Orthopedic Board Review MCQs: OITE & AAOS Part 251

Question 1

During open reduction and internal fixation of a Lisfranc injury, the surgeon must anatomically restore the Lisfranc ligament to ensure proper midfoot stability. What is the precise anatomic attachment of the primary band of the Lisfranc ligament?

Explanation

The Lisfranc ligament is an interosseous ligament composed of up to three bands, with the primary and strongest being the plantar band. It attaches from the plantar-lateral aspect of the medial cuneiform to the plantar-medial aspect of the base of the second metatarsal. There is no direct ligamentous connection between the first and second metatarsal bases, making the Lisfranc ligament crucial for stabilizing the second metatarsal in the 'keystone' position.

Question 2

In the pathogenesis of acute neuroarthropathy (Charcot foot), uncontrolled localized inflammation leads to profound osteolysis and potential midfoot collapse. Which of the following molecular pathways is primarily upregulated, driving the aggressive osteoclastic resorption characteristic of Eichenholtz stage I?

Explanation

Acute Charcot neuroarthropathy is driven by a localized inflammatory response marked by elevated pro-inflammatory cytokines (e.g., TNF-alpha, IL-1beta, IL-6). These cytokines powerfully stimulate the Receptor Activator of Nuclear factor Kappa-B Ligand (RANKL) pathway, shifting the balance away from osteoprotegerin (OPG) and leading to unchecked osteoclastogenesis and aggressive bone resorption. This osteolysis characterizes Eichenholtz stage I (development/fragmentation phase).

Question 3

A 45-year-old female presents with a painful, progressive flatfoot deformity. Examination reveals an inability to perform a single-leg heel rise, flexible hindfoot valgus, and uncovering of the talar head of >40% on AP weight-bearing foot radiographs. Which of the following surgical interventions is most appropriate for this stage of deformity?

Explanation

The patient's clinical and radiographic presentation is consistent with Stage IIB adult-acquired flatfoot deformity (posterior tibial tendon dysfunction). Stage IIB is distinguished from IIA by significant forefoot abduction (uncovering of the talonavicular joint >30%). Therefore, in addition to an FDL transfer and a medial displacement calcaneal osteotomy (MDCO) to correct hindfoot valgus, a lateral column lengthening (e.g., Evans osteotomy) is required to correct the severe forefoot abduction.

Question 4

A 24-year-old professional rugby player undergoes dynamic fluoroscopy revealing isolated syndesmotic instability without a fibular fracture. He is treated with dynamic suture button fixation. Compared to traditional trans-syndesmotic screw fixation, what is the primary biomechanical advantage of dynamic suture button fixation?

Explanation

The primary biomechanical advantage of dynamic suture button fixation for syndesmotic injuries is that it allows for the maintenance of physiologic tibiofibular micromotion. Specifically, it permits the normal external rotation and slight proximal/lateral translation of the fibula that occurs when the wider anterior dome of the talus engages the mortise during ankle dorsiflexion. Rigid screw fixation eliminates this physiologic motion.

Question 5

A 22-year-old collegiate basketball player sustains a Zone II (Jones) fracture of the proximal fifth metatarsal. The high rate of delayed union or non-union in this specific region is directly attributed to its vascular anatomy. Which of the following describes the arterial supply to this watershed area?

Explanation

The base of the 5th metatarsal has two primary blood supplies: the metaphyseal arteries supplying the proximal tuberosity, and the main nutrient artery entering the medial cortex of the diaphysis, which supplies the shaft via intramedullary branches running in a retrograde fashion. Zone II (the metaphyseal-diaphyseal junction, or Jones fracture site) is a relative watershed area between these two distinct vascular supplies, rendering it prone to non-union.

Question 6

In evaluating a patient for femoroacetabular impingement (FAI), a true AP pelvis radiograph demonstrates the projection of the anterior acetabular wall crossing the posterior acetabular wall. This 'crossover sign' is most strongly indicative of which of the following pathomorphologies?

Explanation

The 'crossover sign' is a key radiographic marker seen on an AP pelvis radiograph where the line of the anterior acetabular rim crosses the line of the posterior acetabular rim. It specifically indicates focal cranial (or anterior) acetabular retroversion, which is a common cause of pincer-type femoroacetabular impingement. Global retroversion would also typically show an abnormal prominent ischial spine sign.

Question 7

A 60-year-old male presents with worsening groin pain 6 years after a metal-on-polyethylene total hip arthroplasty utilizing a titanium stem and a large-diameter cobalt-chromium head. Aspiration yields cloudy fluid with negative cultures. MRI demonstrates a large soft-tissue pseudotumor. What is the most likely primary mechanism underlying this presentation?

Explanation

The patient is experiencing an adverse local tissue reaction (ALTR) or ALVAL, characterized by a pseudotumor in a metal-on-polyethylene THA. Because the bearing surface is non-metal-on-metal, the source of the metal ions is the modular head-neck junction (trunnion). Mechanically assisted crevice corrosion (MACC), or trunnionosis, is exacerbated by the use of large-diameter cobalt-chromium heads on titanium stems, leading to metal debris generation and subsequent pseudotumor formation.

