Orthopedic Surgery Prometric exam questions with answers

1. Question 1Basic Science & Principles of Orthopedicseasy

   A displaced transverse forearm shaft fracture in an adult is treated with anatomical reduction and a compression plate, achieving absolute stability. How is this fracture expected to heal?

   1. AFibrous union that later converts to bone
   2. BSecondary healing through abundant external callus
   3. CPrimary (direct) bone healing with little or no external callus
   4. DEndochondral ossification through a cartilage callus
   Show answer and explanation▾

   Answer: C. Primary (direct) bone healing with little or no external callus

   With anatomical reduction, interfragmentary compression and absolute stability, strain at the fracture is very low and healing occurs by direct cutting-cone remodelling across the fracture (primary healing) without visible callus. Secondary healing with callus formation through an endochondral cartilage phase occurs under relative stability, such as casting, nailing or bridge plating. Fibrous union is a failure of healing, not an expected pathway.

2. Question 2Orthopedic Trauma - Adult Fractures, Dislocations & Polytraumamedium

   A 32-year-old man is 8 hours after intramedullary nailing of a tibial shaft fracture. He has escalating pain despite opioids and pain on passive toe extension. His blood pressure is 120/70 mmHg and the anterior compartment pressure is 48 mmHg. What is the most appropriate management?

   1. AEmergency four-compartment fasciotomy through two incisions
   2. BElevate the leg well above heart level and remeasure in 2 hours
   3. CSingle-incision release of the anterior compartment only
   4. DWait for loss of the dorsalis pedis pulse before intervening
   Show answer and explanation▾

   Answer: A. Emergency four-compartment fasciotomy through two incisions

   The clinical picture is supported by a perfusion pressure (diastolic minus compartment pressure) of 22 mmHg, below the accepted threshold of 30 mmHg, so urgent fasciotomy of all four compartments is required. Elevating the limb above the heart further reduces arterial inflow and should be avoided. Pulses are typically preserved until very late, and releasing only one compartment risks missing the deep posterior compartment.

3. Question 3Orthopedic Trauma - Adult Fractures, Dislocations & Polytraumahard

   A 34-year-old man sustains a displaced (Garden IV) intracapsular femoral neck fracture in a motorcycle crash. He has no other significant injuries. What is the most appropriate management?

   1. AUrgent anatomical reduction and internal fixation
   2. BDelayed fixation once soft tissue swelling settles
   3. CHemiarthroplasty
   4. DTotal hip arthroplasty
   Show answer and explanation▾

   Answer: A. Urgent anatomical reduction and internal fixation

   In young adults, preservation of the native femoral head is the priority, so displaced femoral neck fractures are treated with urgent anatomical reduction (open if needed) and stable internal fixation. Arthroplasty is the standard for displaced fractures in older, lower-demand patients but is avoided in the young because of lifetime revision burden. Delay is undesirable because the quality of reduction is the main modifiable factor for avascular necrosis and non-union.

4. Question 4Spinemedium

   A 41-year-old woman with known lumbar disc disease has 24 hours of bilateral sciatica, perineal numbness and new difficulty starting urination. Her post-void residual volume is 450 mL. What is the most appropriate next step?

   1. ALumbar epidural steroid injection
   2. BPhysiotherapy and analgesia with review in 6 weeks
   3. COutpatient MRI within 2 weeks
   4. DEmergency MRI of the lumbosacral spine with a view to urgent decompression
   Show answer and explanation▾

   Answer: D. Emergency MRI of the lumbosacral spine with a view to urgent decompression

   Bilateral radicular pain, saddle anaesthesia and urinary retention indicate cauda equina syndrome, which needs emergency MRI and, if confirmed, urgent surgical decompression to maximise recovery of bladder, bowel and sexual function. Outcomes are worse once complete retention is established, so any delay is harmful. Injections and physiotherapy are for uncomplicated radicular pain.

5. Question 5Adult Reconstruction - Arthritis & Arthroplastyhard

   Three weeks after an uncomplicated primary total knee arthroplasty, a 66-year-old woman has a red, hot, swollen knee with wound drainage. Aspiration shows a synovial white cell count of 45,000 cells/microlitre with 92% neutrophils and cultures grow methicillin-sensitive Staphylococcus aureus. Radiographs show well-fixed components. What is the most appropriate management?

   1. ATwo-stage revision with an antibiotic-loaded spacer
   2. BLong-term suppressive oral antibiotics without surgery
   3. CArthroscopic washout with retention of all components
   4. DDebridement, antibiotics and implant retention with exchange of modular components
   Show answer and explanation▾

   Answer: D. Debridement, antibiotics and implant retention with exchange of modular components

   An early postoperative infection within about 4 weeks of surgery, with well-fixed implants and a susceptible organism, can be treated by open debridement, antibiotics and implant retention (DAIR), exchanging the polyethylene insert, followed by biofilm-active antibiotics such as rifampicin combinations. Two-stage revision is for chronic infection or failed DAIR. Arthroscopic washout cannot achieve adequate debridement or allow modular exchange, and suppression alone is for patients unfit for surgery.

