Menu

2. Trauma MCQs

Practice Set 162 of 640

This practice set contains high-yield board review questions covering key concepts in 2. Trauma. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 3221

Topic: Lower Extremity Trauma

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?

. An mLDFA of 92°.
. An MPTA of 80°.
. A JLCA of 5°.
. An mLPFA of 80°.
. A mechanical axis passing lateral to the knee center.

Correct Answer & Explanation

. An MPTA of 80°.

Explanation

Correct Answer: BThe text states that the Medial Proximal Tibial Angle (MPTA) is the primary indicator of a proximal tibial deformity, and an MPTA < 85° indicates a varus deformity. An MPTA of 80° falls within this range, confirming a proximal tibial varus.Option A (mLDFA of 92°) indicates a valgus deformity of the distal femur (normal 85-90°, >90° valgus). Option C (JLCA of 5°) suggests intra-articular pathology like ligamentous laxity or cartilage wear, not a primary bone deformity. Option D (mLPFA of 80°) indicates a proximal femoral deformity, not proximal tibial. Option E (mechanical axis passing lateral to the knee center) describes a valgus deformity, not a varus deformity.

Question 3222

Topic: Lower Extremity Trauma

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 primary varus deformity of the distal femur.
. A primary valgus deformity of the proximal tibia.
. Significant ligamentous laxity, cartilage wear, or meniscal loss within the knee joint.
. An isolated extra-articular deformity requiring a single-level osteotomy.
. A normal knee joint with no soft tissue involvement.

Correct Answer & Explanation

. Significant ligamentous laxity, cartilage wear, or meniscal loss within the knee joint.

Explanation

Correct Answer: CThe text defines the Joint Line Convergence Angle (JLCA) and its significance: "JLCA: 0-2°. A value > 2° suggests ligamentous laxity, cartilage wear, or meniscal loss on the compressed side of the joint, indicating a soft tissue or intra-articular component to the deformity." A JLCA of 4 degrees is significantly greater than the normal range, strongly indicating intra-articular issues.Options A and B refer to specific bone deformities, which are primarily assessed by mLDFA and MPTA, respectively. Option D is incorrect because a high JLCA suggests an intra-articular component, which complicates planning and may not be an isolated extra-articular deformity. Option E is incorrect as a JLCA of 4° is abnormal.

Question 3223

Topic: Lower Extremity Trauma

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?

. The deformity is solely located in the distal femur, causing a valgus alignment.
. The deformity is solely located in the proximal tibia, causing a valgus alignment.
. There is a combined varus deformity originating from both the distal femur and the proximal tibia.
. There is a combined valgus deformity originating from both the distal femur and the proximal tibia.
. The deformity is primarily intra-articular, indicated by the MAD.

Correct Answer & Explanation

. There is a combined varus deformity originating from both the distal femur and the proximal tibia.

Explanation

Correct Answer: CLet's analyze the given angles based on the normal ranges provided in the text (Avg 87° for both mLDFA and MPTA, range 85-90°):mLDFA = 80°:This is less than 85°, which indicates a varus deformity of the distal femur.MPTA = 82°:This is also less than 85°, which indicates a varus deformity of the proximal tibia.MAD = 35 mm medial:This confirms an overall varus alignment of the limb.Since both the mLDFA and MPTA are indicative of varus deformities in their respective segments, the most accurate interpretation is a combined varus deformity originating from both the distal femur and the proximal tibia.Options A and B are incorrect because the deformity is not solely in one segment and is varus, not valgus. Option D is incorrect because both angles indicate varus, not valgus. Option E is incorrect; while MAD quantifies the problem, it doesn't directly indicate an intra-articular deformity; the JLCA would be the primary indicator for that.

Question 3224

Topic: Lower Extremity Trauma

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?

. Distal femur
. Proximal tibia
. Proximal femur
. Ankle joint
. Intra-articular (ligamentous laxity)

Correct Answer & Explanation

. Proximal tibia

Explanation

Correct Answer: BLet's evaluate the given angles:mLDFA = 87°:The normal range for mLDFA is 85-90°. An mLDFA of 87° falls within the normal range, indicating no significant deformity in the distal femur.MPTA = 78°:The normal range for MPTA is 85-90°. An MPTA < 85° indicates a varus deformity of the proximal tibia. 78° is significantly below the normal range.MAD = 28 mm medial:This confirms an overall varus alignment of the limb.Given that the mLDFA is normal and the MPTA shows a clear varus deviation, the primary apex of the deformity is located in the proximal tibia.Option A is incorrect because the mLDFA is normal. Options C and D are not supported by the provided angles. Option E would be indicated by an elevated JLCA, which is not provided as abnormal here.

