Question 1

A 19-year-old man is reviewed a few days after admission for a spontaneous, primary pneumothorax. He is a non-smoker who plays the trumpet for a local orchestra. He was treated with a chest drain and achieved full inflation of the lung. Which of the following should he strictly avoid for at least the next 6 months?

Explanation

Correct Answer: E- Scuba diving Explanation Scuba diving Scuba diving is not recommended after spontaneous pneumothorax. Advice suggests that, in those who do not dive professionally, who have not undergone a definitive procedure (i.e. bilateral pleurodesis), it should be avoided permanently if possible. Contact sports Contact sports is incorrect. In the absence of a rib fracture, contact sports could re-commence after 2 months. Flying in an aaeroplane Flying in an aeroplane is incorrect. Air travel is not recommended for 1 week after full resolution of a pneumothorax. Long-distance running Long-distance running is incorrect. In the absence of a rib fracture, running could re-commence after 2 months. Playing the trumpet Playing the trumpet is incorrect. Opinions suggest that playing brass instruments can re-start approximately 2 months after the pneumothorax.

Question 2

A 43-year-old woman is referred by her general practitioner with a productive cough and inspiratory crackles at the left base. Which one of the following is considered to be a core adverse prognostic factor under the CURB-65 criteria?

Explanation

Correct Answer: E- Serum urea 7.1 mmol/l Explanation Serum urea 7.1 mmol/l A urea >7 mmol/l is associated with an adverse prognosis and is a component of the CURB-65 scoring system. Core clinical adverse prognostic factors are summarised using the abbreviation CURB-65:

• Confusion (new onset) with a mini-mental test score of less than 8 •

Urea > 7.0 mmol/l • Respiratory rate > 30/min • Blood pressure – systolic < 90 mmHg or diastolic < 60 mmHg • 65 or older (age) If any of these core clinical features is present the patient is at increased risk of death and should not be sent home (British Thoracic Society Guidelines, December 2001) Bilateral changes on chest X-ray Bilateral changes on chest X-ray is incorrect. Although multilobar involvement can signify an adverse prognosis in pneumonia, it does not feature as part of the CURB-65 scoring system. Blood pressure 98/65 mmHg Blood pressure 98/65 mmHg is incorrect. Although and blood pressure is used as part of CURB-65 scoring, the value mentioned would not signify an adverse prognosis. Oxygen saturation 92% on room air Oxygen saturation 92% on room air is incorrect.

Although hypoxia can both signify an adverse prognosis in pneumonia, it does not feature as part of the CURB-65 scoring system. Respiratory rate of 28/min Respiratory rate of 28/min is incorrect. Although respiratory rate is used as part of CURB-65 scoring, the value mentioned would not signify an adverse prognosis.

Question 3

What is the most common cause of haemoptysis in UK patients?

Explanation

Correct Answer: C- Infective exacerbation of COPD Explanation Infective exacerbation of COPD The most common cause of haemoptysis is acute infection, in exacerbation of COPD in particular. But other causes should be excluded while investigating. Bronchial carcinoma, pulmonary infarction and tuberculosis are common causes. Pulmonary haemosiderosis, Goodpasture’s syndrome, microscopic polyangiitis, and trauma are some of the rarer causes worth remembering. The Question: asks for the commonest cause of haemoptysis in the UK therefore infective exacerbation of COPD is the correct answer. Bronchial carcinoma Bronchial carcinoma is incorrect. This is not the “most” common cause of those given. Goodpasture’s syndrome Goodpasture’s syndrome is incorrect. This is not the “most” common cause of those given. Pulmonary infarction Pulmonary infarction is incorrect. This is not the “most” common cause of those given. Tuberculosis Tuberculosis is incorrect. This is not the “most” common cause of those given.

Question 4

A 42-year-old patient was diagnosed with mediastinal tuberculosis 3 weeks ago and commenced on treatment. He presents with worsening breathlessness and stridor. His chest X-ray shows mediastinal lymph nodes that are compressing the carina; although he is distressed, he is alert and orientated and maintaining his oxygenation. You give him an injection of hydrocortisone. What is the next step in the investigation and/or management?

Explanation

Correct Answer: E- Urgent computed tomography (CT) scan Explanation Urgent computed tomography (CT) scan The computed tomographic (CT) scan is the most appropriate investigation. On enhanced CT scans, nodes larger than 2 cm in diameter invariably show central areas of low attenuation and peripheral rim enhancement. Enhanced walls are usually irregular in thickness. CT scan is useful prior to commencing steroid therapy, first to confirm the degree of airway compression and second to assess the response to anti-tuberculous therapy. A number of commentators recommend rapid initiation of steroid therapy, and this would seem sensible prior to progression to CT scanning. Broad-spectrum antibiotics Broad-spectrum antibiotics is incorrect. This gentleman is already on antibiotic treatment for his tuberculosis and his current symptoms are a consequence of enlarged mediastinal nodes secondary to his tuberculosis. There is no need for additional antibiotics. Ethambutol Ethambutol is incorrect. As this gentleman started his antibiotic treatment for his tuberculosis 3 weeks ago he should already be taking ethambutol. Heparin Heparin is incorrect. Heparin would be an appropriate therapy for a pulmonary embolus. This gentleman’s dyspnoea has a clear explanation (extrinsic compression of carina) and so treatment for pulmonary embolus would be inappropriate. Tracheostomy Tracheostomy is incorrect. The gentleman is stated as being alert, orientated and maintaining his oxygenation, therefore there is time to proceed with further

investigation with CT scanning before deciding on definitive management.

Question 5

Which of the following relates to an exacerbation of chronic bronchitis in patients with chronic obstructive pulmonary disease?

Explanation

Correct Answer: D- Moraxella catarrhalis is commonly a cause of COPD exacerbation Explanation Moraxella catarrhalis is commonly a cause of COPD exacerbation Along with Haemophilus influenzae and Streptococcus pneumoniae, M. catarrhalis is a common cause of exacerbations of chronic bronchitis and pneumonia in patients with chronic obstructive pulmonary disease (COPD). Symptoms of moraxella infection tend to be mild to moderate in severity and it is quite common for the white cell count not to be raised. An elevated white cell count indicates exacerbation An elevated white cell count indicates exacerbation is incorrect. An elevated white cell count may be due to another cause, e.g. it may be secondary to oral steroid use. Additionally, white cell count may be normal in an exacerbation of COPD. Clinical symptoms are always severe Clinical symptoms are always severe is incorrect. Symptoms may be mild, moderate or severe. Gram staining is inconclusive and blood cultures are necessary Gram staining is inconclusive and blood cultures are necessary is incorrect. Blood cultures are not indicated unless the patient has a significant fever and/or is significantly unwell. Trimethoprim/sulfamethoxazole combinations are effective in the treatment of M. catarrhalis infection Trimethoprim/sulfamethoxazole combinations are effective in the treatment of M. catarrhalis infection is incorrect. Resistance to both trimethoprim/sulfamethoxazole combinations and tetracycline has been reported. The most appropriate choice would be a combination of ampicillin and clavulinic acid, which suppresses M. catarrhalis ß- lactamases.

Question 6

A 41-year-old woman presents to the Emergency Department with sudden onset of pleuritic chest pain and breathlessness. A chest X-ray reveals a large right-sided pneumothorax. Pleural aspiration fails to result in adequate re-expansion of the lung and you therefore insert an intercostal tube connected to an underwater seal. After 24 hours of intercostal drainage the lung has not re- expanded despite the fact that the drain is still swinging with respiration. What would you do next?

