Medial tenderness revisited: Is medial ankle tenderness predictive of instability in isolated lateral malleolus fractures?

Current Concepts in Ankle Fracture Management

Ankle fractures are one of the more common musculoskeletal injuries that are treated by foot and ankle specialists. A thorough understanding of managing these injuries requires the ability to differentiate between stable and unstable fractures. The current literature supports the nonoperative management of stable Weber B ankle fractures, whereas unstable fractures have much better outcomes with surgical intervention. Specifically, we review the fixation strategies for the lateral, medial, and posterior malleolar fractures respectively. Finally, we discuss the current trends in postoperative management of some of the more common fracture patterns, and the safety in early weight-bearing protocols.

Functional Anatomy of the Rear Attachment of the Deep Deltoid (RAD) Ligament of the Ankle

The deltoid ligament plays a key role in ankle stability. Ankle fractures involving the medial ligamentous complex are evaluated on the basis of medial-sided tenderness and the Ottawa ankle rules. Evolution in our understanding of this ligament over the last three decades has shown that, within this medial ligamentous complex, it is the deep deltoid ligament that confers mechanical stability. The latest evolution in this understanding, and the learning point of this report, is that only a distinct component of the deep deltoid ligament - specifically the discreet posterior third - the rear attachment of the deep deltoid ligament (RAD) - confers mechanical value. The RAD is responsible for providing the medial ligamentous component of ankle stability - specifically talar shift, tilt, and importantly rotational stability. This knowledge is of key importance in the assessment and management of ankle fractures with associated deltoid ligament injuries. In this technical report, we highlight the biomechanical contribution of the RAD, which will help surgeons and physiotherapists to accurately manage ankle injuries.

Multidirectional Chronic Ankle Instability: What Is It?

Not all ankle sprains are the same and not all ankles behave the same way after an injury. Although we do not know the mechanisms behind an injury producing an unstable joint, we do know ankle sprains are highly underestimated. While some of the presumed lateral ligament lesions might eventually heal and produce minor symptoms, a substantial number of patients will not have the same outcome. The presence of associated injuries, such as additional medial chronic ankle instability, chronic syndesmotic instability, has been long discussed as a possible reason behind this. To explain multidirectional chronic ankle instability, this article aims to present the literature surrounding the condition and its importance nowadays.

The effect of partial deltoid ligament injuries on the external rotation stability: A cadaveric study

BACKGROUND

The anterior and posterior part of the deltoid ligament have different functions during ankle flexion motion. Partial ligament injuries have been demonstrated in previous clinical reports. However, the efficacy of external rotation stress test in partial injured cases is unavailable till now.

METHODS

Thirty-two fresh cadaveric specimens were included and allocated into two destabilization groups. In the first group, the anterior portion of deltoid ligament (DL) and syndesmotic ligament were sequentially severed, while in the second group, the posterior portion of DL and syndesmotic ligament were sequentially severed. Mortise view radiographs were taken after each destabilization stage when the ankles were placed at plantarflexion and dorsiflexion positions and stressed in standard external rotation force. The medial clear space (MCS) and talar tilt (TT) angle were measured and compared among different destabilization stages.

RESULTS

When the ankles were placed at neutral position, the TT significantly increased in all destabilization stages. The MCS significantly increased after the partial deltoid ligament ruptures only with presence of syndesmotic ligament injuries. There was no significant difference of MCS at plantarflexion for all stages of destabilization if the anterior portion of DL is preserved. Similarly, no significant increase of MCS was detected at dorsiflexion if the posterior portion of DL and posterior inferior tibiofibular ligament are intact.

CONCLUSION

Partial DL rupture causes ankle rotational instability at different ankle joint positions, especially when combined with syndesmotic injuries. The neutral position is recommended for diagnosis of partial DL ruptures under external rotation stress.

