Lower Extremity Trauma MCQs

When evaluating an ankle mortise radiograph for a suspected syndesmotic injury, which of the following radiographic parameters is the most reliable indicator of syndesmotic diastasis?

Which of the following radiographic parameters on a standard mortise ankle radiograph is the most reliable direct indicator of a syndesmotic injury?

The popliteal artery is at high risk of stretch injury or transection during high-energy knee dislocations. It is particularly vulnerable due to firm tethering proximally at the adductor hiatus and distally at the:

In the setting of an ankle syndesmotic injury, which ligament provides the greatest resistance to lateral displacement of the fibula?

During a posterolateral approach to the tibial plateau, the common peroneal nerve must be carefully identified and protected. As it wraps around the fibular neck, it passes between the two heads of which muscle?

A 14-year-old with Ellis-van Creveld syndrome requires surgical intervention for recurrent patellar instability. The instability in this syndrome is primarily driven by which of the following combined structural factors?

A 6-year-old child with Ellis-van Creveld syndrome presents to the orthopedic clinic with progressive, severe genu valgum. What is the primary anatomic abnormality responsible for this specific deformity in this syndrome?

A patient's lower extremity radiographs reveal a mechanical lateral distal femoral angle (mLDFA) of 81 degrees and a medial proximal tibial angle (MPTA) of 87 degrees. The joint line convergence angle (JLCA) is 2 degrees. What is the primary source of the deformity?

A surgeon is planning a lateral opening wedge osteotomy of the distal femur to correct a valgus deformity. To prevent unintended sagittal plane deformity (flexion or extension), where should the mechanical hinge be aligned?

According to the White-Menelaus rule of thumb for estimating remaining growth, what is the expected annual longitudinal growth from the distal femoral and proximal tibial physes, respectively?

A 45-year-old male presents with severe varus gonarthrosis. Standing long leg radiographs reveal a mechanical axis deviation (MAD) of 45 mm medial to the center of the knee. The mechanical lateral distal femoral angle (mLDFA) is 88 degrees and the medial proximal tibial angle (MPTA) is 80 degrees. The joint line convergence angle (JLCA) is 1 degree. What is the primary source of the varus deformity and the most appropriate site for osteotomy?

A 12-year-old boy presents with a 2.5 cm leg length discrepancy due to a prior left femoral shaft fracture. His skeletal age is identical to his chronological age. Based on the Menelaus approximation of the Green-Anderson charts, and assuming skeletal maturity at age 16, which intervention will most accurately achieve limb length equality at maturity?

A 16-year-old male presents with lateral mechanical axis deviation (MAD) of the lower extremity. Standing alignment radiographs reveal a mechanical lateral distal femoral angle (mLDFA) of 81° and a medial proximal tibial angle (MPTA) of 87°. The joint line convergence angle (JLCA) is 1°. What is the primary anatomic source of his malalignment?

A 12-year-old boy presents with limited knee range of motion and aching pain. Imaging is shown below, demonstrating a protruding bone mass extending into the popliteal fossa. The mass originates from the epiphysis. What is the estimated incidence of this specific developmental disorder?

In a patient with Dysplasia Epiphysealis Hemimelica of the distal femur, what advanced imaging modality is considered the gold standard for evaluating the extent of the unossified cartilaginous cap and its relationship to the articular surface prior to surgery?

A 5-year-old boy is diagnosed with symptomatic Dysplasia Epiphysealis Hemimelica of the distal femur. Surgical intervention is planned. Which imaging modality is most critical for preoperative evaluation of the unossified cartilaginous extent of the lesion and joint congruity?

An 8-year-old boy presents with a bony prominence over the medial aspect of the knee. Radiographs reveal an irregular, multi-lobulated ossified mass arising from the medial epiphysis of the distal femur.

If surgical intervention is planned, which advanced imaging modality is most critical for accurately evaluating the unossified cartilaginous cap and joint congruity prior to excision?

Mechanical Axis Deviation (MAD) of the lower extremity is standardly defined as:

A 45-year-old patient presents with knee pain and a 10-degree valgus alignment. Radiographs reveal a mechanical Lateral Distal Femoral Angle (mLDFA) of 81 degrees and a medial Proximal Tibial Angle (mPTA) of 87 degrees. What is the most appropriate corrective osteotomy?

A patient with a severe mechanical axis deviation is evaluated for deformity correction. Radiographs demonstrate a mechanical Lateral Distal Femoral Angle (mLDFA) of 98 degrees and a Medial Proximal Tibial Angle (MPTA) of 87 degrees. What is the primary source of the patient's deformity?