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Iran Orthopedic Surgery Board Exam study materials
Iran Orthopedic Surgery Board Exam study resources

Iran Orthopedic Surgery Board Exam practice questions

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Question 1Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

During a posterior approach to the hip for hemiarthroplasty, which structure lies immediately deep to the gluteus maximus and is at risk when the surgeon splits the muscle fibers bluntly?

  1. The superior gluteal artery
  2. The lateral femoral cutaneous nerve
  3. The sciatic nerve Correct answer.
  4. The obturator internus tendon

Explanation

The sciatic nerve emerges from the greater sciatic foramen beneath the piriformis and runs deep to gluteus maximus, so blunt splitting of that muscle can injure it. Careful splitting parallel to the fibers and protection of the nerve are standard steps in the posterior approach.

Question 2Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A 24-year-old man has a radial nerve palsy with wrist drop after a midshaft humerus fracture. Which motor deficit most specifically localizes the lesion to the radial nerve proper rather than to a more proximal brachial plexus element?

  1. Loss of finger extension at the metacarpophalangeal joints Correct answer.
  2. Loss of shoulder abduction
  3. Loss of elbow flexion
  4. Loss of thumb opposition

Explanation

The radial nerve supplies the extensor compartment of the forearm, so finger extension at the metacarpophalangeal joints fails in a radial nerve lesion. Shoulder abduction and elbow flexion are supplied by the axillary and musculocutaneous nerves, which arise proximal to the radial nerve.

Question 3Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

In a normal knee, which structure provides the primary restraint to anterior translation of the tibia relative to the femur at 30 degrees of flexion?

  1. The anterior cruciate ligament Correct answer.
  2. The lateral collateral ligament
  3. The posterior cruciate ligament
  4. The medial collateral ligament

Explanation

The anterior cruciate ligament is the primary restraint to anterior tibial translation, and its contribution is greatest near 30 degrees of flexion, which is why the Lachman test is sensitive. The collateral ligaments resist varus and valgus loads rather than sagittal translation.

Question 4Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

Which cell type is primarily responsible for resorbing bone matrix during normal remodeling and in periprosthetic osteolysis?

  1. Osteoblast
  2. Osteocyte
  3. Osteoclast Correct answer.
  4. Chondrocyte

Explanation

Osteoclasts are multinucleated cells of hematopoietic origin that acidify and dissolve mineralized bone matrix. Wear-particle debris stimulates macrophage-mediated osteoclast activation, producing the periprosthetic bone loss seen around loose implants.

Question 5Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A patient with a closed tibial fracture develops gas gangrene 3 days after injury. Which organism is the most likely cause?

  1. Staphylococcus aureus
  2. Clostridium perfringens Correct answer.
  3. Pseudomonas aeruginosa
  4. Neisseria gonorrhoeae

Explanation

Gas gangrene is a necrotizing clostridial myonecrosis, most often caused by Clostridium perfringens, an anaerobic spore-former that produces alpha-toxin and gas. Deep, devitalized, poorly oxygenated wounds favor its growth.

Question 6Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

Which pharmacologic agent inhibits osteoclast function by binding to RANKL and is used to reduce fracture risk in postmenopausal osteoporosis?

  1. Raloxifene
  2. Alendronate
  3. Teriparatide
  4. Denosumab Correct answer.

Explanation

Denosumab is a human monoclonal antibody that binds RANKL and prevents its interaction with RANK on osteoclast precursors, suppressing osteoclast formation and activity. This mechanism is distinct from bisphosphonates, which act directly on mature osteoclasts.

Question 7Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

Which type of collagen predominates in the fibrillar network of hyaline articular cartilage and provides its tensile strength?

  1. Type I
  2. Type IV
  3. Type II Correct answer.
  4. Type III

Explanation

Hyaline cartilage matrix is composed mainly of type II collagen, which forms a fibrillar network interlocking with aggrecan proteoglycans. Type I dominates bone and tendon, type III is found in skin and vessel walls, and type IV is in basement membrane.

Question 8Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A 62-year-old woman has a distal radius fracture with dorsal angulation and dorsal displacement of the distal fragment. Which deforming force most directly explains this displacement pattern?

