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2018 Graduate Professional Course Exam Questions: Pass with Confidence

Master the Graduating Exam ABE: Achieve Your Best Score

23 Apr 2026 66 min read 86 Views
Chinese graduating exam

Key Takeaway

This article provides essential research regarding Master the Graduating Exam ABE: Achieve Your Best Score. This resource summarizes essential urology topics, critical for a graduating exam abe. It covers bladder irritation symptoms (frequent urination, urgency, pain), early prostate hyperplasia signs, typical kidney cancer symptoms (hematuria, pain, mass), and bladder cancer diagnosis (cystoscopy). Additionally, it outlines types of urinary incontinence and treatment principles for bilateral upper urinary tract stones, emphasizing renal function and obstruction severity.

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Question 1

A 45-year-old male presents with acute onset of right shoulder pain and weakness after attempting to lift a heavy object. On examination, he has significant weakness in external rotation and abduction. Deltoid function is intact. Radiographs are normal. Which of the following is the most likely diagnosis?





Explanation

The patient presents with acute shoulder pain and weakness, specifically in external rotation and abduction. While the supraspinatus initiates abduction, the infraspinatus is the primary external rotator. Given the intact deltoid (ruling out axillary nerve palsy) and significant weakness in external rotation, a tear of the infraspinatus is the most likely diagnosis. Subscapularis tears primarily affect internal rotation, and long head of biceps rupture typically presents with a 'Popeye' deformity and weakness in elbow flexion/supination, not primarily shoulder abduction/external rotation.

Question 2

A 62-year-old female with a history of osteoporosis sustains a displaced intra-articular fracture of the distal radius (AO type C3). She is active and has good functional demands. What is the most appropriate definitive management strategy?





Explanation

For a displaced intra-articular distal radius fracture (AO type C3) in an active patient with good functional demands, open reduction and internal fixation with a volar locking plate is considered the gold standard. This approach allows for stable anatomical reduction, early range of motion, and addresses the challenge of comminution and osteopenia often seen in C3 fractures. Closed reduction and splinting is inadequate for displaced intra-articular fractures. Percutaneous pinning or external fixation alone may not provide sufficient stability or allow for direct visualization and reduction of articular fragments, especially in complex, comminuted patterns.

Question 3

A 7-year-old boy presents with a 3-week history of right hip pain and a limp. He denies trauma. On examination, he has decreased internal rotation and abduction of the right hip. Radiographs show increased density of the right femoral epiphysis and a flattened appearance. What is the most likely diagnosis?





Explanation

The clinical presentation of a 7-year-old boy with hip pain, limp, and decreased hip motion (especially internal rotation and abduction), combined with radiographic findings of increased density (sclerosis) and flattening (fragmentation) of the femoral epiphysis, is classic for Legg-Calvé-Perthes disease. Septic arthritis would present acutely with systemic signs and extreme pain, transient synovitis is usually self-limiting with normal radiographs after a few days, SCFE typically occurs in older, often obese adolescents, and DDH is usually diagnosed in infancy or early childhood.

Question 4

A 32-year-old competitive runner presents with chronic pain along the medial aspect of her left foot, exacerbated by activity. Examination reveals tenderness just distal to the medial malleolus, reproducible pain with resisted plantarflexion and inversion, and a pes planus foot posture. What is the most likely diagnosis?





Explanation

The symptoms of chronic medial foot pain exacerbated by activity, tenderness distal to the medial malleolus, pain with resisted plantarflexion and inversion, and an associated pes planus deformity are highly suggestive of Posterior Tibial Tendon Dysfunction (PTTD). PTTD is a progressive condition that can lead to adult-acquired flatfoot. Plantar fasciitis causes heel pain. Achilles tendinopathy causes pain in the posterior ankle/heel. Tarsal tunnel syndrome involves nerve compression, often with burning/tingling. A navicular stress fracture would typically present with localized dorsal midfoot pain and often swelling.

Question 5

A 70-year-old male undergoes a total hip arthroplasty for severe osteoarthritis. Postoperatively, he develops a foot drop and diminished sensation over the dorsum of the foot and lateral leg. Which nerve injury is most likely responsible?





