Lower Extremity Trauma MCQs

When analyzing a full-length standing lower extremity radiograph for deformity planning, an abnormally increased Joint Line Convergence Angle (JLCA) is calculated. This finding most strongly suggests the presence of which of the following?

When performing a high tibial osteotomy (HTO) for a varus knee with isolated medial compartment osteoarthritis, what is the generally accepted target point for the mechanical axis on the tibial plateau to ensure appropriate off-loading?

During preoperative planning for a distal femoral osteotomy in a patient with genu valgum, the mechanical lateral distal femoral angle (mLDFA) is measured. What is the normal value for this angle?

When correcting a valgus deformity of the distal femur using a closing wedge osteotomy, where should the hinge (axis of correction) be optimally placed to adhere to Osteotomy Rule 1?

On a full-length standing AP radiograph of the lower extremities, the mechanical axis deviation (MAD) is measured. How is the mechanical axis of the lower extremity defined?

A 45-year-old male presents with genu valgum. Standing radiographs show a mechanical lateral distal femoral angle (mLDFA) of 81 degrees (normal 85-90) and a medial proximal tibial angle (MPTA) of 87 degrees (normal 85-90). The joint line convergence angle is 1 degree. Where is the primary source of the deformity?

During preoperative planning for a medial opening-wedge high tibial osteotomy (HTO) to treat medial compartment osteoarthritis, the surgeon targets the Fujisawa point. Where is this point anatomically located?

A 60-year-old male presents with progressive medial knee pain and a noticeable bow-legged appearance. Full-length standing radiographs confirm a mechanical axis deviation of 25 mm medial to the center of the knee. Further analysis of the joint orientation angles reveals an mLDFA (Mechanical Lateral Distal Femoral Angle) of 96° and an MPTA (Medial Proximal Tibial Angle) of 87°. Based on Paley's principles, where is the primary source of the deformity located?

A surgeon is planning a complex multiplanar deformity correction of the tibia. During the intraoperative phase, the surgeon uses fluoroscopy to verify the mechanical axis. Which of the following intraoperative techniques is explicitly mentioned in the case as an excellent way to verify the intraoperative Mechanical Axis Deviation (MAD)?

A 48-year-old male presents with a symptomatic varus knee deformity. A standardized 51-inch radiograph is obtained, and the following coronal plane measurements are recorded: Mechanical Lateral Distal Femoral Angle (mLDFA) = 88° and Medial Proximal Tibial Angle (MPTA) = 80°. . Based on these findings and Paley's principles, where is the primary source of the deformity located?

A 30-year-old patient presents with chronic knee pain, but no obvious bowing or knock-knee deformity is noted clinically. A standardized 51-inch standing radiograph is obtained. . The overall limb Mechanical Axis Deviation (MAD) is measured at 5 mm medial to the center of the knee (within normal physiological range). However, individual joint orientation angles reveal an mLDFA of 85° and an MPTA of 92°. What is the most accurate interpretation of these findings according to Paley's principles?

A 16-year-old male presents with genu varum. A full-length standing radiograph reveals a mechanical axis deviation (MAD) of 45 mm medial to the center of the knee. The mechanical medial proximal tibial angle (mMPTA) is 87 degrees, and the mechanical lateral distal femoral angle (mLDFA) is 98 degrees. What is the primary source of the deformity?

A 15-year-old male undergoes radiographic evaluation for symptomatic genu valgum. The mechanical lateral distal femoral angle (mLDFA) is measured at 80 degrees, and the mechanical medial proximal tibial angle (mMPTA) is measured at 87 degrees. What is the interpretation of these joint orientation angles?

The 'lengthening over a nail' (LON) technique combines a classic intramedullary nail with an external fixator. What is the primary clinical advantage of this technique compared to standard Ilizarov lengthening alone?

A 45-year-old patient presents with severe varus deformity of the knee. The standing radiograph reveals a mechanical axis deviation (MAD) of 45 mm medially. The Joint Line Convergence Angle (JLCA) is measured at 8 degrees (apex lateral). What does this elevated JLCA most likely indicate?

When evaluating a patient for a high tibial osteotomy to address a sagittal plane deformity, what is the normal posterior proximal tibial angle (PPTA)?

In the sagittal plane, the mechanical axis of the lower extremity connects the center of the femoral head to the center of the ankle. Where does this normal mechanical axis pass in relation to the knee joint?

A 16-year-old female presents with a valgus deformity of her left knee. A full-length standing radiograph is obtained:

Analysis reveals a normal femoral shaft mechanical axis but an abnormally angled lateral distal femoral condyle, leading to a valgus mechanical axis deviation.

This patient's deformity is best characterized as:

Radiographic evaluation of a varus knee deformity reveals a mechanical axis deviation (MAD) of 40 mm medial to the center of the knee. The mechanical lateral distal femoral angle (mLDFA) is 87 degrees, and the medial proximal tibial angle (MPTA) is 80 degrees. Based on this Malalignment Test, where is the primary source of the deformity?

A 35-year-old male presents with genu valgum. The Mechanical Axis Deviation (MAD) is lateral to the knee center. The mLDFA is 82 degrees, MPTA is 87 degrees, and JLCA is 2 degrees. According to Paley's malalignment test, what is the location of the deformity?