

A Preliminary Study to Assess the Relevance of Shear-Wave Elastography in Characterizing Biomechanical Changes in the Deltoid Ligament Complex in Relation to Ankle Position

BACKGROUND

The purpose of this study was (1) to evaluate the biomechanical properties of the different bundles of the deltoid ligament in various ankle positions in a cohort of healthy adult volunteers; (2) describe the impact of demographic and hindfoot morphology characteristics on their stiffness; (3) to assess the reliability and reproducibility of these measurements.

METHODS

Deltoid ligament complex of both ankles were assessed by shear-wave elastography (SWE) in 20 healthy patients resting on hinge support. The propagation shear-wave speed (SWS) in ligaments was measured, which is related to the tissue's elastic modulus. The following ligaments were analyzed in a neutral position and then in varus, valgus, dorsal, and plantar flexions: tibionavicular ligament (TNL), tibiocalcaneal ligament (TCL), the superficial posterior tibiotalar ligament (SPTL), the anterior tibiotalar ligament (ATTL), and the deep posterior tibiotalar ligament (DPTTL).

RESULTS

The mean SWS increased between neutral and 20 degrees valgus position for TCL (4.08 ± 0.78 m/s vs 5.56 ± 0.62 m/s, respectively; P < .0001) and for DPTTL (2.58 ± 0.52 m/s vs 3.59 ± 0.87 m/s, respectively; P < .0001). The mean SWS increased between neutral and 30 degrees plantarflexion for ATTL (2.11 ± 0.44 m/s vs 3.1 ± 0.5 m/s, respectively; P < .0001) and TNL (2.96 ± 0.66 m/s vs 4.99 ± 0.69 m/s, respectively; P < .0001). The mean SWS increased between neutral and 20 degrees dorsal flexion for SPTL (4.2 ± 1 m/s vs 5.45 ± 0.65 m/s, respectively; P < .0001).Women had less DPTTL SWS than men in the neutral position (2.37 ± 0.35 m/s vs 2.71 ± 0.49 m/s, respectively; P = .007). Other demographics had no impact on the SWS value of other ligaments. All inter- and intraobserver agreements were good to excellent.

CONCLUSION

This study presents a reliable and reproducible SWE measurement protocol to describe the physiological function of all bundles of the medial collateral ligament in healthy adults.

CLINICAL RELEVANCE

This examination technique can be available to orthopaedic surgeons, allowing reliable and reproducible monitoring of the SWS of the various ligaments constituting the medial collateral plane. The biomechanical values described in this study may give insight into in what position medial ankle ligament reconstruction should be tensioned.

The Anatomy and Function of the Individual Bands of the Deltoid Ligament—and Implications for Stability Assessment of SER Ankle Fractures

Background:

Deltoid ligament injury occurs often with supination-external rotation (SER) ankle trauma. SER fibula fractures with concomitant deltoid ligament injury are considered unstable—requiring operative fixation. Recent studies have questioned this general practice with emphasis on better defining the medial side ankle ligamentous injury. The function of the individual bands of the deltoid ligament, and the interplay between them, are not fully understood. We undertook this study to develop a better understanding of these complex ligamentous structures and ultimately aid assessment and treatment choice of SER ankle fractures with concomitant deltoid ligament injuries.

Methods:

Ten fresh-frozen cadaveric foot and ankle specimens were studied. We identified the various ligament bands and did a functional analysis by assessment of ligament length and tension at predefined angles of ankle dorsi-plantarflexion combined with valgus/varus and rotation. The results were determined by manual evaluation with calipers and goniometers, manual stress, and direct visualization.

Results:

We recorded primarily 5 different bands of the deltoid ligament: the tibionavicular (TNL; 10/10) tibiospring (TSL; 9/10), tibiocalcaneal (TCL; 10/10), deep anterior tibiotalar (dATTL; 9/10), and deep posterior tibiotalar (dPTTL; 10/10) ligaments. The tibiospring ligament was tense in plantarflexion, while the tibiocalcaneal and deep posterior tibiotalar ligaments were tense in dorsiflexion. The superficial layer ligaments and the deep anterior tibiotalar ligament length and tension were largely affected by changes in varus/valgus and rotation. The deep posterior tibiotalar ligament length and tension was altered predominantly by changes in dorsi-plantarflexion; varus/valgus positioning had a minor effect on this band.