Explanation

Foot drop and diminished sensation over the dorsum of the foot and lateral leg are classic signs of common peroneal nerve palsy. The common peroneal nerve is a division of the sciatic nerve and is particularly vulnerable during total hip arthroplasty due to traction, direct trauma, or compression, especially in cases of leg lengthening or revision surgery. Femoral nerve injury affects quadriceps strength, obturator nerve injury affects adduction, and tibial nerve injury affects plantarflexion and sensation over the sole of the foot. Superior gluteal nerve injury would affect abductor function.

Question 6

Which of the following describes the most common mechanism of injury for an anterior cruciate ligament (ACL) rupture?





Explanation

The most common mechanism for ACL rupture is a non-contact injury involving deceleration, cutting, or pivoting maneuvers, typically with the knee in slight flexion, valgus, and external rotation of the tibia on the femur. This creates significant tension on the ACL. A direct blow to the anterior tibia (dashboard injury) can cause a posterior cruciate ligament (PCL) injury. Hyperextension with varus force might stress the posterolateral corner, while a direct posterior force to the tibia causes PCL injury. Landing in full extension is less common than dynamic valgus loading for ACL rupture.

Question 7

A 28-year-old male sustains an open Schatzker type VI tibial plateau fracture with significant soft tissue compromise. After initial debridement and external fixation, what is the optimal timing for definitive internal fixation?





Explanation

For complex open tibial plateau fractures with significant soft tissue injury, the 'staged protocol' is generally preferred. This involves initial debridement, provisional stabilization with an external fixator, and then delayed definitive internal fixation once the soft tissues have adequately recovered and the 'wrinkle sign' is present (indicating decreased edema). This typically occurs between 5-10 days (Option C). Operating immediately in compromised soft tissues increases the risk of wound complications and infection. Waiting too long (3 weeks) might lead to fracture stiffness and more difficult reduction. The question specifically asks for definitive internal fixation, not initial debridement or external fixation, which should happen urgently. The 'wrinkle sign' is key to timing definitive fixation in such injuries. Although the explanation previously stated 5-10 days, the given options for a delayed approach make 'between 5-10 days, once the 'wrinkle sign' returns' the most appropriate.

Question 8

What is the most common benign bone tumor of the hand?





Explanation

Enchondroma is by far the most common benign bone tumor of the hand, frequently found in the phalanges and metacarpals. Osteochondromas are common benign tumors but less frequent in the hand than enchondromas. Giant cell tumors are rare in the hand, and aneurysmal bone cysts and osteoid osteomas are also less common in this location compared to enchondromas.

Question 9

A 55-year-old female presents with severe, progressive back pain radiating down both legs, worsening with standing and walking, and relieved by sitting or leaning forward. She also reports bilateral leg numbness and weakness. On examination, she has diminished patellar and Achilles reflexes bilaterally. What is the most likely diagnosis?





Explanation

The classic symptoms of neurogenic claudication – bilateral leg pain, numbness, and weakness exacerbated by standing/walking and relieved by sitting/leaning forward (shopping cart sign) – are highly indicative of lumbar spinal stenosis. While a large disc herniation or spondylolisthesis can cause radiculopathy, bilateral symptoms relieved by flexion strongly point towards stenosis. Cauda equina syndrome would involve acute urinary retention, saddle anesthesia, and severe, progressive neurological deficits. Facet arthropathy typically causes axial back pain, potentially referred pain, but not classic neurogenic claudication.

Question 10

In the management of a displaced femoral shaft fracture in a 3-year-old child, which of the following is the most appropriate initial treatment?





Explanation

For a displaced femoral shaft fracture in a 3-year-old child, spica cast immobilization is the preferred initial treatment. Children in this age group have excellent remodeling potential and tolerate cast immobilization well. Intramedullary nailing is typically reserved for older children (usually >5-6 years) or specific fracture patterns. External fixation is generally reserved for open fractures, polytrauma, or significant soft tissue compromise. Open reduction and plating is used in specific circumstances but not as first-line for this age group. Skeletal traction followed by cast is an older method, largely supplanted by immediate spica casting for this age group.

