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 3101
Topic: Upper Extremity Trauma
While testing the stability of the acromioclavicular joint, you note significant anterior-posterior (A-P) translation but normal superior-inferior stability. Which ligamentous structure is primarily injured?
Correct Answer & Explanation
. Superior AC ligament
Explanation
The superior AC ligament, a thickening of the joint capsule, is the thickest and strongest AC ligament. It provides the primary restraint to anterior-posterior translation of the distal clavicle.
Question 3102
Topic: Upper Extremity Trauma
In evaluating the stability of the acromioclavicular (AC) joint, which of the following structures serves as the primary restraint to anterior-posterior translation of the distal clavicle?
Correct Answer & Explanation
. Acromioclavicular capsule and ligaments
Explanation
The AC joint capsule and its intrinsic ligaments are the primary restraints to anterior-posterior translation. The coracoclavicular ligaments (conoid and trapezoid) primarily resist superior-inferior displacement.
Question 3103
Topic: Upper Extremity Trauma
A 28-year-old cyclist falls directly onto his shoulder. Clinical examination reveals a prominent distal clavicle. To accurately diagnose a Rockwood type IV acromioclavicular joint injury, which radiographic view is most critical?
Correct Answer & Explanation
. Axillary lateral view
Explanation
A Rockwood type IV injury involves posterior displacement of the distal clavicle into or through the trapezius muscle. The axillary lateral view is essential to visualize this posterior horizontal displacement.
Question 3104
Topic: Upper Extremity Trauma
A 34-year-old competitive weightlifter complains of a 6-month history of localized right acromioclavicular joint pain, worsened by bench presses. Radiographs reveal widening of the AC joint and subchondral cysts in the distal clavicle. If conservative management fails, what is the most appropriate surgical intervention?
Correct Answer & Explanation
. Distal clavicle excision
Explanation
Distal clavicle osteolysis (weightlifter's shoulder) presents with localized pain and microcystic changes at the distal clavicle. If rest and activity modifications fail, distal clavicle excision (Mumford procedure) provides excellent pain relief.
Question 3105
Topic: Upper Extremity Trauma
The coracoclavicular (CC) ligaments are the primary restraints to superior translation of the distal clavicle. Regarding their anatomy and biomechanics, which of the following statements is true?
Correct Answer & Explanation
. The conoid ligament attaches approximately 4.5 cm medial to the distal end of the clavicle.
Explanation
The conoid ligament attaches roughly 4.5 cm medial to the distal clavicle and is positioned posteromedial to the trapezoid ligament. The conoid is the primary restraint to superior translation, while the AC ligaments primarily resist AP translation.
Question 3106
Topic: Upper Extremity Trauma
A 32-year-old cyclist falls directly on his right shoulder and is diagnosed with a Rockwood Type IV acromioclavicular (AC) joint injury. Which of the following best describes the anatomical displacement characteristic of this injury?
Correct Answer & Explanation
. Posterior displacement of the clavicle into or through the trapezius fascia.
Explanation
Rockwood Type IV injuries involve posterior displacement of the distal clavicle into or through the trapezius muscle and fascia. An axillary lateral radiograph is essential to diagnose this posterior displacement.
Question 3107
Topic: Upper Extremity Trauma
During surgical reconstruction of a chronic acromioclavicular joint dislocation, a surgeon plans to drill tunnels in the clavicle to recreate the coracoclavicular (CC) ligaments. To accurately reproduce the native anatomy, the medial tunnel (for the conoid) and lateral tunnel (for the trapezoid) should be placed at what respective distances from the distal end of the clavicle?
Correct Answer & Explanation
. 4.5 cm and 3.0 cm
Explanation
The native footprint of the trapezoid ligament is centered approximately 3.0 cm medial to the distal clavicle. The conoid ligament footprint is centered approximately 4.5 cm medial to the distal clavicle.
Question 3108
Topic: Upper Extremity Trauma
A patient undergoes a Weaver-Dunn procedure for a chronic Type V acromioclavicular (AC) joint separation. This procedure involves detaching a ligament from its native insertion and transferring it to the distal clavicle. Which ligament is transferred, and how does its biomechanical strength compare to the intact native coracoclavicular (CC) ligaments?
Correct Answer & Explanation
. Coracoacromial (CA) ligament; it is approximately 20-30% as strong as the native CC ligaments.
