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Orthopedic Board Prep: Interactive Viva Exam Practice for Trauma & Surgical Cases

Interactive Orthopedic MCQ Engine: Master Board Prep & Exam Success

23 Apr 2026 105 min read 152 Views
Illustration of orthopaedic mcq book - Dr. Mohammed Hutaif

Key Takeaway

Our interactive Orthopedic MCQ Engine provides a robust platform for board exam preparation. Featuring Study and Exam modes, users can tackle multiple-choice questions covering core orthopedic concepts. Detailed explanations accompany each answer, aiding in deeper understanding and knowledge retention. This tool is essential for residents and practicing surgeons aiming for comprehensive revision and exam success.

Comprehensive Exam


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Question 1

A 45-year-old male presents with chronic anterior knee pain, worse with climbing stairs and prolonged sitting. Physical examination reveals patellar grind tenderness, pain with patellar compression, and a positive J-sign. Imaging shows lateral patellar tilt and increased tibial tubercle-trochlear groove (TTTG) distance of 18mm. He has failed conservative management. Which of the following surgical interventions is most appropriate?





Explanation

Given the increased TTTG distance (normal < 15mm) indicating significant lateralization of the extensor mechanism, a tibial tubercle anteromedialization (Fulkerson osteotomy) is the most appropriate surgical intervention. This procedure moves the patellar tendon insertion medially and anteriorly, decreasing the Q-angle and patellofemoral contact pressures, thereby addressing both patellar maltracking and chondromalacia. MPFL reconstruction is primarily for recurrent patellar instability due to medial restraint insufficiency, though it can be combined with osteotomy for severe cases. Lateral retinacular release alone is often insufficient for significant maltracking. Trochleoplasty is reserved for severe trochlear dysplasia, and total knee arthroplasty is excessive for isolated patellofemoral pain in a 45-year-old.

Question 2

A 68-year-old male with a history of prostate cancer treated with radiation therapy and androgen deprivation therapy presents with acute onset severe back pain, new neurological deficits including bilateral leg weakness (3/5) and saddle anesthesia. MRI reveals a compression fracture at T12 with significant retropulsion causing severe spinal canal stenosis. What is the most urgent next step in management?





Explanation

The most urgent next step in a patient with suspected metastatic spinal cord compression (SCC) is to initiate high-dose corticosteroids, such as dexamethasone. This helps reduce peritumoral edema, which can alleviate neurological symptoms and buy time for definitive diagnosis and treatment planning. While emergent surgical decompression and stabilization may be indicated, steroids are typically administered first, often even prior to definitive imaging if SCC is strongly suspected clinically. Radiation therapy is often used in conjunction with surgery or as primary treatment for radiosensitive tumors, but steroids provide more immediate relief. Bisphosphonates are for long-term bone protection and pain, not acute SCC. A bone scan is part of workup, but not the most urgent immediate management for acute neurological deficit.

Question 3

A 28-year-old professional basketball player sustains an acute ankle inversion injury. He presents with severe pain and swelling over the lateral ankle. On examination, there is tenderness over the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL). Anterior drawer test is positive, and the talar tilt test is positive. An MRI reveals a complete rupture of the ATFL and CFL. What is the recommended management?





Explanation

For most acute lateral ankle ligament ruptures, even complete tears involving both the ATFL and CFL, non-operative management with a period of immobilization followed by aggressive rehabilitation yields excellent results. A CAM boot allows for controlled motion and early weight-bearing as tolerated. Surgical repair or reconstruction is typically reserved for chronic instability after failed non-operative treatment, or in rare cases, highly demanding athletes with persistent instability. PRP injection lacks strong evidence for superior outcomes in acute ligament tears. Casting for only 2 weeks might be insufficient immobilization.

Question 4

Which of the following conditions is characterized by progressive metaphyseal widening, bowing of long bones, and 'Erlenmeyer flask' deformity on radiographs, often associated with pancytopenia and hepatosplenomegaly?





Explanation

Gaucher disease, an autosomal recessive lysosomal storage disorder, is classically associated with the 'Erlenmeyer flask' deformity (undermodeling of the distal femur), progressive metaphyseal widening, bowing of long bones, and osteopenia. Bone crises, avascular necrosis, and pathological fractures are also common. The systemic manifestations include hepatosplenomegaly and pancytopenia due to glucocerebroside accumulation in macrophages. Osteogenesis imperfecta is characterized by fragile bones, blue sclera, and hearing loss. Rickets involves defective mineralization of bone. Paget's disease involves disorganized bone remodeling. Fibrous dysplasia is a localized lesion.

Question 5

A 55-year-old male presents with progressive right shoulder pain, weakness, and difficulty with overhead activities for 6 months. Physical examination reveals significant deltoid atrophy, an absent acromial-humeral interval on radiographs, and a positive external rotation lag sign. He has intact sensation and deltoid function. What is the most appropriate surgical treatment?





Explanation

The clinical presentation (deltoid atrophy, absent acromial-humeral interval on radiographs, positive external rotation lag sign) strongly suggests rotator cuff arthropathy, which is advanced glenohumeral arthritis associated with a massive, irreparable rotator cuff tear. In such cases, a reverse total shoulder arthroplasty is the treatment of choice, as it medializes and distalizes the center of rotation, allowing the deltoid muscle to function more efficiently and restore active elevation. Rotator cuff repair is not feasible for massive, irreparable tears with cuff arthropathy. Debridement is palliative. Latissimus dorsi transfer is used for isolated irreparable posterosuperior tears, often in younger patients without significant arthropathy. Hemiarthroplasty alone would not address the cuff deficiency.

Question 6

A 3-year-old child presents with a limp and pain in the right hip. Radiographs show flattening and sclerosis of the right femoral head epiphysis, with widening of the medial joint space. What is the most likely diagnosis?





Explanation

The radiographic findings of flattening and sclerosis of the femoral head epiphysis, along with widening of the medial joint space, are classic for Legg-Calvé-Perthes disease (LCPD), an idiopathic avascular necrosis of the femoral head in children typically aged 4-8 years. DDH involves acetabular and femoral head dysplasia. Septic arthritis presents with acute, severe pain and fever, and radiographic changes are typically joint effusions and cartilage destruction. Transient synovitis is a self-limiting inflammatory condition with minimal radiographic changes. SCFE usually occurs in adolescents (10-16 years) and involves a posterior and inferior slippage of the femoral head epiphysis.