Question 11

A 68-year-old male presents with sudden onset of right knee pain and swelling. On aspiration, the synovial fluid is cloudy and contains negatively birefringent, needle-shaped crystals. What is the most appropriate management for this condition?





Explanation

The description of cloudy synovial fluid with negatively birefringent, needle-shaped crystals is pathognomonic for gout (monosodium urate crystal arthropathy). Acute attacks are best managed with NSAIDs and/or colchicine. Intra-articular steroid injection can also be used but NSAIDs/colchicine are often first-line. Oral antibiotics are for septic arthritis (which would show positive gram stain and high WBC count, not crystals). Surgical debridement is not indicated for acute gout. Allopurinol is a long-term urate-lowering therapy used for chronic gout prevention, not for acute attack management.

Question 12

Regarding the vascular supply of the femoral head in an adult, which artery is considered most critical in preventing avascular necrosis following a femoral neck fracture?





Explanation

The medial circumflex femoral artery (MCFA), via its retinacular branches, is the primary blood supply to the femoral head in adults. Displaced femoral neck fractures often disrupt these critical posterolateral retinacular vessels, leading to a high risk of avascular necrosis (AVN). The artery of the ligamentum teres is insignificant in adults but plays a role in children. The lateral circumflex femoral artery mainly supplies the greater trochanter and vastus lateralis. The superior and inferior gluteal arteries supply the gluteal muscles.

Question 13

Which of the following is the most important factor dictating the prognosis and management of osteosarcoma?





Explanation

The presence of metastatic disease at presentation is by far the most important prognostic factor in osteosarcoma. Patients with metastatic disease (most commonly to the lungs) have a significantly worse prognosis than those with localized disease. While tumor size, location, patient age, and histologic subtype can influence prognosis, they are secondary to the presence or absence of metastases.

Question 14

A 10-year-old boy presents with progressive genu varum. Radiographs show irregular metaphyses, flaring, and cupping of the distal femurs and proximal tibias. His vitamin D levels are normal, and he has a normal calcium-phosphate product. What is the most likely diagnosis?





Explanation

The radiographic findings of irregular, flared, and cupped metaphyses are classic signs of rickets. Given the progressive genu varum and normal vitamin D and calcium-phosphate product, hypophosphatemic rickets (e.g., X-linked hypophosphatemia) is the most likely diagnosis. This condition is characterized by renal phosphate wasting despite normal vitamin D levels. Physiologic genu varum usually resolves by age 2. Blount's disease primarily affects the medial proximal tibia. Renal osteodystrophy would have abnormal calcium/phosphate levels. Metaphyseal chondrodysplasia is a broader category, but hypophosphatemic rickets fits the specific laboratory findings.

Question 15

What is the primary function of the posterior cruciate ligament (PCL)?





Explanation

The primary function of the PCL is to prevent posterior translation of the tibia on the femur, especially when the knee is flexed. This is tested clinically with the posterior drawer test. The ACL prevents anterior translation of the tibia. The collateral ligaments resist varus (LCL) and valgus (MCL) stresses. The PCL also helps to limit hyperextension, but its primary role is posterior translation prevention.

Question 16

A 40-year-old male with chronic low back pain reports worsening symptoms with prolonged standing and walking, associated with a burning sensation in his calves. He states he gets relief when he sits down or leans forward over a shopping cart. Neurological examination is unremarkable. Which diagnostic imaging study is most appropriate for initial evaluation?





Explanation

The patient's symptoms are highly classic for neurogenic claudication, characteristic of lumbar spinal stenosis. While plain radiographs can show degenerative changes, an MRI of the lumbar spine is the gold standard for visualizing soft tissue structures, including the intervertebral discs, ligaments, and neural elements within the spinal canal, which are crucial for diagnosing spinal stenosis. A CT scan is excellent for bone detail but less so for soft tissue. EMG/NCS evaluates nerve function but is not the primary imaging for stenosis diagnosis. A bone scan would be more appropriate for infection, tumor, or stress fracture.

Question 17

What is the primary concern when managing a Monteggia fracture-dislocation (ulnar shaft fracture with radial head dislocation)?