Explanation

Correct Answer: E- Wait another 24 hours Explanation Wait another 24 hours If pneumothorax fails to re-expand or if there is a persistent air leak (bubbling present) after 48 hours, then you should refer the patient to a respiratory specialist because negative suction might be required. The normal intrapleural pressure is -3.4 cm H2O during expiration, rising to -8 cm H2O during inspiration. High- volume/low-pressure suction should be considered if there is a persistent air leak and/or full lung re-expansion has not occurred approximately 48 hours following chest drain insertion. High-volume/low-pressure suction should be used High-volume/low-pressure suction should be used is incorrect. If high-volume/high-pressure suction is used, then high-airflow suction might be generated, which can lead to air stealing, hypoxaemia and/or the persistence of air leaks. Negative suction should be started at -1 to -2 cm H2O Negative suction should be started at -1 to -2 cm H2O is incorrect. Negative suction should be started at -10 to -20 cm H2O (-1 to -2 kPa = -7.5 to -15 mmHg) using a high- volume/low-pressure suction system. Refer for immediate surgical intervention Refer for immediate surgical intervention is incorrect. If appropriate suction fails to result in adequate re- expansion by 3–5 days then referral to a thoracic surgeon is indicated. Reposition the chest drain Reposition the chest drain is incorrect. The drain is still swinging with respiration, indicating it is still within the pleural cavity and therefore there is no need to reposition the drain at this stage.

Question 7

A 62-year-old man who is a current smoker has been followed up for breathlessness with productive cough. Five years ago his FEV1/FVC was 80%, but this ratio is now only 50%. Which of the following treatments would have the biggest clinical impact?

Explanation

Correct Answer: E- Smoking cessation Explanation Smoking cessation This man has severe chronic obstructive pulmonary disease (COPD) and has deteriorated significantly during the past 5 years. Currently the only interventions that have been proven to affect mortality are smoking cessation and long-term oxygen therapy (in patients who meet the prescription criteria). Inhaled anticholinergics Inhaled anticholinergics is incorrect. Inhaled long-acting anticholinergics and inhaled combination inhalers containing both a long-acting ß2-agonist and high-dose inhaled steroid have been shown to affect lung function positively. The TORCH study has also shown a positive effect on exacerbations with respect to the combination of LABA and inhaled corticosteroid. Inhaled steroids in isolation are not recommended to treat COPD. Inhaled steroids Inhaled steroids is incorrect. Inhaled long-acting anticholinergics and inhaled combination inhalers containing both a long-acting ß2-agonist and high-dose inhaled steroid have been shown to affect lung function positively. The TORCH study has also shown a positive effect on exacerbations with respect to the combination of LABA and inhaled corticosteroid. Inhaled steroids in isolation are not recommended to treat COPD. Salbutamol Salbutamol is incorrect. Salbutamol therapy may well help with symptomatic relief in COPD, but has no impact on survival. Short course of prednisolone Short course of prednisolone is incorrect. There is no evidence that this gentleman is experiencing an acute exacerbation of COPD that would benefit from oral steroids.

Question 8

A 46-year-old man with a history of asthma, well controlled with regular low-dose Seretide, presents with a cough productive of purulent, blood-stained sputum. On examination his temperature is 38.6 °C, pulse is 90/min and regular; there is a cluster of cold sores on his upper lip. Auscultation reveals left-sided consolidation. Which of the following causes of lower respiratory tract infection is most likely to be associated with herpes labialis?

Explanation

Correct Answer: D- Streptococcus pneumoniae Explanation Streptococcus pneumoniae Streptococcus pneumoniae is a common cause of community-acquired pneumonia and is characteristically associated with herpes labialis. In this case the majority of standard hospital protocols recommend dual therapy with a combination of co- amoxiclav and clarithromycin as the intervention of choice. Haemophilus influenzae Haemophilus influenzae is incorrect. Haemophilus influenzae is seen more frequently in patients with chronic obstructive pulmonary disease (COPD). Mycoplasma pneumoniae Mycoplasma pneumoniae is incorrect. Mycoplasma is a cause of atypical pneumonia. Staphylococcus aureus Staphylococcus aureus is incorrect. Staphylococcus aureus pneumonia is more likely to follow a viral respiratory tract infection such as influenza, and we are given no history of a prodromal viral illness here. Streptococcus pyogenes Streptococcus pyogenes is incorrect. Streptococcus pyogenes is most commonly associated with head and neck infections, eg pharyngitis, and skin and soft tissue infections, eg cellulitis.

Question 9

A 49-year-old homosexual accountant came to the clinic with increased breathlessness. He had begun to become wheezy after a tooth extraction procedure 5 months ago and also had an associated troublesome cough. He used to smoke 15 cigarettes per day but gave up smoking about 2 months ago. Salbutamol and beclometasone inhalers only poorly controlled his symptoms. Recently he had been unwell: he had had a fever and had lost about 3.2 kg (7 lb.) in weight. There was no history of recent foreign travel and no significant past illness. On examination, he had a temperature of 37.2 °C and occasional rhonchi on both sides. Tests showed:

haemoglobin 14.6 g/dl, white cell count 10.2 × 109/l (neutrophils 53%, lymphocytes 30%, raised esoinophils noted), ESR 110 mm in 1st hour; normal U&Es normal urine dipstick. A chest X-ray showed extensive symmetrical, homogenous shadowing affecting all the peripheral lung field. A skin test for inhaled antigens, including Aspergillus fumigatus, was negative. His serum IgE was normal. A serological screen for parasitic infection was negative. Pulmonary function was within normal limits. Oxygen saturations were 97% and there was no desaturation on exercise. What is the probable diagnosis?

Explanation

Correct Answer: B- Cryptogenic pulmonary eosinophilia Explanation Cryptogenic pulmonary eosinophilia This patient has eosinophilia and associated pulmonary signs, but no indications of drug involvement or malignancy. He has cryptogenic pulmonary eosinophilia. Systemic features can occur in this condition, including:

• malaise • weight loss • fever • raised ESR • asthma (in around 50%) The disease responds to steroid treatment, which needs to be continued for about 1 year. Asthma Asthma is incorrect. The lack of response to conventional therapies for asthma, normal total IgE, normal lung function together with the abnormal chest radiograph appearances make asthma unlikely. Granulomatosis with polyangiitis Granulomatosis with polyangiitis is incorrect. Granulomatosis with polyangiitis is not associated with wheeze and eosinophila. Pulmonary involvement is seen on chest radiograph as nodules, often cavitating in nature. There is no indication of extrapulmonary involvement such as nasal disease or renal disease to suggest vasculitis. Loeffler syndrome Loeffler syndrome is incorrect. Loeffler syndrome (transient respiratory illness with blood eosinophilia and pulmonary infiltrates) is self-limiting and lasts less than 1 month. Pneumocystis pneumonia Pneumocystis pneumonia is incorrect. The diagnosis in this case has no relation to the patient’s sexual orientation and Pneumocystis jiroveci infection secondary to HIV is unlikely. Pneumocystis jiroveci pneumonia is associated with central pulmonary infiltrates not peripheral infiltrates and is not associated with eosinophilia.

Question 10

You are asked to see a 32-year-old immigrant who complains of chronic cough and weight loss over the past few months. Examination of sputum reveals acid- and alcohol-fast bacilli (AAFB) and tuberculosis is confirmed. You elect to begin treatment with isoniazid, rifampicin, ethambutol and pyrazinamide as he is from an area where high levels of drug resistance are present. Which of the following blood tests is most desirable before starting therapy?

Explanation

Correct Answer: C- Liver function testing Explanation Liver function testing This is a ‘know it or you don’t’ question. Both isoniazid and rifampicin can be associated with significant hepatic dysfunction. In particular, severe and sometimes fatal hepatitis has been seen with isoniazid. Particular problems occur in slow acetylators, who can have markedly elevated serum isoniazid levels. In patients with existing liver dysfunction, rifampicin and isoniazid should only be used in cases of absolute clinical necessity. Even then, dose reduction of rifampicin is recommended and initial weekly monitoring of liver function tests should be carried out. Clotting screen Clotting screen is incorrect. Clotting screen is not as important as liver function testing in this instance. Haemoglobin Haemoglobin is incorrect. Haemoglobin testing is not as important as liver function testing in this patient. Platelet count Platelet count is incorrect. Platelet count is not as important as liver function testing in this patient. Serum calcium Serum calcium is incorrect. Serum calcium is not as important as liver function testing in this patient.