Question 8

Which of the following pelvic osteotomies used in the treatment of developmental dysplasia of the hip (DDH) involves a complete cut through the innominate bone without entering the true pelvis, relying on the pubic symphysis as a hinge to provide anterolateral acetabular coverage?

Explanation

The Salter innominate osteotomy is a complete, single transiliac cut extending from the sciatic notch to the AIIS. It uses the pubic symphysis as an intrinsic hinge, allowing the entire acetabulum to be rotated anterolaterally to improve coverage in DDH. In contrast, Pemberton and Dega osteotomies are incomplete pericapsular cuts that hinge on the triradiate cartilage.

Question 9

A 12-year-old obese male is diagnosed with an unstable slipped capital femoral epiphysis (SCFE). Current evidence suggests that which of the following surgical intra-operative interventions during fixation is most directly targeted at reducing the risk of avascular necrosis (AVN)?

Explanation

Unstable SCFE has a high rate of avascular necrosis (AVN) due to kinking or tamponade of the retinacular vessels. Performing a routine anterior capsulotomy decompresses the intracapsular hematoma, significantly reducing intracapsular pressure and thereby restoring blood flow and minimizing the risk of AVN. Over-reduction forcefully stretches the vessels and actively increases AVN risk.

Question 10

A 35-year-old male sustains a posterior hip dislocation with an associated Pipkin type II femoral head fracture. Following an urgent closed reduction, a post-reduction CT scan demonstrates a 3 mm step-off of the femoral head fragment without intra-articular loose bodies in the acetabular fossa. Which of the following is the most appropriate surgical approach for open reduction and internal fixation of this fracture?

Explanation

A Pipkin type II fracture is a femoral head fracture extending superior to the fovea capitis (weight-bearing portion). Because the posterior blood supply (medial circumflex femoral artery) is already at risk from the posterior dislocation, an anterior approach (Smith-Petersen) or a trochanteric flip / surgical hip dislocation is preferred. A Kocher-Langenbeck (posterior) approach requires further dissection of the critical posterior soft tissues and jeopardizes the remaining blood supply to the femoral head.

Question 11

In high-velocity knee dislocations, the popliteal artery is at significant risk of intimal tear or transection due to its rigid tethering within the popliteal fossa. Which of the following strictly defines the proximal and distal anatomic tethering points of the popliteal artery?

Explanation

The popliteal artery is tightly tethered proximally as it exits the adductor hiatus (the opening in the adductor magnus at the distal end of Hunter's canal) and distally where it passes deep to the tendinous arch of the soleus muscle. This rigid fixation makes it highly susceptible to stretch and shear injuries during profound tibiofemoral translation seen in knee dislocations.

Question 12

During reconstruction of the medial patellofemoral ligament (MPFL) for recurrent patellar instability, accurate identification of the anatomic femoral attachment (Schöttle's point) is critical to prevent graft anisometry. On a strictly lateral radiograph of the knee, where is Schöttle's point accurately located?

Explanation

According to Schöttle et al., the radiographic landmark for the femoral footprint of the MPFL on a strict lateral radiograph is 1 mm anterior to the posterior cortex extension line, 2.5 mm distal to the posterior origin of the medial femoral condyle, and distinctly proximal to the posterior extension of Blumensaat's line. Placing the graft here ensures optimal isometry during knee flexion and extension.

Question 13

A 45-year-old female presents with acute medial knee pain after a squatting maneuver. MRI reveals a complete radial tear at the posterior root of the medial meniscus, with 4 mm of medial meniscal extrusion. Biomechanically, this specific injury pattern is most equivalent to which of the following conditions?

Explanation

The meniscal roots securely anchor the meniscus to the tibial plateau, allowing the meniscus to convert axial loads into circumferential 'hoop stresses'. A complete tear of the posterior root disrupts these hoop stresses entirely, leading to meniscal extrusion. Biomechanical studies have demonstrated that a root tear results in contact pressures and kinematics that are statistically equivalent to a total meniscectomy.

Question 14

A 10-year-old male (Tanner stage 1, skeletal age 10) sustains a midsubstance anterior cruciate ligament (ACL) rupture. To successfully reconstruct the ligament while minimizing the risk of physeal growth arrest and iatrogenic angular deformity, which of the following reconstructive techniques is most appropriate?

Explanation

In prepubescent children with significant growth potential remaining (Tanner stage 1 or 2), physeal-sparing techniques are strongly recommended to avoid growth arrest or angular deformity. The all-epiphyseal reconstruction places the tunnels entirely within the epiphysis, avoiding the distal femoral and proximal tibial physes completely. Standard transphyseal techniques and bone plugs carry an unacceptably high risk of growth arrest in this age group.

Question 15

A 65-year-old male with isolated medial compartment osteoarthritis is evaluated for a unicompartmental knee arthroplasty (UKA). According to the classic Kozinn and Scott criteria, which of the following is considered an absolute contraindication for proceeding with a medial UKA?