Question 3225

Topic: Lower Extremity Trauma

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?

. Distal Femur
. Proximal Tibia
. Ankle Joint
. Intra-articular (Knee Joint)
. Mid-diaphyseal Femur

Correct Answer & Explanation

. Proximal Tibia

Explanation

Correct Answer: BThe text states that normal mLDFA is 85° to 90° (Avg 87°), and normal MPTA is 85° to 90° (Avg 87°). The patient's mLDFA of 88° is within normal limits, indicating no significant deformity in the distal femur. The JLCA of 1° is also within normal limits (0° to 2°), ruling out significant intra-articular pathology as the primary cause. However, the MPTA of 78° is significantly less than the normal range (85°-90°), indicating a proximal tibial varus deformity. This geometric analysis definitively proves that the patient's overall varus limb malalignment originates entirely from a structural deformity in the proximal tibia.Option A (Distal Femur)is incorrect because the mLDFA is normal.Option C (Ankle Joint)is incorrect as no mLDTA (Mechanical Lateral Distal Tibial Angle) is provided, and the primary angles point elsewhere.Option D (Intra-articular)is incorrect because the JLCA is within normal limits.Option E (Mid-diaphyseal Femur)is not directly assessed by these specific joint orientation angles, which focus on periarticular deformities. While a diaphyseal deformity could exist, the provided angles specifically point to the proximal tibia.

Question 3226

Topic: Lower Extremity Trauma

A 60-year-old patient presents with a severe valgus deformity of the distal femur and a noticeable limb length discrepancy (lengthening). The surgeon plans a varus-producing distal femoral osteotomy to correct the valgus and simultaneously shorten the limb. Based on the Paley principles of wedge mechanics, where should the Axis of Correction of Angulation (ACA) be strategically placed relative to the CORA and the deformity's cortex to achieve this outcome, as illustrated in the diagram?

. At the CORA, on the convex cortex, resulting in a neutral wedge.
. On the convex cortex, distal to the CORA, resulting in an opening wedge.
. On the concave cortex, proximal to the CORA, resulting in a closing wedge.
. On the concave cortex, distal to the CORA, resulting in an opening wedge.
. On the convex cortex, proximal to the CORA, resulting in a closing wedge.

Correct Answer & Explanation

. On the concave cortex, proximal to the CORA, resulting in a closing wedge.

Explanation

Correct Answer: CThe text and the provided diagram (ch_45_fig_b9e598.webp) illustrate wedge mechanics. To achieve a closing wedge osteotomy (which shortens the bone), the ACA (hinge) must be placed on theconcave cortex. For a valgus deformity of the distal femur, the lateral side is convex and the medial side is concave. Therefore, to create a closing wedge to correct valgus and shorten, the hinge (ACA) is placed on the medial (concave) cortex, away from the CORA.Option Adescribes a neutral wedge, which does not change length.Options B and Ddescribe an opening wedge, which lengthens the bone.Option Eis incorrect; placing the ACA on the convex cortex would result in an opening wedge (lengthening) if placed away from the CORA, or a neutral wedge if at the CORA. A closing wedge requires the hinge on the concave side.

Question 3227

Topic: Lower Extremity Trauma

A 70-year-old patient presents with chronic knee pain. Full-length weight-bearing radiographs show a normal Mechanical Axis Deviation (MAD), and both the mLDFA (87°) and MPTA (88°) are within normal limits. However, the Joint Line Convergence Angle (JLCA) is measured at 5°. What is the MOST likely interpretation of these findings according to the Paley principles?

. The patient has a significant varus deformity originating from the proximal tibia.
. The patient has a significant valgus deformity originating from the distal femur.
. The patient has an overall well-aligned limb, and the pain is likely non-orthopedic.
. The patient has significant intra-articular pathology, such as asymmetric cartilage loss or ligamentous laxity.
. The patient has a multiapical deformity requiring complex planning.

Correct Answer & Explanation

. The patient has significant intra-articular pathology, such as asymmetric cartilage loss or ligamentous laxity.