Question 7

Which metabolic bone disorder is characterized by elevated serum alkaline phosphatase, normal serum calcium and phosphate, and disorganized bone remodeling leading to bone pain, deformity, and increased fracture risk?





Explanation

Paget's disease of bone (osteitis deformans) is characterized by a focal disorder of bone remodeling, with abnormally high osteoclast activity followed by compensatory osteoblast activity, leading to disorganized, enlarged, and weak bone. This results in elevated serum alkaline phosphatase (a marker of osteoblast activity) while serum calcium and phosphate levels typically remain normal. Clinical features include bone pain, deformity (e.g., bowing of long bones), pathological fractures, and neurologic complications due to nerve compression. Osteoporosis involves decreased bone mass but normal bone histology. Osteomalacia and rickets (in children) are due to defective mineralization, often with low phosphate and/or calcium. Hyperparathyroidism involves elevated PTH and altered calcium/phosphate levels.

Question 8

A 30-year-old male presents with recurrent episodes of lateral knee pain, especially when running or cycling. Examination reveals tenderness over the lateral femoral epicondyle, approximately 2-3 cm proximal to the joint line. Noble's compression test is positive. What is the most likely diagnosis?





Explanation

The patient's presentation of lateral knee pain, especially with repetitive activities like running and cycling, tenderness over the lateral femoral epicondyle (where the ITB crosses), and a positive Noble's compression test (pain elicited with palpation of the ITB over the lateral epicondyle while the knee is flexed to 30 degrees and extended) are classic signs of Iliotibial Band Friction Syndrome (ITBFS). This overuse injury occurs when the distal ITB rubs against the lateral femoral epicondyle. Other options are less likely given the specific location of tenderness and mechanism.

Question 9

A 72-year-old female presents with severe pain and instability after falling onto her outstretched hand. Radiographs show a comminuted intra-articular fracture of the distal radius with significant dorsal displacement, ulnar positive variance, and disruption of the distal radioulnar joint (DRUJ). Which classification is most appropriate for this injury, and what is its significance?





Explanation

The AO/OTA classification is a comprehensive system that uses alphanumeric codes to describe fracture morphology (e.g., location, articular involvement, comminution) in great detail. For a complex, comminuted intra-articular distal radius fracture with DRUJ disruption, this system provides the most specific and reproducible description for surgical planning, research, and communication among surgeons. While Frykman classifies based on intra/extra-articular involvement and associated ulnar fractures, and Fernandez focuses on mechanism, the AO/OTA provides the highest level of detail for such a complex injury, which is critical for understanding the exact nature of the injury and guiding advanced surgical treatment. The Gartland classification is for pediatric elbow fractures.

Question 10

Which of the following describes the correct orientation for a standard posterior approach to the hip for total hip arthroplasty?





Explanation

The standard posterior approach to the hip involves incising the posterior capsule and releasing the short external rotators, specifically the piriformis, obturator internus, and superior/inferior gemelli, from their insertion on the greater trochanter. The gluteus maximus is typically split, not detached from its insertion, and the abductors (gluteus medius/minimus) are preserved, making this a muscle-sparing approach to the abductors. Option A describes an approach that would damage the abductors. Option C and E describe aspects of an anterolateral or direct lateral approach. Option D describes a medial reflection of the vastus lateralis, not a lateral one, and an anterior capsule incision which is incorrect for a posterior approach.

Question 11

A 10-year-old boy presents with progressive cavovarus foot deformity, hammer toes, and bilateral distal muscle weakness and atrophy, particularly affecting the peroneal muscles. He also reports difficulties with fine motor skills in his hands. Deep tendon reflexes are diminished, and sensation is decreased in a stocking-glove distribution. What is the most likely diagnosis?





Explanation

The constellation of progressive cavovarus foot deformity, hammer toes, distal muscle weakness and atrophy (especially peroneal), hand intrinsic weakness, diminished deep tendon reflexes, and stocking-glove sensory loss is highly characteristic of Charcot-Marie-Tooth disease (CMT). CMT is a hereditary motor and sensory neuropathy (HMSN), the most common inherited neurological disorder, affecting peripheral nerves. Duchenne muscular dystrophy is a primary muscle disorder with proximal weakness. Spina bifida is a congenital spinal cord defect. Cerebral palsy is a brain injury affecting motor control. Friedreich's ataxia primarily affects the cerebellum and spinal cord, presenting with ataxia, dysarthria, and scoliosis, though cavovarus feet can also occur.

Question 12

Which of the following is considered an absolute contraindication to closed reduction and percutaneous pinning of a supracondylar humerus fracture in a child?





Explanation

An open fracture is an absolute contraindication to closed reduction and percutaneous pinning. Open fractures require urgent open reduction, irrigation, and debridement to prevent infection. Significant swelling and ecchymosis, while concerning, are common in these injuries and typically do not preclude closed reduction. A palpable radial pulse is a good sign. Neuropraxia (e.g., median nerve palsy) is common and often resolves with reduction and stabilization; it is not a contraindication to closed reduction. Absence of gross deformity doesn't mean the fracture isn't displaced or unstable.

Question 13

A 35-year-old male with a history of intravenous drug use presents with acute onset of severe low back pain, fever, and progressive bilateral lower extremity weakness. MRI shows discitis and osteomyelitis involving L4-L5 with an epidural abscess. White blood cell count is elevated, and ESR/CRP are significantly raised. What is the most critical initial management step after diagnosis?





Explanation

Given the presence of progressive neurological deficits (bilateral lower extremity weakness) in the setting of an epidural abscess secondary to discitis and osteomyelitis, emergent surgical decompression and debridement of the infection is the most critical initial management step. This is necessary to relieve spinal cord or cauda equina compression and prevent irreversible neurological damage. While IV antibiotics are crucial, they are often initiated pre-operatively but cannot resolve mass effect. Percutaneous drainage may be an option for smaller, non-compressive abscesses without neurological compromise. Corticosteroids are not typically used for infectious epidural abscesses and may be detrimental. Oral antibiotics are inadequate for severe infections like this.

Question 14

What is the primary function of the meniscofemoral ligaments (ligament of Wrisberg and ligament of Humphry)?





