Question 1

Which one of the following statements about cystic fibrosis (CF) is true?

Explanation

Correct Answer: A- Allergic bronchopulmonary aspergillosis is a recognised complication, occurring in 15% of adult CF patients Explanation Allergic bronchopulmonary aspergillosis is a recognised complication, occurring in 15% of adult CF patients The increasing incidence of allergic bronchopulmonary aspergillosis (ABPA) is a recognised phenomenon. Allergic bronchopulmonary aspergillosis (ABPA) is encountered in 1 in 6 adult CF patients. Manifestations of ABPA include asthma symptoms, flitting opacities on the chest X-ray, increased eosinophil count, and hyper- reactivity to the skin prick test and increased specific plasma IgE. The main treatment is high-dose corticosteroids initially, with a smaller maintenance dose. The duration of treatment ranges from a few months to few years. Antifungal agents may be used to allow a reduction in corticosteroid dose. Heterozygotes generally have clinically significant disease Heterozygotes generally have clinically significant disease is incorrect. Different mutations responsible for cystic fibrosis across different racial subtypes are responsible for slightly differing patterns of disease, but drawing definitive correlations between genotype and disease severity is difficult. Neonatal screening for CF results in a better survival rate and reduced decline in lung function Neonatal screening for CF results in a better survival rate and reduced decline in lung function is incorrect. The most common mutation in patients with cystic fibrosis (CF) is the delta- F508 mutation. There is no correlation between genotype, the range of manifestations, the age of onset of symptoms and the survival rate in CF. However, neonatal screening allows the early implementation of prophylactic therapeutic measures. Prospective and retrospective studies have demonstrated that neonates detected by screening have a better nutritional status than those who were discovered by investigation of symptoms. The age of acquisition of Pseudomonas aeruginosa and the decline in lung function were found to be comparable in the two groups. Reduced body mass index is an absolute contraindication for heart-lung transplantation Reduced body mass index is an absolute contraindication for heart-lung transplantation is incorrect. Heart-lung transplantation is offered to patients who exhibit a rapid decline in lung function despite optimal treatment, and to patients with respiratory failure. Moderately reduced body mass index (BMI) is an indication for transplantation. A severe reduction in BMI is a relative contraindication to transplantation because it is associated with reduced survival but it is not an absolute contraindication. The controlled intake of high-calorie food is the first line of management for patients with CF-related diabetes The controlled intake of high-calorie food is the first line of management for patients with CF-related diabetes is incorrect. Diabetes is now seen in almost 10% of CF patients over the age of 20 years, the main manifestations being weight loss, repeated respiratory infections and decline in lung function. The treatment of choice is subcutaneous insulin therapy. Calorie intake should not be restricted in CF patients, who are prone to malnutrition due to their pancreatic insufficiency.

Question 2

A 24-year-old HIV-positive man with a CD4 lymphocyte count of 150 cells/mm3 has been complaining of gradually worsening dyspnoea associated with a non- productive cough and fever for the last 2 weeks. A chest X-ray shows bilateral diffuse ground-glass opacities. What is the diagnosis?

Explanation

Correct Answer: C- Pneumocystis jirovecii pneumonia Explanation Pneumocystis jirovecii pneumonia Pneumocystis jirovecii pneumonia (previously known as Pneumocystis carinii pneumonia (PCP)) typically presents with gradually increasing dyspnoea and cough over several weeks, but sometimes it presents as an acute illness with rapid deterioration over a few days. Cystic abnormalities and spontaneous pneumothoraces in patients with known or suspected HIV infection are usually caused by this pneumonia. In recognition of its genetic and functional distinctness, the organism that causes human PCP was renamed Pneumocystis jirovecii(Frenkel, 1999). Changing the organism’s name does not preclude the use of the acronym PCP. • Chest X-ray – usually shows diffuse ground-glass opacities, which strongly suggests the diagnosis. Sometimes, however, it shows nodular opacities or lobar consolidation, or can even be normal. • Lactate dehydrogenase – raised in approximately 90% of patients with Pneumocystis jirovecii pneumonia (but this can occur with other pulmonary diseases). • CD4 count – Pneumocystis jirovecii pneumonia is unlikely in a patient who has had a CD4 count above 200 cells/mm3 in the preceding 2 months in the absence of other HIV- associated symptoms. Infectious mononucleosis Infectious mononucleosis is incorrect. Infectious mononucleosis can mimic primary HIV infection with fever, sore throat and lymphadenopathy. However, it is not associated with pneumonia. Legionellosis Legionellosis is incorrect. The diagnosis of HIV coupled with low CD4 count should point the candidate towards an opportunistic infecting organism, and with the history of dry cough and diffuse ground-glass opacification, the description in this case is more fitting with P. jiroveciipneumonia than Legionella pneumonia. Toxoplasmosis Toxoplasmosis is incorrect. Toxoplasmosis is caused by infection with the toxoplasma parasite and is usually asymptomatic in healthy individuals. Individuals with HIV and a low CD4 count are at risk of symptomatic infection, which can be life threatening. It is classically associated with CNS infection in severe immunodeficiency with neurological symptoms dominating. Pulmonary involvement is not typical of toxoplasmosis. Tuberculosis Tuberculosis is incorrect. Tuberculosis is a reasonable differential here in an immunocompromised patient, but the radiograph appearances favour Pneumocystis jirovecii pneumonia.