Explanation
The Weaver-Dunn procedure transfers the CA ligament to the distal clavicle. The transferred CA ligament possesses only about 20% to 30% of the ultimate load to failure compared to the native intact CC ligaments.
Question 3109
Topic: 2. Trauma
A surgeon is performing a closing wedge osteotomy to correct a distal femoral valgus deformity. During the procedure, despite meticulous preoperative planning, the surgeon notices that as the osteotomy gap is closed, the distal segment of the femur inadvertently rotates into a flexion deformity. According to the case material, what is the most likely technical error leading to this complication?
Correct Answer & Explanation
. The osteotomy was performed away from the CORA without performing the necessary translation.
Explanation
Correct Answer: CThe case explicitly states: 'The most frequent, frustrating, and functionally detrimental complication of a closing wedge osteotomy is the inadvertent creation of a new deformity in a completely different plane (for example, accidentally creating a flexion deformity while attempting to correct a varus deformity). This multiplanar error almost always results from a single, specific technical failure:the proximal and distal cuts of the bony wedge are not made perfectly parallel to each other in the desired plane of correction.' If the cuts are not parallel, they cannot close flush, forcing the bone into an unintended plane.Option A is incorrect:Failing to account for the kerf leads to unintended overcorrection in theplannedplane, not an out-of-plane deformity.Option B is incorrect:Aggressive periosteal stripping on the concave side would compromise the hinge stability and blood supply, potentially leading to nonunion or hardware failure, but not directly an out-of-plane deformity during closure.Option D is incorrect:The Krackow effect (micro-crushing from compression) also leads to slight overcorrection in theplannedplane, not an out-of-plane deformity. Insufficient compression would lead to undercorrection or delayed union, not a new deformity in a different plane.Option E is incorrect:Performing an osteotomy away from the CORA without translation (violating Rule Three) leads to a residual translation deformity and uncorrected MAD, but not necessarily an inadvertent rotation into adifferentplane during the closure of the wedge itself, assuming the cuts were parallel in the primary plane.
Question 3110
Topic: 2. Trauma
A 28-year-old patient requires a complex multiplanar deformity correction of the tibia following a malunion. The surgeon plans to use an Ilizarov external fixator. According to the case, how can the external fixator be optimally utilized as a precision cutting guide for the closing wedge osteotomy?
Correct Answer & Explanation
. By positioning the mechanical hinge of the fixator at the planned CORA and then using specialized cutting guides attached to the rings, which are aligned parallel to the joint lines.
Explanation
Correct Answer: BThe case describes the advanced technique: 'The external frame is applied strictly based on anatomical landmarks. The proximal rings are mounted perfectly parallel to the proximal joint line, and the distal rings are mounted parallel to the distal joint line. The mechanical hinge of the external fixator is then positioned to coincide exactly with the pre-planned CORA. Once the frame is rigidly secured to the limb, specialized cutting guides are attached directly to the rings. Because the rings are already perfectly aligned with the bone's true axes, these guides automatically orient the oscillating saw blade to resect the precise, mathematically determined wedge of bone needed.'Option A is incorrect:While rings are parallel to axes, the key is aligning them tojoint linesand positioning the hinge at the CORA for precision cutting guides.Option C is incorrect:Rings are typically applied parallel to joint lines or bone axes, not perpendicular to the mechanical axis for cutting guides. Using the rings directly as guides without specialized attachments would be imprecise.Option D is incorrect:While external fixators can distract, this is not their primary role as acutting guidefor a closing wedge osteotomy. Distraction is more common for opening wedge or lengthening procedures.Option E is incorrect:The question specifically asks about using the fixatoras a cutting guide, which implies its usebefore or duringthe osteotomy cuts, not just for post-osteotomy stabilization and adjustment.
Question 3111
Topic: 2. Trauma
A 40-year-old male undergoes a closing wedge osteotomy for a severe tibial varus deformity. Preoperative planning indicates that the CORA is located intra-articularly, making a Rule One osteotomy impractical. The surgeon therefore plans to perform the osteotomy 4 cm distal to the CORA, requiring both angulation and translation. During the procedure, the surgeon performs the through-and-through osteotomy and then immediately closes the wedge to correct the angulation, before attempting to translate the distal segment. Based on Paley's principles and the provided image, what is the most likely outcome of this sequence?