  1. Direct blow to the volar forearm
  2. Traction along the forearm axis
  3. Axial loading of the extended wrist with the hand fixed Correct answer.
  4. Forced wrist flexion with the palm loaded

Explanation

A fall on the outstretched extended wrist produces a Colles-type fracture in which the distal fragment displaces dorsally and angulates dorsally. The mechanism is axial compression through the extended wrist, not volar loading.

Question 9Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

In a patient with a complete median nerve laceration at the wrist, which finding is expected on examination?

  1. Inability to oppose the thumb with thenar wasting Correct answer.
  2. Inability to abduct the shoulder
  3. Loss of sensation over the lateral forearm
  4. Inability to extend the wrist

Explanation

The recurrent motor branch of the median nerve supplies the thenar muscles, including opponens pollicis, so opposition fails and thenar atrophy develops. Sensation is lost over the radial three and a half digits on the palmar surface.

Question 10Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A young athlete reports recurrent giving way of the shoulder with the arm abducted and externally rotated. Which lesion pattern best explains apprehension in this position?

  1. Detachment of the anteroinferior labrum from the glenoid rim Correct answer.
  2. Rupture of the coracohumeral ligament alone
  3. Degeneration of the posterior labrum
  4. Tear of the superior labrum with biceps anchor avulsion

Explanation

Anterior shoulder instability in abduction and external rotation typically reflects a Bankart lesion, that is, detachment of the anteroinferior labrum and capsule from the glenoid. This position places the anterior capsulolabral complex under maximal tension.

Question 11Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

Which biomechanical property describes the region of a stress-strain curve where a ligament returns to its original length after load removal?

  1. The ultimate failure point
  2. The yield point
  3. The plastic region
  4. The elastic region Correct answer.

Explanation

In the elastic region, deformation is reversible and the tissue returns to resting length when load is removed. The slope of this region defines the stiffness of the ligament.

Question 12Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A patient with a healing femoral fracture is treated with a cephalosporin for a concurrent infection. Which process is most directly impaired if the patient is also given high-dose corticosteroids?

  1. Osteoclastic acid secretion
  2. Callus formation and osteoblastic bone synthesis Correct answer.
  3. Collagen cross-linking in mature scar
  4. Platelet aggregation at the fracture site

Explanation

Corticosteroids suppress osteoblast function and the inflammatory signaling required for callus formation, delaying fracture healing. Osteoclast activity and early platelet function are less directly inhibited by this mechanism.

Question 13Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A 30-year-old has a Monteggia fracture pattern. Which combination of injuries defines this lesion?

  1. Midshaft radial fracture with intact ulna
  2. Distal radial fracture with distal radioulnar joint dislocation
  3. Proximal ulnar fracture with radial head dislocation Correct answer.
  4. Distal humeral fracture with elbow dislocation

Explanation

A Monteggia fracture-dislocation consists of a fracture of the proximal third of the ulna with dislocation of the radial head. The Galeazzi pattern, by contrast, is a distal radial fracture with distal radioulnar joint disruption.

Question 14Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

Which structure is most at risk during a lateral approach to the fibula at the level of the fibular neck?

  1. The common peroneal nerve Correct answer.
  2. The femoral artery
  3. The saphenous nerve
  4. The tibial nerve

Explanation

The common peroneal nerve winds around the fibular neck superficially, so dissection in this region can injure it and produce a foot drop. The tibial nerve and femoral artery lie far from this site.

Question 15Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A synovial fluid sample from a native knee is sent for analysis. Which profile is most consistent with septic arthritis?

  1. Viscous fluid with a positive string sign
  2. White cell count above 50,000 per microliter with neutrophil predominance Correct answer.
  3. White cell count below 200 per microliter with mononuclear cells
  4. Fluid containing numerous monosodium urate crystals

Explanation

Septic synovial fluid is typically purulent with a very high white cell count, usually above 50,000 per microliter and often with more than 90 percent neutrophils. Low counts and high viscosity indicate a noninflammatory effusion.

Question 16Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A patient with chronic kidney disease and secondary hyperparathyroidism develops proximal muscle weakness and bone pain. Which laboratory pattern is expected?