Question 3

A 38-year-old man with a history of asthma presents with weakness of his right hand and of plantar flexion of his left foot. His asthma is managed with a salmeterol– fluticasone combination inhaler. On examination, his blood pressure is 152/91 mmHg and he has polyphonic wheeze on auscultation of the chest.

Investigations:

Hb 13.2 g/dl

WCC 8.2 x 109/l (raised eosinophils) PLT 180 x 109/l

Sodium 139 mmol/l

Potassium 4.3 mmol/l

Creatinine 149 µmol/l Urine dipstick testing showed blood + and protein +. Which of the following is the most appropriate autoantibody to test for?

Explanation

Correct Answer: E- Perinuclear anti-neutrophil cytoplasmic antibody (pANCA) Explanation Perinuclear anti-neutrophil cytoplasmic antibody (pANCA) About 70% of patients with eosinophilic granulomatosis with polyangiitis have a positive pANCA (perinuclear anti-neutrophil cytoplasmic antibody) result. Eosinophilic granulomatosis with polyangiitis presents with symptoms of asthma, and more than 7/10 patients also have mononeuritis multiplex. Renal involvement leads to haematuria and proteinuria, hypertension and raised creatinine. The raised eosinophil count here is also typical of eosinophilic granulomatosis with polyangiitis. Treatment consists of corticosteroids, with or without additional therapy with cyclophosphamide. Without treatment, the 5-year survival rate for eosinophilic granulomatosis with polyangiitis is around 25%; with appropriate therapy this rises to over 60%. Anti-double-stranded DNA (anti-dsDNA) antibodies Anti-double-stranded DNA (anti-dsDNA) antibodies is incorrect. Anti-dsDNA antibodies are strongly associated with a diagnosis of systemic lupus erythematosus. Antinuclear antibody (ANA) Antinuclear antibody (ANA) is incorrect. Positive ANA antibodies are associated with systemic lupus erythematosus, Sjögren’s syndrome, scleroderma, and may also be found in Raynaud’s disease, polymyositis, juvenile chronic arthritis, or antiphospholipid antibody syndrome. Anti-smooth muscle antibody Anti-smooth muscle antibody is incorrect. Positive anti- smooth muscle antibodies are associated with autoimmune hepatobiliary disease. Cytoplasmic anti-neutrophil cytoplasmic antibody (cANCA) Cytoplasmic anti-neutrophil cytoplasmic antibody (cANCA) is incorrect. Positive cANCA antibodies are classically associated with granulomatosis with polyangiitis.

Question 4

A 25-year-old patient with epilepsy aspirated gastric juice after a seizure (Mendelson syndrome). What is the most likely clinical symptom or sign?

Explanation

Correct Answer: B- Bronchospasm Explanation Bronchospasm Mendelson syndrome is an acute pneumonia caused by regurgitation of stomach contents and aspiration of chemical material, usually gastric juices. It can cause severe bronchospasm. The pneumonia develops rapidly, and within hours the patient can become tachypnoeic, hypoxic and febrile. There is minimal sputum. The condition often follows anaesthesia, when the gag reflex is depressed. Bradypnoea Bradypnoea is incorrect. Bradypnoea would not be the most likely result of aspiration of gastric juice. Laryngospasm Laryngospasm is incorrect. Laryngospasm would not be the most likely result of aspiration of gastric juice. Paradoxical breathing Paradoxical breathing is incorrect. Paradoxical breathing would not be the most likely result of aspiration of gastric juice. Tenderness to percussion Tenderness to percussion is incorrect. Tenderness to percussion would not be the most likely result of aspiration of gastric juice.

Question 5

Which one of the following conditions is most likely to be associated with obstructive spirometry and a normal

Tlco (transfer factor for carbon monoxide)?