Explanation

Monteggia fracture-dislocations (specifically Bado type I and II, involving an anterior or posterior radial head dislocation) are associated with a significant risk of posterior interosseous nerve (PIN) injury, which can lead to weakness in wrist and finger extension. This nerve is intimately related to the radial head and neck. While nonunion, malunion, and recurrent dislocation are potential complications, the nerve injury is a critical and specific association of this injury pattern, requiring careful assessment and often surgical exploration if deficits persist after reduction. Compartment syndrome is a general risk for all high-energy forearm trauma, but PIN injury is specific to Monteggia.

Question 18

A 6-month-old infant is diagnosed with developmental dysplasia of the hip (DDH). The Ortolani and Barlow tests are negative, but there is asymmetry of the thigh folds and limited hip abduction. What is the most appropriate initial treatment?





Explanation

For an infant diagnosed with DDH between birth and 6-9 months, especially with reducible instability or limited abduction (even if Ortolani/Barlow are negative at this age due to soft tissue contracture), a Pavlik harness is the gold standard initial treatment. It maintains the hips in flexion and abduction, promoting proper acetabular development. Observation is insufficient for true DDH. Spica cast or open reduction are used for older infants, failed harness treatment, or irreducible hips.

Question 19

Which of the following is considered the most common complication following total knee arthroplasty (TKA)?





Explanation

Arthrofibrosis and persistent stiffness are reported as the most common complications after TKA, affecting a significant percentage of patients and often requiring manipulation under anesthesia or revision surgery. While infection, periprosthetic fracture, VTE, and neurovascular injury are serious complications, their incidence is generally lower than that of arthrofibrosis, which can significantly impact functional outcomes. Modern protocols have reduced VTE incidence, and neurovascular injuries are relatively rare.

Question 20

A 16-year-old male presents with chronic anterior knee pain, worsening with prolonged sitting, ascending/descending stairs, and squatting. There is tenderness along the medial facet of the patella. Patellar apprehension test is negative. What is the most likely diagnosis?





Explanation

The classic symptoms of anterior knee pain, exacerbated by prolonged sitting (theater sign), stairs, and squatting, with tenderness around the patella, are highly characteristic of patellofemoral pain syndrome (PFPS). This is a diagnosis of exclusion. Patellar tendinopathy causes pain specifically at the inferior pole of the patella. Osgood-Schlatter affects the tibial tuberosity in younger adolescents. Osteochondritis dissecans would typically cause mechanical symptoms and localized pain in the condyle, not primarily patellofemoral. Medial plica syndrome can mimic PFPS but usually has a palpable painful plica and is less common.

Question 21

Which rotator cuff muscle is primarily responsible for internal rotation of the shoulder?





Explanation

The subscapularis muscle is the primary internal rotator of the shoulder. The supraspinatus is responsible for abduction initiation, and the infraspinatus and teres minor are external rotators. The deltoid is a major abductor and flexor/extensor, but not a primary rotator cuff internal rotator.

Question 22

A 50-year-old construction worker presents with insidious onset of right elbow pain, particularly exacerbated by gripping and lifting. Examination reveals tenderness over the lateral epicondyle and pain with resisted wrist extension. What is the most appropriate initial management?





Explanation

The symptoms are classic for lateral epicondylitis (tennis elbow). The initial management is overwhelmingly conservative, focusing on activity modification, NSAIDs (for pain relief, not primary treatment of the tendinosis), physical therapy (stretching, strengthening, eccentric exercises), and use of a counterforce brace. Corticosteroid injections provide short-term relief but can be detrimental long-term. PRP is an emerging therapy but not initial. Surgery is reserved for recalcitrant cases failing extensive conservative treatment. Immobilization is generally not indicated and can lead to stiffness.

Question 23

What is the most common primary malignant bone tumor in adults?





Explanation

Multiple myeloma is the most common primary malignant bone tumor in adults. While often considered a hematologic malignancy, it manifests primarily as bone lesions. Osteosarcoma and Ewing sarcoma are more common in children and adolescents. Chondrosarcoma is the second most common primary bone sarcoma in adults, but less common than multiple myeloma. Fibrosarcoma is a rare soft tissue sarcoma that can involve bone secondarily.