  1. Normal parathyroid hormone with isolated hypocalcemia
  2. Suppressed parathyroid hormone with low alkaline phosphatase
  3. Elevated calcitonin with normal calcium
  4. Elevated parathyroid hormone with elevated alkaline phosphatase Correct answer.

Explanation

Secondary hyperparathyroidism from chronic kidney disease causes high parathyroid hormone levels and increased bone turnover, reflected by elevated alkaline phosphatase. The resulting renal osteodystrophy produces bone pain and proximal myopathy.

Question 17Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

Which antibiotic mechanism best explains the bactericidal action of vancomycin against methicillin-resistant Staphylococcus aureus?

  1. Inhibition of bacterial DNA gyrase
  2. Disruption of the bacterial cell membrane
  3. Inhibition of the 30S ribosomal subunit
  4. Inhibition of cell wall peptidoglycan cross-linking Correct answer.

Explanation

Vancomycin binds the D-alanyl-D-alanine terminus of peptidoglycan precursors and blocks transglycosylation and cross-linking, weakening the cell wall. Its action is independent of beta-lactamase production, which is why MRSA remains susceptible.

Question 18Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A tibial plateau fracture creates a step-off across the articular surface. Which local factor is the strongest determinant of subsequent post-traumatic osteoarthritis?

  1. Total duration of cast immobilization
  2. Choice of skin closure technique
  3. Incongruity of the articular surface and residual joint step-off Correct answer.
  4. Use of a tourniquet during surgery

Explanation

Articular incongruity and residual step-off alter contact stress distribution across the cartilage, and this mechanical factor drives post-traumatic degeneration. Anatomic reduction of the joint surface is therefore a primary surgical goal.

Question 19Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

During intramedullary nailing of the femur, which vascular structure is at greatest risk from a drill or reamer penetrating the posterior cortex proximally?

  1. The anterior tibial artery
  2. The popliteal vein at the knee
  3. The profunda femoris artery and its perforating branches Correct answer.
  4. The superficial femoral vein at the adductor canal

Explanation

The profunda femoris artery and its perforating branches lie close to the posterior cortex of the proximal femur and can be injured by reamers or screws. The popliteal vessels are at risk more distally near the knee.

Question 20Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

Which feature distinguishes the biology of a giant cell tumor of bone from that of an osteosarcoma on histologic review?

  1. Numerous multinucleated giant cells uniformly distributed among mononuclear stromal cells Correct answer.
  2. Direct formation of osteoid matrix by malignant cells
  3. Presence of a small round blue cell infiltrate
  4. Cartilage cap with atypical chondrocytes

Explanation

Giant cell tumor contains numerous osteoclast-like multinucleated giant cells evenly interspersed with mononuclear stromal cells, and the stromal cells are the neoplastic component. Osteosarcoma is defined by malignant cells producing osteoid matrix directly.

Question 21Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A patient with a closed femoral shaft fracture develops fat embolism syndrome. Which pathophysiologic sequence best accounts for the respiratory failure?

  1. Immune complex deposition in the glomeruli
  2. Fat droplets embolize to the pulmonary capillaries and release free fatty acids that injure the endothelium Correct answer.
  3. Acute left ventricular failure from myocardial infarction
  4. Direct bacterial seeding of the pulmonary alveoli

Explanation

Fat embolism syndrome follows marrow fat entering the venous circulation, lodging in pulmonary capillaries and releasing free fatty acids that cause endothelial injury and capillary leak. The result is hypoxemia with a petechial rash and neurologic change.

Question 22Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A researcher measures the compressive modulus of two cartilage samples and finds sample A has a much lower modulus than sample B at equilibrium. Which compositional difference most plausibly explains this finding?

  1. Lower proteoglycan content and reduced fixed charge density in sample A Correct answer.
  2. Greater water content with increased collagen cross-linking in sample A
  3. Higher type I collagen content in sample A
  4. Increased chondrocyte density in sample A

Explanation

Equilibrium compressive modulus depends largely on proteoglycan fixed charge density and the resulting osmotic swelling pressure. Loss of proteoglycans reduces that pressure and lowers the modulus, as in early cartilage degeneration.

Question 23Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

A patient has a supracondylar humeral fracture with a pulseless, pale hand and severe pain on passive finger extension. Which pathophysiologic process best explains the pain?