Explanation

The classic Kozinn and Scott criteria for unicompartmental knee arthroplasty include absolute contraindications such as inflammatory arthritis (e.g., rheumatoid arthritis), tricompartmental disease, fixed varus deformity >15 degrees, fixed valgus >20 degrees, and flexion contracture >15 degrees. While weight >82kg and age were historically considered relative contraindications, modern literature has relaxed these, but inflammatory arthritis remains an absolute contraindication due to global joint involvement.

Question 16

A 28-year-old male sustains a high-energy Pauwels type III femoral neck fracture (vertical shear angle > 50 degrees). Biomechanical studies have demonstrated that which of the following internal fixation constructs provides the greatest stability and highest load to failure for this specific fracture pattern?

Explanation

Pauwels type III femoral neck fractures have a highly vertical orientation, making them subjected to significant vertical shear forces rather than compressive forces. Multiple biomechanical studies have shown that a fixed-angle device, such as a sliding hip screw (SHS), provides superior resistance to vertical shear compared to multiple parallel cancellous screws. Adding a derotational screw to the SHS construct further increases rotational stability and load to failure.

Question 17

A 45-year-old male sustains a Schatzker IV tibial plateau fracture involving a large, displaced posteromedial shear fragment. The surgeon plans a posteromedial approach in the supine position. The optimal inter-nervous and inter-muscular interval for exposing the posteromedial tibial plateau is bounded by which of the following structures?

Explanation

The posteromedial approach to the tibial plateau utilizes the interval between the medial head of the gastrocnemius (which is retracted laterally and posteriorly to protect the neurovascular bundle) and the pes anserinus tendons (which are retracted medially and anteriorly). This provides direct, safe access to the posteromedial shear fragment for buttress plating.

Question 18

During an ilioinguinal approach for the internal fixation of an anterior column acetabular fracture, massive hemorrhage occurs upon dissection over the superior pubic ramus, approximately 5 cm lateral to the pubic symphysis. This bleeding is most likely originating from the 'corona mortis'. What two vascular systems does this structure anastomose?

Explanation

The 'corona mortis' (crown of death) is an anatomical variant defined as a vascular anastomosis between the obturator vessels (branching from the internal iliac system) and the external iliac or inferior epigastric vessels. It lies on the posterior aspect of the superior pubic ramus, typically 4 to 6 cm from the symphysis pubis, and is at high risk of iatrogenic injury during anterior pelvic approaches.

Question 19

A 32-year-old female sustains a high-energy trauma resulting in an isolated coronal plane shear fracture of the lateral femoral condyle (Hoffa fracture, AO/OTA 33-B3). According to biomechanical principles, what is the optimal trajectory for lag screw fixation of this fragment to achieve maximum interfragmentary compression and stability?

Explanation

Hoffa fractures are coronal shear fractures of the femoral condyle. Biomechanical studies have consistently shown that posterior-to-anterior (PA) directed lag screws provide significantly higher stability, compression, and load to failure compared to anterior-to-posterior (AP) screws. This is due to the thicker, denser subchondral bone posteriorly allowing for superior screw purchase, despite the technical challenge of an intra-articular start point.

Question 20

A 25-year-old male sustains a Hawkins Type III talar neck fracture following a fall from height. Radiographs taken at 8 weeks post-ORIF reveal a subchondral radiolucent band in the dome of the talus on the AP view (Hawkins sign). What is the physiological significance and expected clinical outcome based on this radiographic finding?

Explanation

The Hawkins sign is a subchondral radiolucent band seen in the dome of the talus, typically appearing 6 to 8 weeks after injury. It represents subchondral osteopenia (bone resorption) which can only occur in the presence of an intact blood supply causing localized hyperemia. Therefore, a positive Hawkins sign is a highly reliable indicator that the talar body remains vascularized, predicting a very low risk of avascular necrosis (AVN).

Question 21

When performing an extensile lateral approach for a displaced intra-articular calcaneal fracture, preservation of the full-thickness flap's corner is critical to prevent wound necrosis. Which artery primarily supplies the angiosome at the apex of this flap?

Explanation

The lateral calcaneal artery, a terminal branch of the peroneal artery, provides the primary blood supply to the apex of the standard extensile lateral calcaneal flap. Protecting this vascular supply is essential to prevent tip necrosis.

Question 22

A 4-year-old child with developmental dysplasia of the hip (DDH) is scheduled for a Pemberton osteotomy. Which of the following best describes the biomechanical effect and structure of this specific pelvic osteotomy?

Explanation

The Pemberton osteotomy is an incomplete pericapsular osteotomy that hinges on the flexible triradiate cartilage. It changes the shape of the acetabular roof, effectively reducing acetabular volume and improving anterolateral coverage.

Question 23

During an anterior cruciate ligament (ACL) reconstruction, the surgeon inadvertently places the femoral tunnel too anterior (shallow) in the intercondylar notch. What is the expected kinematic consequence of this technical error?

Explanation

An anteriorly (shallow) placed femoral tunnel in ACL reconstruction captures a rotational axis that causes the graft to become excessively tight in flexion and loose in extension, potentially limiting terminal flexion.