Question 11

A 35-year-old man presents with multiple small nodules on chest X-ray. Which of the following is the most likely diagnosis?

Explanation

Correct Answer: E- Sarcoidosis Explanation Sarcoidosis Sarcoidosis is graded on the appearance of bilateral hilar lymphadenopathy and/or pulmonary infiltrates, with the infiltrates referred to as ‘miliary reticulonodular’. There may be calcification of the hilar lymph nodes or lung parenchyma in chronic sarcoidosis. Bronchopulmonary aspergillosis Bronchopulmonary aspergillosis is incorrect. In bronchopulmonary aspergillosis, a cystic space containing a rounded opacity is seen on chest X-ray. An air space is seen between the fungus and the cavity wall (the ‘halo sign’) in aspergilloma. Granulomatosis with polyangitis Granulomatosis with polyangitis is incorrect. Granulomatosis with polyangitis might be seen as pulmonary infiltrates or multiple pulmonary nodules on chest X-ray, which tend to cavitate. Metastasis of renal carcinoma Metastasis of renal carcinoma is incorrect. Lung metastases from renal carcinoma are seen as solid masses; there may be several, but they are masses rather than nodules. Polyarteritis nodosa Polyarteritis nodosa is incorrect. Polyarteritis nodosua is a vasculitis affecting muscular arteries. It does not affect the lungs, although a related vasculitic disease, eosinophilic granulomatosis with polyangitis, does affect the lungs in the form of pulmonary infiltrates and asthma.

Question 12

A 36-year-old lorry driver who smokes heavily presents with a 2-day history of cough associated with fever. He also complains of right-sided chest pain on inspiration. On examination he is slightly cyanosed. His temperature is 38°C, respiratory rate 38/min, BP 100/70 mmHg and pulse 130 bpm. He has basal crepitations and dullness to percussion at the right lung base. What is the most important next step in confirming the diagnosis?

Explanation

Correct Answer: B- Chest X-ray Explanation Chest X-ray The classic presentation of pneumonia is with cough and fever, with or without sputum production, dyspnoea and pleurisy. Most patients have constitutional symptoms such as malaise, fatigue and asthenia, and many also have gastrointestinal symptoms. Examination of the lung might reveal decreased vesicular breath sounds, localised foci of crepitations, dullness to percussion and sometimes a bronchial wheeze. The chest X-ray is a pivotal test for the confirmation of pneumonia. Blood cultures Blood cultures is incorrect. Blood cultures will identify infection within the blood stream and may be suggestive of pneumonia if pneumococcus is cultured. However, blood cultures are not a diagnostic test for pneumonia. d-Dimer d- Dimer is incorrect. d-Dimer would be an inappropriate test here as the history is suggestive of pneumonia, not of pulmonary embolus.

ESR (erythrocyte sedimentation rate)

ESR (erythrocyte sedimentation rate) is incorrect. ESR is raised in a wide variety of inflammatory and infective conditions and is not a diagnostic test in itself. It is now rarely performed, other than when a diagnosis of temporal arteritis is suspected. Sputum sample Sputum sample is incorrect. A sputum sample will undoubtedly be helpful here but a sputum sample in isolation does not confirm a diagnosis of pneumonia, furthermore it may take several days before a result is available. Chest radiograph will give a more immediate result and reveal the diagnosis of pneumonia and is therefore the most appropriate answer here.

Question 13

A 45-year-old man who races pigeons becomes breathless. Which of the following features is suggestive of extrinsic allergic alveolitis (EAA)?

Explanation

Correct Answer: C- Circulating IgG precipitins Explanation Circulating IgG precipitins Circulating IgG precipitins are suggestive of EAA. Almost immediate onset of symptoms after exposure Almost immediate onset of symptoms after exposure is incorrect. EAA can be classified according to how acutely it presents. • In the acute form, fever, cough and marked shortness of breath occur 4–6 h after exposure • In the subacute form there is weight loss and fatigue • In the chronic form there is exertional shortness of breath and pulmonary fibrosis (typically upper lobe) The chest X-ray shows fine reticular or nodular shadowing, progressing eventually to a fibrotic pattern, with shrunken lungs. Eosinophilia of sputum Eosinophilia of sputum is incorrect. Despite its name, EAA is not allergic and therefore features associated with allergy and type I reactions do not tend to occur in EAA (ie wheeze, immediate symptoms, raised IgE, positive skinprick test, eosinophilia of blood or sputum). Positive skinprick testing Positive skinprick testing is incorrect. Despite its name, EAA is not allergic and therefore features associated with allergy and type I reactions do not tend to occur in EAA (ie wheeze, immediate symptoms, raised IgE, positive skinprick test, eosinophilia of blood or sputum). Type I hypersensitivity reaction Type I hypersensitivity reaction is incorrect. EAA is characterised by type III (immune-complex) and type IV (cell-mediated) hypersensitivity reactions to inhaled antigen(s).

Question 14

A 28-year-old Afro-Caribbean nurse develops painful nodules on the shins of her legs. She has a low-grade fever and has lost 5 kg in weight over the past 2 months. Her chest X-ray shows bilateral hilar lymphadenopathy. The most likely outcome of this patient’s illness is?

Explanation

Correct Answer: B- Complete remission without any specific treatment Explanation Complete remission without any specific treatment This lady has acute sarcoidosis. Spontaneous remission occurs in nearly two-thirds of patients with acute sarcoidosis. Complete initial remission but soon interrupted by increasingly frequent relapses Complete initial remission but soon interrupted by increasingly frequent relapses is incorrect. Stage 1 sarcoidosis (ie bilateral hilar lymphadenopathy on chest radiograph) is not usually associated with frequent relapses. At 5 years following initial diagnosis, 95% of patients previously diagnosed with stage 1 sarcoidosis will be asymptomatic. Complete remission after appropriate course of steroid and cytotoxic drugs Complete remission after appropriate course of steroid and cytotoxic drugs is incorrect. Spontaneous remission of acute sarcoidosis occurs in nearly two-thirds of patients. Diffuse reticulonodular changes in the lung and progressive shortness of breath Diffuse reticulonodular changes in the lung and progressive shortness of breath is incorrect. Acute sarcoidosis is characterised by erythema nodosum with X-ray findings of bilateral hilar adenopathy, often accompanied by joint symptoms, including arthritis at the ankles, knees, wrists or elbows. Diffuse reticulonodular changes in the lung and progressive shortness of breath would be expected in chronic sarcoidosis, which affects 10–30% of patients. Generalised lymphadenopathy and progressive wasting in 5–10 years Generalised lymphadenopathy and progressive wasting in 5–10 years is incorrect. These are not features of sarcoidosis.

Question 15

A 38-year-old woman is brought to the Emergency Department by her husband as she has taken to her bed over the past 48 h with a worsening cough productive of purulent, blood-stained sputum, fevers and shortness of breath, such that she is unable even to walk a few paces. She has no past medical history of note and her only medication is the oral contraceptive pill. Apparently she has been suffering from influenza for a few days before she took to her bed. On examination she is pyrexial 38.9 °C, her BP is 95/50 mmHg and she is tachycardic with a pulse of 105 bpm. There are signs of bilateral lower lobe consolidation. Investigations:

Hb 13.4 g/dl

WCC 17.2 × 109/l

PLT 203 × 109/l

Na+ 136 mmol/l

K+ 4.4 mmol/l

Creatinine 110 μmol/l

CXR Bilateral lower lobe consolidation with evidence of cavitation Which of the following is the most likely diagnosis?