  1. Reflex sympathetic vasoconstriction of the digital arteries
  2. Elevated intracompartmental pressure compromising capillary perfusion and ischemic nerve stimulation Correct answer.
  3. Direct laceration of the median nerve by the fracture spike
  4. Venous thrombosis of the axillary vein

Explanation

Acute compartment syndrome raises tissue pressure above capillary perfusion pressure, producing ischemia and pain with passive stretch, the earliest reliable sign. Pulselessness and pallor are late findings and do not define the mechanism of pain.

Question 24Basic Sciences of the Musculoskeletal System (anatomy, biomechanics, physiology, pathology, microbiology, pharmacology)

In a biomechanical study of a locking plate used for a distal femoral fracture, the construct fails at the plate-screw interface. Which factor most increases stress concentration at that junction?

  1. Reducing the patient's weight-bearing status
  2. A large working length with a short plate span and a gap at the fracture Correct answer.
  3. Increasing the number of screws placed in the diaphysis
  4. Using a plate with a higher bending stiffness

Explanation

A short plate span combined with a fracture gap concentrates bending stress at the screw-plate junction and predisposes to fatigue failure. Longer plates that span the fracture with a more gradual stiffness transition distribute strain more favorably.

Question 25Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A 28-year-old motorcyclist arrives with a 90-minute history of an open tibial shaft fracture, systolic BP 85 mmHg, HR 130/min, and a cold, pulseless foot. According to damage-control orthopedics, which sequence of management is most appropriate?

  1. Angiography of the foot before any fracture stabilization
  2. Immediate intramedullary nailing of the tibia followed by fluid resuscitation
  3. Rapid hemorrhage control and resuscitation, temporary fracture stabilization, then staged definitive fixation Correct answer.
  4. Delayed debridement after 24 hours of observation for compartment syndrome

Explanation

Damage-control orthopedics prioritizes control of hemorrhage and physiologic restoration before definitive skeletal reconstruction. Temporary external fixation and rapid debridement of open fractures limit the second hit of surgery in an unstable patient. Definitive fixation is staged once the patient is resuscitated and normothermic.

Question 26Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

In the lethal triad of trauma physiology that drives damage-control decisions, which combination of derangements is described?

  1. Hypertension, hyperglycemia, and hyperthermia
  2. Hypernatremia, hypocalcemia, and thrombocytosis
  3. Hyperkalemia, alkalosis, and polycythemia
  4. Hypothermia, acidosis, and coagulopathy Correct answer.

Explanation

The lethal triad comprises hypothermia, metabolic acidosis, and coagulopathy, which reinforce one another in severely injured patients. Each component impairs clotting and perfusion, increasing mortality. Damage-control strategies aim to interrupt this cycle by limiting operative time and blood loss.

Question 27Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

Which clinical finding is the earliest and most reliable indicator of developing compartment syndrome in a conscious patient with a tibial shaft fracture?

  1. Pallor of the toes
  2. Absent distal pulses
  3. Radiographic widening of the fracture gap
  4. Disproportionate pain with passive stretch of the compartment muscles Correct answer.

Explanation

Pain out of proportion and pain on passive stretch are the earliest and most sensitive clinical signs of compartment syndrome. Pulselessness and pallor are late findings that indicate established ischemia. Diagnosis should not wait for loss of pulses.

Question 28Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A 45-year-old with a closed femoral shaft fracture and no other injuries has a compartment pressure of 32 mmHg in the thigh and a diastolic blood pressure of 70 mmHg. What is the compartment perfusion pressure (delta pressure)?

  1. 38 mmHg Correct answer.
  2. 32 mmHg
  3. 70 mmHg
  4. 102 mmHg

Explanation

Compartment perfusion pressure (delta pressure) equals diastolic blood pressure minus compartment pressure. Here 70 minus 32 equals 38 mmHg. A delta pressure below 30 mmHg is generally an indication for fasciotomy.

Question 29Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

In the ATLS primary survey of a polytrauma patient with a suspected pelvic ring disruption and hemodynamic instability, which initial measure is most appropriate?