Conclusions:

We confirmed the finding of previous studies that dorsi-plantarflexion affects the tensile engagement of the separate ligament bands differently. Likewise, combined movements with varus/valgus and rotation seem to affect the separate ligament bands differently. Our results suggest that the TNL, TSL, and dATTL are at risk of injury, whereas the TCL and particularly the dPTTL are protected in the event of an SER-type ankle fracture mechanism of injury.

Level of Evidence

Level V, cadaveric study.

Augmented Spring Ligament Repair in Pes Planovalgus Reconstruction

Patients with pes planovalgus deformity often have coexisting spring ligament pathology. A primary repair of the ligament may fail during weightbearing due to chronic degeneration of the ligamentous tissue. Augmentation with a suture tape has been suggested to strengthen the repair. Limited data exist regarding flatfoot reconstruction with augmented spring ligament repair using a suture tape. This is a review of 57 consecutive patients who had flatfoot reconstruction with concomitant spring ligament augmented repair between July 2014 and August 2017. Weightbearing radiographic parameters were obtained preoperatively and compared to radiographs at an average time of 62 ± 46.5 (range 20-220) weeks postoperative. Significant improvements were seen in the radiographic parameters evaluated. Five patients had subsequent operations including one deep infection, 2 hardware removals remote to the spring ligament augmentation, 1 ankle arthrodesis, and 1 triple arthrodesis. Concomitant spring ligament repair augmented with a suture tape was a safe procedure that contributed to radiographic correction in a consecutive series of 57 patients undergoing flatfoot deformity correction.

The Importance of the Medial Column in Progressive Collapsing Foot Deformity: Osteotomies and Stabilization

Adult acquired flatfoot deformity is a complex pathologic condition that requires considerate and thoughtful surgical solutions. Medial column procedures are often supplemented by a medializing calcaneal osteotomy and/or a lateral column lengthening because of the complex nature of progressive collapsing foot deformity and its resultant peritalar instability. Other osteotomies and fusions include a Cotton osteotomy and first tarsometatarsal fusion.

Spring and Deltoid Ligament Insufficiency in the Setting of Progressive Collapsing Foot Deformity. An Update on Diagnosis and Management

The spring ligament and deltoid ligament are important stabilizers of the medial ankle. Together, they form a complex along the medial ankle and foot that is critical to stability of both the ankle and the medial longitudinal arch. Incompetence of the spring and deltoid ligament is a component of both the early and late stages of progressive collapsing foot deformity. As the importance of this medial ligament complex has been recognized, repair and reconstruction of these ligaments have progressively evolved, initially as separate reconstructions, and more recently as combined techniques.

Current Trends in Treatment of Injuries to Spring Ligament

The spring ligament is the main static supporter of the medial longitudinal arch. Identifying every detail of the pathophysiology of each condition in which these structures are involved is the key to an appropriate approach and treatment. Isolated reconstruction of the posterior tibial tendon present long-term results with a high failure rate. It is important to diagnose spring ligament injuries because of the probable consequences if not treated, such as acquired flatfoot deformity and loss of correction of treated flatfoot. The option of surgical treatment is discussed in this article.

Biomechanics of Medial Ankle and Peritalar Instability

The deltoid and spring ligaments are the primary restraints against pronation and valgus deformity of the foot, and in preserving the medial arch. The posterior tibial tendon has a secondary role in plantar arch maintenance, and its biomechanical stress increases considerably when other tissues fail. A thorough understanding of the anatomy and biomechanics of the deltoid-spring ligament is crucial for successful reconstruction of the tibiocalcanealnavicular ligament, hence, to restore ankle and medial peritalar stability. Although effective in correcting the deformity, tibionavicular tenodesis might be critical, as it blocks physiologic pronation of the hindfoot, which may result in dysfunction and pain.

Current Concepts in Treatment of Ligament Incompetence in the Acquired Flatfoot

Flatfoot deformity consists of a loss of medial arch, hindfoot valgus, and forefoot abduction. Historically considered a posterior tendon insufficiency, multiple ligament damage and subsequent incompetence explain the different clinical presentations with varying degrees of deformity. When surgery is deemed necessary, depending on the apex of the deformity, skeletal and soft tissue procedures are considered to keep motion and restore function. Osteotomies are considered at every level where an apex of deformity is found. The recently designated tibiocalcaneonavicular ligament comprises the older superficial and deep deltoid and spring ligaments; its repair or reconstruction should be considered in most flatfoot cases.