Explanation

Correct Answer: D- Staphylococcus aureus Explanation Staphylococcus aureus Staphylococcus aureus leads to pneumonia with cavitation and is recognised to occur after initial influenza infection. In this case IV flucloxacillin would be an appropriate initial therapeutic option, with clarithromycin an alternative in patients who are penicillin allergic. There is increased risk of empyema formation after Staphylococcus aureus pneumonia, if it occurs then thoracic ultrasound with guided drainage may be required. Haemophilus influenzae Haemophilus influenzae is incorrect. The influenza mentioned in this case relates to the influenza virus, not the bacteria Haemophilus influenza. Haemophilus influenzae is a cause of community- acquired pneumonia, but it does not usually cause cavitation. The key clue to the infecting organism here is the history of influenza which is associated with Staphylococcus aureus pneumonia. Klebsiella pneumoniae Klebsiella pneumoniae is incorrect. Klebsiella pneumoniae can cause caviating pneumonia but usually affects the upper lobes and occurs in immunosuppressed individuals or, classically, alcoholics. Mycoplasma pneumoniae Mycoplasma pneumoniae is incorrect. Mycoplasma pneumoniae causes an atypical pneumonia, often with predominant symptoms being dry cough, headache and malaise. It does not cause cavitatory pneumonia. Streptococcus pneumoniae Streptococcus pneumoniae is incorrect. Streptococcus pneumonia is the most common cause of community- acquired pneumonia. It does not usually cause cavitation. It is not associated with preceding influenza infection. A history of a recent/current cold sore would be suggestive of S. pneumoniae pneumonia.

Question 16

A 52-year-old woman with chronic obstructive pulmonary disease is assessed for long-term oxygen therapy (LTOT). She is found to be suitable for LTOT. What is the minimum number of hours per day that she should be using the oxygen?

Explanation

Correct Answer: E-15 Explanation 15 In the early 1980s two large studies (MRC and NOTT) concluded that the minimum duration of long- term oxygen therapy (LTOT) should be 15 hours/day at a flow rate that keeps the arterial Po2 above 8.0 kPa (60 mmHg), and preferably up to 18 hours/day. At 3 years, survival was shown to be 50% better in the LTOT group compared with conventional treatment alone. Indications for LTOT:

Two arterial blood gas measurements should be made at least 3 weeks apart. Indications for LTOT in patients with chronic obstructive pulmonary disease are:

•

Pao2 on air < 7.3 kPa with a normal/elevated Paco2 and an FEV1< 1.5 l •

Pao2 7.3–8.0 kPa with evidence of cor pulmonale, peripheral oedema or nocturnal hypoxaemia 3 3 hours is incorrect. This does not reflect current recommendations. 55 hours is incorrect. This does not reflect current recommendations. 10hours is incorrect. This does not reflect current recommendations. 12 hours is incorrect. This does not reflect current recommendations.

Question 17

Which one of the following statements about sarcoidosis is true?

Explanation

Correct Answer: A- A positive tuberculin test in a patient with chronic sarcoidosis is suggestive of active tuberculosis Explanation A positive tuberculin test in a patient with chronic sarcoidosis is suggestive of active tuberculosis Sarcoidosis is a systemic disorder of unknown cause. Its pathological hallmark is the non-caseating granuloma, which primarily affects the respiratory tract, skin, eye, heart, kidneys and liver. A tuberculin test is usually negative in chronic sarcoidosis, but most patients with sarcoidosis who develop tuberculosis become tuberculin- positive. This is suggestive but not an absolute indicator of active infection. Clubbing of the fingers is an early feature Clubbing of the fingers is an early feature is incorrect. Clubbing of the fingers is not a recognised feature of sarcoidosis. Jaundice and portal hypertension are the predominant features of hepatic sarcoidosis Jaundice and portal hypertension are the predominant features of hepatic sarcoidosis is incorrect. Although liver biopsy reveals granulomatous involvement in 40– 70% of patients, clinically significant hepatic disease is rare. Parenchymal lung disease is often accompanied by pleural effusion Parenchymal lung disease is often accompanied by pleural effusion is incorrect. Pleural disease is relatively infrequent, with effusions occurring in fewer than 5% of patients. When hypercalcaemia manifests, it is usually resistant to steroid therapy When hypercalcaemia manifests, it is usually resistant to steroid therapy is incorrect. Hypercalcaemia, a potentially important complication of sarcoidosis, occurs in fewer than 10% of patients and is thought to be owing to elevated levels of 1,25-dihydroxyvitamin D (calcitriol), which is produced by macrophages within the granulomas. High-dose glucocorticoids are very helpful in vitamin D intoxication, granulomatous diseases such as sarcoidosis, and haematological malignancies known to be or likely to be glucocorticoid- responsive.

Question 18

A thin 24-year-old man complains of constant daytime sleepiness. He mentions involuntary naps, often in the middle of activity, which occur suddenly and without warning. He also caused an accident when he fell asleep while driving home from work. The patient works as an office manager and has no history of exposure to chemicals. Which of the following treatments would be indicated?

Explanation

Correct Answer: D- Modafinil Explanation Modafinil This patient has narcolepsy, which is a sleep disorder that causes hypersomnia and which usually starts in adolescence or young adulthood. Treatment involves the use of central nervous system stimulants such as modafinil to allow daytime functioning. Continuous positive airway pressure breathing device Continuous positive airway pressure (CPAP) breathing device is incorrect. CPAP breathing devices are used in the treatment of sleep apnoea. A typical patient with sleep apnoea is usually older and obese and there will be a long history of gradually worsening snoring with apnoeas, possibly witnessed by a partner (who will probably have moved out of the bedroom because of the noise). There is usually a history of fairly high alcohol intake and smoking. Diazepam Diazepam is incorrect. Diazepam, a benzodiazepine has a sedative effect and would exacerbate this patient’s symptoms. Fluoxetine Fluoxetine is incorrect. The selective serotonin reuptake inhibiting antidepressant fluoxetine is a potential cause of sleep disturbance (typically insomnia). It is not used in the treatment of sleep disorders. Nortriptyline Nortriptyline is incorrect. Nortiptyline is a treatment for insomnia. This patient has hypersomnia due to narcolepsy.

Question 19

A 64-year-old man is brought to the Emergency Department by his wife with drowsiness and confusion. He has a history of chronic obstructive pulmonary disease (COPD) and attends the Chest Clinic. He had been commenced on antibiotics by his GP 2 days earlier for an exacerbation of his COPD. Which of the following blood gases (on 2 l O2/min) fit best with this man’s condition?

Explanation

Correct Answer: B- pH 7.24, Paco2 9.3 kPa, Pao2 8.1 kPa, bicarbonate 29.2 mmol/ Explanation

pH 7.24, Paco2 9.3 kPa, Pao2 8.1 kPa, bicarbonate 29.2 mmol/l This is a ‘know it or you don’t’ question. This patient has acute on chronic respiratory acidosis. In respiratory acidosis there will be raised PaCO2 and hydrogen ion concentration. The elevation of the bicarbonate reflects renal buffering from his chronic respiratory failure. In acute respiratory acidosis every 1-kPa rise in CO2 produces 6 nmol/l of hydrogen ion and a 1-mmol/l increase in bicarbonate. In contrast, in chronic respiratory acidosis, the increase in hydrogen ions per kPa rise in carbon dioxide falls to about 2.5 nmol/l.

pH 7.14, Paco2 7.3 kPa, Pao2 9.1 kPa, bicarbonate 14 mmol/l

pH 7.14, Paco2 7.3 kPa, Pao2 9.1 kPa, bicarbonate 14 mmol/l is incorrect. These results would not be expected with this man’s clinical presentation.

pH 7.38, Paco2 5.3 kPa, Pao2 8.1 kPa, bicarbonate 30 mmol/l

pH 7.38, Paco2 5.3 kPa, Pao2 8.1 kPa, bicarbonate 30 mmol/l is incorrect. These results would not be expected with this man’s clinical presentation.

pH 7.38, Paco2 8.3 kPa, Pao2 8.1 kPa, bicarbonate 38 mmol/l

pH 7.38, Paco2 8.3 kPa, Pao2 8.1 kPa, bicarbonate 38 mmol/l is incorrect. These results would not be expected with this man’s clinical presentation.

pH 7.54, Paco2 3.3 kPa, Pao2 9.1 kPa, bicarbonate 24 mmol/l

pH 7.54, Paco2 3.3 kPa, Pao2 9.1 kPa, bicarbonate 24 mmol/l is incorrect. These results would not be expected with this man’s clinical presentation.