  1. Immediate open reduction and internal fixation of the pubic symphysis
  2. Application of a pelvic binder at the level of the greater trochanters and initiation of blood transfusion Correct answer.
  3. Manual traction of the lower limbs to reduce the pelvis
  4. Immediate CT scan before any pelvic stabilization

Explanation

A pelvic binder applied at the greater trochanter level temporarily closes the pelvic volume and reduces hemorrhage. It is combined with activation of a massive transfusion protocol in the unstable patient. Definitive fixation and imaging follow physiologic stabilization.

Question 30Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

Which of the following is a classic radiographic sign of posterior shoulder dislocation on an anteroposterior view?

  1. Dinner fork deformity
  2. Light bulb sign Correct answer.
  3. Fat pad sign
  4. Tear drop angle

Explanation

The light bulb sign results from internal rotation of the humeral head in posterior dislocation, giving it a rounded appearance. A trough line or rim sign may also be seen. An axillary lateral view is essential to confirm the diagnosis.

Question 31Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A patient has a posterior hip dislocation. Which complication should be specifically monitored for in the first 24 to 48 hours after reduction?

  1. Avascular necrosis of the femoral head within 24 hours
  2. Compartment syndrome of the thigh
  3. Femoral artery rupture
  4. Sciatic nerve palsy Correct answer.

Explanation

Posterior hip dislocation can injure the sciatic nerve, and nerve function should be documented before and after reduction. Avascular necrosis is a later complication that develops over months. Early reduction within 6 hours reduces both risks.

Question 32Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

In an open fracture, which factor most strongly determines the urgency of surgical debridement?

  1. The fracture pattern on radiographs
  2. The patient's handedness
  3. The time elapsed since injury and adequacy of antibiotic prophylaxis Correct answer.
  4. The size of the skin wound

Explanation

The interval since injury and timely administration of antibiotics influence infection risk and guide the urgency of debridement. Wound size alone does not reliably predict contamination. Early intravenous antibiotics are the single most important early intervention.

Question 33Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

Which antibiotic regimen is standard initial prophylaxis for a Gustilo-Anderson type III open tibial fracture?

  1. Intravenous cefazolin plus an aminoglycoside, with penicillin added for soil or farm contamination Correct answer.
  2. No antibiotics until intraoperative cultures return
  3. Topical bacitracin only
  4. Oral amoxicillin alone

Explanation

Type III open fractures require broad-spectrum coverage with a first-generation cephalosporin plus gram-negative coverage such as an aminoglycoside. Penicillin is added when anaerobic contamination is suspected, such as farm injuries. Antibiotics should be given as soon as possible.

Question 34Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A 70-year-old woman sustains a distal radius fracture with dorsal comminution and dorsal angulation. Which eponym describes this injury pattern?

  1. Galeazzi fracture
  2. Colles fracture Correct answer.
  3. Barton fracture
  4. Smith fracture

Explanation

A Colles fracture is a distal radius fracture with dorsal displacement and angulation, often with dorsal comminution. A Smith fracture displaces volarly. Barton and Galeazzi fractures involve different articular and forearm patterns.

Question 35Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A patient has a both-bone forearm fracture in the proximal third with a dislocated radial head. What is the eponym for this injury?

  1. Essex-Lopresti injury
  2. Monteggia fracture-dislocation Correct answer.
  3. Galeazzi fracture-dislocation
  4. Nightstick fracture

Explanation

A Monteggia injury is a proximal ulnar fracture with dislocation of the radial head. The radial head dislocation must be recognized and reduced to restore forearm mechanics. Missed radial head dislocation leads to chronic pain and loss of rotation.

Question 36Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

Which finding on a pelvic radiograph suggests an unstable pelvic ring injury requiring urgent stabilization?

  1. Isolated pubic ramus fracture without displacement
  2. Widening of the pubic symphysis greater than 2.5 cm Correct answer.
  3. Degenerative changes of the sacroiliac joint
  4. Small avulsion of the anterior superior iliac spine

Explanation

Symphyseal widening beyond 2.5 cm indicates disruption of the anterior ring with likely posterior ligamentous injury and instability. Such injuries are associated with major hemorrhage. They require reduction and stabilization, often with a binder or external fixator initially.

Question 37Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

In a patient with an ipsilateral femoral neck and femoral shaft fracture, which principle guides surgical treatment?