Anatomy of the Deltoid-Spring Ligament Complex

A thorough knowledge of the anatomy of the deltoid and spring ligament complex is important for treatment of deformities that impact the foot and ankle. Both ligaments are interconnected, and the study of their anatomic characteristics is better performed together than in isolation. The deltoid ligament is a group of ligaments that derives its origin from the medial malleolus, and the spring ligament complex consist of a group of ligaments that connects the navicular and the sustentaculum tali of the calcaneus. They both play an important role in stabilization of the medial ankle and medial column of the foot.

The tibiocalcaneal bundle of the deltoid ligament - Prevalence and variations

INTRODUCTION

A precise understanding of the anatomy of the multiple bundles of the deltoid ankle ligament might have clinical impact. The most relevant deltoid anatomical series report a variable frequency of the tibiocalcaneal ligament, possibly the most important bundle to be reconstructed in medial ankle insufficiency. Our purpose was to access the deltoid's tibiocalcaneal ligament morphology in a large anatomical study as well as to perform a historical literature review on the reasons for its variable prevalence.

MATERIALS AND METHODS

Forty-three ankle specimen were dissected to describe the prevalence of superficial and deep deltoid bundles, with special attention to the tibiocalcaneal ligament and its variants.

RESULTS

All ankles had distinct deep and superficial bundles. In all 43 ankles the tibionavicular and tibiospring ligaments were clearly identified. The superficial posterior tibiotalar ligament was identified in 38 ankles (88%). The deep anterior tibiotalar bundle was identified in 35 ankles (81%). The deep posterior tibiotalar bundle was identified in all ankles. The tibiocalcaneal ligament was identified in 33 ankles (77%). In ten ankles there wasn't a direct bundle between the tibia and the sustentaculum tali. In all of these, however, we found some fibers spanning the gap between the tibiospring ligament and the sustentaculum tali.

CONCLUSION

The tibiocalcaneal ligament is present in most specimens. In those in which we could not identify a direct bundle between the tibia and the calcareous we found a variant of the tibiospring ligament that connects to the sustentaculum tali.

Acute Deltoid Ligament Repair in Ankle Fractures

There is no consensus on whether the deltoid ligament must be repaired in ankle fractures. Recent studies have shown better early radiologic results when the deltoid ligament is repaired, but no differences in long term functional outcomes. However, there is evidence suggesting that patients with high fibular fractures or injuries with concomitant syndesmotic instability may benefit from repair. The authors recommend repairing the deltoid ligament complex in bimalleolar equivalent fractures associated with syndesmotic or gross multiligamentous instability as well as in heavier patients with greater mechanical requirements.

Treatment concepts for pes valgoplanus with concomitant changes of the ankle joint : Tibiotalocalcaneal arthrodesis, total ankle replacement and joint-preserving surgery

Concomitant valgus deformities of the ankle joint are found in approximately 3% of patients with symptomatic flat foot deformities. Conservative treatment is mostly successful only in the short term or in low-demand patients. The operative treatment of flat foot deformities follows the standard algorithm for flat foot treatment. The ankle joint can be treated while retaining mobility or by arthrodesis depending on the degree and rigidity of the deformity, degenerative changes, patient factors and expectations. Achieving an orthograde hindfoot and midfoot is obligatory for successful treatment as well as in ankle reconstructive or arthrodesis procedures.

Painful Accessory Navicular and Spring Ligament Injuries in Athletes

Painful accessory navicular and spring ligament injuries in athletes are different entities from more common posterior tibialis tendon problems seen in older individuals. These injuries typically affect running and jumping athletes, causing medial arch pain and in severe cases a pes planus deformity. Diagnosis requires a detailed physical examination, standing radiographs, and MRI. Initial treatment focuses on rest, immobilization, and restriction from sports. Orthotic insoles may alleviate minor pain, but many patients need surgery to expedite recovery and return to sports. The authors review their approach to these injuries and provide surgical tips along with expected rehabilitation to provide optimal outcomes.

Peritalar Kinematics With Combined Deltoid-Spring Ligament Reconstruction in Simulated Advanced Adult Acquired Flatfoot Deformity

BACKGROUND

Adult acquired flatfoot deformity (AAFD) is a complex and progressive deformity involving the ligamentous structures of the medial peritalar joints. Recent anatomic studies demonstrated that the spring and deltoid ligaments form a greater medial ligament complex, the tibiocalcaneonavicular ligament (TCNL), which provides medial stability to the talonavicular, subtalar, and tibiotalar joints. The aim of this study was to assess the biomechanical effect of a spring ligament tear on the peritalar stability. The secondary aim was to assess the effect of TCNL reconstruction in restoration of peritalar stability in comparison with other medial stabilization procedures, anatomic spring or deltoid ligament reconstructions, in a cadaveric flatfoot model.

