ABFAS Practice Exam Questions and Answers A 45-year-old male sustained a crush-type injury with early soft tissue necrosis to the left foot. Radiographs are negative for fracture or dislocation.Which of the following tests would be most helpful for determining skin-flap viability?fluorescein dye study.distal plethysmography.segmental pressure gradients.
indium scan. - -Rationale: Fluorescein dye studies might not be routinely
ordered, but of the available answer choices, this would provide the best information on soft tissue viability following a crush injury. Digital plethysmography and segmental pressure gradient would provide information about macrovascular perfusion, but not microvascular skin-flap tissue viability. An indium scan is non-specific for skin-flap viability.-A patient presents eight weeks after sustaining a fracture through the talar neck. Which finding is a prognostic indicator that the vascular supply is intact?resorption of subchondral bone of the talar dome.increased trabecular pattern across the fracture.increased sclerosis of the talar body.absence of degenerative arthritis. - -Resorption or subchondral lucency of the talar dome usually indicates that there is sufficient vascularity in the talus, often termed Hawkins sign. Increased sclerosis of the talar body may suggest avascular necrosis. Absence of degenerative arthritis and increased trabecular pattern across the fracture are not prognostic findings for an intact vascular supply.-For which condition is a bone stimulator most efficacious?synovial pseudarthrosis.hypertrophic nonunion.fibrous nonunion.
fibrous malunion. - -Rationale: Hypertrophic nonunion is the most
appropriate answer choice for a bone stimulator because it is the only non union amongst the available answer choices listed that theoretically has sufficient vascularity to heal. A hypertrophic non union may be lacking stability or normal axial alignment, but is able to heal at a cellular level.Synovial pseudoarthrosis, fibrous non union and malunion are all caused by inadequate immobilization and inadequate blood supply and may be more limited in its ability to heal. 1 / 2
-A 25-year-old female sustained an inversion ankle sprain 24 hours ago. The area is severely edematous and ecchymotic. Diagnostic tests show rupture of the lateral collateral ligaments. What should the treatment consist of at this time?compression dressing for 24 to 48 hours.open ligament repair.posterior splint and warm compresses for 24 to 48 hours.
short leg walking cast. - -Acute soft-tissue ankle injuries), Rationale:
Compression dressing for 24 to 48 hours is the best answer. An open ligament repair is not indicated this early due to the severe edema. A posterior splint may be indicated but the warm compress is not indicated, as icing would be more appropriate. A short leg cast can be used however the patient has severe edema so this is not the best answer as it does not address the swelling.-A 30-year-old male complains of a painful right ankle after sustaining a forced plantarflexion injury. Plantarflexion of the foot and dorsiflexion of the hallux greatly exacerbate the symptoms of pain at the posterior ankle. What is the most probable diagnosis?flexor digitorum longus tendinitis.fracture of the sustentaculum tali.fracture of the posterior lip of the tibia.
fracture of the posterior tubercle of the talus. - -Rationale: The injury
mechanism, combined with the current symptoms point to an injury at the posterior ankle, specifically fracture of the posterior tubercle of the talus, irritated by movement of the flexor hallucis longus tendon. Flexor digitorum longus tendinitis is incorrect since the patient indicates he has pain with great toe motion. Fracture of the sustentaculum tali is incorrect since the patient expresses pain at the posterior ankle, not medial. Fracture of the posterior lip of the tibia is incorrect since pain with plantar flexion of the ankle and dorsiflexion of the toe would point to motion at the talar groove as the likely cause of the pain. The other options are not the most appropriate answer for this question based on the choices given.-The radiograph is for a 14-year-old male who fell six feet and presented to the emergency department two hours later. What other diagnostic test is appropriate to rule out concomitant injury in the emergency room?axial radiography of the foot.computed tomography of the foot.magnetic resonance imaging of the foot.radiography of the spine. - - -During a subtalar arthroereisis for a flexible pediatric flatfoot deformity, release of which encountered anatomic structure should be avoided so as to not destabilize the subtalar joint?interosseous talocalcaneal ligament.
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