6. Question 6Adult Reconstruction - Arthritis & Arthroplastyeasy

   After total hip arthroplasty through a posterior approach, which combination of hip positions most increases the risk of dislocation?

   1. AExtension, adduction and internal rotation
   2. BFlexion, adduction and internal rotation
   3. CExtension, abduction and external rotation
   4. DFlexion, abduction and external rotation
   Show answer and explanation▾

   Answer: B. Flexion, adduction and internal rotation

   The posterior approach divides the short external rotators and posterior capsule, so the hip is most likely to dislocate posteriorly with flexion, adduction and internal rotation, as when rising from a low chair or crossing the legs. Extension with external rotation is the position of risk for anterior dislocation. Soft tissue repair of the posterior capsule and rotators reduces this risk.

7. Question 7Upper Limb - Shoulder, Elbow, Hand & Wristmedium

   A 22-year-old man falls on an outstretched hand. He has anatomical snuffbox tenderness, but four-view scaphoid radiographs are normal. What is the most appropriate next step?

   1. AReassure and discharge without follow-up
   2. BSplint the wrist and arrange MRI of the scaphoid
   3. CCast for 12 weeks without further imaging
   4. DMobilise freely and repeat radiographs in 2 weeks
   Show answer and explanation▾

   Answer: B. Splint the wrist and arrange MRI of the scaphoid

   Initial radiographs miss a significant proportion of scaphoid fractures, so a clinically suspected fracture should be immobilised and MRI arranged as the first-line further investigation, as recommended by NICE. Missing the fracture risks non-union and avascular necrosis of the proximal pole. Prolonged empirical casting without diagnosis unnecessarily immobilises the many patients who do not have a fracture.

8. Question 8Upper Limb - Shoulder, Elbow, Hand & Wristmedium

   A 35-year-old woman has a fracture of the proximal third of the ulna with an anterior dislocation of the radial head. She cannot extend her fingers at the metacarpophalangeal joints, but she can extend her wrist with radial deviation and sensation is intact. Which nerve is injured?

   1. AUlnar nerve at the cubital tunnel
   2. BRadial nerve proximal to the elbow
   3. CPosterior interosseous nerve
   4. DAnterior interosseous nerve
   Show answer and explanation▾

   Answer: C. Posterior interosseous nerve

   The posterior interosseous nerve winds around the radial neck and is at risk with anterior radial head dislocation in a Monteggia injury. Its palsy causes finger and thumb extension weakness with radial wrist deviation (extensor carpi radialis longus is spared) and no sensory loss. A radial nerve injury above the elbow would cause wrist drop and dorsal hand sensory loss, while the anterior interosseous nerve is a motor branch of the median nerve.

9. Question 9Foot & Anklemedium

   A 45-year-old woman has a Weber B fracture of the lateral malleolus. On the mortise view the medial clear space measures 7 mm, and there is medial tenderness and swelling. What is the most appropriate management?

   1. AWeight-bearing in a walking boot for 6 weeks
   2. BNon-weight-bearing cast without reduction for 6 weeks
   3. COpen reduction and internal fixation to restore the mortise
   4. DSyndesmotic screw fixation without fibular fixation
   Show answer and explanation▾

   Answer: C. Open reduction and internal fixation to restore the mortise

   A widened medial clear space (greater than about 4 to 5 mm) indicates deltoid ligament disruption with lateral talar shift, making this a bimalleolar-equivalent, unstable fracture that requires operative fixation to restore talar congruence. Isolated stable Weber B fractures with a normal medial clear space can be managed in a boot. Fixing the syndesmosis without restoring fibular length and alignment will not reduce the mortise.

10. Question 10Pediatric Orthopedicshard

    A 6-year-old has a Gartland type III extension supracondylar humerus fracture. The radial pulse is absent, but the hand is warm and pink with brisk capillary refill. What is the most appropriate management?

    1. AUrgent closed reduction and percutaneous pinning, then reassess perfusion
    2. BPreoperative angiography before any reduction
    3. CCollar and cuff with the elbow flexed beyond 120 degrees
    4. DBrachial artery exploration before reducing the fracture
    Show answer and explanation▾

    Answer: A. Urgent closed reduction and percutaneous pinning, then reassess perfusion

    In a displaced supracondylar fracture with a perfused but pulseless hand, the first step is urgent reduction and stabilisation, which often restores the pulse by relieving kinking or tethering of the brachial artery. If the hand remains pink after reduction, close observation is usually appropriate, whereas a white, poorly perfused hand after reduction requires exploration. Angiography delays treatment without changing management, and hyperflexion in a swollen elbow risks compartment syndrome.