Question 20

A 64-year-old woman is referred to the medical team from the orthopaedic ward. She underwent a right total hip replacement 6 days ago. She is known to suffer from mild chronic obstructive pulmonary disease and is on regular inhaled steroids and a short-acting β2-agonist. She now complains of left-sided chest pain and is also dyspnoeic. Your clinical diagnosis is pulmonary embolism. Which one of the following would not be a feature of pulmonary embolism in this patient?

Explanation

Correct Answer: A- Bradycardia Explanation Bradycardia The clinical features of pulmonary embolism are:

• Dyspnoea • Tachypnoea (respiratory rate > 20/min) – the commonest feature, occurring in 85% of patients • Tachycardia – occurs in 30% of patients • Atrial flutter, atrial fibrillation and premature beats can also occur • Fever – a frequent finding, occurs in 34–50% of patients Dyspnoea Dyspnoea is incorrect. Dyspnoea is a feature of pulmonary embolism. Fever Fever is incorrect. Fever is a feature of pulmonary embolism. New-onset atrial fibrillation New-onset atrial fibrillation is incorrect. New-onset atrial fibrillation is a feature of pulmonary embolism. Tachypnoea Tachypnoea is incorrect. Tachypnoea is a feature of pulmonary embolism.

Question 21

A 35-year-old male sustains an anteroposterior compression (APC) pelvic ring injury. Radiographs demonstrate a 3.5 cm diastasis of the pubic symphysis. Which of the following ligamentous complexes remains intact in an APC-II injury but is disrupted in an APC-III injury?

Explanation

In an APC-II pelvic injury, the anterior sacroiliac, sacrotuberous, and sacrospinous ligaments are disrupted, but the posterior sacroiliac ligaments remain intact. Disruption of the thick posterior sacroiliac ligaments defines an APC-III injury, leading to complete spinopelvic instability.

Question 22

A 6-year-old boy presents with an extension-type supracondylar humerus fracture. Examination reveals an inability to flex the interphalangeal joint of the thumb and the distal interphalangeal joint of the index finger. Which nerve is most likely injured?

Explanation

The anterior interosseous nerve (AIN) is the most commonly injured nerve in extension-type pediatric supracondylar humerus fractures. It innervates the flexor pollicis longus and the flexor digitorum profundus to the index and middle fingers.

Question 23

A 28-year-old male presents with a slow-growing, painful mass near his knee joint. Biopsy reveals a biphasic spindle cell neoplasm. Which of the following chromosomal translocations is highly specific for this diagnosis?

Explanation

Synovial sarcoma is characterized by the t(X;18) chromosomal translocation, resulting in the SYT-SSX fusion gene. It commonly presents in young adults as a slow-growing mass near a large joint and is classically described as having a biphasic histology.

Question 24

In total hip arthroplasty, which of the following bearing surface combinations is associated with the lowest linear wear rate but carries a specific risk of audible squeaking and catastrophic component fracture?

Explanation

Ceramic-on-ceramic bearings offer the lowest wear rates in total hip arthroplasty, making them suitable for young, active patients. However, they are associated with unique complications including audible squeaking and catastrophic ceramic shattering.

Question 25

A 13-year-old obese boy undergoes in situ pinning for a stable, left-sided slipped capital femoral epiphysis (SCFE). Which of the following is the strongest indication for prophylactic pinning of the contralateral asymptomatic hip?

Explanation

Prophylactic pinning of the contralateral hip in SCFE is highly recommended in patients with endocrine disorders (e.g., hypothyroidism, renal osteodystrophy) due to a significantly higher risk of bilateral involvement. Age less than 10 years at presentation is another strong indication.

Question 26

A 24-year-old carpenter sustains a laceration to the volar aspect of his index finger, exactly at the level of the proximal interphalangeal (PIP) joint. Both the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) are severed. This injury occurs in which flexor tendon zone?

Explanation

Zone II extends from the proximal A1 pulley to the insertion of the FDS at the middle phalanx (often called "no man's land"). Lacerations here frequently involve both the FDS and FDP tendons and historically have poorer surgical outcomes due to adhesions.

Question 27

A 45-year-old farmer sustains a Grade IIIb open tibia fracture heavily contaminated with soil and farm debris. According to current guidelines, which of the following antibiotic regimens is most appropriate for initial emergency department management?

Explanation

In farm-related or heavily soil-contaminated open fractures, there is a high risk of Clostridium infection. The recommended regimen is a first-generation cephalosporin, an aminoglycoside for Gram-negative coverage, and high-dose penicillin to cover anaerobes.

Question 28

A 72-year-old woman presents with neck pain following a ground-level fall. Imaging reveals a fracture through the base of the dens. Which of the following factors is most strongly associated with nonunion if this is treated with a rigid cervical collar alone?

Explanation

Type II odontoid fractures (base of the dens) have a high nonunion rate. Risk factors for nonunion with conservative management include age > 50 years, initial displacement > 5 mm, and posterior displacement.

Question 29

A 65-year-old man presents with a chronic, massive, irreparable posterosuperior rotator cuff tear. He has severe external rotation weakness but an intact subscapularis. Which of the following tendon transfers is most appropriate to restore active external rotation?

Explanation

The latissimus dorsi tendon transfer is indicated for younger, active patients with irreparable posterosuperior rotator cuff tears and an intact subscapularis. It helps restore active external rotation and forward elevation.

Question 30

Which of the following physiological events represents the primary pathophysiologic mechanism initiating acute compartment syndrome in a traumatized extremity?

Explanation

Acute compartment syndrome begins when local tissue pressure exceeds venous pressure, leading to venous outflow obstruction. This creates a cycle of increasing hydrostatic pressure, further edema, and eventual capillary collapse causing muscle ischemia.

Question 31

When comparing a bone-patellar tendon-bone (BPTB) autograft to a quadrupled hamstring autograft for anterior cruciate ligament reconstruction, which of the following is a recognized characteristic of the BPTB graft?

Explanation

The BPTB autograft benefits from bone-to-bone healing in the osseous tunnels, typically completing incorporation by 6 weeks. Soft-tissue grafts like the quadrupled hamstring rely on slower Sharpey's fiber integration.

Question 32

A 22-year-old man falls onto an outstretched hand and sustains a displaced fracture through the proximal pole of the scaphoid. What is the primary anatomical reason this specific fracture pattern is at a high risk for avascular necrosis?

Explanation

The scaphoid is predominantly supplied by branches of the radial artery that enter the dorsal ridge near the distal pole and flow retrogradely to the proximal pole. Fractures at the proximal pole disrupt this precarious blood supply, leading to a high rate of avascular necrosis.

Question 33

A 14-year-old girl is diagnosed with high-grade intramedullary osteosarcoma of the distal femur. Following neoadjuvant chemotherapy, she undergoes wide surgical resection. Which of the following histologic findings in the resected specimen is the most important prognostic indicator of long-term survival?