Question 24

A 60-year-old male sustains a comminuted intertrochanteric hip fracture. He is medically fit. Which surgical implant offers the most stable fixation and allows for early mobilization?





Explanation

For a comminuted intertrochanteric hip fracture, especially in an elderly patient, a cephalomedullary nail (intramedullary hip screw) generally provides superior biomechanical stability and allows for earlier weight-bearing compared to a dynamic hip screw (DHS), particularly in unstable fracture patterns (e.g., reverse obliquity, subtrochanteric extension). Cannulated screws are typically for non-displaced femoral neck fractures. Hemiarthroplasty and total hip arthroplasty are typically reserved for femoral neck fractures, not intertrochanteric fractures, unless there's severe pre-existing osteoarthritis or nonunion.

Question 25

Which of the following conditions is most commonly associated with a 'double bubble' sign on prenatal ultrasound?





Explanation

The 'double bubble' sign on prenatal ultrasound, characterized by two adjacent fluid-filled structures (stomach and dilated duodenum), is pathognomonic for duodenal atresia. This is a common anomaly in infants with Down syndrome. The other conditions listed are unrelated to this specific gastrointestinal finding.

Question 26

What is the most common cause of painful pes planus in an adult, often leading to progressive flatfoot deformity?





Explanation

Posterior tibial tendon dysfunction (PTTD) is the most common cause of adult-acquired flatfoot deformity, leading to progressive painful pes planus. The posterior tibial tendon is a primary supporter of the medial longitudinal arch. Its dysfunction leads to failure of the arch. While spring ligament insufficiency can contribute, it's often secondary to PTTD. Accessory navicular syndrome is a congenital anomaly that can cause pain, but not typically progressive flatfoot. Tibialis anterior tendon rupture results in a cavus-like deformity, and Charcot arthropathy is a neuropathic joint condition seen in diabetes, not the most common cause of painful acquired flatfoot.

Question 27

A 4-year-old boy falls from a height and sustains a supracondylar humerus fracture. He presents with a pulseless but warm and pink hand. What is the immediate next step in management after initial stabilization and pain control?





Explanation

In a supracondylar humerus fracture with a pulseless but perfused (warm, pink, good capillary refill) hand, the immediate priority after initial stabilization is gentle closed reduction and percutaneous pinning. Often, the pulse will return with reduction of the fracture and relief of mechanical obstruction/kinking of the brachial artery. If the pulse does not return after successful reduction, then further vascular workup (angiography) or surgical exploration is indicated. Immediate exploration without attempting reduction is usually not necessary unless there are signs of overt ischemia (cold, pale hand) or a hard sign of vascular injury. Observation is inappropriate for a pulseless extremity.

Question 28

Regarding avascular necrosis (AVN) of the femoral head, which of the following statements is true?





Explanation

Alcohol abuse is a well-established non-traumatic risk factor for avascular necrosis (AVN) of the femoral head, similar to corticosteroid use, sickle cell disease, and caisson disease. Corticosteroid use is a risk factor, not protective. The most sensitive imaging for early AVN is MRI, not plain radiography (which shows changes late). Core decompression is indicated for early stages (pre-collapse) to halt progression, not advanced stages. Total hip arthroplasty is a viable treatment option for advanced, collapsed AVN, especially in older patients, making the statement that it's always contraindicated incorrect.

Question 29

What is the most common location for osteochondritis dissecans (OCD) in the knee?





Explanation

The medial femoral condyle is the most common location for osteochondritis dissecans (OCD) in the knee, particularly the lateral aspect of the medial femoral condyle. While OCD can occur in other locations, it is significantly less frequent there.

Question 30

A 65-year-old female presents with severe pain, swelling, and redness in her left great toe, acutely worsening over the past 24 hours. She has a history of hypertension and takes a diuretic. Synovial fluid aspiration shows negatively birefringent, needle-shaped crystals. What is the definitive long-term pharmacologic treatment to prevent future attacks?