Explanation

Correct Answer: DThe text defines the JLCA as measuring 'the angle between the distal femoral and proximal tibial joint lines. An increased JLCA suggests intra-articular pathology, such as significant asymmetric cartilage loss or ligamentous laxity allowing the joint to pathologically 'gap open.'' A normal JLCA is 0° to 2°. A JLCA of 5° is significantly elevated, indicating a problem within the joint itself, even if the overall limb alignment (MAD) and bone segment angles (mLDFA, MPTA) are normal. This suggests that the joint space itself is compromised, likely due to cartilage wear or ligamentous instability.Option A and Bare incorrect because the mLDFA and MPTA are within normal limits, ruling out significant bony varus or valgus deformities in the femur or tibia.Option Cis incorrect; while the overall limb alignment is normal, the elevated JLCA points to a specific orthopedic pathology within the knee joint, which is a significant finding.Option Eis incorrect; a multiapical deformity would typically manifest with abnormal mLDFA and/or MPTA, which are normal in this case. The isolated elevated JLCA points to an intra-articular issue.

Question 3228

Topic: Lower Extremity Trauma

When evaluating lower extremity alignment, a malalignment test is performed on a full-length weight-bearing radiograph. The Mechanical Axis Deviation (MAD) is found to be 30 mm medial to the center of the knee joint. The mechanical lateral distal femoral angle (mLDFA) is 97 degrees, and the mechanical medial proximal tibial angle (mMPTA) is 87 degrees. What is the primary source of the patient's deformity?

. Proximal tibial varus
. Proximal tibial valgus
. Distal femoral varus
. Distal femoral valgus
. Intra-articular ligamentous laxity

Correct Answer & Explanation

. Distal femoral varus

Explanation

The normal mLDFA is approximately 87 degrees (range 85-90) and the normal mMPTA is 87 degrees. An mLDFA of 97 degrees indicates an abnormal varus deformity in the distal femur, which correlates with the medial MAD.

Question 3229

Topic: Lower Extremity Trauma

In evaluating sagittal plane deformity of the femur, the mechanical posterior distal femoral angle (mPDFA) is measured. If the mPDFA is found to be 96 degrees (normal ~83 degrees), what specific deformity does this indicate?

. Distal femoral recurvatum
. Distal femoral procurvatum
. Proximal femoral varus
. Proximal femoral valgus
. Distal femoral flexion deformity

Correct Answer & Explanation

. Distal femoral procurvatum

Explanation

The normal mPDFA is 83 degrees. An increased mPDFA means the distal segment is flexed relative to the proximal shaft, which creates an anterior bowing or procurvatum deformity of the distal femur.

Question 3230

Topic: Lower Extremity Trauma

A 38-year-old male is 8 weeks into a tibial deformity correction using a circular ring fixator. He reports mild pain, erythema, and a small amount of serous drainage at a single medial pin site. The pin is not loose, and there are no systemic symptoms. What is the most appropriate initial management?

. Immediate removal of the pin and application of a new pin in a different plane
. Intravenous antibiotics and surgical debridement of the pin tract
. Oral antibiotics and intensified local pin site care
. Discontinuation of any frame adjustments until the drainage stops
. Immediate frame removal and conversion to an intramedullary nail

Correct Answer & Explanation

. Oral antibiotics and intensified local pin site care

Explanation

This represents a superficial pin site infection (Checketts-burns Grade 1-2). In the absence of pin loosening or systemic signs, the standard initial treatment is oral antibiotics and aggressive local pin site care.

Question 3231

Topic: 2. Trauma

In an adult patient undergoing a large angular correction of the tibial diaphysis using a circular fixator, a concurrent fibular osteotomy is typically required. To minimize the risk of fibular nonunion or cross-union, what is a crucial principle regarding the fibular osteotomy?

. It must be performed at the exact same transverse level as the tibial osteotomy.
. It should be performed at a different level than the tibial osteotomy, and a small segment of fibula is often resected.
. It should be fixed rigidly with a plate and screws prior to initiating tibial distraction.
. It must always be performed in the proximal third of the fibula, regardless of the tibial deformity.
. It should be an incomplete 'greenstick' osteotomy to preserve the intramedullary blood supply.

Correct Answer & Explanation

. It should be performed at a different level than the tibial osteotomy, and a small segment of fibula is often resected.