Correct Answer & Explanation
. The bone segments will become 'jammed,' making the planned translation physically impossible or extremely difficult, leading to a residual deformity.
Explanation
Correct Answer: CThe case explicitly details the 'Unforgiving Sequence: Order of Correction in Complex Cases' and illustrates it with the provided image. Path B (The Incorrect, 'Jammed' Method) shows that if the surgeon mistakenly first closes the wedge to correct the angulation, 'This premature action immediately creates massive friction and extreme compression between the two flat, raw osteotomy surfaces. Furthermore, the tightened concave periosteal sleeve acts as a tether, securely 'locking' the segments together. At this point, attempting to translate the bone is physically akin to trying to slide two pieces of rough sandpaper against each other while clamped in a heavy-duty vise. The required force is immense, risking iatrogenic fracture, severe soft tissue damage, and ultimately making the planned translation physically impossible. The deformity is left permanently 'jammed' in a poorly corrected, highly compromised position.'Option A is incorrect:This contradicts the 'jammed' effect described in the text and image.Option B is incorrect:The text clearly states this incorrect sequence leads to a 'poorly corrected, highly compromised position' and a residual deformity.Option D is incorrect:For a Rule Two osteotomy requiring translation, a complete through-and-through osteotomy is typically performed, meaning the concave periosteal sleeve is not preserved as a hinge in the same way as a Rule One osteotomy. Even if some soft tissue remains, it acts as a tether, hindering translation.Option E is incorrect:The scenario describes a situation where both angulation and translation are required (Rule Two). If translation is not achieved due to the incorrect sequence, the correction will not be pure angulation, and a residual translation deformity will persist.
Question 3112
Topic: 2. Trauma
A 42-year-old male with a severe distal femoral recurvatum deformity (PDFA 108°) is scheduled for a closing wedge osteotomy. The CORA is identified at the anterior cortex and physis. The surgeon plans to perform a Rule One osteotomy, preserving the concave cortex as a hinge. Which of the following statements accurately reflects the biological and mechanical considerations for this approach?
Correct Answer & Explanation
. The osteotomy achieves profound intrinsic stability, potentially allowing stabilization with low-profile hardware like staples.
Explanation
Correct Answer: CThe case states: 'If the concave cortex is left intact and utilized as the primary hinge, the osteotomy achieves such profound intrinsic stability that it can often be effectively stabilized with simple, low-profile hardware, such as surgical staples or a tension band wire construct, rather than massive, bulky locking plates.' In a recurvatum deformity, the anterior cortex is the concave side, and preserving it as a hinge provides this stability.Option A is incorrect:The case explicitly states: 'For a Rule One osteotomy, surgical dissection on the concave side should be minimal to entirely non-existent. Preserving the periosteal sleeve is absolutely paramount for maintaining the local blood supply and ensuring the stability of the cortical hinge.'Option B is incorrect:In a recurvatum deformity, the posterior side is the convex side where the wedge is removed. The anterior cortex is the concave side and is preserved as the hinge.Option D is incorrect:The case mentions that in a Rule Two scenario (requiring translation), the half-wedge of bone that was resected can be preserved and used as vital autograft to fill the structural space created on the translated concave side. While not directly applicable to a pure Rule One osteotomy, it shows the resected bone can have utility.Option E is incorrect:The primary risk of a closing wedge osteotomy is often the creation of an out-of-plane deformity if cuts are not parallel, or issues with hardware failure. Creating a varus deformity from an anterior hinge in a recurvatum correction is not the primary or expected risk; the hinge is designed to facilitate the planned correction.
Question 3113
Topic: Lower Extremity Trauma
A 68-year-old patient with a long-standing genu varum deformity is scheduled for a high tibial osteotomy. Preoperative radiographs confirm a significant varus deformity with a Mechanical Lateral Distal Femoral Angle (mLDFA) of 87°, a Medial Proximal Tibial Angle (MPTA) of 75°, and a Joint Line Convergence Angle (JLCA) of 4°. The surgeon plans to correct the deformity to restore neutral alignment. Based on these findings, what is the most appropriate interpretation of the patient's deformity?
Correct Answer & Explanation
. The JLCA suggests significant intra-articular deformity or ligamentous laxity contributing to the malalignment.