Explanation

The clinical picture and synovial fluid analysis (negatively birefringent, needle-shaped crystals) confirm a diagnosis of gout. While NSAIDs, colchicine, and prednisone are used to treat acute attacks, allopurinol is the definitive long-term pharmacologic treatment for prevention of future attacks by decreasing uric acid production. Probenecid is also a uricosuric agent but acts differently. Allopurinol is typically initiated once the acute attack has resolved.

Question 31

Which surgical approach to the hip carries the highest risk of sciatic nerve injury?





Explanation

The posterior (Moore) approach to the hip involves dissecting through the short external rotators and often requires retraction of the sciatic nerve, placing it at the highest risk of injury compared to other approaches. The anterior, direct lateral, and anterolateral approaches generally pose a lower risk to the sciatic nerve as they are distant from its course.

Question 32

A 12-year-old boy presents with a painful mass in his distal femur. Biopsy reveals osteosarcoma. Which of the following statements regarding the management of osteosarcoma is true?





Explanation

The primary goal of surgery for osteosarcoma, whether limb salvage or amputation, is complete tumor resection with adequate oncologic margins to prevent local recurrence. Chemotherapy (neoadjuvant and adjuvant) is a cornerstone of treatment for virtually all localized osteosarcomas. While limb salvage is often attempted, it depends on tumor characteristics and patient factors, and amputation remains a viable and sometimes necessary option. Radiation therapy has a limited role in osteosarcoma due to its radioresistance, typically reserved for unresectable tumors or palliative care. Monitoring involves chest CT for lung metastases and often bone scans, but not bone scans only.

Question 33

What is the most common type of soft tissue sarcoma in adults?





Explanation

Undifferentiated pleomorphic sarcoma (UPS), formerly known as malignant fibrous histiocytoma (MFH), is considered the most common type of soft tissue sarcoma in adults. Liposarcoma is also very common, often cited as the second most common, but UPS usually takes the top spot overall. Synovial sarcoma and leiomyosarcoma are less common. Rhabdomyosarcoma is primarily a sarcoma of childhood.

Question 34

Which nerve is most commonly injured in a displaced midshaft humerus fracture?





Explanation

The radial nerve is intimately associated with the midshaft of the humerus as it courses through the spiral groove. Therefore, it is the most commonly injured nerve in midshaft humerus fractures. Injury to the radial nerve typically results in wrist drop and sensory deficits on the dorsum of the hand.

Question 35

A 72-year-old female presents with hip pain and progressive difficulty walking after a fall. Radiographs show a displaced femoral neck fracture. She has a history of Parkinson's disease, cognitive impairment, and is a poor surgical candidate for prolonged procedures. What is the most appropriate surgical management?





Explanation

For a displaced femoral neck fracture in an elderly patient with significant comorbidities (Parkinson's, cognitive impairment) who is a poor candidate for extensive surgery, hemiarthroplasty (bipolar or unipolar) is generally the preferred treatment. It provides immediate stability and pain relief with a shorter operative time than THA, reducing the risks associated with prolonged anesthesia. THA is often considered the gold standard for healthy, active elderly patients, but less so for those with significant cognitive or medical burden. ORIF with screws has a higher risk of failure and AVN in displaced femoral neck fractures in the elderly. Non-operative management leads to poor outcomes.

Question 36

What is the most common pathogen responsible for septic arthritis in a healthy adult?





Explanation

Staphylococcus aureus is by far the most common pathogen responsible for septic arthritis in healthy adults, as well as in children and those with prosthetic joints. While other bacteria can cause septic arthritis, S. aureus accounts for the majority of cases. Neisseria gonorrhoeae is common in young, sexually active individuals but less overall than S. aureus. S. epidermidis is common in prosthetic joint infections but less so in native joint septic arthritis.

Question 37

Which of the following is the hallmark radiological sign for a slipped capital femoral epiphysis (SCFE)?





Explanation

The hallmark radiological sign for SCFE is a failure of Klein's line (a line drawn along the superior border of the femoral neck) to intersect the lateral portion of the femoral epiphysis on an AP pelvic radiograph. Normally, Klein's line should cross at least a portion of the epiphysis. Widening of the physis with metaphyseal sclerosis can be seen, but the relationship with Klein's line is more definitive. Increased neck-shaft angle is not specific, and bone fragmentation/collapse suggests AVN, not acute SCFE.

