Orthopedic Surgery Mock Exam - Set B29D06

A 25-year-old male is brought to the emergency department after a high-speed motorcycle collision. He is hemodynamically unstable. A pelvic binder is appropriately placed. Radiographs reveal a rotationally unstable but vertically stable pelvic ring injury with symphyseal widening greater than 2.5 cm (APC-II pattern).

Which of the following ligaments is predominantly disrupted at the sacroiliac joint in this specific injury pattern?

A 12-year-old obese boy presents with 3 weeks of vague knee pain and a new inability to bear weight on the right leg. On physical examination, the affected leg is resting in external rotation. What is the most significant clinical risk factor for the development of avascular necrosis (AVN) in this patient's condition?

A 22-year-old female collegiate soccer player undergoes anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BTB) autograft. During the first year postoperatively, she complains of significant anterior knee pain. Which of the following is the most likely cause of her pain associated with this specific graft choice?

A 65-year-old active male underwent a total hip arthroplasty utilizing a ceramic-on-ceramic bearing surface. Two years later, he complains of an audible 'squeaking' sound from his hip during ambulation. Which of the following factors is most strongly associated with this complication?

A 24-year-old man falls on an outstretched hand and sustains a proximal pole scaphoid fracture.

Which of the following vascular supplies is most directly responsible for the high rate of nonunion and avascular necrosis in this specific fracture location?

A 30-year-old construction worker sustains an axial load to a plantarflexed foot. Weight-bearing radiographs demonstrate a 3 mm diastasis between the base of the first and second metatarsals. Which of the following correctly describes the primary anatomy of the Lisfranc ligament?

A 70-year-old man presents with deteriorating handwriting and difficulty buttoning his shirts. Physical examination demonstrates a positive inverted supinator reflex. What is the most likely level of spinal cord compression?

A 15-year-old male presents with worsening pain in his distal femur. Radiographs reveal a destructive metaphyseal lesion with a 'sunburst' periosteal reaction and Codman's triangle.

Which of the following is the most significant prognostic factor for overall survival in this patient?

Which of the following biomechanical conditions is required for primary (strain-free) bone healing to occur?

A 32-year-old male sustains a closed tibial shaft fracture. You suspect acute compartment syndrome. His diastolic blood pressure is 80 mmHg. What is the absolute minimum intracompartmental pressure reading that would typically mandate emergency fasciotomy based on the Delta-P concept?

A 6-year-old girl falls off the monkey bars and sustains a displaced extension-type supracondylar humerus fracture. On examination, she is unable to make an 'A-OK' sign, instead demonstrating a pinch with the pulps of her index finger and thumb. Which nerve is most likely injured?

A 68-year-old female with severe valgus osteoarthritis of the knee undergoes a total knee arthroplasty with an extensive lateral soft tissue release.

Postoperatively, she exhibits a foot drop. Which structure is most likely compromised?

A 21-year-old male suffers a traumatic anterior shoulder dislocation. An MRI reveals a Bankart lesion. What is the defining anatomical characteristic of a classic Bankart lesion?

A laceration to the volar surface of the hand occurs between the distal palmar crease and the proximal interphalangeal joint. Both the flexor digitorum superficialis (FDS) and profundus (FDP) tendons are severed. This injury is located in which flexor tendon zone?

A 45-year-old weekend warrior feels a sudden 'pop' in his heel while accelerating to play a tennis ball. On examination, squeezing the calf does not result in plantar flexion of the foot. This specific clinical maneuver (Simmonds-Thompson test) evaluates the integrity of which of the following structures?

A 72-year-old woman complains of bilateral leg pain and cramping that worsens with walking and standing upright, but is rapidly relieved when she leans forward over a shopping cart. Which of the following physical examination findings is most consistent with her likely diagnosis?

An 11-year-old boy presents with a diaphyseal tumor of the femur. Radiographs show an 'onion-skin' periosteal reaction. A biopsy reveals small, round blue cells. Which of the following cytogenetic abnormalities is most pathognomonic for this tumor?

