Orthopedic Surgery Mock Exam - Set 2915AD

A 45-year-old male presents after a high-speed crush injury to the pelvis. Imaging demonstrates an Anteroposterior Compression Type III (APC-III) pelvic ring disruption with severe pubic symphysis diastasis and bilateral sacroiliac joint disruption.

Severe hemodynamic instability in this specific fracture pattern is most frequently due to disruption of which of the following structures?

An 11-year-old obese male presents with left groin pain and an obligatory external rotation with hip flexion. Radiographs confirm a severe, stable slipped capital femoral epiphysis (SCFE). During percutaneous in situ fixation, the surgeon inadvertently places the single cannulated screw into the posterior-superior quadrant of the femoral head. Which of the following complications is most likely to occur as a direct result of this specific trajectory?

A 28-year-old carpenter sustains a volar laceration to his index finger at the level of the proximal phalanx.

Surgical exploration reveals a complete transection of both the Flexor Digitorum Profundus (FDP) and Flexor Digitorum Superficialis (FDS) within Zone II. A core suture repair is planned. Which of the following core suture configurations provides the highest tensile strength and gap resistance to allow for early active mobilization?

A 65-year-old man presents with progressive hand clumsiness and broad-based gait over 6 months. Physical exam reveals bilateral Hoffmann signs and 3+ patellar reflexes. An MRI of the cervical spine is obtained. Which of the following specific MRI findings is most strongly predictive of a poor postoperative neurologic prognosis following surgical decompression for cervical spondylotic myelopathy?

A 19-year-old female soccer player is undergoing an arthroscopic anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft. If the surgeon drills the femoral tunnel in an excessively anterior (shallow) position within the intercondylar notch relative to the native anatomic footprint, what will be the resultant kinematic behavior of the graft?

A 72-year-old active female undergoes evaluation for hip pain 8 years after a primary total hip arthroplasty (THA).

Imaging reveals eccentric wear and significant osteolysis. During the revision surgery, bearing surface selection is discussed. Which of the following THA bearing surface combinations boasts the lowest volumetric wear rate, but carries a unique risk of catastrophic brittle failure?

A 15-year-old male presents with severe, aching night pain in his distal femur. Radiographs reveal an aggressive osseous lesion with a 'sunburst' periosteal reaction and a Codman triangle. Biopsy confirms a diagnosis of high-grade conventional osteosarcoma. Pathogenesis of this primary bone tumor is most frequently linked to a mutation in which of the following genes?

During the process of secondary fracture healing, endochondral ossification is paramount. During the soft callus phase, chondrocytes proliferate and eventually undergo hypertrophy. Which type of collagen is uniquely and predominantly synthesized by hypertrophic chondrocytes to facilitate matrix calcification?

A 55-year-old male with long-standing, poorly controlled type II diabetes presents with an acutely swollen, erythematous, and warm left foot. He denies any penetrating trauma or fevers. Radiographs show fragmentation and early subluxation of the tarsometatarsal joints. Which of the following mediators is most directly responsible for driving the aggressive osteoclastic bone resorption seen in the acute, active phase of this disease process?

During arthroscopic stabilization for recurrent anterior shoulder instability in a 22-year-old rugby player, the surgeon encounters an ALPSA (Anterior Labroligamentous Periosteal Sleeve Avulsion) lesion. Which of the following morphologic features distinguishes an ALPSA lesion from a classic Bankart lesion?

A 14-year-old female presents for operative evaluation of adolescent idiopathic scoliosis. Standing full-length spine radiographs show a main thoracic curve of 55 degrees and a lumbar curve of 35 degrees. The proximal thoracic curve is 20 degrees. On side-bending radiographs, the main thoracic curve corrects to 30 degrees, the lumbar curve corrects to 15 degrees, and the proximal thoracic curve corrects to 5 degrees. Based on the Lenke classification, what is the correct curve type?

A 62-year-old female is 6 months post-operative from a volar locked plating of a comminuted distal radius fracture. She presents to the clinic complaining of a new inability to actively flex the interphalangeal (IP) joint of her thumb. Passive IP flexion is intact. Which of the following technical errors during the initial surgery is most likely responsible for this complication?

A 6-year-old boy sustains a severe extension-type supracondylar humerus fracture after a fall. Radiographs classify it as a Gartland Type III. The distal fragment is severely displaced posteromedially relative to the proximal shaft. Based on this specific displacement pattern, which of the following nerve structures is at greatest risk of tethering or injury from the proximal fragment?