  1. Treat only the shaft fracture because the neck fracture heals spontaneously
  2. Perform traction for six weeks before any surgery
  3. Fix both fractures, addressing the femoral neck with anatomic reduction and stable fixation Correct answer.
  4. Amputate if the patient is over 50 years old

Explanation

Ipsilateral femoral neck fractures are easily missed and can displace if untreated, risking avascular necrosis. Both injuries require fixation, with anatomic reduction of the neck prioritized. Dedicated imaging or CT is used to detect occult neck fractures.

Question 38Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

Which nerve is most commonly injured in a midshaft humeral fracture?

  1. Axillary nerve
  2. Median nerve
  3. Radial nerve Correct answer.
  4. Ulnar nerve

Explanation

The radial nerve runs in the spiral groove of the humerus and is the most frequently injured nerve in midshaft fractures. Injury presents with wrist drop and sensory loss over the dorsal first web space. Most closed injuries recover with observation.

Question 39Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A patient with a supracondylar humeral fracture has a pulseless, pale hand with severe pain. What is the most appropriate immediate management?

  1. Urgent reduction and stabilization, with vascular exploration if perfusion does not return Correct answer.
  2. Application of a cast in extension and discharge
  3. Observation with serial pulse checks
  4. Elective surgery in one week

Explanation

A dysvascular limb after supracondylar fracture often improves after prompt closed reduction, which relieves brachial artery kinking. If perfusion does not return, vascular exploration is required. Delay risks Volkmann ischemic contracture.

Question 40Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

Which of the following best describes the concept of 'damage-control resuscitation' in the polytrauma patient?

  1. Aggressive crystalloid loading to normalize blood pressure before surgery
  2. Immediate high-dose vasopressors to maintain systolic pressure above 120 mmHg
  3. Withholding transfusion until hemoglobin falls below 7 g/dL
  4. Balanced blood product transfusion with permissive hypotension and correction of coagulopathy Correct answer.

Explanation

Damage-control resuscitation emphasizes balanced transfusion of red cells, plasma, and platelets, limited crystalloid, permissive hypotension before hemorrhage control, and correction of hypothermia and acidosis. This approach reduces dilutional coagulopathy. It complements damage-control surgery.

Question 41Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A patient with a tibial plateau fracture develops a tense calf, pain with passive toe flexion, and a delta pressure of 22 mmHg. What is the definitive treatment?

  1. Aspiration of the hematoma
  2. Elevation and ice only
  3. Urgent four-compartment fasciotomy Correct answer.
  4. Compression bandaging

Explanation

A delta pressure below 30 mmHg with clinical signs indicates compartment syndrome requiring urgent fasciotomy. Release of all compartments prevents muscle and nerve necrosis. Delay leads to contracture and possible amputation.

Question 42Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

Which classification system is used to grade open fractures based on wound size, soft tissue injury, and contamination?

  1. Gustilo-Anderson classification Correct answer.
  2. Salter-Harris classification
  3. Schatzker classification
  4. Neer classification

Explanation

The Gustilo-Anderson system grades open fractures from type I to IIIC based on wound size, soft tissue damage, contamination, and vascular injury. Higher grades correlate with infection risk and guide antibiotic and surgical decisions. It is the standard for open fracture communication.

Question 43Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A patient with a displaced femoral neck fracture is being planned for surgery. Which factor most increases the risk of avascular necrosis of the femoral head?

  1. Initial fracture displacement and disruption of the medial femoral circumflex artery Correct answer.
  2. Use of a spinal anesthetic
  3. Delayed physical therapy
  4. Male sex

Explanation

The blood supply to the femoral head comes largely from the medial femoral circumflex artery via the lateral epiphyseal vessels. Greater displacement disrupts these vessels and raises avascular necrosis risk. Early reduction and stable fixation reduce but do not eliminate the risk.

Question 44Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

In a multiply injured patient, which parameter is commonly used to define the 'borderline' state in which early total care may be unsafe?

  1. Number of prior surgeries
  2. Base deficit and lactate reflecting the degree of shock Correct answer.
  3. Patient height
  4. Serum sodium level

Explanation

Base deficit and lactate quantify the magnitude of shock and predict tolerance of prolonged surgery. A large base deficit or elevated lactate identifies the borderline patient in whom damage-control surgery is preferred. Physiologic markers guide the timing of definitive fixation.