Explanation

The histologic response to neoadjuvant chemotherapy is the single most important prognostic factor in classic osteosarcoma. A good response is defined as greater than 90% tumor necrosis in the resected specimen, which correlates strongly with improved overall survival.

Question 34

A 42-year-old male presents to the emergency department with severe lower back pain, bilateral sciatica, and new-onset urinary incontinence. Examination reveals perineal numbness. Which of the following is the most appropriate next step in management?

Explanation

This patient presents with classic signs of cauda equina syndrome, an orthopedic and neurosurgical emergency. The most appropriate immediate step is to obtain an emergent MRI of the lumbar spine to confirm the diagnosis and level of compression prior to urgent surgical decompression.

Question 35

Which of the following Bone Morphogenetic Proteins (BMPs) is an FDA-approved osteoinductive agent currently utilized as an alternative to autologous bone graft in single-level anterior lumbar interbody fusion (ALIF)?

Explanation

Recombinant human BMP-2 (rhBMP-2) is utilized in spine surgery as a potent osteoinductive agent and is FDA-approved for specific fusions like ALIF. BMP-3 actually inhibits osteogenesis, and BMP-7 (OP-1) was previously used for nonunions but has less commercial utilization today.

Question 36

During an open carpal tunnel release, the surgeon must avoid injury to the recurrent motor branch of the median nerve. According to the most common anatomical variant (extraligamentous configuration), how does this branch typically course in relation to the transverse carpal ligament?

Explanation

In the majority of individuals (46-90%), the recurrent motor branch of the median nerve is extraligamentous, arising distal to the transverse carpal ligament and curving back retrogradely to supply the thenar muscles. The transligamentous variant occurs in about 20% of people.

Question 37

A 35-year-old male presents with a pelvic ring injury after a motorcycle accident. Radiographs show symphyseal diastasis of 3.5 cm and widening of the anterior sacroiliac joints. He remains hypotensive despite 2 liters of crystalloid and pelvic binder placement. FAST scan is negative. What is the next best step in management?

Explanation

Hemodynamically unstable pelvic fractures with a negative FAST scan are highly suspicious for arterial bleeding. Pelvic angiography with embolization is the standard of care for identifying and stopping retroperitoneal arterial hemorrhage.

Question 38

A 25-year-old male sustains a C1 ring fracture. On the open-mouth odontoid view, the sum of the lateral mass overhang of C1 on C2 is 8 mm. Which of the following statements regarding his injury is most accurate?

Explanation

The Rule of Spence states that a combined C1 lateral mass overhang on C2 of greater than 6.9 mm indicates a rupture of the transverse alar ligament. This renders the C1 ring fracture unstable, necessitating rigid immobilization with a halo vest or surgical stabilization.

Question 39

An obese 13-year-old boy undergoes in-situ percutaneous pinning for a stable slipped capital femoral epiphysis (SCFE). Which of the following is the most common long-term complication associated with this condition?

Explanation

The most common long-term complication after in-situ pinning of a SCFE is cam-type femoroacetabular impingement (FAI) due to the residual prominent anterior metaphysis. Avascular necrosis is more commonly seen in unstable SCFE.

Question 40

A 22-year-old collegiate football player undergoes anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BPTB) autograft. Compared to hamstring autografts, which of the following is an expected advantage or characteristic of the BPTB graft?

Explanation

Bone-patellar tendon-bone (BPTB) autografts benefit from reliable bone-to-bone healing at the aperture sites, leading to faster graft incorporation. However, they carry a higher risk of anterior knee pain and patellar fracture compared to hamstring grafts.

Question 41

A 55-year-old woman presents with persistent groin pain and a palpable mass three years after a metal-on-metal total hip arthroplasty. Aspiration yields sterile, cloudy fluid. MRI demonstrates a large cystic periprosthetic collection. What is the most appropriate definitive management?

Explanation

The patient is experiencing an adverse local tissue reaction (ALTR) or pseudotumor associated with metal-on-metal bearings. The definitive management for a symptomatic, enlarging pseudotumor is revision arthroplasty to a different bearing surface.

Question 42

Which of the following fracture fixation constructs relies primarily on primary (intramembranous) bone healing without intermediate cartilage formation?

Explanation

Absolute stability achieved through interfragmentary compression (e.g., lag screw and plate) minimizes strain and promotes primary (intramembranous) bone healing without a callus. Techniques utilizing relative stability lead to secondary (endochondral) bone healing.

Question 43

A 30-year-old carpenter lacerates his index finger flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) tendons at the level of the proximal phalanx. This injury occurs in which flexor tendon zone, historically known as "no man's land"?

Explanation

Zone II extends from the proximal A1 pulley to the insertion of the FDS at the middle phalanx. It was historically called "no man's land" due to poor surgical outcomes secondary to adhesions between the FDP and FDS tendons within the tight fibro-osseous sheath.

Question 44

A 62-year-old patient with poorly controlled diabetes presents with a swollen, erythematous, and warm foot. Radiographs show fragmentation of the midfoot bones, joint subluxation, and periarticular debris. According to the Eichenholtz classification of Charcot arthropathy, which stage does this represent?

Explanation

Eichenholtz Stage I (Developmental/Fragmentation) is characterized clinically by a red, hot, swollen foot and radiographically by bone fragmentation, joint subluxation, and debris. Stage II involves coalescence, and Stage III involves reconstruction and remodeling.

Question 45

A 15-year-old boy is diagnosed with a conventional high-grade intramedullary osteosarcoma of the distal femur. He completes neoadjuvant chemotherapy and undergoes surgical resection. Pathological evaluation of the resected specimen reveals 95% tumor necrosis. What is the most significant prognostic indicator for this patient's long-term survival?

Explanation

The degree of tumor necrosis following neoadjuvant chemotherapy (specifically >90%) is the most significant prognostic factor for long-term survival in conventional osteosarcoma. This histological response predicts both local recurrence and overall survival.

Question 46

A 6-week-old female infant is diagnosed with developmental dysplasia of the hip (DDH). Ultrasound confirms a dislocated right hip that is reducible. She is prescribed a Pavlik harness. Which of the following nerve palsies is most commonly associated with excessive hip flexion in this device?

Explanation

Femoral nerve palsy is the most common nerve injury associated with the Pavlik harness and occurs when the hips are maintained in hyperflexion. This manifests as an inability to actively extend the knee, requiring harness adjustment.

Question 47

A 45-year-old male falls from a ladder and sustains a volar marginal articular fracture of the distal radius with volar displacement of the carpus. Which of the following eponyms best describes this injury?

Explanation

A volar Barton fracture is an intra-articular fracture of the distal radius with a displaced volar lip (marginal fracture) that carries the carpus volarly. A Smith fracture is an extra-articular distal radius fracture with volar displacement.

Question 48

When inserting a cortical screw, increasing the core diameter of the screw primarily affects which of its mechanical properties?

Explanation

The core diameter of a screw is the most critical factor determining its bending strength and fatigue resistance (proportional to the radius to the 4th power). Conversely, pullout strength is primarily determined by the outer diameter and thread depth.

Question 49

During a posterior-stabilized total knee arthroplasty, the surgeon notes that the knee is tight in flexion and well-balanced in extension. Which of the following intraoperative adjustments is most appropriate to balance the gaps?

Explanation

A knee that is tight in flexion but balanced in extension has an isolated tight flexion gap. Downsizing the femoral component (to a thinner AP dimension) or augmenting the posterior slope of the tibia will increase the flexion gap without affecting the extension gap.

Question 50

A 16-year-old gymnast presents with persistent lower back pain. Radiographs reveal an L5-S1 isthmic spondylolisthesis with 65% forward translation of L5 on S1. According to the Meyerding classification, what grade is this slip?