The Lateral Drawer Test: A New Clinical Test to Assess Mortise Instability in Weber B Fibula Fractures

Background

Assessment of mortise stability is paramount in determining appropriate management of ankle fractures. Although instability is readily apparent in bimalleolar or trimalleolar ankle fractures, determination of instability in the isolated Weber B fibula fracture often requires further investigation. Prior authors have demonstrated poor predictive value of physical examination findings such as tenderness, ecchymosis, and swelling with instability. The goal of this study is to test the validity of a new clinical examination maneuver, the lateral drawer test, against the gravity stress view (GSV) in a cohort of patients with Weber B fibula fractures. Secondary goals included assessing pain tolerability of the lateral drawer test, as well as testing interobserver reliability.

Methods

Sixty-two patients presenting with isolated fibula fractures were prospectively identified by an orthopaedic nurse practitioner or resident. Three nonweightbearing radiographic views of the ankle as well as a GSV were obtained. Radiographs were not visualized before conducting the lateral drawer test. Two foot and ankle fellowship-trained orthopaedic surgeons performed and graded the lateral drawer test. Radiographs were then examined and medial clear space (MCS) was measured. Visual analog scale (VAS) pain scores were obtained before and after testing. The results of the lateral drawer test were compared with radiographic measurements of MCS on GSV. A cadaveric experiment was devised to assess interobserver reliability of the lateral drawer test.

Results

Thirty (48%) of 62 consecutively enrolled patients demonstrated radiographic instability with widening of the MCS ≥5 mm on GSV. When correlated with MCS measurement, the lateral drawer test demonstrated a sensitivity of 83%, specificity of 97%, positive predictive value (PPV) of 96%, and negative predictive value (NPV) of 86%. There was a strong correlation between the lateral drawer test grade and amount of MCS widening (Spearman correlation ρ = 0.82, P < .005). Patients tolerated the maneuver well with an average increase of 0.7 on the VAS pain scale. Testing of 2 observers utilizing the cadaveric model demonstrated a Cohen's Kappa coefficient of 0.7 indicating moderate interobserver agreement.

Conclusion

The lateral drawer test demonstrates high sensitivity, specificity, PPV, and NPV with moderate interobserver reliability compared with the MCS on GSV in patients presenting with Weber B fibula fractures. Although further external validation is required, the lateral drawer test may offer an adjunct tool via physical examination to help determine mortise stability.

Level of Evidence

Level II, Prospective Cohort Study.

Arthroscopic Quantitative Measurement of Medial Clear Space for Deltoid Injury of the Ankle: A Cadaveric Comparative Study With Stress Radiography

BACKGROUND

The deltoid ligament (DL) is an important stabilizer of the ankle. DL injury of varying severity can occur alone or with syndesmotic injury and fibular fracture. Limited diagnostic tools are available to assess DL injury quantitatively.

PURPOSE

To establish an arthroscopic quantitative assessment of DL injury and to compare its performance with that of external rotation stress (ERS) and gravity stress (GS) radiography.

STUDY DESIGN

Controlled laboratory study.

METHODS

In total, 24 cadaveric lower extremities were divided into 4 groups: group 1 consisted of intact DL, group 2 of superficial DL disruption, group 3 of deep DL disruption, and group 4 of complete DL (superficial and deep) disruption. All specimens underwent sequential sectioning of syndesmotic ligaments, and medial clear space (MCS) was measured with ankle arthroscopy, ERS radiography, and GS radiography at different stages of syndesmotic sectioning.

