Dislocations of the Foot

STJ DISLOCATIONS

100

What structures impede closed reduction of subtalar dislocations? (must name at least 2)

What is extensor retinaculum, TN caplsule, deep peroneal NV bundle, peroneal tendon.

200

Forceful inversion with plantar-flexed foot (which directions of dislocation

What is medial subtalar dislocation

300

Appearance of a medial subtalar dislocation

What is heel displaced medially due to severe inversion, plantar flexion, and adduction of the entire foot, with apparent shortening of the medial border. (Apparent club foot) Prominent, palpable talar head dorsolat and over the lateral malleolus

400

How do you reduce a STJ dislocation?

What is flexion of the knee to relax the proximal pull of the gastroc-soleus complex on the calc, followed first by accentuation and then by reversal of the deformity. Traction applied to the heel and counteraction is applied to the posterior aspect of the thigh proximal to the flexed knee. Direct pressure n the prominent talar head facilitates the reduction. MEDIAL- PF and inversion of the foot followed by eversion and DF LATERAL-eversion followed by inversion of the foot with lateral pressure applied ot the medially displaced talar head POSTERIOR- PF the forefoot to disengage the superior edge of the navicular from the undersurface of the talar neck. The heel is then translated distally as longitudinal traction is applied and the foot is finally DF while plantar pressure is applied to the dorsally displaced talar head. ANTERIOR- longitudinal traction must be applied to the foot to disengage the posterosuperior edge of the posterior facet from the talar sulcus. Proximal translation of the foot while maintainign longitudinal traction of the heel completes the reduction.

500

Common fractures associated with subtalar dislocations

What is cuboid, anterior calc process, lateral talar process, and lateral malleolus

MTJ DISLOCATIONS

100

ANATOMY OF THE MTJ

What is TN (more elastic medial column- condyloid in shape and is supported by the TN ligament and its adjacent superomedial and lateral CN ligament) and CC joints (more inherently stable, lateral column, saddle shape, stabilized by the medial, dorsolateral, and plantar CC ligament.

200

What MOI causes compression of the MTJ? (Nutcracker syndrome)

What is forcible adbuction of the forefoot. (lateral stress injury) Comprise 17% of MTJ injuries. = fracture of the cuboid or anterior calc process, avulsion fracture of the attachment of the posterior tibial tendon or CN spring ligament onto the navic tuberosity and lateral subluxation of the MTJ TX- 2 months of immobilization and restricted WB (after closed reduction)

300

How does a rupture of multiple posterior tibial tendon insertions present?

What is plantar ecchymosis. Clinical presentation- tenderness, swelling and ecchymosis over the TN and CC joints Pain is elicited with attempted MTJ motion

400

TREAT ET

What is early closed reduction, non-weight-bearing BK cast for 6-8 weeks (for non displaced MTJ injuries) True anatomic reduction is achieved via ORIF with K wires and screws. (should be attempted in all cases, even SEVERE (over triple arthrodesis) Triple arthrodesis performed as a late salvage procedure for patients with unsatisfactory results.

500

Complication of failed initial treatment

What is gait disturbances, planovalgus collapse with painful MTJ arthritis (occurs when nondisplaced lateral strain injuries remain undiagnosed), chronic stiffness, pain, swelling, and midfoot collapse. Longitudinal and crush injuries which involve high energy impacts have the worst prognosis. --> severe soft tissue injuries and displaced, open fracture-dislocations.

LISFRANC INJURIES

100

Are Lisfranc injuries more common in men or women?

What is men are 2-4 times more likely to sustain a Lisfranc injury.

200

How many articular compartments is the joint capsule of the Lisfranc joint complex divided into?

What is 3. Medial, central, and lateral Medial- first tarsoMT articulation Central- second and thrid tarsometatarsal joints and their sagittal extension Lateral- fourth and fifth tarsometatarsal articulations and their distal extensions between these metatarsal bases.

300

What is plantar ecchymosis sign?

What is midfoot ecchymotic area on the plantar surface. Has been ID as a clinical indicator of Lisfranc's injury.

400

What is the normal position of the 4th metatarsal on internal oblique X-ray view?

What is medial border of the 4th MT forms a continuous straight line with the medial edge of the cuboid. 1st MT aligns itself with the medial cuneiform both medially and laterally on AP and internal oblique views. 1st intermt space corresponds precisely with 1st intertarsal space on both the AP and internal oblique views. Medial border of the 2nd MT aligns exactly with the medial edge of the middle cunieform. Best seen on AP 2nd interMT space aligns with the intertarsal space between the middle and lateral cuneiform. Best seen on internal oblique view 3rd interMT space is continuous with corresponding intertarsal space between the lateral cuneiform and cuboid, and the lateral border of the 3rd MT aligns to the lateral edge of the lateral cuneiform. Best seen on internal oblique view. On lateral view, an uninterrupted line along the dorsal surface of the tarsal bone proximally and the corresponding MT base distally. Any dorsal displacement of the MT is abnormal and indicates a significant Lisfranc injury with instability. Slight plantar displacement of 1 mm or less may be normal.

500

How many degrees of sagittal plane motion is present at the tarsometatarsal joint?

What is 10-20 degrees. This mobility gets progressively less in the medial joints with the exception of the 1st tarsometatarsal articulation, which also allows significant sagittal and coronal plane motion.

OTHER DISLOCATIONS

100

MOI for isolated navicular dislocation

What is PF of the foot causing plantar dislocation of the NC joint, followed by recoil of the foot against the plantar surface of the navicular, causing dorsal TN dislocation.

200

What direction do cuboid bones dislocated? cunieforms?

What is plantar for the cuboid and generally dorsal for the cunieforms, unless a dorsal crushing forces overcomes the strong bony and ligamentous constraints to plantar dislocation, increasing the propensity for open injury and compartment syndrome.

300

Goal of reduction of cunieform dislocations.

What is reestablish the anatomy of the second tarsometatarsal join as the keystone of the midfoot arch by establishing length through longitudinal traction, stabilizing the middle cuneiform in its reduced position and then doing the same to the second metatarsal base.

400

Method to close reduce a cuboid dislocation

What is supination and adduction of the forefoot combine with dorsally directed pressure over the plantar aspect of the cuboid. (Usually unstable) The PL has been reported to impede closed reduction Preferred approach- expose the cuboid through a dorsolateral approach and confirm an anatomic reduction, which is stabilized with multiple K wires. Simultaneous interosseous ligament repair has also been recommended.

500

Treatment of hallux IPJ sprain

What is rigid sole shoe or orthoses to limit MTP dislocation for plantar sprains for 2-3 weeks.

RANDOM

100

Name a classification system for Lisfranc injuries.

What is Quenu and Kuss Hardcastle Myerson

200

Two most important early complications of Lisfranc injury

What is compartment syndrome and vascular compromise.

300

Is osteochondritis dissecans an acute or chronic condition?

What is chronic. - a chronic condition in which a loose fragment of cartilage and necrotic bone have fractured from its ischemic subchondral bed.

400

Complications associated with talar neck fractures? (need at least 2)

What is AVN, non union, malunion, infection, arthritis, bone loss

500

Name structures at risk in Lisfranc surgery

What is superficial peroneal nerve, dorsalis pedis, and deep peroneal nerve