METHODS

Ten fresh-frozen cadaveric foot specimens were used. Reflective markers were mounted on the tibia, talus, navicular, calcaneus, and first metatarsal. Peritalar joint kinematics were captured by a multiple-camera motion capture system. Mild, moderate, and severe flatfoot models were created by sequential sectioning of medial capsuloligament complex followed by cyclic axial loading. Spring only, deltoid only, and combined deltoid-spring ligament (TCNL) reconstructions were performed. The relative kinematic changes were compared using 2-way analysis of variance (ANOVA).

RESULTS

Compared with the initial condition, we noted significantly increased valgus alignment of the subtalar joint of 5.1 ± 2.3 degrees (P = .031) and 5.8 ± 2.7 degrees (P < .01) with increased size of the spring ligament tear to create moderate to severe flatfoot, respectively. We noted an increased tibiotalar valgus angle of 5.1 ± 2.0 degrees (P = .03) in the severe model. Although all medial ligament reconstruction methods were able to correct forefoot abduction, the TCNL reconstruction was able to correct both the subtalar and tibiotalar valgus deformity (P = .04 and P = .02, respectively).

CONCLUSION

The TCNL complex provided stability to the talonavicular, subtalar, and tibiotalar joints. The combined deltoid-spring ligament (TCNL) reconstructions restored peritalar kinematics better than isolated spring or deltoid ligament reconstruction in the severe AAFD model.

CLINICAL RELEVANCE

The combined deltoid-spring ligament (TCNL) reconstruction maybe considered in advanced AAFD with medial peritalar instability: stage IIB with a large spring ligament tear or stage IV.

The Role of Deltoid Repair and Arthroscopy in Ankle Fractures

Despite the fact that ankle fractures are common injuries, not all patients obtain satisfactory results. Historically, the deltoid ligament injury and intra-articular pathology have not often been treated at the time of fracture stabilization. Recent literature has suggested that repair of the deltoid ligament may lead to better stability of the ankle mortise. Additionally, the use of arthroscopy in conjunction with fracture fixation may allow for better identification and treatment of intra-articular lesions and improve detection and reduction of subtle instability.

Strain pattern of each ligamentous band of the superficial deltoid ligament: a cadaver study

BACKGROUND

There are few reports on the detailed biomechanics of the deltoid ligament, and no studies have measured the biomechanics of each ligamentous band because of the difficulty in inserting sensors into the narrow ligaments. This study aimed to measure the strain pattern of the deltoid ligament bands directly using a Miniaturization Ligament Performance Probe (MLPP) system.

METHODS

The MLPP was sutured into the ligamentous bands of the deltoid ligament in 6 fresh-frozen lower extremity cadaveric specimens. The strain was measured using a round metal disk (clock) fixed on the plantar aspect of the foot. The ankle was manually moved from 15° dorsiflexion to 30° plantar flexion, and a 1.2-N-m force was applied to the ankle and subtalar joint complex. Then the clock was rotated every 30° to measure the strain of each ligamentous band at each endpoint.

RESULTS

The tibionavicular ligament (TNL) began to tense at 10° plantar flexion, and the tension becomes stronger as the angle increased; the TNL worked most effectively in plantar flex-abduction. The tibiospring ligament (TSL) began to tense gradually at 15° plantar flexion, and the tension became stronger as the angle increased. The TSL worked most effectively in abduction. The tibiocalcaneal ligament (TCL) began to tense gradually at 0° dorsiflexion, and the tension became stronger as the angle increased. The TCL worked most effectively in pronation (dorsiflexion-abduction). The superficial posterior tibiotalar ligament (SPTTL) began to tense gradually at 0° dorsiflexion, and the tension became stronger as the angle increased, with the SPTTL working most effectively in dorsiflexion.

CONCLUSION

Our results show the biomechanical function of the superficial deltoid ligament and may contribute to determining which ligament is damaged during assessment in the clinical setting.

