Foot Injury

Anatomy

Talus: articulates with navicular and calcaneus; no muscular attachmentsMedial column: 1st MT + medial cunefiormMiddle column: 2-3rd MT + middle + lateral cuneiformsLateral column: 4-5th MT + cuboid Hindfoot: talus + calcaneusChopart joint: hindfoot/midfootMidfoot: med/mid/lat cuneiforms, navicular, cuboidLisfranc: joint between tarsal and metatarsal bones (between midfoot and forefoot)Forefoot: metatarsals and phalanxesTarsus: hindfoot + midfoot

Pain in mid-foot AND Inability to weight bear (4 steps) immediately and in ED OR Tender base 5th metatarsal / navicular100% sensitivity, 79% specificity for clinically significant midfoot fractures

May be able to weight bear if impacted; tender ant-lat, axial compression and abduction; leg shortened and externally rotated if extracapsular (internally rotated in dislocation)MRI: 100% sensitivity Bone scan: 95% sensitivity USS: demonstrates effusion

Assessment

X-ray Interpretation

Ottawa Foot Rules

AP: Med border 2nd MT lines with medial border middle cuneiform

Oblique: Medial + lateral border 3rd MT lines with medial + lateral border lateral cuneiformMedial border 4th MT lines with medial border of cuboid

Lateral:MT should never be more dorsal than respective tarsal bone

Neck and body fracture: neck most common (ie. 50%); due to forced dorsiflexion; associated with subtalar dislocations, avascular necrosis; neck and head fracture require OT ASAPHawkin’s classification: I non-displaced; no incongruity of subtalar joint; avascualr necrosis in 10%II displaced; ankle joint OK (may be subluxation of subtalar joint – distal talus and rest of foot while proximal talus stays OK); 30-50% risk of avascular necrosisIII displaced; dislocation of talus from ankle and subtalar Joint; (head goes anterioly, body goes post-medially, tibia goes between); avascular necrosis in 90%; reduce ASAP

Talar dome (ie. Plateau) fracture: difficult to detect; consider in non-healing sprain; OT if displacedLateral process fracture: OTPosterior process fracture: Shepherd’s #, dancers and kickersPilon fracture: due to talus being forced into tibial metaphysis (eg. Fall from height); OT

Talar Fracture

May be mistaken for ankle dislocation; foot inverted and internally rotated; talonavicular and talocalcneal ligament rupture; calcaneonavicular ligament intact; often associated with talar fracture; difficult to reduce

Subtalar Dislocation

Most common fractured tarsal bone; associated with other leg injury in 25%, vertebral fracture in 10%, also with pelvic; 75% intra-articular; bilateral in 7%; risk of compartment syndrome; can also get avulsion fractures off anterior process and lateral calcaneum; 50% get chronic painMOI: fall from heightBohler’s salient angle: post tuberosity to highest midpoint / anterior tuberosity to midpoint; normal = 20-40°; fracture if <20°Management: conservative if non-displaced and extra- articular; all need admission

Calcaneal Fracture

Navicular Fracture

Rare; usually dorsal avulsion fracture; due to eversion injury; assoc iatedwith deltoid ligament injury; risk of avascular necrosis; ortho review if displaced, intra-articular or comminuted

Base of 5th MT Fracture

Buddy strap; OT if great toe and unstable / intra-articular

Following inversion injury; usually extra-articularTuberosity / styloid fracture: are proximal to jointJones fracture: transverse fracture base 5th MT 1.5-3cm distal to proximal tubercle; intra-articular (intermetatarsal joint between 4th + 5th MT’s); 35-50% non-union rate; OT if >30% articular surface / >2mm displacement (otherwise POP)Pseudo-Jones fracture: avulsion of peroneus brevis tendon (tuberosity); usually non-dispaced; POPDiaphyseal stress #

Lisfranc Fracture /

Dislocation

Most common midfoot fractureMOI: high speed MVA; maybe rotational trauma; hyperextension of forefoot on midfoot dorsal dislocation at tarsoMT joint; may fracture 1st cuneiform and 2nd MT; fracture midfoot in 40%; Lisfranc ligament runs from lateral base medial cunieform to medial base of 2nd MTAssessment: may look normal; pain on passive movement / torsion of forefoot/midfoot with hindfoot heldXR: doesn’t line up as above; may need weight bearing views; bony displacement >1mm = unstable; need CT to see properly; should be <1mm between 1st and 2nd MTClassification: horizontal (all 5 MT’s move); partial / isolated (1 or 2 move); divergent (1st MT moves medially, others laterally)Management: ortho review; maybe conservative if undisplaced; OT if displacedComplication: dorsalis pedis artery compression / laceration; reflex sympathetic dystrophy; ongoing pain and disability; compartment syndrome if significant injury

Phalanx Fracture

If >3-4mm displacement or >10° angulation, require OTMT Fracture