In the microstructure of articular cartilage, which zone is characterized by vertically aligned collagen fibers and is primarily responsible for resisting compressive forces?

A 30-year-old male sustains a high-energy vertical shear fracture of the femoral neck (Pauwels Type III).

What biomechanical force predominantly contributes to the high risk of nonunion and loss of fixation in this specific fracture pattern?

An infant is being treated with a Pavlik harness for developmental dysplasia of the hip (DDH). At the two-week follow-up, the mother notes the infant has stopped kicking with the affected leg. On examination, active knee extension is absent, though passive motion is full. Which of the following complications has most likely occurred?

A 35-year-old male sustains a severe crushing injury to his pelvis. Examination reveals a large, fluctuant swelling over the greater trochanter with ecchymosis. Aspiration of the lesion yields serosanguinous fluid with fat globules.

Which of the following is the most appropriate definitive management for a large, chronic lesion of this type?

A 65-year-old female presents with a painful total knee arthroplasty 2 years post-operatively. Synovial fluid analysis shows a WBC count of 3,500 cells/µL with 75% PMNs. The alpha-defensin immunoassay is positive. What is the primary cellular source of alpha-defensin in this context?

A 45-year-old male presents with chronic wrist pain. Radiographs demonstrate scapholunate advanced collapse (SLAC).

In a Stage II SLAC wrist, the degenerative changes involve which of the following articulations?

A 25-year-old male presents after an MVA with neck pain and right C6 radiculopathy. Radiographs show a unilateral facet dislocation at C5-C6. MRI confirms no herniated disc. He is awake and cooperative but unable to undergo closed reduction. What is the next best step in management?

A 13-year-old obese male presents with left thigh pain and a limp. He walks with an externally rotated leg. Radiographs reveal a severe slipped capital femoral epiphysis (SCFE) with a slip angle of 60 degrees. What is the most significant risk associated with performing an acute anatomical reduction prior to pinning?

When comparing the tibial inlay technique to the transtibial tunnel technique for posterior cruciate ligament (PCL) reconstruction, the tibial inlay technique has the theoretical biomechanical advantage of decreasing what phenomenon?

A 55-year-old active male underwent a total hip arthroplasty using a ceramic-on-ceramic bearing.

He presents 2 years post-operatively complaining of a squeaking noise from the hip during walking. Which of the following component malpositions is most commonly associated with this phenomenon?

A 14-year-old female presents with pain in her proximal humerus. Radiographs show an eccentric, expansile, lytic lesion with thin cortices. MRI demonstrates fluid-fluid levels. A biopsy confirms an aneurysmal bone cyst (ABC). What is the genetic translocation most commonly associated with primary ABCs?

A 60-year-old female undergoes volar locked plating for a displaced distal radius fracture. Eight weeks post-operatively, she returns complaining of the sudden inability to actively flex the interphalangeal joint of her thumb. Which of the following surgical errors most likely led to this complication?

An athlete sustains a hyperplantarflexion injury to the midfoot. Radiographs demonstrate widening of the space between the medial and middle cuneiforms.

The primary stabilizing ligament of the Lisfranc joint complex attaches to which two bones?

A rugby player sustains a closed injury to his right ring finger while grabbing an opponent's jersey. He is unable to actively flex the DIP joint. Imaging shows an avulsion fracture of the distal phalanx base retracted to the level of the PIP joint. According to the Leddy and Packer classification, what type of injury is this?

An 18-year-old gymnast complains of chronic lower back pain. Lateral radiographs demonstrate a pars interarticularis defect at L5 with an anterior translation of the L5 vertebral body over S1 by 60%. What is the appropriate Meyerding grade for this slip?

When managing a congenital talipes equinovarus (clubfoot) using the Ponseti method, the first step in the casting sequence aims to correct which deformity?