Question 24

A 65-year-old patient sustains a highly comminuted distal femur fracture (OTA/AO 33C) treated with a lateral locking plate. Which of the following mechanical factors most significantly increases the risk of fatigue failure or nonunion of the implant?

Explanation

In comminuted fractures treated with bridge plating, decreasing the working length (placing screws too close to the fracture site) makes the construct too rigid over a short segment. This concentrates strain, increasing the risk of construct fatigue failure and nonunion.

Question 25

A 55-year-old active male presents with advanced hallux rigidus (Coughlin and Shurnas Grade 3) and severe pain. He wishes to maintain maximum walking activity levels without pain. Which surgical procedure offers the most reliable, long-term functional outcome?

Explanation

First MTP joint arthrodesis is the gold standard for advanced (Grade 3 and 4) hallux rigidus. It provides the most reliable long-term pain relief and restores excellent functional push-off for active patients.

Question 26

In the evaluation of a 22-year-old athlete with suspected femoroacetabular impingement (FAI), a cross-table lateral radiograph of the hip demonstrates an alpha angle of 65 degrees. Where is the cam morphology most likely located based on this specific view?

Explanation

The cross-table lateral radiograph best profiles the anterosuperior aspect of the femoral head-neck junction, which is the most common location for cam lesions in FAI.

Question 27

A patient with chronic posterolateral corner (PLC) deficiency presents with a varus thrust during gait. Full-length standing radiographs reveal a mechanical axis that passes medial to the medial tibial plateau. What is the most appropriate initial surgical intervention?

Explanation

In a patient with chronic PLC deficiency and significant varus malalignment, a valgus-producing high tibial osteotomy should be performed first. Soft tissue reconstruction alone in the presence of severe varus malalignment has a high failure rate.

Question 28

A 30-year-old sustains a closed tibial shaft fracture. Continuous compartment pressure monitoring is initiated. Which of the following parameters is the most widely accepted and reliable threshold indicating the need for an emergent fasciotomy?

Explanation

A differential pressure (Delta P) of less than 30 mmHg (diastolic blood pressure minus intracompartmental pressure) is the most reliable threshold for diagnosing acute compartment syndrome and indicating fasciotomy.

Question 29

A 24-year-old track athlete is diagnosed with a high-risk tarsal navicular stress fracture. The navicular has a unique vascular anatomy that predisposes it to delayed union and nonunion. Which region of the navicular is relatively avascular and most prone to stress fractures?

Explanation

The central third of the tarsal navicular is a relative watershed area with poor blood supply. This avascularity makes it the most common site for stress fractures and increases the risk of nonunion.

Question 30

A 28-year-old patient sustains a vertical, Pauwels type III femoral neck fracture. To maximize biomechanical stability and resist the high shear forces inherent to this fracture pattern, which internal fixation construct is most appropriate?

Explanation

Pauwels type III fractures are highly vertical and experience massive shear forces. A fixed-angle device, such as a dynamic hip screw (DHS) combined with an anti-rotation screw, provides superior biomechanical resistance to shear compared to multiple cancellous screws.

Question 31

During medial patellofemoral ligament (MPFL) reconstruction, the surgeon places the femoral tunnel proximal and anterior to the true anatomic insertion (Schottle point). What is the primary kinematic abnormality caused by this error?

Explanation

A femoral tunnel placed too proximal and anterior in MPFL reconstruction will result in the graft increasing in tension as the knee flexes. This excessive tightness in flexion restricts motion and increases medial patellofemoral contact pressures.

Question 32

A patient with a lateral compression pelvic ring injury is noted to have a crescent fracture of the ilium. According to the Day classification, a type II crescent fracture involves which of the following fracture patterns?

Explanation

In the Day classification of crescent fractures, a Type II fracture enters the sacroiliac (SI) joint directly. This leaves a posterior fragment of the ilium securely attached to the sacrum while the anterior ilium is displaced.

Question 33

A 22-year-old basketball player undergoes intramedullary screw fixation for a Zone 2 proximal fifth metatarsal fracture (Jones fracture). Which anatomical characteristic dictates that the correct entry point must be high and medial on the fifth metatarsal base?

Explanation

The fifth metatarsal has a natural lateral and plantar bow. To safely place a straight intramedullary screw without breaching the medial or plantar cortices, the starting point must be located high (dorsal) and medial on the base.

Question 34

A patient sustains a posterior dislocation of a total hip arthroplasty (THA) while sitting in a low chair. Intraoperative assessment during revision reveals impingement of the prosthetic femoral neck against the anterior acetabular rim during flexion and internal rotation. This mechanism is most likely caused by which acetabular component malposition?

Explanation

A retroverted acetabular cup promotes anterior femoroacetabular impingement when the hip is in flexion and internal rotation. This impingement acts as a fulcrum, levering the femoral head out posteriorly.

Question 35

A 35-year-old roofer falls from a height and sustains a Sanders type III calcaneus fracture. An extensile lateral approach is planned for open reduction and internal fixation. To minimize the risk of wound slough and flap necrosis, the full-thickness flap must be elevated in a subperiosteal plane. Which of the following arterial branches is the primary vascular supply to this lateral flap?