Explanation

To avoid cross-union (synostosis) and minimize nonunion risk, the fibular osteotomy should be performed at a different level than the tibial osteotomy (typically mid-diaphyseal or distal) and a small segment (1-2 cm) is often excised.

Question 3232

Topic: 2. Trauma

In distraction osteogenesis for a tibial lengthening, a 7-day latency period is utilized prior to initiating distraction at a rate of 1 mm per day. What is the primary biological rationale for this latency period?

. To allow primary bone healing to bridge the fracture gap
. To allow for acute resolution of postoperative edema
. To permit revascularization and formation of a soft fibrocartilaginous callus
. To prevent premature consolidation of the regenerate bone
. To allow the external fixator pins to osteointegrate into the cortex

Correct Answer & Explanation

. To permit revascularization and formation of a soft fibrocartilaginous callus

Explanation

The latency period allows the initial fracture hematoma to organize and revascularize, forming a soft callus. Initiating distraction too early disrupts this vital vascularity, significantly increasing the risk of poor regenerate formation and nonunion.

Question 3233

Topic: Lower Extremity Trauma

A 45-year-old female presents with bilateral knee pain. Standing full-length radiographs reveal a medial mechanical axis deviation (MAD) of 25 mm bilaterally. Analysis of joint orientation angles demonstrates a mechanical lateral distal femoral angle (mLDFA) of 96 degrees, a mechanical medial proximal tibial angle (mMPTA) of 87 degrees, and a joint line convergence angle (JLCA) of 1 degree. Where is the primary source of the deformity?

. Proximal tibia
. Distal femur
. Intra-articular knee joint
. Distal tibia
. Combined distal femur and proximal tibia

Correct Answer & Explanation

. Distal femur

Explanation

The normal mLDFA is 88 degrees (range 85-90). An mLDFA of 96 degrees indicates a significant varus deformity of the distal femur. The mMPTA (normal 87) and JLCA (normal 0-2) are within normal physiological limits.

Question 3234

Topic: 2. Trauma

A 25-year-old male is undergoing deformity correction for a midshaft tibial malunion. The surgeon plans an osteotomy based on Paley's rules. If the osteotomy and the hinge (axis of rotation) are both placed exactly at the Center of Rotation of Angulation (CORA), what is the expected geometric outcome?

. Pure angulation correction without translation
. Angulation correction with intentional translation
. Pure translation without angulation
. Angulation correction with secondary limb lengthening
. Angulation correction with secondary limb shortening

Correct Answer & Explanation

. Pure angulation correction without translation

Explanation

According to Paley's Osteotomy Rule 1, when both the osteotomy and the axis of rotation (hinge) pass through the CORA, the bone ends angulate without any translation. This restores colinear alignment of the mechanical axis.

Question 3235

Topic: Lower Extremity Trauma

A patient presents with a varus deformity of the lower extremity. Radiographic evaluation reveals a mechanical lateral distal femoral angle (mLDFA) of 88 degrees, a mechanical medial proximal tibial angle (mMPTA) of 79 degrees, and a joint line convergence angle (JLCA) of 2 degrees. What is the primary source of the varus deformity?

. Distal femur
. Proximal tibia
. Intra-articular knee joint
. Proximal femur
. Diaphyseal femur

Correct Answer & Explanation

. Proximal tibia

Explanation

The normal mMPTA is approximately 87 degrees. An mMPTA of 79 degrees indicates a proximal tibial varus deformity. The mLDFA (normal 88 degrees) and JLCA (normal 0-2 degrees) are within normal limits.

Question 3236

Topic: 2. Trauma

During distraction osteogenesis using the Ilizarov method, what is the optimal rate and rhythm of distraction to promote high-quality regenerate bone formation while avoiding premature consolidation or nonunion?

. 1.0 mm per day divided into 4 increments
. 0.5 mm per day divided into 2 increments
. 1.5 mm per day divided into 3 increments
. 2.0 mm per day divided into 4 increments
. 1.0 mm per day performed as a single adjustment

Correct Answer & Explanation

. 1.0 mm per day divided into 4 increments

Explanation

The optimal rate of distraction osteogenesis is 1.0 mm per day, typically divided into four 0.25 mm increments (rhythm). This provides a steady mechanical stimulus for osteogenesis while minimizing soft tissue complications.