Arthroscopic Reconstruction of the Anterior Tibiotalar Ligament Using a Free Tendon Graft

Deltoid ligament injuries account for 5.1% to 15.8% of ankle sprains and occur with concomitant lateral ankle sprains. The anterior tibiotalar ligament (ATTL), located within the deep layer of the deltoid ligament complex, connects the talus and the tibia on the medial side of the ankle and controls ankle eversion and rotation. If conservative treatment for chronic medial ankle instability after an ankle sprain fails, ATTL repair or reconstruction might be necessary. Arthroscopic reconstruction techniques of the lateral ankle ligaments recently have been reported. Here, we describe arthroscopic reconstruction of the ATTL using a free tendon graft (ARATTL). This technique is less invasive than other treatments and results in a more stable medial ankle joint.

Biomechanics and Orthotic Treatment of the Adult Acquired Flatfoot

The adult acquired flatfoot deformity resulting from posterior tibial tendon dysfunction is the result of rupture of the posterior tibial tendon as well as key ligaments of the ankle and hindfoot. Kinematic studies have verified certain levels of deformity causing hindfoot eversion, lowering of the medial longitudinal arch and forefoot abduction. The condition is progressive and left untreated will cause significant disability. Bracing with ankle-foot orthoses has shown promising results in arresting progression of deformity and avoiding debilitating surgery. Various types of ankle-foot orthoses have been studied in terms of effects on gait as well as efficacy in treatment.

Adding deltoid ligament repair in ankle fracture treatment: Is it necessary? A systematic review

BACKGROUND

Deltoid ligament injuries are typically caused by supination-external rotation or pronation injury. Numerous ligament reconstruction techniques have been proposed; however, clear indications for operative repair have not yet been well established in the literature.

METHODS

We reviewed primary research articles comparing ORIF treatment for ankle fracture with versus without deltoid ligament repair.

RESULTS

Five studies were identified with a total of 281 patients. 137 patients underwent ORIF with deltoid repair, while 144 patients underwent ORIF without deltoid ligament repair. Clinical, radiographic, and functional outcomes, as well as complications were considered. The average follow-up was 31 months (range, 5-120).

CONCLUSIONS

Current literature does not provide clear indication for repair of the deltoid ligament at the time of ankle fracture repair. There may be some advantages of adding deltoid ligament repair for patients with high fibular fractures or in patients with concomitant syndesmotic fixation.

LEVEL OF CLINICAL EVIDENCE

III.

Three-Dimensional Morphological Variations of the Human Calcaneus Investigated Using Geometric Morphometrics

The shape of the calcaneus determines the mechanical interaction of the foot with the ground during the heel-strike in human walking. Detailed knowledge of the pattern of sexual dimorphism of the human calcaneus could help to clarify the pathogenetic mechanism of foot and knee disorders, which are more prevalent in females. Therefore, the aim of this study was to characterize and visualize the three-dimensional shape variations of the calcaneus in relation to sex and age using geometric morphometrics. Computed tomography images of 56 feet without subtalar injuries or disorders were used in this study. Thirty-seven anatomical landmarks were identified on the bone model of the calcaneus to calculate principal components (PCs) of shape variations among specimens. The PC scores were compared between males and females, and their correlations with age were also analyzed. The female calcaneus was longer in length and shorter in height than that of males. The medial process of the calcaneal tuberosity in females was more inferiorly projected and the tuberosity was shifted more laterally. Also, the calcaneus was wider and the sustentaculum tali thickened with aging. Female structural features of the calcaneus alter the kinematics of the foot during walking and could be a structural factor in foot and knee disorders. This study contributes to a comprehensive understanding of shape variations in the human calcaneus. Clin. Anat., 33:751-758, 2020. © 2019 Wiley Periodicals, Inc.

Morphology of Spring Ligament Fibrocartilage Complex Lesions

BACKGROUND

The spring ligament fibrocartilage complex (SLFC) is an important static foot stabilizer comprising the superomedial ligament (SML) and the inferior ligament, with anatomical variations (third ligament). The aim of this study was to describe the patterns of the lesions found during SLFC surgery, to allow direct comparison between the results with various surgical techniques.

METHODS

Fourteen consecutive patients with SLFC lesions were analyzed during surgical treatment. The mean patient age was 37.3 years, and the mean time from injury was 6.9 months. Intraoperative assessments and anatomical descriptions of the lesions were collected.

RESULTS

Three types of lesion were found. In 13 of 14 cases, only the superomedial ligament was involved: five superomedial ligament distentions and eight superomedial ligament ruptures. In one case, total SLFC (superomedial and inferior ligaments) rupture was observed.

CONCLUSIONS

The first classification of SLFC lesions is presented, which is simple, consistent, and based on anatomical description.