Explanation

The meniscofemoral ligaments (MFLs) are typically two ligaments: the anterior meniscofemoral ligament (ligament of Humphry) and the posterior meniscofemoral ligament (ligament of Wrisberg). Both arise from the posterior horn of the lateral meniscus and insert onto the medial femoral condyle, specifically joining the posterior cruciate ligament (PCL). Their primary function is to stabilize the posterior horn of the lateral meniscus, particularly in relation to the PCL, and to a lesser extent, contribute to PCL function. They do not primarily stabilize the patella, reinforce the ACL, or provide varus stability.

Question 15

A 40-year-old male sustains a Lisfranc injury after a motor vehicle accident. Radiographs and CT scans confirm a homolateral Lisfranc dislocation with diastasis between the first and second metatarsal bases. There is no open wound. What is the optimal treatment for this injury?





Explanation

For unstable Lisfranc injuries, particularly those with significant diastasis and dislocation, open reduction and internal fixation (ORIF) is the treatment of choice. Accurate anatomical reduction and rigid fixation are paramount to restore the arch and prevent post-traumatic arthritis. Screws are typically placed from the medial cuneiform to the second metatarsal base (Lisfranc screw) and potentially other intercuneiform or metatarsal base screws depending on the specific pattern. Closed reduction and casting alone are insufficient for unstable injuries. Primary arthrodesis may be considered for severe comminuted injuries or after failed ORIF, but ORIF is preferred initially. Excision of an accessory navicular is unrelated. Immobilization in a walking boot is inadequate.

Question 16

Which of the following statements regarding osteosarcoma is FALSE?





Explanation

Chemotherapy is a crucial component of treatment for nearly all osteosarcomas, including localized disease. It is administered both pre-operatively (neoadjuvant) and post-operatively (adjuvant) to improve limb salvage rates, reduce tumor burden, treat micrometastatic disease, and assess tumor response. Therefore, the statement that chemotherapy is only indicated for metastatic disease is false. All other statements are true: osteosarcoma is the most common primary malignant bone tumor in children/adolescents, often found in long bone metaphyses, characterized by classic radiographic features, and most commonly metastasizes to the lungs.

Question 17

A 60-year-old active male sustains an acute rupture of his Achilles tendon. Physical examination reveals a palpable gap and a positive Thompson test. He is otherwise healthy. What is the most appropriate management approach to minimize the risk of re-rupture while maintaining functional outcome?





Explanation

For active patients who sustain an acute Achilles tendon rupture, surgical repair followed by early protected mobilization has generally demonstrated lower re-rupture rates compared to non-operative treatment, especially in high-demand individuals. Early protected mobilization protocols typically involve a controlled ankle motion (CAM) boot with progressive plantarflexion to neutral. Non-operative management can be successful, but typically involves a prolonged period of immobilization, and carries a higher re-rupture risk. PRP injection lacks strong evidence for superior outcomes. Long leg cast for 8 weeks is too restrictive and would lead to significant stiffness and atrophy. Immediate aggressive physical therapy without immobilization would risk re-rupture.

Question 18

Which of the following is the most reliable radiographic sign for detecting a slipped capital femoral epiphysis (SCFE)?





Explanation

Trethowan's sign, or Klein's line, is considered the most reliable radiographic sign for detecting SCFE on an anteroposterior (AP) view. Klein's line is drawn along the superior border of the femoral neck; normally, it should intersect a portion of the femoral head epiphysis. In SCFE, due to posterior and inferior slippage, Klein's line will fail to intersect or will intersect a smaller portion of the epiphysis. While widening of the physis and decreased femoral neck-shaft angle can be present, Klein's line is the most sensitive and specific sign for early diagnosis on standard AP radiographs.

Question 19

A 22-year-old male sustains a dislocated hip secondary to a high-energy trauma. After successful closed reduction, what is the most important follow-up imaging study to assess for common complications?





Explanation

After closed reduction of a traumatic hip dislocation, a CT scan of the hip and pelvis is essential. The most important reason is to evaluate for concentric reduction, identify any incarcerated bone fragments (especially from the femoral head or acetabulum), and assess for occult fractures (e.g., acetabular rim, femoral head impaction fractures) that might not be visible on plain radiographs. Missed fragments can lead to poor outcomes, including post-traumatic arthritis. While repeat radiographs are done immediately post-reduction, they are often insufficient. MRI is used later to assess for avascular necrosis, but not immediately. Ultrasound and bone scans are not primary assessments for acute post-reduction complications.

Question 20

What type of bone graft offers osteoinductive, osteoconductive, and osteogenic properties?





Explanation

Autograft (cancellous) is considered the 'gold standard' for bone grafting because it possesses all three essential properties: osteoconduction (provides a scaffold for new bone growth), osteoinduction (contains growth factors that stimulate host mesenchymal stem cells to differentiate into osteoblasts), and osteogenesis (contains living osteocytes and osteoblasts from the donor site that can immediately form new bone). Allografts are primarily osteoconductive and osteoinductive but lack viable osteogenic cells. DBM is primarily osteoinductive and osteoconductive. Ceramic bone substitutes are mainly osteoconductive. BMPs are purely osteoinductive.

Question 21

A 4-year-old presents with a congenital muscular torticollis. On examination, there is right sternocleidomastoid contracture, with the head tilted to the right and rotated to the left. What is the most important initial management strategy?





Explanation

For congenital muscular torticollis, intensive physical therapy, consisting of passive stretching, active range-of-motion exercises, and strengthening of the neck muscles, is the most important initial management strategy. It is highly effective, with resolution rates exceeding 90% if started early, typically before 6-12 months of age. Surgical release is reserved for cases that fail extensive physical therapy, usually after 1 year of age or if there are significant facial or cranial asymmetries. Observation alone is not adequate for significant contracture. Casting is rarely used. Botulinum toxin can be considered as an adjunct but is not the primary initial treatment.

Question 22

Which of the following is a classic radiographic finding for chronic osteomyelitis?





Explanation

Sequestrum and involucrum are classic radiographic findings for chronic osteomyelitis. A sequestrum is a piece of dead, devascularized bone that has become separated from the living bone during the process of necrosis. An involucrum is a sheath of new bone that forms around a sequestrum. These findings indicate a chronic, established infection. Codman's triangle is typically seen in aggressive bone tumors or acute osteomyelitis. Soft tissue swelling and joint effusion are more indicative of acute infection or inflammatory processes. Widening of the growth plate is associated with rickets or SCFE. Punctate calcifications are non-specific and can be seen in various soft tissue lesions.