Question 3237

Topic: 2. Trauma

A 35-year-old male presents with a long-standing lower extremity deformity. Historically, such deformities were often corrected using a subjective 'eyeball' technique or simple wedge resections. According to the provided text, what is the most significant iatrogenic consequence frequently associated with this older, less precise approach to frontal plane deformity correction?

. A. Delayed union or nonunion at the osteotomy site.
. B. Increased risk of infection due to prolonged surgical time.
. C. Secondary translations, new deformities, and failure to restore the limb's overall mechanical axis.
. D. Nerve or vascular injury during surgical dissection.
. E. Postoperative stiffness requiring extensive physical therapy.

Correct Answer & Explanation

. C. Secondary translations, new deformities, and failure to restore the limb's overall mechanical axis.

Explanation

Correct Answer: CThe text explicitly states that the subjective 'eyeball' technique or simple wedge resections 'frequently led to disastrous iatrogenic consequences: secondary translations, new deformities, joint obliquity, and a failure to restore the limb's overall mechanical axis.' This highlights the core problem of the older methods, which failed to address the global alignment of the limb, leading to new biomechanical issues. The ultimate result was often early-onset osteoarthritis, altered gait biomechanics, and poor functional outcomes.Incorrect Options:A. Delayed union or nonunion at the osteotomy site:While these are potential complications of any osteotomy, the text specifically emphasizes the biomechanical and alignment-related iatrogenic consequences of thesubjective planning method, rather than general healing issues.B. Increased risk of infection due to prolonged surgical time:Infection is a general surgical risk. The text does not link the 'eyeball' technique specifically to increased infection rates or prolonged surgical time as its primary iatrogenic consequence.D. Nerve or vascular injury during surgical dissection:These are risks inherent to surgical procedures, but the text focuses on theplanning errorsand their resulting alignment issues as the specific iatrogenic consequences of the older method.E. Postoperative stiffness requiring extensive physical therapy:Stiffness can occur after surgery, but it is not presented as the defining iatrogenic consequence of the 'eyeball' technique in the context of frontal plane deformity correction, which primarily concerns alignment.

Question 3238

Topic: 2. Trauma

A 50-year-old patient requires a distal femoral osteotomy for genu valgum. The surgeon plans to use an intramedullary nail for fixation, necessitating a transition from mechanical axis planning to anatomic axis planning. Based on the principles outlined in the text, what is the critical angular relationship that must be accounted for in the femur during this transition?

. A. The Anatomic Mechanical Angle (AMA) of approximately 7 degrees of varus.
. B. The Anatomic Mechanical Angle (AMA) of approximately 7 degrees of valgus.
. C. The Mechanical Lateral Distal Femoral Angle (mLDFA) of 88 degrees.
. D. The Medial Proximal Femoral Angle (MPFA) of 84 degrees.
. E. The fact that the anatomic and mechanical axes are nearly parallel in the femur.

Correct Answer & Explanation

. B. The Anatomic Mechanical Angle (AMA) of approximately 7 degrees of valgus.

Explanation

Correct Answer: BThe text explicitly states: 'The anatomic axis has a natural valgus bow. It diverges from the mechanical axis by an average ofseven degrees. This critical relationship is known as theAnatomic Mechanical Angle (AMA).' This 7-degree valgus relationship is paramount for transitioning between mechanical axis planning (used for overall limb alignment and external fixation) and anatomic axis planning (essential for internal fixation like intramedullary nailing), especially in the femur where the axes diverge significantly.Incorrect Options:A. The Anatomic Mechanical Angle (AMA) of approximately 7 degrees of varus:The text specifies a 'natural valgus bow' for the femoral anatomic axis relative to the mechanical axis, not varus.C. The Mechanical Lateral Distal Femoral Angle (mLDFA) of 88 degrees:While the mLDFA is a crucial joint orientation angle for assessing distal femoral alignment, it defines the relationship between the distal femoral articular surface and the mechanical axis. It is not the angle that describes the divergence between the anatomic and mechanical axes of the femur itself.D. The Medial Proximal Femoral Angle (MPFA) of 84 degrees:The MPFA is an anatomic joint orientation angle for the proximal femur. It is important for proximal femoral osteotomies but does not describe the overall relationship between the femoral anatomic and mechanical axes.E. The fact that the anatomic and mechanical axes are nearly parallel in the femur:The text clearly states that the anatomic and mechanical axesdivergein the femur by approximately 7 degrees. It is in thetibiawhere these axes are nearly parallel and often superimposed.