RESULTS

For noninjured deltoid (group 1) and injured deltoid (groups 2-4), area under the receiver operating characteristic curve (AUC) of measurement of MCS was 0.939 for arthroscopy, 0.932 for ERS radiography, and 0.874 for GS radiography, with a significant difference between arthroscopy and GS radiography (P = .014). For incomplete deltoid injury (groups 1-3) and complete deltoid injury (group 4), the AUC of MCS was 0.811 for arthroscopy, 0.656 for ERS radiography, and 0.721 for GS radiography, with a significant difference between arthroscopy and ERS radiography (P < .001) and between arthroscopy and GS radiography (P = .035). For all stages of syndesmotic sectioning, cutoff values of arthroscopic MCS with intact fibula were ≤2.5 mm for intact DL, between 2.5 and 3.5 mm for partial DL injury (superficial or deep), and ≥3.5 mm for complete DL injury. Arthroscopy was unable to detect a difference between superficial deltoid injury (group 2) and deep deltoid injury (group 3) in partial DL injury, with a measured MCS between 2.5 and 3.5 mm. The intraclass correlation coefficient of interrater reliability was 0.975 for arthroscopy, 0.917 for ERS radiography, and 0.811 for GS radiography.

CONCLUSION

Arthroscopic MCS measurement can differentiate intact DL, partial DL injury, and complete DL injury. Compared with ERS and GS radiography, arthroscopic MCS measurement has greater accuracy with excellent interrater reliability.

CLINICAL RELEVANCE

For patients with suspected DL injury, arthroscopic MCS is useful for determining deltoid lesion severity based on defined cutoff values for consideration in preoperative planning to improve surgical outcomes.

Diagnostic tools to evaluate ankle instability caused by a deltoid ligament rupture in patients with supination-external rotation ankle fractures: A systematic review and meta-analysis

AIM

Supination-external rotation (SER) ankle fractures account for the majority of ankle fractures and can be divided into stable or unstable fractures, based on the state of the deltoid ligament. The objective of this review was to appraise the available literature concerning diagnostic tools to evaluate deltoid ligament integrity in patients with SER-type ankle fractures.

METHODS

A comprehensive literature search of Pubmed and Embase was performed up to December 2020. The outcome measures were sensitivity, specificity and positive and negative predictive value of the diagnostic tools. A meta-analysis was performed to obtain an overview of sensitivity, specificity and area under the curve (AUC). The methodological quality of the articles was evaluated using Quality Assessment of Diagnostic Accuracy Studies.

RESULTS

A total of 12 studies investigating tools for deltoid ligament rupture in patients with SER-type ankle fractures were included. The present study found sensitivity (and specificity) ranges of 0.20-0.90 (and 0.38-0.97) for clinical features, Magnetic Resonance Imaging (MRI) 0.57-0.85 (and 0.81-1.00), ultrasonography 1.00 (and 0.89-1.00), Malleolar Medial Fleck Sign (MMFS) 0.25 (and 0.99), conventional ankle mortise radiography 0.33-0.57 (and 0.60-0.94), gravity stress radiography 0.71-1.00 (and 0.72-0.88) and manual stress ankle radiography 0.65-1.00 (and 0.00-0.77). The largest AUC was found for ultrasonography, followed by MMFS, gravity stress radiography and MRI.

CONCLUSION

Ultrasonography and gravity stress radiography seem the most accurate diagnostic tools to evaluate deltoid ligament integrity. To strengthen this conclusion, future research should use an identical reference test to ensure comparability of results. Nevertheless, present study is of high value to close the knowledge gap about which presently available diagnostic tool is to be preferred to evaluate deltoid ligament integrity in patients with SER-type ankle fractures.

Deltoid ligament arthroscopic repair in ankle fractures: Case series

INTRODUCTION

Diagnosis and treatment of ankle medial ligament lesions in malleolar fractures has always been a matter of controversy. Even when deltoid involvement is clear, the direct repair of this structure is not a consensus. Recently, deltoid repair through an arthroscopic technique was described aiming to potentialize better clinical results and minimize complications.

OBJECTIVE

Demonstrate safety and functional results on patients with ankle fractures submitted to open reduction and internal fixation and arthroscopic deltoid repair.

METHODS

This is a retrospective study in patients diagnosed with ankle fractures associated with acute deltoid injuries submitted to open malleolar fixation and deltoid arthroscopic repair between June 2016 and January 2020. All patients were evaluated for pain and functionality according to the Visual Analogue Scale (VAS) and the American Orthopedic Foot and Ankle Society Score (AOFAS) at a minimum of 6 months follow-up.