Question 23

A 48-year-old construction worker presents with insidious onset of unilateral elbow pain and weakness, primarily affecting grip strength. He describes pain exacerbated by pronation and resisted wrist flexion. Tenderness is noted over the pronator teres muscle belly and the origin of the flexor carpi radialis. Compression of the median nerve in the proximal forearm reproduces symptoms. What is the most likely diagnosis?





Explanation

The symptoms of unilateral elbow pain, weakness, pain with pronation and resisted wrist flexion, tenderness over the pronator teres/flexor carpi radialis origin, and reproduction of symptoms with median nerve compression in the proximal forearm are highly suggestive of Pronator Teres Syndrome. This is a median nerve entrapment neuropathy in the proximal forearm, typically at the level of the pronator teres. Medial epicondylitis involves the common flexor origin but typically without neurological symptoms. Lateral epicondylitis involves the common extensor origin. Cubital tunnel syndrome is ulnar nerve entrapment at the elbow. Radial tunnel syndrome involves the posterior interosseous nerve (PIN), causing pain without motor weakness or sensory deficits initially.

Question 24

Which of the following is a recognized risk factor for the development of periprosthetic joint infection (PJI) following total hip arthroplasty?





Explanation

Poorly controlled diabetes mellitus is a significant and well-recognized risk factor for periprosthetic joint infection (PJI). Hyperglycemia impairs immune function, wound healing, and increases the risk of surgical site infection. Other risk factors include obesity (BMI > 30), male gender, revision surgery, prolonged operative time, active infection elsewhere, and immunosuppression. BMI < 25 is protective. Female gender is generally not a risk factor. Elective primary procedures have a lower risk than revision or trauma. Prophylactic antibiotics reduce, rather than increase, the risk of PJI.

Question 25

What is the primary mechanical function of the ACL?





Explanation

The primary mechanical function of the anterior cruciate ligament (ACL) is to prevent anterior translation of the tibia on the femur. It also plays a significant role in limiting internal rotation of the tibia and to a lesser extent, hyperextension. The posterior cruciate ligament (PCL) prevents posterior translation. The medial collateral ligament (MCL) resists valgus stress, and the lateral collateral ligament (LCL) resists varus stress. While the ACL contributes to rotational stability, its primary role is sagittal plane stability against anterior tibial translation.

Question 26

A 7-year-old child sustains a Salter-Harris Type II fracture of the distal tibia. Which zone of the physis is involved in this fracture pattern?





Explanation

Salter-Harris Type II fractures involve a fracture line through the hypertrophic zone of the physis, extending into the metaphysis but sparing the epiphysis. The hypertrophic zone is the weakest layer of the growth plate and is typically where Salter-Harris fractures occur. The germinal and proliferative zones are spared, which is crucial for continued growth. Type I fractures are through the physis, Type III involve the epiphysis and physis, Type IV involve epiphysis, physis, and metaphysis, and Type V is a crush injury to the physis.

Question 27

Which type of nonunion is characterized by a hypertrophic, 'elephant foot' appearance on radiographs, often responding well to biological stimulation without extensive debridement or bone grafting, provided stability is achieved?





Explanation

Hypertrophic nonunion is characterized by abundant callus formation at the fracture site, giving it an 'elephant foot' or 'horse hoof' appearance on radiographs, but without bridging bone. This indicates that the fracture has biological activity (sufficient blood supply and cellular response) but lacks mechanical stability. The primary treatment for hypertrophic nonunion is achieving mechanical stability, often through rigid internal fixation (e.g., larger plate, longer nail, external fixation with increased rigidity), sometimes with dynamization. Atrophic nonunion lacks callus and has poor biology. Oligotrophic nonunion has minimal callus. Pseudoarthrosis is a synovial-lined false joint. Infected nonunion has signs of infection.

Question 28

A 65-year-old male undergoes total knee arthroplasty. On postoperative day 2, he develops acute shortness of breath, pleuritic chest pain, and hypoxemia. What is the most likely diagnosis?





Explanation

Acute shortness of breath, pleuritic chest pain, and hypoxemia occurring post-total knee arthroplasty are classic symptoms of a pulmonary embolism (PE). Deep vein thrombosis (DVT) and subsequent PE are serious and relatively common complications of major orthopedic surgery. While atelectasis is common post-operatively, it usually presents with more subtle symptoms. Pneumonia and myocardial infarction are possibilities but less likely to manifest with pleuritic pain so acutely after TKA. Fat embolism syndrome usually occurs earlier (within 24-48 hours), often after long bone fractures, and includes petechial rash and neurological changes, which are not mentioned here.

Question 29

Which of the following conditions is most commonly associated with spontaneous bilateral avascular necrosis of the femoral head in adults?





Explanation

Corticosteroid use (especially high-dose and prolonged) is the most common non-traumatic cause and a strong risk factor for spontaneous bilateral avascular necrosis (AVN) of the femoral head in adults. While alcohol abuse and systemic lupus erythematosus are also risk factors, corticosteroids are implicated in the largest percentage of cases. Sickle cell disease can cause AVN, but it is less common than corticosteroid-induced AVN in the general adult population. Trauma typically causes unilateral AVN due to disruption of blood supply.

Question 30

Which ligament is critical for maintaining the stability of the distal tibiofibular syndesmosis?





Explanation

The anterior inferior tibiofibular ligament (AITFL) is a primary stabilizer of the distal tibiofibular syndesmosis, along with the posterior inferior tibiofibular ligament (PITFL) and the interosseous ligament. Injuries to these ligaments result in syndesmotic (high ankle) sprains. The ATFL, PTFL, and CFL are components of the lateral ankle collateral ligaments, stabilizing the talocrural joint. The deltoid ligament is the medial collateral ligament of the ankle.

Question 31

A 3-month-old infant is diagnosed with developmental dysplasia of the hip (DDH) after a positive Ortolani test. Radiographs show a dislocated left hip with an acetabular index of 35 degrees. What is the most appropriate initial treatment?