Explanation

The lateral calcaneal artery, a branch of the peroneal artery, provides the primary blood supply to the lateral flap of the calcaneus. The flap must be elevated full-thickness subperiosteally to preserve this delicate vascular network and prevent apical necrosis.

Question 36

A 55-year-old male presents with audible squeaking from his total hip arthroplasty, performed three years ago using a ceramic-on-ceramic bearing. Which of the following component malpositions is most strongly associated with the development of this specific acoustic phenomenon?

Explanation

Squeaking in ceramic-on-ceramic THA is highly associated with edge loading, which occurs with a steeply positioned acetabular cup (inclination > 50 degrees) or excessive anteversion. This leads to disruption of fluid-film lubrication and localized stripe wear.

Question 37

During a posterior-stabilized total knee arthroplasty, trial reduction reveals the knee is tight in extension but well-balanced and symmetric in flexion. Which of the following intraoperative adjustments is the most appropriate next step to achieve balanced gaps?

Explanation

A tight extension gap with a balanced flexion gap indicates an asymmetric extension space. The appropriate management includes releasing the posterior capsule or resecting more distal femur, which selectively increases the extension gap without affecting flexion.

Question 38

A 40-year-old male is brought to the trauma bay following a motorcycle collision. He is hypotensive with a mechanically unstable anteroposterior compression (APC-III) pelvic ring injury. A pelvic binder is applied. To optimally reduce pelvic volume and stabilize the fracture, the binder should be centered over which of the following anatomical landmarks?

Explanation

Pelvic binders are most effective at reducing pelvic volume and controlling hemorrhage when centered directly over the greater trochanters. Placement over the iliac crests is less effective and may inadvertently cause paradoxical widening of the pelvic ring.

Question 39

A 45-year-old female presents with severe bunion pain. Radiographs show a hallux valgus angle (HVA) of 45 degrees, an intermetatarsal angle (IMA) of 18 degrees, and hypermobility of the first tarsometatarsal (TMT) joint. Which of the following surgical procedures is most appropriate?

Explanation

The Lapidus procedure (1st TMT arthrodesis) is indicated for severe hallux valgus (IMA > 15 degrees) combined with first ray hypermobility. Distal or proximal osteotomies alone fail to address the apex of deformity at the unstable TMT joint in this specific presentation.

Question 40

A 28-year-old male sustains a vertically oriented, high-shear femoral neck fracture (Pauwels type III). Open reduction and internal fixation is planned. Biomechanically, which of the following construct choices provides the greatest resistance to vertical shear forces and varus collapse?

Explanation

In young patients with vertically oriented (Pauwels III) femoral neck fractures, a fixed-angle construct such as a sliding hip screw with a derotation screw provides superior biomechanical stability. It resists vertical shear forces and varus collapse significantly better than multiple cannulated screws.

Question 41

During medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar instability, the surgeon uses fluoroscopy to identify Schöttle's point for the femoral tunnel. Which of the following radiographic landmarks correctly defines this location on a strict lateral radiograph?

Explanation

Schöttle's point identifies the anatomic femoral origin of the MPFL. On a strict lateral view, it is located 1 mm anterior to a line extending the posterior femoral cortex, 2.5 mm proximal to the posterior articular border, and proximal to Blumensaat's line.

Question 42

A 30-year-old male is undergoing intramedullary nailing of a proximal third tibial shaft fracture via an infrapatellar approach. What is the most common postoperative malalignment associated with this specific technique for this fracture pattern?

Explanation

Proximal third tibial shaft fractures fixed with an infrapatellar IM nail commonly displace into an apex anterior (procurvatum) and valgus deformity. This is driven by the pull of the patellar tendon and the geometric effect of the nail passing posterior to the anterior tibial cortex.

Question 43

A 55-year-old diabetic male presents with an acutely swollen, warm, erythematous foot without ulceration. Radiographs show periarticular fragmentation and dorsal subluxation of the midfoot. Which of the following is the most appropriate initial management?

Explanation

This patient is in Eichenholtz Stage I (developmental/fragmentation) of Charcot neuroarthropathy. The gold standard initial treatment is strict offloading and immobilization using a total contact cast to arrest the inflammatory cascade and prevent further collapse.

Question 44

A 25-year-old professional hockey player presents with groin pain exacerbated by hip flexion and internal rotation. Imaging reveals a prominent osseous bump at the anterolateral femoral head-neck junction with an alpha angle of 68 degrees. This morphology primarily leads to which type of labral and chondral damage?

Explanation

Cam morphology (alpha angle >55 degrees) produces shear forces during hip flexion/internal rotation, causing 'outside-in' delamination of the anterosuperior acetabular cartilage. The labrum is often pushed outward and spared initially, unlike pincer impingement where labral failure is primary.

Question 45

A 13-year-old obese male presents with an unstable slipped capital femoral epiphysis (SCFE). He undergoes in-situ percutaneous pinning. Postoperatively, he develops severe hip pain and restricted range of motion. Radiographs show profound uniform joint space narrowing but no collapse of the femoral head. What is the most likely diagnosis?