Explanation

The Meyerding classification grades spondylolisthesis based on the percentage of vertebral translation: Grade I (0-25%), Grade II (26-50%), Grade III (51-75%), Grade IV (76-100%), and Grade V (>100% or spondyloptosis). A 65% slip is Grade III.

Question 51

A 72-year-old man presents with chronic shoulder pain and pseudoparalysis. Radiographs show superior migration of the humeral head and acetabularization of the acromion. He has a functioning deltoid. What is the most appropriate surgical intervention?

Explanation

The patient has cuff tear arthropathy with pseudoparalysis but a functioning deltoid. Reverse total shoulder arthroplasty (RTSA) is the treatment of choice, as it medializes and distalizes the center of rotation, maximizing the moment arm of the deltoid.

Question 52

A 40-year-old secretary complains of numbness in her ring and small fingers, and weakness with pinch. Examination shows a positive Froment's sign. Which muscle is compensating for the weakened adductor pollicis during this test?

Explanation

Froment's sign indicates ulnar nerve palsy leading to weakness of the adductor pollicis. The patient compensates by using the flexor pollicis longus (innervated by the anterior interosseous nerve) to hyperflex the thumb interphalangeal joint during key pinch.

Question 53

A 28-year-old male sustains a closed tibia fracture and develops acute compartment syndrome. During a four-compartment fasciotomy via a two-incision technique, which nerve is at greatest risk of injury during the lateral incision?

Explanation

The lateral incision for a two-incision lower leg fasciotomy is typically placed between the anterior and lateral compartments. The superficial peroneal nerve is at high risk during this incision as it exits the deep fascia in the distal third of the leg.

Question 54

A 12-year-old boy presents with a painful mid-diaphyseal femur lesion with an "onion-skin" periosteal reaction. A biopsy is consistent with Ewing sarcoma. Which chromosomal translocation is most characteristically associated with this tumor?

Explanation

Ewing sarcoma is classically associated with the t(11;22)(q24;q12) translocation, which results in the EWS-FLI1 fusion gene. This molecular marker is highly sensitive and specific for tumors in the Ewing sarcoma family.

Question 55

In articular cartilage, which zone is characterized by the highest concentration of proteoglycans, the lowest water content, and chondrocytes arranged in vertical columns?

Explanation

The deep (radial) zone of articular cartilage contains the highest concentration of proteoglycans and the lowest water content. Its collagen fibers and chondrocytes are organized in vertical columns perpendicular to the articular surface to resist compressive loads.

Question 56

A 38-year-old male recreational tennis player presents with a suspected acute Achilles tendon rupture. Which clinical test is most sensitive and specific for diagnosing this injury?

Explanation

The Thompson (squeeze) test is performed by squeezing the calf muscle with the patient prone. An intact Achilles tendon results in plantarflexion of the foot; an absence of plantarflexion indicates a complete Achilles tendon rupture.

Question 57

A 35-year-old hemodynamically unstable male is brought to the trauma bay after a high-speed motor vehicle collision. Radiographs demonstrate an anteroposterior compression type III (APC-III) pelvic ring injury. Following application of a pelvic binder and initiation of a massive transfusion protocol, the patient remains hypotensive. A FAST exam is negative. What is the most appropriate next step in management?

Explanation

In hemodynamically unstable patients with pelvic ring injuries and a negative FAST, the source of bleeding is presumed to be the pelvis. Immediate mechanical stabilization followed by preperitoneal packing or angiography is critical to control venous and arterial hemorrhage.

Question 58

A 13-year-old obese male presents with a 3-week history of vague right knee pain and a limp. Physical examination reveals an antalgic gait and obligatory external rotation of the right hip during passive flexion. Which of the following is the most appropriate initial diagnostic imaging?

Explanation

The clinical presentation is highly suspicious for Slipped Capital Femoral Epiphysis (SCFE), which often presents with referred knee pain. AP and frog-leg lateral radiographs of the pelvis are the gold standard for initial diagnosis, allowing comparison of both hips.

Question 59

A 22-year-old female soccer player undergoes primary anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BTB) autograft. Which of the following is the most frequently reported complication specific to this graft choice compared to hamstring autograft?

Explanation

Anterior knee pain, especially with kneeling, is the most common specific morbidity associated with bone-patellar tendon-bone (BTB) harvest. Rerupture rates are historically slightly lower or equivalent to hamstring grafts, but donor site morbidity is higher.

Question 60

A 65-year-old female undergoes a right total hip arthroplasty via a posterior approach. On postoperative day 1, she exhibits a profound right foot drop and inability to dorsiflex her great toe. A compressive hematoma has been ruled out by urgent MRI. What is the most appropriate management?

Explanation

Sciatic nerve palsy (specifically the peroneal division) is a known complication of THA. In the absence of a compressive hematoma or obvious intraoperative transection, the management is observation and an AFO to prevent equinus contracture while awaiting recovery.

Question 61

A 28-year-old male is admitted with a closed midshaft tibia fracture. Six hours post-admission, he requires increasing doses of opioids and complains of excruciating pain with passive stretch of his toes. A compartment pressure measurement using a Stryker needle shows 45 mmHg. His diastolic blood pressure is 60 mmHg. What is the indicated treatment?

Explanation

The patient has signs of acute compartment syndrome, confirmed by a delta pressure (diastolic BP - compartment pressure) of less than 30 mmHg (60 - 45 = 15 mmHg). A four-compartment fasciotomy is the definitive and urgent surgical treatment.

Question 62

Following a primary repair of a Zone II flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) laceration, which of the following rehabilitation protocols is best supported by current evidence to maximize tendon excursion and minimize adhesions without risking rupture?

Explanation

Early active motion protocols (using a dorsal blocking splint to prevent hyperextension) are favored for Zone II flexor tendon repairs. They have been shown to significantly decrease tendon adhesions and improve functional outcomes compared to static immobilization.

Question 63

A 15-year-old male presents with distal femur pain. Plain radiographs show an aggressive, ill-defined lytic lesion in the metaphysis with a "sunburst" periosteal reaction and a Codman's triangle. After initial laboratory tests, what is the most appropriate next step in the local staging of this lesion?

Explanation

Before a biopsy is performed, local staging must be completed. MRI of the entire involved bone is required to evaluate the soft tissue extent, neurovascular involvement, and the presence of any intramedullary skip lesions.

Question 64

A 45-year-old male presents to the emergency department with a 24-hour history of severe lower back pain, bilateral leg weakness, and numbness in the perineal region. Bladder ultrasound reveals a post-void residual volume of 500 mL. What is the best initial step in management?

Explanation

The patient is presenting with classic signs of cauda equina syndrome, including saddle anesthesia and urinary retention. Urgent MRI of the lumbar spine is the gold standard diagnostic step prior to surgical decompression.

Question 65

A 4-month-old female infant is found to have asymmetric thigh skin folds and limited hip abduction on the left side. An ultrasound confirms a dislocated left hip with an alpha angle of 40 degrees. What is the standard first-line management?

Explanation

For Developmental Dysplasia of the Hip (DDH) in an infant under 6 months of age, the Pavlik harness is the primary standard of care. It maintains the hip in flexion and abduction to allow for natural remodeling of the acetabulum.

Question 66

A highly active 70-year-old female who plays tennis three times a week sustains a displaced femoral neck fracture (Garden IV) after a ground-level fall. She has no significant medical comorbidities. Which of the following surgical options offers the best long-term functional outcome and lowest revision rate for this patient?

Explanation

In an active, physiologically young, and independently ambulating older adult, Total Hip Arthroplasty (THA) is preferred for a displaced femoral neck fracture. It provides better functional outcomes and lower revision rates compared to hemiarthroplasty.

Question 67

A 25-year-old male falls onto an outstretched hand and complains of radial-sided wrist pain. On examination, he has distinct tenderness in the anatomic snuffbox. Initial AP, lateral, and scaphoid-view radiographs demonstrate no visible fracture. What is the most appropriate management plan?