RESULTS

From January 2016 to January 2020, 20 ankles with fractures or dislocations were operated and the deltoid ligament rupture was repaired arthroscopically. A mean follow-up of 14.45 months (6-48) was observed, and patients presented an average AOFAS of 93.5 (SD 7.25) and a VAS of 0.75 (SD 1.05). Three minor complications were noticed and no signs of medial chronic instability, loss of reduction or osteoarthritis were observed.

DISCUSSION

The repair of the deltoid complex and the low morbidity of the arthroscopic technique used may improve the clinical outcomes of these patients. Additional studies, with a prospective and comparative methodology are required to sustain this proposal.

DESIGN

Level IV. Retrospective case series.

State of the Art in Treatment of Chronic Medial Ankle Instability

Chronic deltoid instability (CDI), or medial ankle instability, can happen following traumas of the foot and ankle, predominantly rotational injuries. CDI is frequently underdiagnosed or misdiagnosed. Long-term residual instability can lead to ankle posttraumatic arthritis. Adequate assessment of patients with suspected CDI is paramount. Conservative treatment can be tried for stable or mildly unstable cases, but surgical treatment is usually needed for the more severely unstable patients, or when conservative measures fail. Few reconstruction techniques have been proposed in the setting of posttraumatic CDI. This article describes our preferred technique for reconstruction of the deep components of the deltoid ligament.

Clinical Appearance of Medial Ankle Instability

Whereas tenderness, ecchymosis, and swelling over the deltoid ligament have relatively poor sensitivity, resulting valgus and pronation deformity that is seen to disappear when the patient is asked to activate the posterior tibial muscle or to go in tiptoe position is the hallmark for the presence of medial ankle instability. A pain on palpation at anteromedial edge of the ankle confirms the diagnosis. Various stress tests permit to confirm and specify the injury pattern. A pseudo hallux rigidus is the consequence of a hyperactivity of flexor hallucis longus muscle to protect the foot against the valgus and pronation deformity.

Therapeutic approach to combined deltoid ligament disruption with lateral malleolus fracture: Current evidence and literature review

Ankle fractures are among the most common injuries treated by orthopaedic traumatologists. These fractures range from stable, simple injuries to complex, multi-planar unstable ones. Osseo-ligamentous structures play a paramount role in maintaining the stability of the ankle joint. The deltoid ligament is among the most important ankle static stabilizers. Rupture of this ligament along with a lateral malleolar fracture is considered by many as an unstable type of injury and usually requires surgical treatment (bi-malleolar equivalent). Left untreated, it may lead to chronic pain, loss of function and secondary arthritis. Due to lack of high-quality evidence, there are no welldefined, well-accepted criteria for the diagnosis and treatment for treating this type of injury.

[Unstable injuries of the deltoid ligament complex in ankle fractures : How to diagnose, how to treat?]

Unstable injuries of the deltoid ligament complex can have a substantial negative effect on the prognosis and treatment of ankle injuries. Lesions of the deltoid ligament are often overlooked at the initial presentation, both as isolated ruptures and in combination with more complex injuries of the ankle. Neglected unstable injuries of medial ankle ligaments may result in chronic instability, especially following correct treatment of fractures and lateral ligament injuries. These are accompanied by reduced ankle mobility, persisting pain, reduced load bearing and osteoarthritis. Despite the possible subsequent damage, the need for surgical repair of the deltoid ligament in patients with ankle fractures is controversially discussed. Although in most cases of ligament injuries of the upper ankle joint conservative treatment leads to very good results, there is increased interest in acute surgical treatment particularly for unstable injuries in order to avoid secondary instability and the associated sequelae. When surgical treatment should be given priority over conservative treatment has not yet been sufficiently clarified. This article gives an overview of the diagnosis and treatment of injuries of the deltoid ligament complex in patients with ankle fractures based on the current literature.