Deltoid-Spring Ligament Reconstruction in Adult Acquired Flatfoot Deformity With Medial Peritalar Instability

BACKGROUND

A spring ligament tear is commonly present in advanced stages of adult acquired flatfoot deformity (AAFD). Previous anatomic studies have demonstrated that the superficial deltoid ligament blends with the superomedial spring ligament, forming the tibiocalcaneonavicular ligament (TCNL). Adding allograft TCNL reconstruction to osseous correction has been suggested to augment medial peritalar stability in advanced AAFD with large spring ligament tears. We aimed to investigate the clinical and radiographic outcomes of TCNL reconstruction for flexible AAFD with medial peritalar instability.

METHODS

Fourteen feet in 12 patients who underwent osseous and TCNL reconstructions for advanced AAFD (stage IIB with large spring ligament tears or stage IV) were recruited for the study. The mean postoperative follow-up was 24 (range, 12-33) months. Pre- and postoperative clinical outcomes were assessed by the Foot and Ankle Ability Measure (FAAM), SF-36, and Patient-Reported Outcomes Measurement Information System (PROMIS). Correction of forefoot abduction and the sagittal arch were measured from pre- and postoperative weightbearing radiographs.

RESULTS

The FAAM Activities of Daily Living improved from 69.3 to 90.1 (P = .001). The SF-36 Physical Function (PF) and Pain subscales both improved significantly (39.4 to 87.8 and 44.6 to 93.1, respectively, P < .001 for each). The PROMIS PF improved from 38.2 to 46.8 (P = .002) and the PROMIS Pain Interference (PI) from 62.6 to 50.1 (P = .003). Radiographic measures showed an improved anterior-posterior (AP) talo-first metatarsal angle of 24.7 to 11.8 degrees (P < .001) and talonavicular coverage angle of 47.4 to 23.1 degrees (P < .01). An improved Meary's angle of 29.7 to 12.5 degrees (P < .001) and a calcaneal pitch angle of 11.7 to 16.9 degrees (P = .14) were noted in the lateral view.

CONCLUSION

Considering the anatomic characteristics of the deltoid-spring ligament complex, TCNL reconstruction may play a significant role in maintaining peritalar stability when performed with osseous correction. Deltoid-spring ligament (TCNL) reconstruction is a viable surgical option for those with advanced stage AAFD with medial peritalar instability that leads to improved functional and radiographic outcomes.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Anatomic study of the medial side of the ankle base on the joint capsule: an alternative description of the deltoid and spring ligament

Background

Adult acquired flatfoot deformity (AAFD) is caused by impaired medial ligamentous structures and posterior tibialis tendon dysfunction (PTTD). Although degeneration and trauma could separately cause AAFD, how these factors interact in the pathomechanism of AAFD is unclear. The joint capsule in the medial ankle is considered an important structure, providing passive stability by limiting joint movement. Previous reports on the joint capsule suggest its involvement in pathological changes of the ankle, but because of the high priority placed on the ligaments, few reports address the ankle joint from the joint capsule standpoint. The current study aimed to anatomically examine the medial ankle joint, focusing on the deltoid and spring ligaments in perspective of the joint capsule.

Methods

We conducted a descriptive anatomical study of 19 embalmed cadavers (mean 82.7 years, range 58 to 99). We included 22 embalmed cadaveric ankles. We detached the joint capsule in 16 ankles from the anterior to posteromedial joint, analyzed the capsular attachments of the ankle and adjacent joints, and measured the widths of the bony attachments. We histologically analyzed the joint capsule using Masson’s trichrome staining in 6 ankles.

Results

The capsule could be separated as a continuous sheet, including 3 different tissues. The anterior capsule was composed of fatty tissue. Between the medial malleolus and talus, the capsule was strongly connected and was composed of fibrous tissue, normally referred to as the deep deltoid ligament. The tibial attachment formed a steric groove, and the talar side of the attachment formed an elliptical depressed area. On the medial part of the subtalar and talonavicular joints, the capsule covered the joints as cartilaginous tissue, normally referred to as the superomedial ligament of the spring ligament. The outer side of the cartilaginous and fibrous tissue formed the sheath floor of the posterior tibialis tendon. Histological analysis revealed three different tissue types.

Conclusions

The capsules of the ankle, subtalar, and talonavicular joints could be detached as a continuous sheet. The deltoid and the superomedial ligament of the spring ligaments could be interpreted as a part of the continuous capsule, which had different histological features.

Level of evidence

Descriptive Laboratory Study.