Explanation

For an infant diagnosed with DDH (dislocatable hip, positive Ortolani, and radiographic evidence) at 3 months of age, the Pavlik harness is the gold standard initial treatment. It maintains the hips in flexion and abduction, allowing for gradual reduction and acetabular development. Open reduction and spica cast are reserved for cases that fail Pavlik harness or for older infants. Hip arthroscopy is not a primary treatment for DDH. Serial casting is used for clubfoot. Observation is inappropriate for a diagnosed dislocated hip.

Question 32

In the setting of total knee arthroplasty, what is the 'Q-angle' primarily used to assess?





Explanation

The Q-angle (quadriceps angle) is primarily used to assess patellofemoral tracking. It is the angle formed by a line from the anterior superior iliac spine (ASIS) to the center of the patella and a line from the center of the patella to the center of the tibial tubercle. An increased Q-angle suggests lateral pull on the patella, predisposing to patellar maltracking and instability, which is a critical consideration in total knee arthroplasty to prevent anterior knee pain and instability. The other options relate to different aspects of knee arthroplasty alignment or balance.

Question 33

What is the most common direction of glenohumeral dislocation?





Explanation

Anterior dislocations are by far the most common direction of glenohumeral dislocation, accounting for over 95% of cases. This typically occurs due to an injury with the arm in abduction and external rotation. Posterior dislocations are much rarer (2-4%), often associated with seizures or electrocution. Inferior and superior dislocations are extremely rare. Multidirectional instability is a different clinical entity, often without a specific traumatic event.

Question 34

A 50-year-old male with a history of chronic alcoholism presents with pain and swelling in his left great toe. On examination, the joint is warm, erythematous, and exquisitely tender to touch. Serum uric acid level is elevated. What is the most appropriate acute management?





Explanation

The presentation is classic for an acute gouty arthritis attack (podagra). The most appropriate acute management is to prescribe non-steroidal anti-inflammatory drugs (NSAIDs) like indomethacin, or colchicine. Oral corticosteroids can also be used if NSAIDs are contraindicated or ineffective. Allopurinol is a urate-lowering therapy and should not be initiated during an acute attack, as it can worsen symptoms by mobilizing uric acid crystals; it is for long-term management once the acute attack has subsided. Joint aspiration and corticosteroid injection are options if only one or two joints are involved and diagnosis is confirmed. Surgical fusion is for end-stage arthritis, not acute management.

Question 35

Which imaging modality is most sensitive for detecting early avascular necrosis (AVN) of the femoral head?





Explanation

Magnetic Resonance Imaging (MRI) is the most sensitive imaging modality for detecting early avascular necrosis (AVN) of the femoral head. It can identify changes in bone marrow edema and signal intensity, typically before any changes are visible on plain radiographs or even CT scans. Early detection with MRI allows for earlier intervention, potentially preventing progression to femoral head collapse. Plain radiographs are often negative in early stages. CT scan can show sclerosis and collapse but is less sensitive than MRI for early changes. Bone scan shows increased uptake but is less specific. Ultrasound has no role in diagnosing femoral head AVN.

Question 36

A 2-year-old child presents with a limp, pain, and refusal to bear weight after a low-energy fall. Radiographs of the tibia and fibula are unremarkable. Examination reveals exquisite tenderness over the mid-tibia. What is the most likely diagnosis?





Explanation

The clinical scenario of a 2-year-old with a limp and pain after a low-energy fall, refusal to bear weight, and tenderness over the mid-tibia with unremarkable initial radiographs is classic for a Toddler's fracture. This is a non-displaced spiral or oblique fracture of the distal tibia, often difficult to visualize on initial X-rays. A repeat radiograph in 10-14 days may show periosteal reaction. Septic arthritis would involve a joint. Osteosarcoma is rare in this age group and usually visible on X-ray. Osgood-Schlatter disease occurs in adolescents. Stress fractures are typically seen in older, more active children/adolescents.

Question 37

What is the primary function of the deltoid ligament in the ankle?





Explanation

The deltoid ligament is the strong medial collateral ligament complex of the ankle. Its primary function is to resist excessive eversion of the talus and valgus stress at the ankle joint. It consists of multiple fascicles (tibionavicular, tibiocalcaneal, posterior tibiotalar, and anterior tibiotalar). The lateral collateral ligaments (ATFL, CFL, PTFL) resist inversion. The syndesmotic ligaments stabilize the tibiofibular joint. The PTL prevents posterior talar translation, and the ATFL prevents anterior talar translation. The Achilles tendon limits dorsiflexion.

Question 38

Which of the following describes the most common classification system for hip fractures?





Explanation

All the listed classifications are commonly used for different types of hip fractures, reflecting the complexity and need for specific guidance depending on the fracture location. Garden classification is specifically for femoral neck fractures (Garden I-IV based on displacement and impaction). Pauwels classification also applies to femoral neck fractures, based on the angle of the fracture line to the horizontal, predicting nonunion risk. Evans classification is used for intertrochanteric fractures, assessing stability. The comprehensive AO/OTA classification system can be applied to all hip fractures, providing detailed morphological descriptions for surgical planning and research.

Question 39

A 16-year-old male presents with chronic anterior knee pain, exacerbated by kneeling and direct pressure. Examination reveals swelling and tenderness directly over the patellar tendon insertion on the tibial tubercle. Radiographs show fragmentation and irregularity of the tibial tubercle. What is the most likely diagnosis?





Explanation

The clinical picture of anterior knee pain, swelling, and tenderness over the tibial tubercle, along with radiographic fragmentation/irregularity of the tibial tubercle in an adolescent male, is classic for Osgood-Schlatter disease. This is an apophysitis (traction apophysitis) of the tibial tubercle due to repetitive stress from the quadriceps tendon pulling on the developing bone. Sinding-Larsen-Johansson syndrome is similar but affects the inferior pole of the patella. Patellofemoral pain syndrome and chondromalacia patellae involve the patellofemoral joint. Patellar tendinopathy (jumper's knee) affects the patellar tendon, usually in older adolescents or adults, without tibial tubercle fragmentation.

Question 40

Which of the following is the most common primary malignant bone tumor in adults?





Explanation

Multiple myeloma is the most common primary malignant bone tumor in adults. It is a malignancy of plasma cells that arises in the bone marrow and typically presents with multifocal lytic lesions throughout the skeleton. While osteosarcoma and Ewing sarcoma are common in children and adolescents, and chondrosarcoma is another primary adult bone tumor, multiple myeloma has a higher incidence overall in adults. Fibrosarcoma is a very rare primary bone tumor.