Explanation
Correct Answer: CThe Joint Line Convergence Angle (JLCA) is measured at 4°. The normal range for JLCA is 0-2°. The case states: '>2° strongly suggests joint space narrowing or ligamentous instability.' A JLCA of 4° is significantly elevated, indicating a substantial intra-articular component to the deformity, likely due to medial compartment cartilage loss or medial collateral ligament laxity, which contributes to the overall varus alignment.Option A is incorrect:The mLDFA is 87°, which is within the normal range of 85-90°. This indicates no significant deformity in the distal femur. The MPTA of 75° (normal 85-90°) indicates a significant proximal tibial varus deformity, making the tibia the primary site of extra-articular deformity.Option B is incorrect:The MPTA is 75°. An MPTA <85° indicates varus, while >90° indicates valgus. Therefore, 75° indicates a varus deformity of the proximal tibia, not valgus.Option D is incorrect:The mLDFA of 87° is within the normal range (85-90°), indicating no significant varus deformity of the distal femur.Option E is incorrect:Genu varum (bow-legged) means the mechanical axis passes medial to the knee joint, overloading the medial compartment. If it passed lateral, it would indicate genu valgum.
Question 3114
Topic: Lower Extremity Trauma
A 35-year-old male presents with a long-standing varus knee deformity and a 2 cm limb length discrepancy in the affected limb. Preoperative planning reveals a CORA located in the distal femoral metaphysis. The surgeon plans an acute correction using internal fixation. Based on Paley's principles and the patient's specific presentation, which osteotomy technique would be most appropriate?
Correct Answer & Explanation
. Opening wedge osteotomy with structural allograft
Explanation
Correct Answer: DThe patient presents with a varus knee deformity and a concomitant 2 cm limb length discrepancy. The case content explicitly states that a primary advantage of anopening wedge osteotomyis that itincreases overall limb length, which is highly beneficial for patients presenting with a concomitant limb length discrepancy alongside their angular deformity. Since the CORA is in the distal femoral metaphysis, an opening wedge osteotomy at this site would allow for both angular correction and limb lengthening. The use of structural allograft is often necessary with internal fixation to bridge the created gap and provide initial stability, as mentioned in the disadvantages of opening wedge osteotomies with internal fixation.Option A (Closing wedge osteotomy with bone graft)is incorrect because closing wedge osteotomies inherently shorten the limb, which would exacerbate the existing limb length discrepancy. While bone graft can be used, it doesn't address the shortening.Option B (Neutral wedge osteotomy)is incorrect because it results in no net change in overall limb length, which would not address the 2 cm limb length discrepancy.Option C (Closing wedge osteotomy without bone graft)is incorrect for the same reason as option A; it shortens the limb, which is contraindicated in this patient.Option E (Acute correction with intramedullary nailing and blocking screws)is less appropriate for a metaphyseal deformity around the knee. While IM nailing can correct diaphyseal deformities, acute metaphyseal corrections with IM nails are challenging and often require specialized jigs or temporary external fixators (FAN). More importantly, IM nailing itself does not inherently lengthen the limb in the same controlled manner as an opening wedge osteotomy, and the primary issue here is addressing the limb length discrepancy.
Question 3115
Topic: 2. Trauma
A 28-year-old male presents with a complex multi-planar tibial deformity following a malunited fracture. Preoperative planning identifies a CORA located in the mid-diaphysis, but due to poor bone quality and previous hardware in that exact location, the surgeon decides to perform the osteotomy 5 cm distal to the CORA. The mechanical hinge of the external fixator is meticulously placed at the true CORA. Which of Paley's Osteotomy Rules is being applied, and what is the expected outcome?
Correct Answer & Explanation
. Rule 2; angular correction accompanied by predictable, collinear translation.