Question 3239

Topic: 2. Trauma

A 28-year-old patient presents with a tibial malunion requiring corrective osteotomy. The surgeon is performing preoperative planning using Paley's geometric methodology. When considering the relationship between the anatomic axis and the mechanical axis of the tibia, which statement accurately reflects this relationship as described in the text?

. A. The tibial anatomic axis diverges from the mechanical axis by an average of 7 degrees of valgus.
. B. The tibial anatomic axis diverges from the mechanical axis by an average of 7 degrees of varus.
. C. The tibial anatomic and mechanical axes are nearly parallel and often superimposed.
. D. The tibial anatomic axis is always perpendicular to the mechanical axis.
. E. The tibial anatomic axis is used for external fixation, while the mechanical axis is used for intramedullary nailing.

Correct Answer & Explanation

. C. The tibial anatomic and mechanical axes are nearly parallel and often superimposed.

Explanation

Correct Answer: CThe text explicitly states under the 'Anatomic Axis' definition: 'Tibia: The anatomic and mechanical axes are nearly parallel and often superimposed, making tibial planning relatively straightforward.' This is a key distinction from the femur.Incorrect Options:A. The tibial anatomic axis diverges from the mechanical axis by an average of 7 degrees of valgus:This describes the relationship in thefemur(Anatomic Mechanical Angle), not the tibia.B. The tibial anatomic axis diverges from the mechanical axis by an average of 7 degrees of varus:This is incorrect. The 7-degree divergence is in the femur and is valgus, not varus, and not applicable to the tibia.D. The tibial anatomic axis is always perpendicular to the mechanical axis:This is incorrect. Axes of a long bone are generally longitudinal, not perpendicular to each other.E. The tibial anatomic axis is used for external fixation, while the mechanical axis is used for intramedullary nailing:This statement reverses the typical application. Mechanical axis planning is ideal for assessing joint alignment and using external fixation, while anatomic axis planning is essential for internal fixation like intramedullary nailing, especially in the femur where the axes diverge. However, for the tibia, due to their parallelism, the distinction is less critical for fixation choice itself, but the statement as presented is generally incorrect in its assignment.

Question 3240

Topic: Lower Extremity Trauma

A 40-year-old patient presents with a complex multi-apical femoral deformity. The surgeon is using Paley's geometric methodology for preoperative planning. The text emphasizes that the goal of this methodology is not merely to make the bone look straight on an X-ray. What is the primary biomechanical imperative of restoring the mechanical axis in frontal plane deformity correction?

. A. To ensure optimal bone healing at the osteotomy site.
. B. To minimize surgical blood loss during the procedure.
. C. To restore the mechanical axis so that it passes through the center of the knee joint, thereby normalizing joint reactive forces.
. D. To facilitate easier insertion of intramedullary nails.
. E. To prevent nerve and vascular injury during surgical correction.

Correct Answer & Explanation

. C. To restore the mechanical axis so that it passes through the center of the knee joint, thereby normalizing joint reactive forces.

Explanation

Correct Answer: CThe text explicitly states: 'The goal of Paley's methodology is not simply to make the bone look straight on an X-ray, but to restore the mechanical axis so that it passes through the center of the knee joint, thereby normalizing joint reactive forces and preserving the longevity of the native cartilage.' This is the fundamental biomechanical reason for precise alignment correction.Incorrect Options:A. To ensure optimal bone healing at the osteotomy site:While good alignment contributes to stable fixation and thus healing, the primary biomechanical imperative ofrestoring the mechanical axisis about joint load, not directly about osteotomy healing itself.B. To minimize surgical blood loss during the procedure:Blood loss is a general surgical concern and not the primary biomechanical goal of restoring the mechanical axis.D. To facilitate easier insertion of intramedullary nails:While understanding the anatomic axis is crucial for IM nailing, theprimary biomechanical imperativeof restoring themechanical axisis about joint load distribution, not the ease of implant insertion.E. To prevent nerve and vascular injury during surgical correction:This is a critical aspect of surgical safety, but it is not the primary biomechanical goal of restoring the mechanical axis in the context of joint load and longevity.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page