Question 38

A 35-year-old male presents with persistent pain and tenderness over the dorsal aspect of his wrist following a fall onto an outstretched hand 6 weeks ago. Initial radiographs were reported as normal. What is the most appropriate next step in diagnosis?





Explanation

Given persistent wrist pain and tenderness, especially in the anatomical snuffbox (implied location, though not explicitly stated for scaphoid), after a fall, and normal initial radiographs, avascular necrosis (AVN) of the scaphoid or a missed scaphoid fracture is a significant concern. MRI is the most sensitive and specific imaging modality for detecting occult scaphoid fractures and early AVN of the scaphoid. Repeat radiographs might show changes but are less sensitive than MRI. CT is excellent for bone detail but less sensitive for early occult fractures or AVN. Bone scan can be sensitive but less specific. Ultrasound is not typically used for scaphoid fractures.

Question 39

What is the primary mechanism of action of bisphosphonates in the treatment of osteoporosis?





Explanation

Bisphosphonates are the most commonly prescribed class of drugs for osteoporosis. Their primary mechanism of action is to inhibit osteoclast activity, thereby decreasing bone resorption and slowing down bone loss, which helps to increase bone mineral density over time. They do not directly stimulate osteoblast activity, increase gut calcium absorption, enhance renal calcium reabsorption, or modulate estrogen receptors (that's the role of SERMs).

Question 40

Which structure provides the primary static restraint against posterior translation of the tibia in the knee?





Explanation

The posterior cruciate ligament (PCL) is the primary static stabilizer that prevents posterior translation of the tibia relative to the femur. This is its defining function, particularly at higher flexion angles. The ACL prevents anterior translation. The collateral ligaments provide varus/valgus stability. The menisci are secondary stabilizers and shock absorbers.

Question 41

A 5-year-old child presents with a painful, swollen knee after a fall. Radiographs show a fracture involving the physis and epiphysis of the distal femur, without metaphyseal involvement. Which Salter-Harris classification type describes this injury?





Explanation

A fracture involving the physis and epiphysis but sparing the metaphysis is a Salter-Harris Type III injury. Type I is a purely physeal slip. Type II involves physis and metaphysis. Type IV involves epiphysis, physis, and metaphysis. Type V is a crush injury to the physis.

Question 42

What is the most common cause of acute compartment syndrome in the lower leg?





Explanation

Tibial shaft fractures are the most common cause of acute compartment syndrome in the lower leg. The high-energy trauma associated with these fractures, along with the anatomy of the leg compartments, predisposes to increased compartmental pressure. While direct crush injury and vascular injury can certainly cause compartment syndrome, tibial fractures are statistically the most frequent etiology. Exertional activity can cause chronic exertional compartment syndrome, which is different from acute.

Question 43

Regarding idiopathic scoliosis, which finding on physical examination warrants the most concern for a non-idiopathic (e.g., congenital or neurological) etiology?





Explanation

A left thoracic curve is highly atypical for idiopathic scoliosis, which is overwhelmingly characterized by right thoracic curves. A left thoracic curve should prompt a thorough workup to rule out an underlying neurological (e.g., syrinx, tethered cord) or congenital cause. A rib hump is a common finding in idiopathic scoliosis. Progressive curve magnitude is a feature, not a differentiator from idiopathic. A normal neurological exam supports idiopathic. Leg length discrepancy can cause compensatory scoliosis, but the curve morphology (left thoracic) is a stronger indicator of non-idiopathic origin.

Question 44

Which type of osteogenesis imperfecta (OI) is generally considered the most severe, often lethal in the perinatal period?





Explanation

Osteogenesis Imperfecta Type II is the most severe form, typically lethal in the perinatal period due to severe skeletal deformity, multiple intrauterine fractures, and pulmonary hypoplasia. Type I is the most common and mildest, Type III is severe but not usually lethal perinatally, and Type IV and V are intermediate in severity.