Explanation

Chondrolysis is a severe complication of SCFE, notably associated with unstable slips and unrecognized hardware penetration into the joint. It is characterized by acute, uniform joint space narrowing, severe stiffness, and pain, differentiating it from the segmental collapse seen in avascular necrosis.

Question 46

During reconstruction of the posterior cruciate ligament (PCL), anatomically recreating the anterolateral (AL) bundle is crucial for restoring native kinematics. What is the primary biomechanical function of the AL bundle of the PCL?

Explanation

The PCL consists of two main bundles: the anterolateral (AL) and posteromedial (PM). The AL bundle is tightest in flexion and is the primary restraint to posterior tibial translation at 90 degrees of knee flexion, making it the primary target in single-bundle reconstructions.

Question 47

An extensile lateral approach is utilized for open reduction and internal fixation of a joint-depressed calcaneus fracture. Which of the following neurovascular structures is at greatest risk of iatrogenic injury during the inferior aspect of this surgical exposure?

Explanation

The sural nerve courses along the lateral border of the foot, posterior to the lateral malleolus. It is highly vulnerable to transection, traction injury, or neuroma formation during the inferior subperiosteal dissection of the standard extensile lateral approach to the calcaneus.

Question 48

According to the Young-Burgess classification, which of the following injury patterns is the anatomical hallmark of an Anteroposterior Compression Type III (APC III) pelvic ring injury?

Explanation

An APC III injury is characterized by the complete disruption of the anterior sacroiliac (SI) ligaments, the sacrospinous and sacrotuberous ligaments, AND the posterior SI ligaments. This results in complete global (rotational and vertical) pelvic instability.

Question 49

A 55-year-old man undergoes total hip arthroplasty using a ceramic-on-ceramic bearing. At a 2-year follow-up, he complains of an audible squeaking sound during gait but denies any pain. What mechanical phenomenon is primarily associated with this specific complication?

Explanation

Squeaking in ceramic-on-ceramic total hip arthroplasties is strongly correlated with edge loading, typically secondary to component malposition (such as excessive cup anteversion or inclination). Edge loading leads to localized stripe wear on the ceramic head, generating the acoustic phenomenon.

Question 50

A 45-year-old patient suffers an acute medial meniscus posterior root tear during a squatting maneuver. Biomechanically, what is the direct consequence of this unaddressed injury to the knee joint?

Explanation

A posterior root tear of the medial meniscus disrupts its circumferential fibers. This leads to meniscal extrusion and a complete loss of hoop stresses, effectively mimicking the biomechanical state and rapid chondral wear of a total meniscectomy.

Question 51

During fixation of a pronation-external rotation ankle fracture, the surgeon assesses syndesmotic stability via the Cotton test. Which ligament provides the greatest inherent resistance to anterior translation of the distal fibula relative to the tibia?

Explanation

The anterior inferior tibiofibular ligament (AITFL) is the primary restraint against anterior displacement of the fibula relative to the tibia. It is typically the first structure injured in syndesmotic sprains and rotational ankle fractures.

Question 52

When performing open reduction and internal fixation of a 3-part proximal humerus fracture, anatomic restoration of the medial calcar hinge is critical. Failure to achieve medial cortical support is most strongly associated with which of the following mechanical complications?

Explanation

Lack of medial calcar support in proximal humerus fractures predisposes the construct to biomechanical failure characterized by varus collapse. As the head collapses into varus, the superiorly directed locking screws can penetrate the articular surface, leading to joint destruction.

Question 53

A 30-year-old male sustains a Pauwels type III femoral neck fracture. Due to the highly vertical fracture line, the site is subjected to immense shear forces. Which of the following fixation constructs offers the greatest biomechanical stability to counteract these forces and prevent varus collapse?

Explanation

For vertically oriented (Pauwels III) femoral neck fractures in young adults, the shear stresses are exceptionally high. A sliding hip screw (SHS) combined with an anti-rotation screw provides superior biomechanical resistance to shear and varus collapse compared to multiple cancellous screws.

Question 54

During a posterior-stabilized total knee arthroplasty, trial reduction reveals the knee is perfectly balanced in extension but is excessively tight in 90 degrees of flexion. Which of the following intraoperative modifications is most appropriate to resolve this specific imbalance?

Explanation

A knee that is tight in flexion but balanced in extension has an isolated tight flexion gap. Downsizing the femoral component decreases the posterior condylar offset, thereby increasing the flexion gap without altering the extension gap.

Question 55

Recent randomized controlled trials comparing operative versus modern functional rehabilitation (non-operative) protocols for acute Achilles tendon ruptures have predominantly demonstrated which of the following outcomes?

Explanation

With the advent of early functional weight-bearing rehabilitation protocols, the historically higher re-rupture rate of non-operative management has dropped, becoming comparable to operative treatment. However, operative management still carries a significantly higher risk of complications such as infection and wound breakdown.

Question 56

When treating a proximal third tibial shaft fracture with an intramedullary nail via an infrapatellar approach, the fracture frequently drifts into a classic malalignment pattern. What is this typical deformity, and where should a Poller (blocking) screw be placed to prevent it?