Spring ligament tear decreases static stability of the ankle joint

BACKGROUND

Spring ligament tear is often found in advanced adult acquired flatfoot deformity and its reconstruction in conjunction with the deltoid ligament has been proposed to restore the tibiotalar and talonavicular joint stability. The aim of the present study is to determine the effect of spring ligament injury and subsequent reconstruction on static joint reactive force using a non-invasive method of measurement.

METHODS

Ten fresh-frozen human cadaveric lower legs were disarticulated at the knee joint. Static joint reactive force of the tibiotalar and talonavicular joint were measured at baseline, after spring ligament injury, and after ligament reconstruction. Reconstruction consisted of a forked semitendinosis allograft with dual limbs to reconstruct the tibionavicular and tibiocalcaneal ligaments.

FINDINGS

The mean baseline joint reactive force of the tibiotalar and talonavicular joints were 37.2 N + 8.1 N and 13.4 N + 4.2 N, respectively. The spring ligament injury model resulted in a significant 29% decrease in tibiotalar joint reactive force. Reconstruction of the tibionavicular limb resulted in a significant increase in tibiotalar and talonavicular joint reactive force compared to those seen in the injury state. Furthermore, the addition of the tibiocalcaneal limb significantly increased tibiotalar joint reactive force compared to those results obtained from the injury state and the tibionavicular limb alone.

INTERPRETATION

This is the first study to demonstrate diminished tibiotalar static joint reactive force in a spring ligament injury model with subsequent joint reactive force restoration using two-limbed reconstruction of the deltoid and spring ligament.

LEVEL OF EVIDENCE

Biomechanical Study.

Spring Ligament Instability

The crucial role of the spring ligament complex within the pathologic process that leads to flatfoot deformity has evolved recently. There has been improvement in the anatomic knowledge of the spring ligament and understanding of its complex relationship to the deltoid complex and outstanding advances in biomechanics concepts related to the spring ligament. Optimization of flatfoot treatment strategies are focused on a renewed interest in the spring ligament and medial soft tissue reconstruction in concert with bony correction to obtain an adequate reduction of the talonavicular deformity and restoration of the medial longitudinal arch.

Anatomy of the ankle capsule: A cadaveric study

Although bony and ligamentous injuries of the ankle are well understood, little is known about the degree to which injury of the ankle capsule can be a component of such injuries. The purpose of this study was to determine the dimensions of the ankle capsule and its relationship to adjacent structures. Thirteen fresh-frozen ankle specimens were systematically dissected. Methylene blue solution was injected to identify the dimensions of the ankle capsule. External dimensions were measured as the distance from the capsular reflection to the bony margin of the ankle. Internal dimensions were measured as the distance from the capsular attachment of the distal tibia, fibula, and talus to the cartilage margin. The anterior aspect of the capsule demonstrated the most proximal capsular reflection in all specimens. The most proximal reflections of the anteromedial, anterior middle and anterolateral capsule were 10.3, 13.5, and 9.8 mm, respectively. The most proximal reflections of the posteromedial, posterior middle and posterolateral region were 8.7, 6.2, and 3.5 mm, respectively. There was no capsular reflection over the medial malleolus and less than 1 mm over the posterior lateral malleolus. There was a confluence of the capsule and ligamentous complex on the medial side, and also with the transverse tibiofibular ligament about the posterolateral ankle. The most proximal attachment of the ankle capsule was located at the anterior aspect of the distal tibia. The medial and posterolateral capsules were confluent with the ligamentous complexes of the ankle in those regions. Clin. Anat. 31:1018-1023, 2018. © 2018 Wiley Periodicals, Inc.

Anatomy of the Subtalar Joint

The subtalar joint is divided into the talocalcaneonavicular and the talocalcaneal joint, separated by a conical interosseous tunnel (canalis and sinus tarsi). The talocalcaneonavicular joint is a ball-and-socket articulation (coxa pedis). An important part of the coxa pedis is the spring ligament. The canalis and sinus tarsi are occupied by the roots of the inferior extensor retinaculum, cervical ligament, interosseous talocalcaneal ligament, and anterior talocalcaneal ligament. Three-dimensional motion in the subtalar joint complex (eversion/inversion) is guided by the axial alignment of the talus, calcaneus, and navicular; the ligaments; and the shape of the articular surfaces.

