Lower Extremity Trauma MCQs

A surgeon is performing a medial opening wedge high tibial osteotomy (HTO) for a varus knee deformity. To avoid unintentionally altering the sagittal plane biomechanics, the surgeon must carefully manage the anterior and posterior wedge gaps. If the surgeon opens the anterior gap less than the posterior gap, what will be the effect on the tibial plateau?

A 55-year-old patient presents with a malunited distal femoral fracture. Preoperative planning involves assessing the coronal alignment of the distal femur. Which of the following joint orientation angles is most critical for evaluating this specific aspect of the deformity and planning a distal femoral osteotomy (DFO)?

A 40-year-old male presents with a valgus knee deformity. 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°. Where is the primary source of the patient's deformity?

A 45-year-old female presents with a progressive valgus deformity of her right knee. Standing full-length radiographs reveal a mechanical axis deviation (MAD) of 30 mm lateral to the center of the knee. The mechanical lateral distal femoral angle (mLDFA) is 78°, the medial proximal tibial angle (MPTA) is 87°, and the joint line convergence angle (JLCA) is 1°. Based on Paley's malalignment test, which of the following is the primary source of the deformity?

A 55-year-old male with medial compartment knee osteoarthritis presents with a varus thrust. Radiographs show a medial MAD of 40 mm, mLDFA of 87°, MPTA of 86°, and a JLCA of 7° opening laterally. What does the abnormal JLCA primarily signify in the context of deformity planning?

When analyzing the sagittal plane alignment of the tibia for deformity correction, which of the following represents the normal Posterior Proximal Tibial Angle (PPTA)?

A 60-year-old male presents with advanced medial compartment gonarthrosis and a varus deformity.

A high tibial osteotomy (HTO) is planned. The patient has a mechanical axis deviation (MAD) of 20 mm medial. If the surgeon aims to deliberately overcorrect the MAD to unload the medial compartment, where should the postoperative mechanical axis ideally pass through the tibial plateau?

Evaluating a full-length standing radiograph of a 40-year-old female with bilateral knee pain, the mechanical axis deviation (MAD) is found to be 30mm lateral to the center of the right knee. Which of the following normal radiographic parameter values is most critical for determining if the deformity originates in the distal femur?

A 15-year-old male presents with a valgus knee deformity. Full-length radiographs reveal an mLDFA of 78 degrees and an MPTA of 88 degrees. The joint line convergence angle (JLCA) is 2 degrees. Where is the primary source of his deformity?

A 14-year-old boy is undergoing a 4 cm tibial lengthening over an intramedullary nail (LON). At 3 cm of length gained, he develops an inability to actively extend his great toe and reports decreased sensation over the first web space. What is the most appropriate initial management?

A 50-year-old woman presents with knee pain. Standing full-length radiographs reveal a medial mechanical axis deviation (MAD). The mLDFA is 88 degrees and the MPTA is 87 degrees. However, the joint line convergence angle (JLCA) is measured at 7 degrees open laterally. What is the primary cause of her varus alignment?

During radiographic analysis of a lower extremity deformity, the surgeon evaluates the mechanical lateral distal femoral angle (mLDFA). What is the accepted normal range for this angle?

A 45-year-old patient presents with monoarticular knee swelling, stiffness, and brown-colored joint aspirate. Plain radiographs are ordered. What is the most characteristic radiographic finding in the later stages of Pigmented Villonodular Synovitis (PVNS)?

A 32-year-old patient undergoes a full-length weight-bearing radiograph of the lower extremity. The mechanical axis is drawn from the center of the femoral head to the center of the tibial plafond. In a perfectly aligned, non-pathological limb, where should this mechanical axis pass?

A surgeon is evaluating a patient for a distal femoral deformity. Which of the following joint orientation angles is the primary indicator for assessing a deformity originating in the distal femur?

A 40-year-old patient presents with a varus deformity primarily affecting the proximal tibia. Which of the following radiographic findings would be most consistent with this diagnosis?

During preoperative planning for a lower extremity osteotomy, a surgeon measures a Joint Line Convergence Angle (JLCA) of 4 degrees. What does this finding primarily suggest?

A 50-year-old patient presents with a complex knee deformity. Radiographic analysis, similar to the principles illustrated in the diagram, reveals the following measurements: Mechanical Lateral Distal Femoral Angle (mLDFA) = 80°, Medial Proximal Tibial Angle (MPTA) = 82°, and a Mechanical Axis Deviation (MAD) of 35 mm medial. What is the most accurate interpretation of these findings?

A 48-year-old male presents with medial knee pain and a varus thrust during gait. Full-length weight-bearing radiographs show a Mechanical Axis Deviation (MAD) of 28 mm medial. Further angular analysis reveals an mLDFA of 87° and an MPTA of 78°. Based on these findings, where is the primary apex of the deformity located?

A 42-year-old patient presents with progressive medial compartment osteoarthritis and a significant varus deformity. Preoperative planning radiographs reveal a Mechanical Axis Deviation (MAD) of 25 mm medial to the center of the knee. Further analysis of joint orientation angles yields the following measurements: mLDFA = 88°, MPTA = 78°, and JLCA = 1°. Based on these findings and the Paley principles, where is the primary anatomical source of this patient's varus malalignment?