Explanation

Proximal third tibial fractures nailed in extension typically deform into valgus and procurvatum due to the pull of the patellar tendon and the wide metaphyseal flare. Poller screws should be placed on the concave side of the anticipated deformity (lateral and posterior) to centralize the nail and redirect its path.

Question 57

In the pathomorphology of femoroacetabular impingement (FAI), what specific pattern of articular cartilage damage is most characteristic of a classic Cam-type lesion?

Explanation

Cam impingement occurs when a non-spherical femoral head engages the acetabulum during flexion. This creates severe shear forces that typically result in anterosuperior labral tears and classic 'delamination' of the adjacent acetabular articular cartilage.

Question 58

Reconstruction of the medial patellofemoral ligament (MPFL) requires highly accurate femoral tunnel placement to ensure isometry. According to Schöttle's method, what is the correct radiographic location of the femoral footprint of the MPFL on a true lateral radiograph?

Explanation

Schöttle's point identifies the anatomic femoral origin of the MPFL. It is located just anterior to a line extending the posterior femoral cortex, proximal to the posterior articular margin, and just distal to the intersection of Blumensaat's line with the posterior cortex.

Question 59

A 40-year-old female presents with a severe hallux valgus deformity (Intermetatarsal Angle = 18 degrees, Hallux Valgus Angle = 45 degrees). Clinical examination reveals profound multiplanar hypermobility of the first tarsometatarsal (TMT) joint. Which of the following surgical procedures is most strongly indicated?

Explanation

The Lapidus procedure involves an arthrodesis of the first tarsometatarsal joint. It is the gold standard for correcting moderate-to-severe hallux valgus deformities when concurrent first ray hypermobility is present, as it provides definitive stabilization and powerful triplanar correction.

Question 60

A 68-year-old female on long-term alendronate therapy presents with vague, increasing dull pain in her right thigh. Radiographs reveal focal lateral cortical thickening and a subtle transverse radiolucent line in the subtrochanteric region of the femur. What is the most appropriate next step in management?

Explanation

The patient is exhibiting signs of an impending atypical femur fracture (AFF) associated with long-term bisphosphonate use. Because she is symptomatic (thigh pain) and has radiographic evidence of an incomplete fracture (radiolucent line/lateral spiking), prophylactic intramedullary nailing is indicated to prevent completion.

Question 61

A 28-year-old patient sustains a posterior fracture-dislocation of the hip in a high-speed motor vehicle collision. Following closed reduction, neurologic examination reveals an inability to actively dorsiflex the ankle or extend the great toe, while plantar flexion remains fully intact. Which specific nerve structure has been injured?

Explanation

The peroneal (fibular) division of the sciatic nerve is located laterally and is more securely tethered than the tibial division. This anatomy makes it highly susceptible to stretch or contusion injuries during a posterior dislocation of the hip, manifesting as a foot drop.

Question 62

During an extensile lateral approach for open reduction and internal fixation of a displaced intra-articular calcaneus fracture, the sural nerve is at significant risk. At the level of the lateral malleolus, what is the predictable anatomic relationship of the sural nerve to the tip of the fibula?

Explanation

The sural nerve courses distally in the posterolateral leg and predictably passes approximately 1.5 to 2.0 cm posterior and inferior to the tip of the lateral malleolus. Knowledge of this anatomy is critical when making the vertical limb of the extensile lateral approach to avoid painful neuromas.

Question 63

A 25-year-old male sustains a vertically oriented (Pauwels type III) femoral neck fracture. Which of the following fixation constructs offers the highest biomechanical stability against the extreme shear forces characteristic of this specific fracture pattern?

Explanation

Pauwels type III fractures are highly unstable due to significant shear forces across the vertical fracture line. Biomechanical studies demonstrate that a fixed-angle construct, such as a sliding hip screw combined with a derotation screw, provides superior resistance to shear compared to multiple cancellous screws.

Question 64

A 9-year-old male (Tanner Stage I) sustains a complete midsubstance anterior cruciate ligament (ACL) rupture. He has significant growth remaining. Which surgical technique is most appropriate to minimize the risk of iatrogenic limb length discrepancy and angular deformity?

Explanation

In prepubescent patients with substantial growth remaining (Tanner Stage I or II), physeal-sparing techniques such as an all-epiphyseal or extra-articular reconstruction are indicated. Transphyseal techniques crossing the open physes risk premature arrest and subsequent angular or leg-length deformities.

Question 65

In the management of a Gustilo-Anderson Type IIIB open tibia fracture, current evidence suggests that definitive soft-tissue flap coverage should optimally be performed within what timeframe to most effectively minimize deep infection rates?

Explanation

Early soft-tissue coverage of Type IIIB open tibia fractures, ideally within 72 hours of injury, is associated with significantly lower rates of deep infection and flap failure. Delays beyond this window dramatically increase colonization and complication rates.

Question 66

A 55-year-old female presents with severe hallux valgus (HVA 45 degrees, IMA 19 degrees) and demonstrable clinical hypermobility of the first tarsometatarsal (TMT) joint. Which surgical procedure is most appropriate to address her deformity and prevent long-term recurrence?

