2. Trauma MCQs

A patient requires correction of a uniapical tibial deformity. The osteotomy is planned distant to the center of rotation of angulation (CORA), but the hinge axis is placed exactly on the CORA. According to Paley's osteotomy rules, what is the expected outcome of this correction?

A 38-year-old male presents with progressive right knee pain and a noticeable bowing deformity of his lower extremity. A full-length, weight-bearing anteroposterior radiograph reveals a mechanical axis that passes 15 mm medial to the center of the knee joint. Further analysis shows a Mechanical Lateral Distal Femoral Angle (mLDFA) of 88° and a Medial Proximal Tibial Angle (MPTA) of 78°. Based on these findings, which of the following statements is most accurate regarding the patient's deformity?

A 32-year-old male presents with progressive knee pain and a noticeable bowing of his left lower extremity. A standing, full-length AP radiograph is obtained, revealing a mechanical axis that passes 25 mm medial to the center of the knee joint. Further analysis of joint orientation angles shows a Mechanical Lateral Distal Femoral Angle (mLDFA) of 87° and a Medial Proximal Tibial Angle (MPTA) of 78°. The Joint Line Convergence Angle (JLCA) is 1°. Based on Paley's principles, which of the following statements best describes the primary anatomical location of this patient's deformity?

A 24-year-old patient undergoes a malalignment test for a suspected genu valgum deformity. The mechanical axis falls lateral to the center of the knee. What is the normal physiological range for the mechanical Lateral Distal Femoral Angle (mLDFA)?

A patient presents with a recurvatum deformity of the proximal tibia following trauma. Evaluation of the sagittal plane joint orientation angles is performed. What is the normal value for the Posterior Proximal Tibial Angle (PPTA)?

During tibial lengthening using distraction osteogenesis, a patient returns for a 4-week follow-up. Radiographs reveal a sparse, patchy regenerate with a central radiolucent gap wider than 5 mm. The patient has been distracting at a rate of 1.5 mm per day. What is the most appropriate next step in management?

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

When planning a sagittal plane correction of a proximal tibial recurvatum deformity, the normal posterior proximal tibial angle (PPTA) must be considered. What is the normal anatomic range for the PPTA?

A 45-year-old female presents with a mechanical axis deviation (MAD) of 20 mm medial to the knee center. The mechanical lateral distal femoral angle (mLDFA) is 95 degrees, and the medial proximal tibial angle (MPTA) is 87 degrees. Which of the following is the primary source of the deformity?

A 30-year-old patient presents with a post-traumatic femoral valgus deformity requiring corrective osteotomy. Preoperative planning identifies a single Center of Rotation of Angulation (CORA) in the distal femur. The surgeon plans to use a monolateral external fixator for gradual correction. According to Paley's Osteotomy Rule One, which of the following statements accurately describes the geometric outcome if both the osteotomy and the hardware hinge are placed precisely at the CORA?

A 12-year-old patient presents with a complex, multiplanar deformity of the tibia involving significant angulation, shortening, and rotation due to a malunited fracture. The surgeon needs a fixation system that offers the highest degree of versatility for gradual correction in six degrees of freedom. Which of the following hardware options is the most appropriate choice based on Paley's principles and general practice?

During a gradual angular correction of a femoral deformity using an external fixator, the surgeon observes that the bone ends at the osteotomy site are distracting apart, putting tension on the surrounding soft tissues. This phenomenon is a predictable geometric consequence of the angular correction. According to Paley's principles, what critical action must the surgeon take to prevent neurovascular injury, delayed union, or nonunion?

A 62-year-old male presents with progressive knee pain. A full-length, weight-bearing radiograph is obtained, as shown in the image below. Which of the following lines on the provided radiograph accurately represents the Mechanical Axis of the lower limb?

A 60-year-old patient presents with severe knee pain and a "bow-legged" appearance. A full-length radiograph, as seen in , shows a Mechanical Axis Deviation passing 22mm medial to the knee center. Further analysis reveals an mLDFA of 80 degrees. Based on these findings, what is the most accurate interpretation of the patient's deformity?

A patient undergoing distal femoral lengthening over a motorized intramedullary nail is found to have rapid, dense regenerate bone formation on the two-week postoperative radiograph, raising concerns for premature consolidation. What is the most appropriate initial management step?

In the context of distraction osteogenesis, what is the primary biological rationale for observing a latency period of 5 to 7 days after the osteotomy before initiating distraction?

A patient with severe genu varum is evaluated with preoperative standing radiographs. The Mechanical Lateral Distal Femoral Angle (mLDFA) is 88 degrees, the Mechanical Medial Proximal Tibial Angle (MPTA) is 87 degrees, and the Joint Line Convergence Angle (JLCA) is 6 degrees with medial widening. Which of the following best describes the primary source of the varus deformity?

During distraction osteogenesis of the tibia using an Ilizarov frame, a patient inadvertently adjusts the frame to distract at a rate of 2.0 mm per day rather than the prescribed 1.0 mm per day. Which of the following complications is most likely to result from this accelerated distraction rate?

A 35-year-old male is evaluated for a severe lower extremity deformity. Radiographic measurements reveal a mechanical axis deviation (MAD) of 25 mm lateral to the knee center. The mechanical Lateral Distal Femoral Angle (mLDFA) is 87 degrees, and the Mechanical Medial Proximal Tibial Angle (MPTA) is 98 degrees. The Joint Line Convergence Angle (JLCA) is 1 degree. Where is the primary source of the deformity?

Half-pins are inserted directly laterally into the distal third of the femur for a monolateral fixator construct. Which muscle is directly penetrated by these pins, frequently leading to postoperative knee stiffness?