A 28-year-old overhead throwing athlete undergoes arthroscopy for a suspected SLAP tear. The surgeon notes fraying of the superior labrum but the biceps anchor is intact and firmly attached to the glenoid. According to the Snyder classification, this represents:

During normal knee flexion, the phenomenon of femoral rollback is primarily facilitated by which of the following structures?

A 30-year-old female presents with knee pain. Radiographs reveal an eccentric, lytic lesion in the distal femoral epiphysis extending to the subchondral bone. Biopsy confirms a giant cell tumor. She is treated with denosumab preoperatively. What is the mechanism of action of denosumab?

A 32-year-old male sustains a severe inversion injury resulting in a displaced fracture of the talar neck with subluxation of the subtalar joint, while the tibiotalar joint remains congruous. According to the Hawkins classification, what type of injury is this and what is the approximate rate of avascular necrosis (AVN)?

A 55-year-old male with poorly controlled diabetes mellitus presents with a swollen, erythematous, and warm left foot. Radiographs demonstrate periarticular fragmentation, subluxation, and bony debris at the midfoot. According to the Eichenholtz classification, this presentation is most consistent with which stage?

Following rigid internal fixation of a diaphyseal fracture with absolute stability, primary bone healing occurs without callus formation. This process is mediated primarily by:

A 42-year-old pregnant female presents with numbness and tingling in her right thumb, index, and long fingers. EMG/NCS is obtained.

Which of the following is the earliest and most sensitive nerve conduction study finding in carpal tunnel syndrome?

A 45-year-old manual laborer presents with chronic right wrist pain. He recalls a severe sprain 10 years ago that was untreated. Radiographs demonstrate an established scaphoid nonunion with arthritic changes at the radioscaphoid and capitolunate joints, but preservation of the radiolunate articulation. Based on the expected stage of this disease process, which of the following is the most appropriate surgical treatment?

A 32-year-old male is brought to the trauma bay following a high-speed motorcycle collision. He is hemodynamically unstable. An anteroposterior radiograph of the pelvis demonstrates a 'symphysis pubis diastasis of 4 cm and disruption of the anterior sacroiliac ligaments with intact posterior ligaments' (an APC II injury). During surgical exploration to control hemorrhage, brisk arterial bleeding is encountered posterior to the superior pubic ramus. This vessel is most likely an anastomosis between which two vascular distributions?

An 8-year-old child presents with a limp and poorly localized knee pain. Radiographs confirm a unilateral slipped capital femoral epiphysis (SCFE). Given the patient's age, an endocrine workup is indicated. Which of the following is the most common underlying endocrine abnormality associated with SCFE in this patient population?

A 24-year-old male presents with a slowly growing, painful mass in the anterior compartment of his left leg. Radiographs show an eccentric, multi-loculated, 'soap-bubble' osteolytic lesion in the diaphysis of the tibia. A biopsy is performed. Histological analysis reveals nests of epithelial-appearing cells in a fibrous stroma. Immunohistochemistry is strongly positive for cytokeratin. What is the most likely diagnosis?

In the biomechanical design of a pedicle screw, which of the following modifications most effectively increases the screw's pullout strength in osteoporotic bone?

During arthroscopy for an acute anterior cruciate ligament (ACL) tear, a systematic evaluation of the knee is performed. The surgeon places the arthroscope through the intercondylar notch into the posteromedial compartment. A longitudinal tear is observed at the meniscocapsular junction of the posterior horn of the medial meniscus. What is the term for this specific lesion?

During a primary total knee arthroplasty using a measured resection technique, the surgeon utilizes trial components and finds that the knee is symmetric and balanced in full extension, but perfectly symmetric and overly tight in 90 degrees of flexion. Which of the following adjustments is the most appropriate to balance the knee?

A 28-year-old female presents to the emergency department after a motor vehicle collision. She is awake, alert, and cooperative. She complains of severe neck pain. Neurological examination is completely intact. Lateral cervical spine radiographs show an anterior translation of C5 on C6 of approximately 60% of the vertebral body width, with dislocated facets bilaterally. What is the most appropriate next step in management?