Question 41

What is the primary indication for surgical management of a pediatric femoral shaft fracture?





Explanation

The primary indication for surgical management of a pediatric femoral shaft fracture, particularly in older children and adolescents, includes open fractures, multiple trauma, and polytrauma where early mobilization is crucial, as well as unstable fractures that cannot be adequately managed with casting or flexible nailing. While specific age cutoffs and displacement criteria influence management, open fractures and polytrauma universally point towards surgical stabilization to facilitate wound care, minimize complications, and aid in overall patient recovery. Young children often undergo casting or flexible nailing. Length discrepancy of less than 1 cm or angulation less than 15 degrees are typically managed non-operatively.

Question 42

A 55-year-old female presents with chronic wrist pain and weakness, particularly with pinch and grip. Examination reveals tenderness over the radial styloid and pain with active wrist ulnar deviation and passive wrist radial deviation, while the thumb is flexed into the palm (Finkelstein's test). What is the most likely diagnosis?





Explanation

The patient's symptoms of chronic wrist pain over the radial styloid, weakness with pinch and grip, and a positive Finkelstein's test (pain with passive ulnar deviation of the wrist while the thumb is flexed into the palm) are pathognomonic for De Quervain's tenosynovitis. This condition involves stenosing tenosynovitis of the first dorsal compartment of the wrist, affecting the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons. Carpal tunnel syndrome involves median nerve compression. Intersection syndrome involves the tendons of the first and second dorsal compartments crossing. Trigger finger is stenosing tenosynovitis of a flexor tendon. Basal joint arthritis affects the trapeziometacarpal joint.

Question 43

What is the most common cause of osteonecrosis of the jaw (ONJ) in orthopedic patients?





Explanation

In orthopedic patients, bisphosphonate therapy is the most common cause of osteonecrosis of the jaw (ONJ), often referred to as bisphosphonate-related osteonecrosis of the jaw (BRONJ). Bisphosphonates, especially IV forms used in metastatic bone disease or osteoporosis, inhibit osteoclast activity, which can impair bone remodeling and healing in the jaw, particularly after dental procedures or trauma. While radiation and infection can cause ONJ, bisphosphonate use is a specific and significant risk factor in the orthopedic population. Corticosteroids and trauma are less commonly implicated as primary causes compared to bisphosphonates.

Question 44

Which of the following is an accepted indication for surgical treatment of scoliosis in an adolescent with idiopathic scoliosis?





Explanation

Surgical treatment for adolescent idiopathic scoliosis is generally indicated for skeletally immature patients with progressive curves or curves that are already large. A thoracic curve exceeding 45-50 degrees (or lumbar/thoracolumbar curves exceeding 40-45 degrees) in a skeletally immature patient is a common indication for surgery to prevent further progression and manage cosmetic deformity. Smaller curves (15-25 degrees) in skeletally immature patients are typically observed or braced. A 25-degree curve in a skeletally mature patient or an asymptomatic 30-degree curve in a mature patient would typically be observed, as progression is less likely after skeletal maturity. Curve progression criteria for bracing often apply to 20-40 degree curves, but surgery is for larger, progressive curves.

Question 45

What is the primary mechanism of action of parathyroid hormone (PTH) in bone metabolism?





Explanation

Parathyroid hormone (PTH) plays a crucial role in calcium homeostasis. Its primary mechanism of action related to bone metabolism is to increase serum calcium levels. It achieves this by stimulating osteoclasts (indirectly, via osteoblasts) to resorb bone, releasing calcium into the bloodstream. It also increases calcium reabsorption in the renal tubules and stimulates the synthesis of calcitriol (active vitamin D), which in turn enhances intestinal calcium absorption. PTH does not directly stimulate osteoblasts for net new bone formation in a sustained manner, nor does it inhibit osteoclasts or decrease serum calcium.

Question 46

A 40-year-old female presents with persistent pain, stiffness, and catching in her right wrist after a fall. Radiographs are normal. MRI reveals a tear of the triangular fibrocartilage complex (TFCC). Which part of the TFCC is most commonly involved in chronic mechanical symptoms?





Explanation

The triangular fibrocartilage complex (TFCC) is a critical stabilizer of the distal radioulnar joint (DRUJ) and acts as a cushion for the ulnar carpus. While all parts contribute, tears of the dorsal and volar radioulnar ligaments (RULs) are most commonly associated with instability and chronic mechanical symptoms such as pain, clicking, and reduced grip strength. The articular disc can tear, but the RULs are key for DRUJ stability. The meniscus homologue and ulnolunate ligament are components, but the RULs are paramount for DRUJ integrity. The ECU subsheath is adjacent but not part of the TFCC proper.

Question 47

Which of the following is the most effective bracing technique for an adolescent with idiopathic scoliosis with a Cobb angle of 28 degrees and Risser 0-1 (skeletally immature)?





Explanation

For skeletally immature adolescents with idiopathic scoliosis (Risser 0-1) and a Cobb angle between 20-40 degrees, bracing is indicated to prevent curve progression. While full-time rigid TLSOs are traditional, recent evidence and guidelines support the efficacy of nighttime-only bracing with a rigid TLSO for similar outcomes, improving patient compliance and quality of life. Soft braces or dynamic braces have not shown superior efficacy. The Milwaukee brace is rarely used now due to its bulkiness and cosmetic issues, reserved for very high thoracic curves. Observation only is inappropriate for a progressive curve in an immature patient.

Question 48

A 32-year-old female develops a sudden, painful, and complete loss of active finger extension at the metacarpophalangeal (MCP) joints, with intact wrist extension, after a fall onto her outstretched hand. Sensation is normal. What is the most likely nerve injury?





Explanation

A posterior interosseous nerve (PIN) injury, often due to trauma, fracture, or compression in the supinator muscle, specifically results in a loss of active finger and thumb extension at the MCP joints, and thumb IP joint extension. Wrist extension is preserved or only minimally weakened (due to preserved extensor carpi radialis longus/brevis, which are innervated proximally to the PIN). Sensation is typically spared, as PIN is purely motor. Radial nerve injury at the spiral groove would also involve wrist drop. Median nerve injury affects thumb opposition and sensation. Ulnar nerve injury affects intrinsic hand muscles and sensation. AIN injury affects flexor pollicis longus, profundus to index/middle fingers, and pronator quadratus.