A 35-year-old manual laborer presents with chronic, progressive central dorsal wrist pain. Grip strength is markedly decreased. Radiographs demonstrate sclerosis and collapse of the lunate, without fixed scaphoid rotation or adjacent carpal degenerative changes (Lichtman Stage IIIA Kienböck's disease). Radiographic ulnar variance is determined to be negative 3 mm. Which of the following surgical interventions is considered the primary, most appropriate biomechanical treatment for this patient?

During a measured resection primary total knee arthroplasty (TKA) for an osteoarthritic varus knee, the surgeon utilizes spacer blocks to assess the gaps. The knee is found to be excessively tight in full extension, but perfectly balanced in 90 degrees of flexion. Which of the following isolated bone resection steps is the most appropriate next maneuver to achieve a balanced knee?

A 65-year-old male with a known history of advanced renal cell carcinoma presents with a solitary, highly destructive lytic lesion in the proximal diaphysis of the right femur. He complains of excruciating pain with weight-bearing. The Mirels score is 11, and an impending fracture is diagnosed. A wide local excision and endoprosthetic reconstruction is planned. Given the specific primary histology, which of the following preoperative interventions is most critical?

A 24-year-old male sustains a severe twisting injury to his knee during a rugby match. Physical examination under anesthesia reveals 15 degrees of increased tibial external rotation compared to the contralateral knee at both 30 degrees and 90 degrees of knee flexion (Positive Dial Test). Based on this physical exam finding, which of the following structural combinations is definitively injured?

A 30-year-old male is evaluated in the emergency department for a severe crush injury to his lower leg. He has pain out of proportion to exam and paresthesias in the first dorsal web space. Continuous compartment pressure monitoring is initiated. His absolute anterior compartment pressure is 45 mmHg. His mean arterial pressure (MAP) is 75 mmHg, and his diastolic blood pressure is 60 mmHg. According to current evidence-based guidelines, which of the following criteria is the strongest physiological indication for emergent four-compartment fasciotomy?

A 45-year-old female presents with severe pain over the medial eminence of her first metatarsophalangeal (MTP) joint. Weight-bearing radiographs reveal a Hallux Valgus Angle (HVA) of 38 degrees and an Intermetatarsal Angle (IMA) of 16 degrees. Clinical examination reveals hypermobility at the first tarsometatarsal (TMT) joint. The distal metatarsal articular angle (DMAA) is normal. Which of the following surgical procedures is the most mechanically appropriate to permanently correct this deformity?

Articular cartilage relies on complex bio-tribological mechanisms to maintain a nearly frictionless surface. Which of the following specific mechanisms of joint lubrication is primarily responsible for preventing direct cartilage-to-cartilage wear during high-load, static, or slow-speed activities (e.g., prolonged standing)?

A 65-year-old active female presents to the emergency department after a mechanical fall. She complains of severe right groin pain and inability to bear weight. A representative radiograph of her injury is shown below.

Assuming the image demonstrates a displaced (Garden IV) femoral neck fracture, which of the following is the most appropriate surgical intervention to maximize her functional outcome and minimize her lifetime revision rate?

A 54-year-old male with a history of intravenous drug use presents with severe back pain, fever, and progressively worsening bilateral lower extremity weakness over the last 48 hours. A representative MRI is shown below.

Given the classic findings for this pathology, what is the most likely causative organism, and what is the standard definitive treatment?

A 55-year-old man presents with chronic, dull, aching shoulder pain. Radiographs reveal an aggressive lytic lesion with 'popcorn' calcifications in the proximal humerus. A core needle biopsy is obtained and the histology slide is shown below.

Assuming the biopsy demonstrates hypercellular atypical chondrocytes in a myxoid stroma consistent with a Grade II Chondrosarcoma, what is the most appropriate management strategy?

In the evaluation of Slipped Capital Femoral Epiphysis (SCFE), which of the following scenarios is a widely accepted indication for prophylactic in situ pinning of the contralateral, asymptomatic hip?

A biomaterials researcher is studying the wear properties of highly cross-linked polyethylene (HXLPE) used in total hip arthroplasty. Which of the following manufacturing processes is critical for eliminating the free radicals generated during the cross-linking process, thereby reducing the risk of oxidative degradation?