Explanation
Correct Answer: B. This scenario perfectly describes Paley's Osteotomy Rule 2. The case content states: 'The osteotomy is performed at a level different from the CORA, but the mechanical hinge remains placed at the CORA. Result: Angular correction accompanied by a predictable, necessary, and collinear translation.' In this patient, the osteotomy is performed 5 cm distal to the CORA, but the hinge is placed at the CORA. This will result in a controlled, predictable translation of the bone segments at the osteotomy site, in addition to the angular correction, while still restoring the mechanical axis. Option A is incorrect. Rule 1 applies when both the osteotomy and the hinge are exactly at the CORA, which is not the case here. Option C is incorrect. Rule 3 applies when both the osteotomy and the mechanical hinge are placed at locations different from the CORA. In this scenario, the hinge is correctly placed at the CORA, preventing an iatrogenic deformity. Option D is incorrect. This scenario does not fit Rule 1, and the translation in Rule 2 is predictable, not unpredictable. Option E is incorrect. Rule 2 specifically results in translation, not an absence of it. While limb length can be affected by the type of osteotomy (opening vs. closing wedge), the primary outcome of Rule 2 is controlled translation, not necessarily increased limb length.
Question 3116
Topic: 2. Trauma
A 40-year-old patient with a complex multi-planar femoral deformity is scheduled for correction. The surgeon is considering different hardware options. The patient has a history of poor compliance with external fixator care and desires a quicker return to work. However, the deformity is large, and there is concern for significant acute soft tissue stretching. Given these factors, which hardware selection strategy aligns best with the principles discussed in the case?
Correct Answer & Explanation
. A hexapod circular external fixator, despite compliance concerns, due to its ability to perform gradual, multi-planar correction.
Explanation
Correct Answer: CThe case content highlights thatcircular external fixation systems (traditional Ilizarov and modern hexapod systems) remain the absolute gold standard for complex, multi-planar, multi-apical deformities. While the patient has compliance concerns and desires a quicker return to work (which favors internal fixation), the critical factor here is the"large" and "complex multi-planar" deformity with concern for "significant acute soft tissue stretching."The text explicitly states that"acute correction with plates is less suitable for large-magnitude deformities or complex multiplanar deformities due to acute soft tissue stretching (e.g., peroneal nerve palsy in large valgus corrections)."A hexapod system allows for gradual correction, mitigating the risks of acute soft tissue stretching and nerve palsies, which is paramount in complex, large deformities, even with compliance challenges.Option A (Acute correction with a locking plate)is incorrect because, as stated in the text, plates are less suitable for large-magnitude or complex multiplanar deformities due to acute soft tissue stretching. While it offers advantages, it's not the best choice for this specific deformity complexity.Option B (Intramedullary nailing with blocking screws)is incorrect. While IM nails are load-sharing and avoid external fixation, they are primarily used for diaphyseal deformities. Complex multi-planar deformities, especially around joints, are often better managed with external fixators that allow for multi-planar correction and gradual adjustment.Option D (A monolateral external fixator)is incorrect. While simpler, monolateral fixators are generally less versatile than circular or hexapod frames for complex, multi-planar deformities, which require more robust and adjustable constructs.Option E (A combination of a locking plate and an intramedullary nail)is incorrect. This is not a standard or recommended approach for primary deformity correction and would introduce unnecessary complexity and potential complications without addressing the core issue of gradual correction for large, complex deformities.
Question 3117
Topic: Lower Extremity Trauma
A 30-year-old patient with a congenital femoral bowing deformity is undergoing correction using an intramedullary nail. The preoperative radiographs show a significant diaphyseal curve. To ensure the straight IM nail corrects the deformity and does not follow the original curved canal, which technique, as described in the case, would be most appropriate?
Correct Answer & Explanation
. Placing blocking (Poller) screws strategically on the concave side of the deformity.
Explanation
Correct Answer: CThe case content specifically addresses this scenario under "Intramedullary Nailing Techniques":"Because the IM canal in a deformed bone is much wider than the nail, a straight nail will often follow the path of least resistance, recreating the deformity. To guide a straight nail through a deformed bone segment and force it into the center of the canal,blocking screws are placed strategically into the cancellous bone on the concave side of the deformity. These screws physically block the nail from translating, ensuring the mechanical axis is maintained."This technique is precisely designed to prevent the recreation of the deformity when using a straight IM nail in a curved canal.Option A (Performing a fixator-assisted nailing (FAN) procedure)is incorrect. While FAN is a valid technique for acute correction with IM nailing, its primary purpose is to acutely obtain and rigidly hold the correctionbeforenail insertion, not specifically to guide a straight nail through a curved canal once the nail is being inserted. Blocking screws are usedduringnail insertion to guide it.Option B (Using a longer, larger diameter intramedullary nail)is incorrect. A larger diameter nail might fill the canal more, but it doesn't guarantee correction of the deformity if the canal is curved. A longer nail doesn't inherently guide it into a corrected path.Option D (Performing a closing wedge osteotomy prior to nail insertion)is incorrect. While an osteotomy is necessary for correction, performing a closing wedgepriorto nail insertion doesn't, by itself, ensure the nail will maintain the correction or prevent it from following the remaining curve. Blocking screws are still needed to guide the nail through the corrected segment.Option E (Utilizing a custom-bent intramedullary nail)is incorrect. The case content focuses on usingstraightIM nails and techniques to guide them. Custom-bent nails are not discussed as a primary strategy for deformity correction in this context.