Explanation

Occult scaphoid fractures can initially be invisible on plain radiographs. Standard practice for clinical snuffbox tenderness with negative x-rays is immobilization in a thumb spica splint with follow-up imaging (repeat x-rays in 10-14 days or prompt MRI).

Question 68

A 42-year-old male feels a "pop" in his lower calf while playing squash. He presents to the clinic with an inability to perform a single-leg heel raise. The Thompson test is positive. Which of the following best describes a positive Thompson test?

Explanation

The Thompson test evaluates the integrity of the Achilles tendon. A positive test occurs when squeezing the calf muscle fails to elicit passive plantar flexion of the ankle, indicating a complete rupture of the tendon.

Question 69

A 68-year-old male presents with severe knee pain and swelling two years after a primary total knee arthroplasty (TKA). Joint aspiration yields synovial fluid with a white blood cell count of 55,000 cells/mcL and 92% polymorphonuclear leukocytes (PMNs). What is the standard surgical management for this condition?

Explanation

This patient has a chronic periprosthetic joint infection. The gold standard treatment in North America for a chronic, late-onset periprosthetic infection is a two-stage revision arthroplasty utilizing an antibiotic spacer.

Question 70

When treating congenital talipes equinovarus (clubfoot) using the Ponseti method of serial casting, the deformities are corrected in a specific sequential order. Which component of the deformity is the last to be corrected, often requiring a percutaneous tenotomy?

Explanation

In the Ponseti method, the mnemonic CAVE dictates the order of correction: Cavus, Adductus, Varus, and finally Equinus. The equinus contracture frequently requires a percutaneous Achilles tenotomy for definitive correction.

Question 71

A 14-year-old female gymnast complains of mechanical lower back pain for 8 months that limits her sports participation. Lateral lumbar radiographs reveal a bilateral pars interarticularis defect at L5 with a 40% anterior translation of L5 on S1 (Grade II isthmic spondylolisthesis). She has failed 6 months of structured physical therapy. What is the most appropriate surgical treatment?

Explanation

For a symptomatic, low-grade (Grade I or II) isthmic spondylolisthesis in an adolescent who has failed conservative treatment, an L5-S1 in situ posterolateral arthrodesis is the surgical treatment of choice.

Question 72

A 32-year-old male sustains a diaphyseal fracture of the proximal third of the radial shaft. Following the fracture, the proximal fragment assumes a characteristic resting position. Which of the following describes the typical position of the proximal fragment and its primary deforming forces?

Explanation

In proximal-third radius fractures, the proximal fragment is acted upon by the supinator and the biceps brachii, leading to a flexed and supinated position. The distal fragment is pulled into pronation by the pronator teres and pronator quadratus.

Question 73

During open reduction and internal fixation of a transverse diaphyseal fracture, a surgeon applies a dynamic compression plate to achieve absolute stability and rigid fixation. Which mode of bone healing is primarily expected under these biomechanical conditions?

Explanation

Absolute stability (e.g., via compression plating) eliminates interfragmentary motion, leading to primary bone healing. This process occurs via cutting cones and direct Haversian remodeling without the formation of a visible fracture callus.

Question 74

An orthopedic surgeon is performing an open carpal tunnel release. If the longitudinal incision is erroneously extended too far distally beyond Kaplan's cardinal line, which of the following vascular structures is at the highest immediate risk of iatrogenic transection?

Explanation

The superficial palmar arch lies just distal to the transverse carpal ligament, roughly corresponding to the level of Kaplan's cardinal line. Extending a carpal tunnel release too far distally places this arterial arch at significant risk of transection.

Question 75

A 25-year-old male presents to the emergency department with a grossly contaminated, open middle-third humeral shaft fracture. Upon neurologic examination, he is unable to extend his wrist or fingers, and lacks sensation in the first dorsal web space. What is the most appropriate management plan regarding the fracture and nerve injury?

Explanation

While closed humeral shaft fractures with radial nerve palsies are typically observed, an open humeral shaft fracture is an absolute indication for surgical intervention. In the setting of an open fracture with a nerve palsy, simultaneous nerve exploration is indicated during the I&D and ORIF.

Question 76

A 24-year-old motorcyclist sustains an Anteroposterior Compression (APC) III pelvic ring injury. Disruption of which of the following ligamentous structures distinguishes an APC III injury from an APC II injury?

Explanation

An APC II injury involves disruption of the anterior sacroiliac, sacrotuberous, and sacrospinous ligaments. An APC III injury is characterized by the additional complete disruption of the posterior sacroiliac ligaments, leading to complete hemipelvic instability.

Question 77

In the treatment of a proximal pole scaphoid nonunion, vascularized bone grafting is being considered. The major blood supply to the scaphoid enters distally and is derived primarily from which of the following vessels?

Explanation

The scaphoid is predominantly supplied by the dorsal carpal branch of the radial artery, which enters the dorsal ridge distally. This retrograde blood supply puts the proximal pole at high risk for avascular necrosis following fracture.

Question 78

A 5-year-old boy presents with a completely displaced posteromedial Gartland type III supracondylar humerus fracture. Which of the following neurologic structures is most at risk with this specific displacement pattern?

Explanation

In a posteromedially displaced supracondylar fracture, the proximal fragment is displaced anterolaterally, putting the radial nerve at greatest risk. Posterolateral displacement places the median nerve and anterior interosseous nerve at highest risk.

Question 79

In aseptic loosening of a total hip arthroplasty, particulate wear debris initiates a macrophage-mediated inflammatory response. What is the critical final common pathway mediator directly responsible for osteoclast activation in this process?

Explanation

While macrophages release inflammatory cytokines like TNF-alpha and IL-1 in response to wear debris, RANKL is the essential final common pathway mediator. RANKL binds to RANK on osteoclast precursors, stimulating their differentiation and leading to osteolysis.

Question 80

A 45-year-old man presents with acute bilateral lower extremity radiculopathy, perianal numbness, and urinary retention following a heavy lifting injury. Which of the following is the most appropriate initial diagnostic imaging modality?

Explanation

This patient exhibits classic signs of cauda equina syndrome, a surgical emergency. An urgent MRI of the lumbar spine is the gold standard imaging modality to identify the level and extent of neural compression.

Question 81

A 15-year-old girl presents with knee pain and a mixed lytic-blastic lesion with a "sunburst" periosteal reaction in the distal femur. Biopsy confirms high-grade intramedullary osteosarcoma. What is the standard sequence of management?

Explanation

The standard of care for high-grade osteosarcoma involves neoadjuvant chemotherapy, followed by wide surgical resection (limb salvage or amputation), and subsequent adjuvant chemotherapy. This approach treats micrometastatic disease early and allows assessment of tumor necrosis.

Question 82

During an endoscopic anterior cruciate ligament (ACL) reconstruction, the surgeon places the femoral tunnel too anteriorly. What is the expected clinical consequence of this technical error?

Explanation

Placing the femoral tunnel too anteriorly (high in the notch) results in an ACL graft that is excessively tight in flexion and loose in extension. This can lead to a loss of full knee flexion and residual laxity in extension.

Question 83

A 30-year-old carpenter sustains a deep laceration to the volar aspect of his index finger precisely at the level of the A1 pulley, resulting in loss of active flexion. This injury corresponds to which flexor tendon zone?

Explanation

Zone II of the flexor tendon system, historically known as "no man's land", extends from the level of the A1 pulley to the insertion of the flexor digitorum superficialis. Injuries here are notoriously difficult to treat due to the tight fibro-osseous tunnel.

Orthopedic Prometric MCQs - Chapter 4 Part 1

Orthopedic Prometric MCQs - Chapter 4 Part 4

Orthopedic Prometric MCQs - Chapter 4 Part 4

Chapter Index