11/2/17. Lateral Collateral Complex Medial Collateral Complex Distal Tibiofibular Syndesmosis Spring Ligament

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Augustus Perkins
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Andrew J Grainger Leeds, UK Lateral Collateral

Syndesmosis Spring Ligament Brief anatomy review Scan

$Radiographically occult fracture 40.$ 5% ATFL complete disruption 20.

ligament involvement (Posterior Talofibular ligament)

1 Andrew J Grainger Leeds, UK Lateral Collateral Complex ial Collateral Complex Distal Tibiofibular Syndesmosis Spring Ligament Brief anatomy review Scan tips and tricks Pathological appearances andrewgrainger@nhs.net Often not imaging modality of choice Radiographically occult fracture 40.2% low-grade lateral ligament injuries 39.5% ATFL complete disruption 20.3% Syndesmotic injuries Regardless of lateral ligament involvement (Posterior Talofibular ligament) Usually not seen at ultrasound Injury usually requires ankle dislocation 7.7% Osteochondral lesions 35.2% Deltoid 16.1% Sinus tarsi 3.8% Spring Roemer et al. AJSM 2014; 42(7):

Anterior Talofibular ligament Frequently comprises superior and

plantar flexion Sonographic anterior drawer plantar flexion

artery branches run between the two bundles Superior Bundle

tendons Tense in Crosses subtalar joint Isolated rupture very

Oblique scanning of double bundle may simulate cleft in

discontinuity Partial or full Dynamic assessment Calcified

Loss of fibrillar pattern Joint effusion Dynamic assessment may

Tears Acutely may see cleft, confirm full thickness nature

2 Anterior Talofibular ligament Frequently comprises superior and inferior bands Weakest and most frequently injured Tenses in plantar flexion Sonographic anterior drawer Anterior Talofibular ligament Frequently comprises superior and inferior bands Weakest and most frequently injured Tenses in plantar flexion Superior bundle is more at risk of injury Perforating peroneal artery branches run between the two bundles Superior Bundle Inferior Bundle Calcaneofibular ligament Crossed by peroneal tendons Tense in Crosses subtalar joint Isolated rupture very rare If torn usually also an ATFL tear (20% of ATFL tears) Oblique scanning of double bundle may simulate cleft in ligament CFL Ligament Tears Acutely may see cleft, discontinuity Partial or full Dynamic assessment Calcified fragment - avulsion Edematous ligament Thickened/ reflective* Loss of fibrillar pattern Joint effusion Dynamic assessment may confirm full thickness nature *Care with anisotropy Ligament Tears Acutely may see cleft, discontinuity Partial or full Dynamic assessment Calcified fragment - avulsion Edematous ligament Thickened/ reflective* Loss of fibrillar pattern Joint effusion Dynamic assessment may confirm full thickness nature *Care with anisotropy Peetrons. J Clin Ultrasound 2004;32:491 2

assessment Calcified fragment - avulsion

Loss of fibrillar pattern Joint effusion

thickness nature Superior Calcaneofibular

Tear may be proximal or distal Inspect both

tibia and fibula Allow slight movement due

orientation Tibia Posterior ligament has

avulsion injuries Injury less common Tibia

lateral ligaments too Anterior syndesmosis

3 Ligament Tears Acutely may see cleft, discontinuity Partial or full Dynamic assessment Calcified fragment - avulsion Edematous ligament Thickened/ reflective* Loss of fibrillar pattern Joint effusion Dynamic assessment may confirm full thickness nature Superior Calcaneofibular ligament Poorly visualised ligament may signify tear Look at peroneal tendons Location Fluid Movement with ligament on Tear may be proximal or distal Inspect both bundles Full width of ligament Inferior Peetrons. J Clin Ultrasound 2004;32:491 Calcaneofibular ligament Poorly visualised ligament may signify tear Look at peroneal tendons Location Fluid Movement with ligament on Tear may be proximal or distal Peron Ensure stability between distal tibia and fibula Allow slight movement due to shape of talus Greatest width of joint in Anterior (AITFL) has two bands Inferior (Distal) = Bassett ligament Very oblique orientation Tibia Posterior ligament has more transverse orientation Stronger bone avulsion injuries Injury less common Tibia Anterior tears readily detected Review lateral ligaments too Anterior syndesmosis torn in 11% of ankle sprains* If anterior torn often end up with MRI Posterior ligament Interosseous membrane Tibia *Hermans. J Anat 2010;217:633 3

4 Distal (inferior) fascicle of the AITFL If thickened may impinge on the talar dome in Can assess dynamically Deep Components Tibiotalar Superficial Components Tibiocalcaneal Tibionavicular Spring Ligament Superomedial band Tibio-Spring Ligament Deep Components Tibiotalar Superficial Components Tibiocalcaneal Tibionavicular Spring Ligament Superomedial band Tibio-Spring Ligament Posterior tibiotalar is strongest M. Deep res Susten Anterior Superficial Deltoid Periosteum Flexor Retinaculum FDL Crim & Longenecker. AJR 2015;204:W63 4

$malleolar fracture Failure of complete$ demonstration tear Demonstration less

Suspected injury usually necessitates MRI

Pathology Chronic insufficiency Associated

5 Rarely encountered in isolation Lateral malleolar fracture Failure of complete demonstration tear Demonstration less reliable on US compared to Lateral Suspected injury usually necessitates MRI Check spring ligament Check flexor retinaculum M. Calcaneus to navicular Technically 3 components Superomedial ial plantar Inferoplantar Superomedial is only component reliably shown on US. but clinically most important Identify deep to tibialis posterior Normally echogenic Normal thickness <5mm Gliding layer between Lig & PTT (1-3mm) Chronic injury Absence of ligament PTT FDL PTT Pathology Chronic insufficiency Associated with PTT dysfunction Acquired flatfoot deformity Acute tears Sports injury Uncommon Sus.T Mansour, R. Skeletal Radiology, 2008:18;2670 PTT Chronic Injury Thickened Low reflective Hypervascularity Regenerates Thickened Thin Normal Stays Absent May appear lax Lat Mansour, R. Skeletal Radiology, 2008:18;2670 5

Anterior syndesmotic ligament easily evaluated Associated LCL injury Posterior may need MRI Deltoid visualised,

6 Instability Further ligament injury Impingement Hypertrophy of soft tissues Impingement * Lat Lat Lateral Collateral Complex easily evaluated Use dynamic assessment ATFL tightens in plantar flexion CFL tightens in Anterior syndesmotic ligament easily evaluated Associated LCL injury Posterior may need MRI Deltoid visualised, but not reliably MRI may be preferable Don t assume failure to visualize = tear Spring ligament injury usually chronic 6

BIOMECHANICS OF ANKLE FRACTURES

BIOMECHANICS OF ANKLE FRACTURES William R Reinus, MD MBA FACR Significance of Ankle Fractures Most common weight-bearing Fx 70% of all Fxs Incidence is increasing Bimodal distribution Men 15-24 Women over