During an anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft, the surgeon opts to drill the femoral tunnel via an accessory anteromedial portal rather than using a transtibial technique. Compared to transtibial drilling, the anteromedial portal technique is more likely to result in a femoral tunnel that is:

A 32-year-old manual laborer presents with progressive dorsal wrist pain and decreased range of motion. Radiographs demonstrate Kienböck's disease characterized by sclerosis, fragmentation, and collapse of the lunate. The scaphoid demonstrates fixed flexion, resulting in a radioscaphoid angle of 65 degrees, but there are no signs of radiocarpal or midcarpal osteoarthritis. What Lichtman stage does this represent?

In the Eichenholtz classification of Charcot neuroarthropathy of the foot and ankle, which of the following radiographic and clinical findings characterizes Stage II (Coalescence)?

Nitrogen-containing bisphosphonates, such as alendronate, are frequently prescribed to prevent osteoporotic fractures. What is the primary molecular mechanism by which these drugs inhibit osteoclast-mediated bone resorption?

A 45-year-old male sustains a high-energy posterior bicondylar tibial plateau fracture (Schatzker VI). The surgeon plans a posteromedial approach to directly buttress the posteromedial shear fragment. During the superficial dissection of this approach, the internervous/intermuscular plane is typically developed between which two anatomical structures?

A 3-month-old infant is being treated with a Pavlik harness for developmental dysplasia of the left hip. At the 2-week follow-up, the parents report the child has stopped kicking the left leg. On physical examination, the left knee rests in extension and there is absent active knee extension to tactile stimulation. Which of the following harness maladjustments is the most likely cause of this complication?

During a primary posterior-stabilized total knee arthroplasty, after making the standard bone cuts and placing trial components, the surgeon assesses the gap kinematics. The knee is perfectly balanced and symmetrical in full extension. However, it is symmetrically tight at 90 degrees of flexion. Which of the following is the most appropriate intraoperative adjustment to achieve gap balance?

A 62-year-old male presents with deteriorating manual dexterity, a feeling of imbalance, and progressive lower extremity spasticity. Physical examination reveals a positive Hoffmann's sign bilaterally and hyperreflexia in both knees and ankles. MRI of the cervical spine reveals severe central canal stenosis. Which of the following MRI findings is associated with the poorest postoperative prognosis for neurologic recovery in this patient?

In the surgical repair of lacerated flexor tendons within Zone II of the hand, maintaining gliding function while resisting early active motion protocols is paramount. Biomechanical studies have demonstrated that the ultimate tensile strength of the tendon repair immediately postoperatively is most directly correlated with which of the following factors?

A 68-year-old male is evaluated for a massive, retracted rotator cuff tear involving the supraspinatus and infraspinatus. The surgeon notes significant fatty infiltration of the muscle bellies on the sagittal T1-weighted MRI. According to the Goutallier classification, which stage represents the critical prognostic threshold where there is an equal amount of fat and muscle within the muscle belly?

The Lisfranc ligament complex provides essential stability to the midfoot, and its rupture can lead to significant functional impairment. The primary component of the Lisfranc ligament is an interosseous ligament that connects which two osseous structures?

A 16-year-old patient diagnosed with high-grade, intramedullary osteosarcoma of the distal femur completes a course of neoadjuvant multi-agent chemotherapy. Subsequently, he undergoes a wide surgical resection of the tumor with endoprosthetic reconstruction. Which of the following is considered the most significant prognostic factor for long-term survival in this patient?

Regarding the highly organized ultrastructure of normal human articular cartilage, which zone is uniquely characterized by possessing the highest concentration of water, the lowest concentration of proteoglycans, and collagen fibrils that are oriented tightly parallel to the joint surface?

An 18-year-old pedestrian is struck by a motor vehicle and sustains a severe pelvic ring injury. AP, inlet, and outlet radiographs suggest an Anteroposterior Compression (APC) mechanism. According to the Young-Burgess classification system, an APC Type III injury is fundamentally distinguished from an APC Type II injury by the complete disruption of which of the following specific structures?

A 7-year-old boy with spastic diplegic cerebral palsy presents to the orthopedic clinic for his routine hip surveillance program. Examination reveals significant bilateral hip adductor spasticity. AP pelvis radiographs are obtained to measure the Reimers migration percentage. According to established international guidelines for hip surveillance in cerebral palsy, a migration percentage strictly above which threshold designates the hip as subluxated and generally warrants surgical intervention?

To decrease construct stiffness and promote secondary bone healing via callus formation in a comminuted diaphyseal fracture managed with a locking plate, which of the following modifications should be made?

A 45-year-old male sustains the injury pattern depicted in the provided image.