[Injuries of the medial collateral ligament and spring ligament complexes]

The medial collateral ligament (MCL) complex is characterized by a complex anatomical arrangement of the individual ligamentous structures including three joints and the spring ligament complex. Biomechanically it serves as the main stabilizing structure in the ankle region against rotational and pronating forces. Lesions in the region of the MCL complex are more frequent than previously thought and like lesions of the spring ligament complex can lead to pain and instability. A thorough examination including the patient history with possible injury mechanisms often yields valuable information on the diagnosis of injuries to the MCL or spring ligament complex. In many cases these are primarily overlooked and concomitant lesions, such as fractures, syndesmotic and lateral ligament lesions frequently occur; however, the clinical assessment of stability is often primarily impossible in an acute setting. High-resolution magnetic resonance imaging (MRI) plays a key role in identifying the ligamentous components. In addition, MRI plays a supportive role in the preoperative planning before reconstruction of acute and especially chronic lesions. In most cases the surgical treatment of acute ruptures of the MCL is not indicated. Various options for treatment of acute and chronic lesions of the MCL and spring ligament complex are available including the use of free tendon grafts. Controversy exists regarding the operative treatment of MCL lesions in the case of ankle fractures. It is recommended for cases with impinging tissue in the medial gutter serving as a barrier to adequate reduction of the joint and in cases of unstable fractures after reduction.

The Morphology and Prevalence of the Deltoid Complex Ligament of the Ankle

The deltoid ligament is a complex structure of the tibiotalar joint that limits the translation and tilting of the talus. It is often associated with injuries of the ankle joint. The deltoid complex ligament has 2 layers; one superficial with 4 bands and the other deep with 2 bands. Nevertheless, the prevalence and size of its components are reported with some variability in the literature. The aim of this meta-analysis is to generate weighted values of the prevalence, size, and attachment surface areas of its components. Eight studies met the inclusion criteria with a total of 142 ankle specimens. The analyses demonstrate that the most consistent component is the deep posterior tibiotalar (100%), followed by the tibiospring (≈94%), the tibionavicular (≈90%), and the tibiocalcaneal (85%). The superficial posterior ligament and the deep anterior tibiotalar ligament were the least prevalent (≈80% and ≈63%, respectively). The longest ligament was found to be the tibionavicular ligament and the shortest band was the deep posterior tibiotalar ligament. The tibionavicular ligament was the thinnest of all deltoid complex ligament components. This study yielded more accurate data on the frequency and size of its components. The possible absence of a component, particularly of the superficial layer, might compromise joint stability in acute ankle injuries.

LEVELS OF EVIDENCE

Systematic review of level III studies: prospective studies.

Medial-sided Ankle Pain: Deltoid Ligament and Beyond

Abnormalities of the medial ligaments and posterior tibial tendon can occur because of acute injury or chronic instability or malalignment. Medial ankle injuries may occur because of pronation or supination-external rotation injuries. Deltoid ligament injuries have a significant impact on lateral ankle instability but can be overlooked in patients with lateral ligament injuries. Posterior tibial tendon dysfunction is usually associated with spring ligament or flexor retinaculum injury. Tarsal tunnel syndrome, accessory flexor muscles, and subtalar coalition should be considered as well as ligament and tendon tears in differential diagnosis of chronic medial ankle pain.

Arthroscopic Anatomy of the Ankle Joint

There are a number of variations in the intra-articular anatomy of the ankle which should not be considered pathological under all circumstances. The anteromedial corner of the tibial plafond (between the anterior edge of the tibial plafond and the medial malleolus) can have a notch, void of cartilage and bone. This area can appear degenerative arthroscopically; it is actually a normal variant of the articular surface. The anterior inferior tibiofibular ligament (AITF) can possess a lower, accessory band which can impinge on the anterolateral edge of the talar dome. In some cases it can cause irritation along this area of the talus laterally. If it is creating local irritation it can be removed since it does not provide any additional stabilization to the syndesmosis. There is a beveled region at the anterior leading edge of the lateral and dorsal surfaces of the talus laterally. This triangular region is void of cartilage and subchondral bone. The lack of talar structure in this region allows the lower portion of the AITF ligament to move over the talus during end range dorsiflexion of the ankle, preventing impingement. The variation in talar anatomy for this area should not be considered pathological.

Percutaneous Deltoid Ligament Augmentation Using Suture Tape for Medial Ankle Instability

Compared with lateral ankle instability, medial ankle instability has many fewer treatment strategies and fewer reconstructive options available. The best method for deltoid ligament reconstruction remains unclear. Percutaneous deltoid ligament augmentation using suture tape represents a novel alternative technique for chronic medial ankle instability.