Question 45

What is the most common complication of a calcaneal fracture?





Explanation

Post-traumatic subtalar arthritis is the most common long-term complication of intra-articular calcaneal fractures, regardless of treatment method. The fracture often disrupts the articular surface of the subtalar joint, leading to incongruity and subsequent degenerative changes. While the other options can occur, subtalar arthritis significantly impacts long-term function and is the most prevalent. Compartment syndrome of the foot is an acute concern, not a long-term complication per se.

Question 46

A 58-year-old male undergoes arthroscopic rotator cuff repair. Postoperatively, he develops sudden, severe anterior shoulder pain and inability to actively abduct or externally rotate the shoulder. On examination, he has a positive 'drop arm' sign. What is the most likely cause of this acute decline?





Explanation

The sudden onset of severe anterior shoulder pain, inability to actively abduct or externally rotate the shoulder, and a positive 'drop arm' sign after rotator cuff repair are highly suggestive of an acute recurrent rotator cuff tear. Adhesive capsulitis typically develops gradually with progressive stiffness. Infection would present with systemic signs and increasing pain but not usually acute inability to move. Axillary nerve injury would primarily affect deltoid function (abduction). Subdeltoid impingement would cause pain but not typically complete inability to move or a positive drop arm sign post-repair.

Question 47

Which anatomical structure is most commonly entrapped in a Salter-Harris Type II fracture of the distal tibia, potentially preventing successful closed reduction?





Explanation

In a Salter-Harris Type II fracture, particularly of the distal tibia, the metaphysis fractures and the periosteum is typically torn on the convex side and often remains intact on the concave side. This intact periosteal sleeve can become invaginated into the fracture site, preventing a concentric reduction of the epiphysis and metaphysis. This is often referred to as a 'periosteal hinge.' The tendons and nerve are less likely to be directly entrapped in a way that prevents reduction of this specific fracture pattern.

Question 48

In a patient with a stable C2 odontoid type II fracture, which of the following treatment options is generally preferred in a younger, active patient?





Explanation

For a stable C2 odontoid type II fracture, anterior odontoid screw fixation is often preferred in a younger, active patient. It allows for direct fixation of the fracture, preserves C1-C2 rotation, and avoids the need for prolonged external immobilization (halo vest), which can be uncomfortable and associated with complications. Halo vest immobilization has a higher nonunion rate and often prolonged discomfort. Transarticular screw fixation or posterior C1-C2 fusion are options, but they sacrifice C1-C2 rotation, which anterior odontoid screw fixation preserves. A soft cervical collar is inadequate for an odontoid fracture.

Question 49

Which of the following conditions is characterized by a gradual onset of hip pain in an obese adolescent, often presenting with a painful limp and limited internal rotation and abduction?





Explanation

Slipped capital femoral epiphysis (SCFE) classically presents in obese adolescents (typically 10-16 years old) with a gradual onset of hip or knee pain, a painful limp, and characteristic limited internal rotation and abduction of the hip. Legg-Calvé-Perthes disease occurs in younger children (4-8 years). Transient synovitis is acute and resolves. Septic arthritis is acute with systemic signs. Juvenile idiopathic arthritis has a more chronic inflammatory presentation.

Question 50

What is the most common type of congenital clubfoot (talipes equinovarus)?





Explanation

Idiopathic clubfoot (talipes equinovarus) is the most common type, meaning it occurs without an identifiable underlying cause or associated syndrome. Positional clubfoot is a mild, flexible deformity that often resolves with stretching. Flexible and rigid refer to the clinical presentation, not the etiology. Neuropathic and syndromic clubfoot are associated with specific neurological conditions or syndromes, making them less common than the idiopathic form.

Question 51

Which specific ligament provides the primary restraint against valgus stress to the knee?





Explanation

The medial collateral ligament (MCL) is the primary static restraint against valgus stress to the knee. The LCL resists varus stress. The ACL and PCL provide anterior and posterior stability, respectively. The posterolateral corner (PLC) provides rotational and varus stability but is not the primary valgus stabilizer.

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Prof. Dr. Mohammed Hutaif
Consultant Orthopedic & Spine Surgeon
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