A 55-year-old male with long-standing, poorly controlled type 2 diabetes presents with a red, hot, swollen right foot. He denies any recent trauma, fevers, or systemic illness. Laboratory studies reveal a normal white blood cell count, ESR of 25 mm/h, and CRP of 1.0 mg/L. Radiographs demonstrate soft tissue swelling, profound joint subluxation at the tarsometatarsal joints, and bony fragmentation without focal osteopenia. What is the most appropriate initial treatment?

In the anatomy of the flexor tendon sheath of the digits, preservation of certain structures is critical to prevent bowstringing of the flexor tendons. During an extensive tenolysis procedure of the index finger, which two annular pulleys are the most critical to preserve?

Fracture healing can occur via endochondral or intramembranous ossification. Intramembranous ossification occurs without a cartilaginous intermediate and is primarily seen in flat bones and during rigid plate fixation (primary bone healing). Which of the following transcription factors is the critical master regulator that directs multipotent mesenchymal stem cells down the osteoblastic lineage during intramembranous bone formation?

An infant is diagnosed with severe, rigid idiopathic congenital talipes equinovarus (clubfoot). Treatment using the Ponseti method is initiated. According to the specific sequence of the Ponseti method, what is the required primary manipulation in the first casting to correct the multi-planar deformity?

A 34-year-old male sustains a closed talar neck fracture following a fall from height. He undergoes urgent open reduction and internal fixation. At his 8-week postoperative follow-up, an anteroposterior radiograph of the ankle demonstrates a linear subchondral radiolucent band in the dome of the talus. What does this radiographic finding indicate regarding the prognosis of his injury?

A 65-year-old female with known multiple myeloma presents with escalating back pain. Radiographs reveal diffuse osteopenia and multiple 'punched-out' lytic lesions in her vertebral bodies. The profound osteolysis seen in multiple myeloma is primarily driven by an imbalance in bone remodeling. Which of the following factors is directly secreted by myeloma cells to upregulate osteoclast activity via the RANK/RANKL pathway?

A 70-year-old patient returns to the emergency department three weeks following an uncomplicated primary total hip arthroplasty (posterior approach) with complaints of sudden severe hip pain. Radiographs demonstrate a posterior dislocation of the femoral component. Closed reduction is successful. In evaluating the cause of this early instability, which of the following component malpositions is the most common etiology for posterior dislocation in THA?

A 19-year-old collegiate swimmer presents with bilateral shoulder pain. She reports a sensation that her shoulders are constantly 'slipping out' of place, especially during the pull phase of her stroke. Physical examination demonstrates generalized ligamentous laxity, a positive sulcus sign bilaterally, and positive apprehension tests anteriorly and posteriorly. Scapular dyskinesia is prominent. What is the most appropriate initial management?

A patient sustained a C6 burst fracture in a diving accident. On initial neurological examination in the ICU, he demonstrates active wrist extension against gravity (Grade 3/5) but no active triceps or hand intrinsic function. He has no voluntary anal contraction, but he has preserved sensation to pinprick in the perianal area (S4-S5). Additionally, he has trace voluntary movement of his right great toe (Grade 1/5). According to the ASIA Impairment Scale (AIS), how should this patient be classified?

Osteochondral lesions (OCDs) of the talus frequently occur following ankle sprains. Based on classic descriptions of these injuries, what is the typical morphology and mechanism for an anterolateral talar dome lesion?

A 60-year-old female underwent volar locked plating of a comminuted distal radius fracture 4 months ago. She now presents complaining of the sudden inability to bend the tip of her thumb. She reports hearing a 'pop' in her wrist yesterday while opening a jar. Which of the following technical errors during the initial surgery is the most likely cause of her current presentation?

A 22-year-old male suffers a highly comminuted tibia-fibula fracture. Within hours, he develops extreme leg pain out of proportion to the injury, pain with passive stretch of the toes, and a tense, woody swelling of the leg. Compartment syndrome is suspected. If the anterior compartment is predominantly involved, which of the following sensory deficits is most likely to be found on examination?