11. Question 11Musculoskeletal Infectionmedium

    A 7-year-old refuses to bear weight on the right leg. Temperature is 39.0 C, ESR 52 mm/h and white cell count 15.6 x10^9/L. Ultrasound shows a hip effusion. What is the most appropriate next step?

    1. AOral ibuprofen and review in 48 hours for transient synovitis
    2. BUrgent hip aspiration and surgical drainage with intravenous antibiotics
    3. CIntravenous antibiotics alone without joint aspiration
    4. DOutpatient MRI of the pelvis next week
    Show answer and explanation▾

    Answer: B. Urgent hip aspiration and surgical drainage with intravenous antibiotics

    All four Kocher criteria (non-weight-bearing, fever above 38.5 C, ESR above 40 mm/h and white cell count above 12 x10^9/L) are present, giving a very high probability of septic arthritis. The hip requires urgent aspiration for culture and surgical washout, with intravenous antibiotics, to prevent destruction of the articular cartilage and femoral head. Treating as transient synovitis or giving antibiotics without drainage risks irreversible joint damage.

12. Question 12Musculoskeletal Oncologyhard

    A 64-year-old woman with metastatic breast cancer has a lytic lesion in the subtrochanteric femur involving more than two-thirds of the cortical diameter, with pain on weight-bearing. Using the Mirels scoring system, which management is indicated?

    1. AIntravenous bisphosphonate as the only treatment
    2. BProphylactic intramedullary fixation of the femur, followed by radiotherapy
    3. CRadiotherapy alone with protected weight-bearing
    4. DObservation with repeat radiographs in 6 weeks
    Show answer and explanation▾

    Answer: B. Prophylactic intramedullary fixation of the femur, followed by radiotherapy

    The lesion scores 3 for peritrochanteric site, 3 for functional pain, 3 for lytic appearance and 3 for involving more than two-thirds of the diameter, a total of 12; scores of 9 or more indicate a high fracture risk and prophylactic fixation is recommended. A long cephalomedullary nail protects the whole femur and postoperative radiotherapy improves local control. Radiotherapy alone is appropriate for lower scores, as bone strength falls further during treatment.

13. Question 13Metabolic Bone Disease & Systemic Skeletal Disordersmedium

    A 70-year-old woman who has taken alendronate for 8 years has 2 months of aching in the left thigh. Radiographs show focal lateral cortical thickening with a transverse lucent line in the femoral diaphysis. What is the most appropriate management of this femur?

    1. AProphylactic intramedullary nailing of the left femur
    2. BPlate fixation of the lateral femoral cortex
    3. CSwitch to risedronate and restrict activity
    4. DContinue alendronate with protected weight-bearing
    Show answer and explanation▾

    Answer: A. Prophylactic intramedullary nailing of the left femur

    A painful incomplete atypical femoral fracture with a visible transverse lucency has a high risk of completion, so prophylactic intramedullary nailing is recommended. The bisphosphonate should be stopped, not switched to another bisphosphonate, and the contralateral femur should be imaged because these fractures are often bilateral. Plate fixation is associated with higher failure in atypical fractures than nailing.

14. Question 14Perioperative Care, Rehabilitation & Complicationseasy

    Thirty-six hours after a closed femoral shaft fracture, a 21-year-old man becomes confused and hypoxaemic, with petechiae over the axillae and conjunctivae. What is the most likely diagnosis?

    1. AHospital-acquired pneumonia
    2. BPulmonary thromboembolism
    3. CAlcohol withdrawal delirium
    4. DFat embolism syndrome
    Show answer and explanation▾

    Answer: D. Fat embolism syndrome

    The triad of respiratory distress, neurological dysfunction and petechial rash 24 to 72 hours after a long-bone fracture is characteristic of fat embolism syndrome. Pulmonary embolism can cause hypoxaemia but not a petechial rash, and typically occurs later. Management is supportive, and early stabilisation of long-bone fractures reduces the risk.

15. Question 15Patient Safety, Professionalism, Ethics & Evidence-Based Practiceeasy

    A surgeon compares outcomes in 300 patients who received a new implant with matched historical controls from the department's records. What is the main limitation of this design compared with a randomised controlled trial?

    1. AIt cannot be analysed with standard statistical tests
    2. BIt always overestimates complication rates
    3. CConfounding and selection bias are not controlled by randomisation
    4. DIt cannot measure patient-reported outcomes
    Show answer and explanation▾

    Answer: C. Confounding and selection bias are not controlled by randomisation

    Randomisation balances known and unknown confounders between groups, whereas historical controls differ in time period, case selection, surgical technique and perioperative care, so differences in outcome may not be due to the implant. Matching only addresses measured variables. Such studies can be analysed statistically and can include patient-reported outcomes, but their level of evidence is lower.

Last reviewed September 2026. Questions are original and written to the published exam blueprint; they are not taken from any real paper.