During surgical reconstruction of the lateral collateral ligament complex, identifying the correct isometric origin of the lateral ulnar collateral ligament (LUCL) on the distal humerus is critical. Where is this point located?

In a Zone II flexor tendon repair, which of the following core suture configurations provides the best balance of increasing tensile strength while preventing excessive tendon bulk and gliding resistance?

A 62-year-old male of East Asian descent presents with progressive myelopathy. His imaging is shown.

Which of the following specific CT findings is the strongest independent predictor of a dural tear during an anterior cervical corpectomy and decompression for this condition?

A total hip arthroplasty is planned for a 55-year-old active patient. The surgeon selects highly cross-linked polyethylene (HXLPE) to reduce wear. Which of the following represents a known mechanical tradeoff associated with the irradiation and remelting/annealing process used to create HXLPE?

A 56-year-old male with poorly controlled diabetes mellitus presents with a swollen, erythematous, and warm left foot without open ulcerations. Radiographs show periarticular fragmentation and debris at the tarsometatarsal joints. According to the Eichenholtz classification, what is the appropriate stage and initial management?

A 78-year-old female with a history of a posterior-stabilized total knee arthroplasty sustains the injury shown.

According to the Lewis and Rorabeck classification, which factor dictates whether open reduction internal fixation (ORIF) or distal femoral replacement (DFR) is the primary treatment of choice?

A 15-year-old male presents with deep thigh pain. A biopsy of a diaphyseal femur lesion reveals sheets of uniform small round blue cells. Cytogenetic analysis demonstrates a t(11;22)(q24;q12) chromosomal translocation. Which fusion protein, which acts as an aberrant transcription factor, is produced by this translocation?

A 10-year-old boy presents with a unilateral stable Slipped Capital Femoral Epiphysis (SCFE). In addition to treating the affected hip, the surgeon considers prophylactic in situ pinning of the contralateral hip. Which of the following conditions is the strongest indication for prophylactic fixation?

A 24-year-old man sustains a proximal pole scaphoid fracture. The high risk of avascular necrosis (AVN) in this fracture pattern is primarily due to the retrograde intraosseous blood supply of the scaphoid. The predominant vascular supply enters the scaphoid at the dorsal ridge. From which artery does this critical vessel directly originate?

In preoperative planning for a long posterior spinal fusion to correct adult spinal deformity, achieving appropriate sagittal balance is critical. To minimize the risk of adjacent segment disease and mechanical failure, the postoperative lumbar lordosis (LL) should be matched to the patient's pelvic incidence (PI). What is the generally accepted target relationship between PI and LL?

Romosozumab is an anabolic agent used in the treatment of severe osteoporosis. It exerts its effect by binding to and inhibiting sclerostin. At a cellular level, what is the direct consequence of sclerostin inhibition in bone tissue?

During a measured resection posterior-stabilized total knee arthroplasty, the surgeon checks the trial components and notes that the knee is perfectly balanced in full extension but is excessively tight in 90 degrees of flexion. Which of the following interventions will best address this isolated tight flexion gap?

Recent high-quality randomized controlled trials comparing operative repair to non-operative management (with functional rehabilitation) for acute Achilles tendon ruptures have demonstrated which of the following regarding clinical outcomes?

A 65-year-old male sustains a subtrochanteric femur fracture. Due to the deforming muscle forces on the proximal fragment, what is the typical anatomical position of the proximal fragment prior to reduction?

A 32-year-old female undergoes intralesional curettage and cementation for a giant cell tumor (GCT) of the distal radius. Two years later, she presents with local recurrence. The multidisciplinary tumor board recommends a trial of Denosumab. By what mechanism does this drug target the tumor?

The Ponseti method is the gold standard for the non-operative correction of congenital idiopathic clubfoot (talipes equinovarus). According to the principles of this method, in what order should the components of the deformity be corrected?

A 21-year-old collegiate football player sustains a recurrent anterior shoulder dislocation. A pre-operative 3D CT scan reveals a bipolar bone loss pattern, with an engaging Hill-Sachs lesion and an anterior glenoid bone defect measuring 28% of the glenoid width. What is the most appropriate surgical intervention to prevent further instability?

During an open carpal tunnel release, the transverse carpal ligament is divided. If the surgical incision is extended proximally across the wrist flexion creases in a radial direction (radial to the palmaris longus tendon), which nerve is at greatest risk of iatrogenic transection?

Articular cartilage is highly specialized and organized into four distinct zones: superficial, middle (transitional), deep, and calcified. Which of the following characteristics accurately describes the deep zone of articular cartilage?