Question 3118
Topic: 2. Trauma
The image below illustrates the biomechanical principles of external fixation in deformity correction.
Based on the top diagram showing a monolateral fixator, which of Paley's Osteotomy Rules is being demonstrated, and what is its key characteristic?
Correct Answer & Explanation
. Rule 1; the osteotomy is at the CORA, and the hinge is at the CORA, resulting in pure angular correction with no translation.
Explanation
Correct Answer: AThe image description in the case content states:"The top diagram illustrates a monolateral fixator correcting a simple angular deformity. The red and blue lines represent the mechanical axes of the proximal and distal bone segments.Notice how the fixator's hinge is placed exactly at the CORA (Rule 1). As the device is adjusted, the bone segments are brought into perfect, collinear alignment without translation."This directly describes Paley's Osteotomy Rule 1, where both the osteotomy (implied at the CORA for ideal correction) and the mechanical hinge are at the CORA, leading to pure angular correction without translation.Option B (Rule 2; the osteotomy is different from the CORA, and the hinge is at the CORA, resulting in angular correction with predictable translation)is incorrect. While Rule 2 involves the hinge at the CORA, the osteotomy isdifferentfrom the CORA, which is not what the diagram explicitly shows as the ideal correction without translation.Option C (Rule 3; the osteotomy and hinge are different from the CORA, resulting in an iatrogenic translation deformity)is incorrect. Rule 3 results in an iatrogenic deformity, which is clearly not the ideal correction depicted.Option D (Rule 1; the osteotomy is at the CORA, but the hinge is distal to it, resulting in angular correction with unpredictable translation)is incorrect. Rule 1 requires the hinge to beatthe CORA, and the outcome is no translation, not unpredictable translation.Option E (Rule 2; the osteotomy is proximal to the CORA, and the hinge is at the CORA, resulting in angular correction with limb lengthening)is incorrect. While Rule 2 involves the hinge at the CORA and an osteotomy elsewhere, the diagram shows no translation, and limb lengthening is a characteristic of opening wedge osteotomies, not a direct result of Rule 2 itself without specifying the osteotomy type.
Question 3119
Topic: Lower Extremity Trauma
A 24-year-old male requires correction of a distal femur deformity. The CORA is located 1 cm from the articular surface. The surgeon places the hinge at the CORA to avoid joint penetration but performs the osteotomy 4 cm proximally. Based on Paley's rules, what is the expected mechanical outcome?
Correct Answer & Explanation
. The mechanical axis will realign, but the osteotomy site will translate.
Explanation
Paley's Rule 2 states that if the hinge is placed at the CORA but the osteotomy is at a different level, the mechanical and anatomic axes will fully realign. However, translation will inherently occur at the osteotomy site to achieve this collinearity.
Question 3120
Topic: Lower Extremity Trauma
A 50-year-old female presents with bilateral knee pain and clinical genu varum. Standing full-length radiographs show a mechanical axis deviation (MAD) of 40 mm medially on the right leg. The right mechanical lateral distal femoral angle (mLDFA) is 87 degrees (normal 85-90 degrees) and the medial proximal tibial angle (MPTA) is 76 degrees (normal 85-90 degrees). The joint line convergence angle (JLCA) is 1 degree. Where is the primary source of the varus deformity?
Correct Answer & Explanation
. The proximal tibia
Explanation
The source of the mechanical axis deviation must be analyzed using joint orientation angles. An mLDFA of 87 degrees is normal, while an MPTA of 76 degrees is abnormally decreased, indicating that the varus deformity is isolated to the proximal tibia. The normal JLCA rules out intra-articular laxity.
Test Yourself
Switch to an interactive, timed exam simulation to truly master this topic.