Question 45Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

Which is the recommended initial immobilization for a suspected unstable cervical spine injury during transport of a polytrauma patient?

  1. Soft foam collar only
  2. Rigid cervical collar with manual in-line stabilization and log-roll precautions Correct answer.
  3. Hyperextension of the neck to open the airway
  4. No immobilization to avoid pressure sores

Explanation

A rigid collar combined with manual in-line stabilization and log-roll precautions protects the spinal cord during transport and early care. Hyperextension or flexion can worsen an unstable injury. Spinal precautions are maintained until clinical and radiographic clearance.

Question 46Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A patient sustains a closed tibial shaft fracture treated with an intramedullary nail and develops worsening pain and swelling in the anterior compartment 12 hours postoperatively. Which action is most appropriate?

  1. Reassure the patient and continue analgesia
  2. Remove the nail immediately in the operating room
  3. Measure compartment pressures and proceed to fasciotomy if delta pressure is below 30 mmHg Correct answer.
  4. Apply a tighter cast for support

Explanation

Postoperative compartment syndrome must be suspected with disproportionate pain and swelling. Compartment pressure measurement with delta pressure guides the decision for fasciotomy. Nail removal is not the primary treatment and could destabilize the fracture.

Question 47Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

Which of the following best describes the role of temporary external fixation in damage-control orthopedics for a severe tibial pilon fracture?

  1. It eliminates the need for later surgery
  2. It spans the joint to maintain length and alignment while soft tissues recover before definitive fixation Correct answer.
  3. It replaces antibiotic therapy
  4. It provides definitive articular reconstruction

Explanation

Temporary spanning external fixation restores length and alignment and protects the soft tissue envelope in severe pilon fractures. Definitive articular reconstruction is staged after soft tissue recovery. This reduces wound complications and infection.

Question 48Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A patient with a scapular body fracture and a displaced clavicle fracture is found to have a flail chest and pulmonary contusion. Which principle guides the timing of operative fixation?

  1. Clavicle fixation is contraindicated in all chest trauma
  2. Surgery is optimized after pulmonary stabilization, with damage-control measures if physiology is poor Correct answer.
  3. Operative fixation should be performed immediately regardless of pulmonary status
  4. Only the scapula requires fixation

Explanation

Chest injury with pulmonary contusion increases operative risk, so timing should follow respiratory stabilization. In physiologically compromised patients, temporary measures and staged care are preferred. Coordinated multidisciplinary planning improves outcomes.

Question 49Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

Which of the following is the most appropriate first-line analgesic strategy in a hemodynamically stable polytrauma patient with multiple long bone fractures awaiting surgery?

  1. High-dose intramuscular nonsteroidal anti-inflammatory drugs alone
  2. Withholding analgesia until definitive fixation
  3. Multimodal analgesia including regional nerve blocks when feasible Correct answer.
  4. Long-acting oral opioids without monitoring

Explanation

Multimodal analgesia combining systemic agents with regional blocks improves pain control and reduces opioid requirements. Regional anesthesia can facilitate early mobilization and respiratory hygiene. Analgesia should not be withheld pending surgery.

Question 50Trauma and Fracture Management (including polytrauma and damage-control orthopedics)

A 34-year-old motorcyclist has a closed femoral shaft fracture and a contralateral open tibial shaft fracture. He is hemodynamically stable with a lactate of 1.8 mmol/L and no chest or head injury. Which treatment strategy best fits the principles of early appropriate care?

  1. Nailing of the femur only, with tibial fixation deferred until soft tissues settle
  2. Staged fixation with a 5-day interval between the two procedures
  3. Temporary external fixation of both fractures with delayed conversion at 2 weeks
  4. Definitive fixation of both fractures within the first 24 hours Correct answer.

Explanation

Early appropriate care permits definitive fixation within roughly 24 hours in physiologically stable patients with resuscitated physiology, since this reduces pulmonary complications, length of stay, and late sepsis without increasing mortality. The patient has no borderline physiology, so staged or temporizing strategies add morbidity without benefit.