Question 49

Which of the following is the primary deforming force that causes varus angulation and apex anterior displacement in a midshaft clavicle fracture?





Explanation

In a midshaft clavicle fracture, the weight of the arm (unsupported by the clavicle) and the pull of the deltoid muscle (which originates from the clavicle and inserts onto the humerus) are the primary deforming forces that cause inferior (apex anterior, varus) displacement and shortening of the distal fragment. The sternocleidomastoid pulls the medial fragment superiorly. The pectoralis major and trapezius contribute to maintaining shoulder position but are not the primary cause of inferior displacement of the distal fragment. Biceps brachii is not directly involved in clavicle fracture displacement.

Question 50

What is the recommended treatment for a traumatic posterior dislocation of the hip in an otherwise healthy 30-year-old male with no associated fractures?





Explanation

Traumatic hip dislocations are orthopedic emergencies. The most crucial factor for preventing avascular necrosis (AVN) of the femoral head is prompt reduction. Emergent closed reduction should be attempted as soon as possible, ideally within 6 hours of injury. Delay in reduction significantly increases the risk of AVN. Open reduction is reserved for failed closed reduction or incarcerated fragments. Skeletal traction is not the primary treatment for acute dislocation without fracture. Delayed reduction or conservative management would lead to poor outcomes and high AVN rates.

Question 51

A 12-year-old female presents with pain and swelling over the medial aspect of her right foot, just distal to the navicular. A palpable prominence is noted, and radiographs show an accessory navicular bone. What is the most common cause of symptoms associated with an accessory navicular?





Explanation

An accessory navicular (os naviculare accessorium) is an extra bone on the medial side of the navicular. Symptoms, when present, are most commonly caused by inflammation or disruption of the synchondrosis (fibrocartilaginous joint) between the accessory navicular and the main navicular, particularly due to the pull of the posterior tibial tendon, which inserts into this region. Overuse or trauma can exacerbate this. It often presents during adolescence when ossification centers are active. Direct impingement, fracture, or nerve compression are less common causes of pain from this condition, and rupture of the posterior tibial tendon is a more severe, distinct pathology.

Question 52

Which of the following describes a typical radiographic appearance of Ewing sarcoma?





Explanation

Ewing sarcoma is classically associated with an 'onion skin' (lamellated) periosteal reaction on radiographs, which represents layers of new bone formation. This, along with a permeative or moth-eaten lytic pattern, indicates a highly aggressive tumor. While a soft tissue mass is often present, the 'sunburst' appearance is more characteristic of osteosarcoma. Geographic lytic lesions with a narrow zone of transition are seen in benign lesions. Ground-glass matrix with a shepherd's crook deformity is characteristic of fibrous dysplasia. Popcorn calcification is seen in enchondromas or chondrosarcomas.

Question 53

A 25-year-old runner presents with heel pain that is worse in the morning and after periods of rest, improving with activity. Examination reveals tenderness at the plantar fascial insertion on the medial calcaneal tuberosity. What is the most appropriate initial treatment?





Explanation

The patient's symptoms are classic for plantar fasciitis. The most appropriate initial treatment for plantar fasciitis is a conservative regimen that includes night splints (to keep the foot in dorsiflexion, stretching the fascia), plantar fascia stretching exercises, calf stretching, appropriate footwear, and activity modification. Corticosteroid injections provide short-term relief but can weaken the fascia. Surgical release is a last resort for refractory cases. Custom orthotics and ESWT are often considered after initial conservative measures fail. Initial management should focus on non-invasive therapies.

Question 54

What is the most common causative organism for septic arthritis in a healthy adult?





Explanation

Staphylococcus aureus is the most common causative organism for septic arthritis in healthy adults, accounting for over 80% of cases. Streptococcus pyogenes is also a significant pathogen but less common than S. aureus. Neisseria gonorrhoeae is a common cause in young, sexually active individuals but not the overall most common. E. coli and Pseudomonas aeruginosa are typically seen in immunocompromised patients, those with urinary tract infections, or intravenous drug users.

Question 55

Which factor is most predictive of persistent instability and the need for surgical stabilization in a patient with a Grade III acromioclavicular (AC) joint separation?





Explanation

In a Grade III AC joint separation (disruption of AC and coracoclavicular ligaments), the stability is primarily maintained by the deltoid and trapezius muscles. If the fascial attachments of the deltoid and trapezius muscles from the distal clavicle are also significantly disrupted, it can lead to more severe and persistent instability, often manifesting as a 'step-off' deformity and pain, increasing the likelihood of surgical intervention. Patient age, activity level, or associated injuries like coracoid fracture are important but the integrity of the muscle-fascial envelope is a key determinant of stability in Type III injuries and therefore the need for surgery. Grade III AC joint injuries are often managed non-operatively unless there is significant symptomatic instability or patient preference for reduction.

Question 56

Which of the following is considered an unstable pelvic ring injury according to the Young-Burgess classification?





Explanation

According to the Young-Burgess classification, Vertical Shear (VS) injuries are inherently unstable. They involve complete disruption of the posterior pelvic ring (sacroiliac joint or sacral fractures) and often the anterior ring as well, with vertical displacement. LC-I, APC-I, and APC-II are generally considered stable or rotationally unstable but vertically stable (APC-II has partial posterior disruption). LC-II involves posterior ligamentous disruption (sacrotuberous and sacrospinous ligaments) but the posterior arch may remain intact, making it rotationally unstable but not necessarily vertically unstable without further disruption.

Question 57

A 6-month-old infant presents with a 'clicky' hip on examination, but the Ortolani and Barlow tests are negative. Ultrasound reveals an alpha angle of 55 degrees and a beta angle of 65 degrees. What is the most appropriate next step in management?