Explanation

The Lapidus procedure (1st TMT arthrodesis) is specifically indicated for patients with moderate to severe hallux valgus coupled with first ray hypermobility. It uniquely restores medial column stability and provides robust correction of the intermetatarsal angle.

Question 67

A 62-year-old female with a metal-on-metal total hip arthroplasty presents with progressive groin pain. MRI reveals a large cystic pseudotumor. Histological examination of the revised periprosthetic tissue is most likely to demonstrate which of the following characteristic findings?

Explanation

Adverse local tissue reactions (ALTR) in metal-on-metal implants are characterized histologically by Aseptic Lymphocytic Vasculitis-Associated Lesions (ALVAL). This represents a delayed-type hypersensitivity reaction to metal ions (cobalt and chromium).

Question 68

A trauma patient presents with a suspected posterolateral corner (PLC) knee injury. The dial test demonstrates 15 degrees of increased external rotation at 30 degrees of knee flexion compared to the uninjured side, but symmetric rotation at 90 degrees of flexion. This finding is diagnostic of an isolated injury to which structure?

Explanation

An increase in external rotation of more than 10 degrees at 30 degrees of flexion, but not at 90 degrees, indicates an isolated injury to the posterolateral corner (PLC). If increased external rotation is present at both 30 and 90 degrees, a combined PLC and PCL injury is diagnosed.

Question 69

A patient is brought to the trauma bay with an APC III pelvic ring injury and a blood pressure of 80/50 mmHg. To effectively reduce pelvic volume and stabilize the fracture, an external pelvic binder should be centered directly over which anatomic landmark?

Explanation

To maximize the reduction of pelvic volume in anterior-posterior compression (APC) injuries, pelvic binders must be centered over the greater trochanters. Placement over the iliac crests is a common error and can paradoxically open the pelvis further.

Question 70

An elite soccer player sustains a zone II proximal fifth metatarsal fracture (Jones fracture). To minimize the risk of nonunion and hardware failure during intramedullary screw fixation, which technical parameter is most crucial?

Explanation

In the intramedullary fixation of Jones fractures, utilizing the largest solid screw diameter that safely fits the canal (often 4.5mm, 5.5mm, or 6.5mm) provides maximum bending stiffness and resistance to failure. The threads must bypass the fracture site entirely to achieve compression.

Question 71

Which of the following clinical profiles serves as the strongest absolute indication for prophylactic in situ pinning of the contralateral, asymptomatic hip in a child presenting with a unilateral slipped capital femoral epiphysis (SCFE)?

Explanation

Endocrinopathies (such as hypothyroidism or panhypopituitarism) are a strong indication for prophylactic pinning of the contralateral hip due to an extremely high risk of bilateral involvement. Other indications include age under 10 years or inability to follow up reliably.

Question 72

During reconstruction of the medial patellofemoral ligament (MPFL), identifying the anatomic femoral footprint (Schottle's point) is critical for graft isometry. Radiographically on a true lateral view, where is this point located?

Explanation

Schottle's point defines the anatomic femoral origin of the MPFL. On a strict lateral radiograph, it is situated 1 mm anterior to the posterior cortex line, just proximal to the posterior extension of Blumensaat's line, and distal to the posterior origin of the medial femoral condyle.

Question 73

A 70-year-old female sustains a Lewis-Rorabeck Type II periprosthetic distal femur fracture above a well-fixed posterior-stabilized (PS) total knee arthroplasty component. Which fixation strategy is considered the gold standard for providing mechanical stability while accommodating the prosthesis design?

Explanation

A Lewis-Rorabeck Type II fracture is displaced but has a well-fixed component. Lateral locked plating is the standard of care. Retrograde nails often cannot be used due to the closed box design of many posterior-stabilized knee components blocking the intercondylar entry portal.

Question 74

Recent randomized controlled trials comparing operative versus non-operative management of acute Achilles tendon ruptures, when utilizing aggressive early functional rehabilitation protocols, have most consistently demonstrated which of the following outcomes?

Explanation

Current high-level evidence indicates that with early functional weight-bearing rehabilitation, non-operative management yields re-rupture rates similar to operative repair. However, operative management carries a higher risk of complications, such as surgical site infections and sural nerve injury.

Question 75

In femoroacetabular impingement (FAI), cam morphology leads to specific patterns of intra-articular damage. Which biomechanical mechanism primarily drives the characteristic chondral injury associated with a cam lesion during repetitive hip flexion?

Explanation

Cam impingement occurs when an aspherical femoral head-neck junction forcefully enters the acetabulum during flexion. This generates significant shear forces at the chondrolabral junction, characteristically causing delamination of the anterosuperior acetabular cartilage from the subchondral bone.

Orthopedic Surgery Board Review MCQs: Arthroplasty, Trauma & Spine Part 255

Orthopedic Board Review MCQs: Foot, Hip, Knee & Fracture | Part 251

Key Takeaway

Orthopedic Board Review MCQs: Foot, Hip, Knee & Fracture | Part 251

Chapter Index