Explanation

The Graf ultrasound classification for DDH uses alpha and beta angles. An alpha angle of 55 degrees (normal > 60 degrees) indicates a dysplastic acetabulum, and a beta angle of 65 degrees (normal < 55 degrees) indicates an unossified cartilaginous roof. This combination suggests a Graf Type IIa hip, which is considered 'immature' but not frankly dysplastic or dislocated in an infant under 3 months. However, for a 6-month-old, an alpha angle of 55 degrees is considered abnormal. Given the negative Ortolani/Barlow tests, and the age, this is likely a mild dysplasia. The most appropriate next step is observation with close follow-up and repeat ultrasound in 3 months. Intervention with a Pavlik harness is typically for dislocated or dislocatable hips (Graf types III/IV or IIc/IId/III/IV in older infants), or if the hip has not matured by 3 months. Open reduction is for failed conservative management. Double diapering is not an effective treatment. Spica cast is for older or more severe cases.

Question 58

What is the most effective method for differentiating between an infected and aseptic total joint arthroplasty failure?





Explanation

Synovial fluid aspiration for cell count, differential, and culture is considered the gold standard for differentiating between an infected and aseptic total joint arthroplasty failure (PJI). High synovial white blood cell (WBC) count (>3,000-10,000 cells/µL, varying by criteria), high polymorphonuclear leukocyte (PMN) percentage (>70-80%), and a positive culture are highly indicative of infection. While ESR and CRP are useful screening tools, they are not definitive. Plain radiographs show loosening but not the cause. Bone scans are non-specific. Histopathology is definitive but requires surgical biopsy, which isn't the first diagnostic step.

Question 59

Which of the following describes the 'safe zone' for anterior screw placement into the vertebral body during pedicle screw fixation of the lumbar spine?





Explanation

The 'safe zone' for pedicle screw placement typically involves directing the screw along the superior cortical border of the pedicle and aiming it toward the anterior two-thirds of the vertebral body. This trajectory helps ensure maximum purchase and minimizes the risk of neural (medial breach) or vascular (anterior breach) injury. Angulation should be medial, but the specific degree varies. Aiming for the center of the vertebral body on AP view is important, but the superior cortical border of the pedicle is the entry point reference. Parallel to the superior endplate ensures length but doesn't define the entire trajectory or safety.

Question 60

What is the typical characteristic finding on physical examination for a patient with a complete rupture of the pectoralis major tendon?





Explanation

A complete rupture of the pectoralis major tendon typically presents with an asymmetry of the anterior axillary fold (loss of contour on the affected side) and significant weakness in shoulder adduction and internal rotation. A 'Popeye' deformity is characteristic of a biceps brachii rupture. Loss of external rotation is more common with rotator cuff injuries. Inability to abduct past 90 degrees points to rotator cuff or deltoid dysfunction. Deltoid atrophy suggests axillary nerve injury. Therefore, the combination of a visibly flattened axillary fold and functional weakness in its primary actions are key indicators of a pectoralis major rupture.

Question 61

Which of the following is the most common benign bone tumor?





Explanation

Osteochondroma (exostosis) is the most common benign bone tumor. It is a cartilage-capped bony projection on the external surface of bone, arising from the metaphysis of long bones, typically around the knee. Non-ossifying fibroma (fibrous cortical defect) is also very common but often an incidental finding and a developmental anomaly rather than a true neoplasm. Enchondroma and osteoid osteoma are common but less so than osteochondroma. Giant cell tumor is locally aggressive but less common than osteochondroma.

Question 62

A 68-year-old female undergoes cemented total hip arthroplasty. Intraoperatively, during reaming of the acetabulum, she develops hypotension, hypoxia, and a sudden drop in end-tidal CO2. What is the most likely cause of these acute physiological changes?





Explanation

The described intraoperative triad of hypotension, hypoxia, and a sudden drop in end-tidal CO2 during total hip arthroplasty, especially during reaming or cementing, is highly suggestive of Fat Embolism Syndrome (FES). Bone marrow fat emboli can enter the circulation, leading to pulmonary and systemic effects. While a pulmonary embolism could cause similar symptoms, the acute onset during specific surgical maneuvers points more to FES. Anaphylaxis would typically involve rash, bronchospasm, and more severe cardiovascular collapse. Periprosthetic fracture is a mechanical complication, not a systemic physiological event. Cardiac arrest is the end result, not the primary cause of these specific changes.

Question 63

What is the most critical anatomical structure to preserve during surgical repair of a mallet finger?





Explanation

During surgical repair of a mallet finger, which involves rupture or avulsion of the extensor tendon at the distal interphalangeal (DIP) joint, it is absolutely critical to preserve the germinal matrix of the nail. The germinal matrix is responsible for nail growth. Damage to this structure can result in permanent nail deformity, which is a significant functional and cosmetic complication. The flexor tendons are on the opposite side. The central slip is involved in PIP extension. The extensor digitorum communis is the tendon that ruptures, but its overall preservation is not as critical as the germinal matrix for post-op function and appearance.

Question 64

A 4-year-old child presents with a high fever, refusal to bear weight, and exquisite pain on passive range of motion of the right hip. Laboratory tests show elevated white blood cell count, ESR, and CRP. Plain radiographs of the hip are normal. What is the most appropriate immediate diagnostic and therapeutic step?





Explanation

The clinical presentation (fever, refusal to bear weight, exquisite pain on passive hip ROM, elevated inflammatory markers, normal radiographs) is highly suggestive of septic arthritis of the hip, an orthopedic emergency in children. The most appropriate immediate step is to aspirate the hip joint. This allows for definitive diagnosis (cell count, Gram stain, culture) and therapeutic decompression of the joint. Delay in diagnosis and treatment can lead to rapid cartilage destruction and long-term joint damage. Oral antibiotics are inadequate. MRI and CT can confirm effusions but aspiration is critical for diagnosis and treatment. NSAIDs and bed rest are for transient synovitis, which has lower inflammatory markers and less severe pain on ROM.

Question 65

Which biomechanical principle explains the benefit of using an intramedullary nail over a plate for load-sharing in diaphyseal long bone fractures?





Explanation

Intramedullary nails are considered load-sharing devices because they are placed within the medullary canal, closer to the mechanical axis of the bone. This allows the bone to continue to bear a significant portion of the physiological load, which promotes secondary bone healing (callus formation). Plates, on the other hand, are typically load-bearing (load-sparing), carrying most of the load themselves, which can lead to stress shielding of the underlying bone and potentially delayed healing. The tension band principle is specific to certain fracture types. Wolff's Law describes bone remodeling. Strain hardening is a material property. Stress shielding is a consequence of load-bearing implants.

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Dr. Mohammed Hutaif
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