Explanation

Correct Answer: A- Asthma Explanation Asthma Asthma is associated with airflow obstruction. Transfer factor is usually unaffected. The Tlco is sometimes increased in patients with bronchial asthma during an attack, but the cause of this change is not known. The other options are all incorrect. These conditions are all associated with a reduced transfer factor. The diffusion of carbon monoxide (CO) from the alveoli to the pulmonary blood is governed by the integrity of the alveolar membrane, the capillary blood volume, or both (the air–blood barrier). A reduction in the diffusion capacity of CO is encountered in conditions affecting the capillary bed size (eg pulmonary emboli, pulmonary vasculitis) or conditions that cause changes in the characteristics of the alveolar membrane, such as diseases in which some form of intra-alveolar filling process has occurred and the air–blood diffusion pathway is actually lengthened (eg pneumonia, pulmonary oedema, alveolar proteinosis). Similarly, the transfer factor for carbon monoxide (Tlco) is reduced in patients with infiltrative disorders of the lung that affect both the capillary bed size and the alveolar membrane integrity (eg sarcoidosis, interstitial lung diseases, collagen vascular diseases). Removal or destruction of lung tissue (eg post-surgery, emphysema) decreases both membrane and blood volume components and produces a low Tlco. An increase in Tlco results occasionally from an increase in capillary blood volume secondary to haemodynamic changes in the pulmonary circulation, an increase in pulmonary artrial or left atrial pressures (eg in congestive heart failure) or an increase in pulmonary blood flow (eg in artrial septal defect). Alveolar haemorrhage from any cause can result in a false increase of the Tlco despite the presence of an underlying diffusion defect. Emphysema Emphysema is incorrect. Emphysema is associated with a reduced transfer factor. Interstitial lung disease Interstitial lung disease is incorrect. Interstitial lung disease is associated with a reduced transfer factor. Pulmonary hypertension Pulmonary hypertension is incorrect. Pulmonary hypertension is associated with a reduced transfer factor. Sarcoidosis Sarcoidosis is incorrect. Sarcoidosis is associated with a reduced transfer factor.

Question 6

What are the NICE indications for home oxygen?

Explanation

Correct Answer: A- Cor pulmonale and low PO2 Explanation Cor pulmonale and low PO2 The National Institute for Health and Care Excellence (NICE) states that the following are indications for considering long-term oxygen therapy (LTOT):

• Stable patients with a PaO2 of < 7.3 kPa when stable • Patients with a PaO2 of 7.3–8.0 kPa who are stable but who have an additional risk factor (e.g. secondary polycythaemia, nocturnal hypoxaemia, peripheral oedema, pulmonary hypertension). Oxygen should be used for at least 15 h per day. Ischaemic heart disease Ischaemic heart disease is incorrect. Ischaemic heart disease is not an indication for home oxygen. Low forced expiratory volume in 1 s (FEV1) Low forced expiratory volume in 1 s (FEV1) is incorrect. A patient with a low FEV1 may also have significant chronic hypoxia and therefore would benefit from home oxygen therapy. However, a low FEV1 without significant chronic hypoxia is not an indication for home oxygen therapy. Low PCO2 Low PCO2 is incorrect. High PCO2 associated with chronic hypoxia may be an indication for home oxygen therapy if the patient meets the above thresholds. Low PO2 during exacerbations Low PO2 during exacerbations is incorrect. Chronic rather than acute significant hypoxia is an indication for home oxygen therapy.

Question 7

A 77-year-old man is referred to the Respiratory Clinic with a cough, stridor and a hoarse voice. He is noted on X-ray to have a lung mass, and biopsy confirms squamous-cell carcinoma of the bronchus. On examination, his BP is 125/72 mmHg, pulse is 74/min, atrial fibrillation. There are coarse crackles and wheeze on auscultation of the chest.

Investigations:

Hb 12.6 g/dl

WCC 10.0 × 109/l

PLT 200 × 109/l

Na+ 135 mmol/l

K+ 4.2 mmol/l

Creatinine 128 μmol/l Ca++ 2.88 mmol/l Laryngoscopy Left vocal cord palsy Which of the following is the greatest contra-indication to surgery?

Explanation

Correct Answer: E- Vocal cord palsy Explanation Vocal cord palsy The vocal cord palsy implies recurrent laryngeal nerve injury, and the most likely explanation for this is invasion by the underlying bronchial carcinoma. As such the tumour is almost certainly not amenable to surgery. Atrial fibrillation Atrial fibrillation is incorrect. Although atrial fibrillation is associated with increased operative risk, it is subsidiary to the probable nerve injury due to tumour invasion.

Creatinine 128 μmol/l

Creatinine 128 μmol/l is incorrect. Although renal impairment is associated with increased operative risk, it is subsidiary to the probable nerve injury due to tumour invasion. His age (77 years) His age (77 years) is incorrect. Although his age is associated with increased operative risk, it is subsidiary to the probable nerve injury due to tumour invasion. Hypercalcaemia Hypercalcaemia is incorrect. Although hypercalcaemia is associated with increased operative risk, it is subsidiary to the probable nerve injury due to tumour invasion.

Question 8

A 29-year-old woman noticed shortness of breath and dry cough while jogging last winter. Her GP trialed a salbutamol inhaler that she says gave her some relief,

although she now wakes up twice a week at 0400 h with a troublesome cough despite using the inhaler a number of times per day. On examination there is scattered wheeze and her peak flow is 460 (530 predicted). What is the most appropriate therapy?

Explanation

Correct Answer: D- Salbutamol inhaler and inhaled steroids Explanation Salbutamol inhaler and inhaled steroids This patient needs to move to step 2 of the British Thoracic Society (BTS) guidelines for asthma therapy (regular preventer therapy). Inhaled steroids should be considered for patients who:

• Have had exacerbations of asthma in the last 2 years • Are using inhaled ß2-agonists three times a week or more • Are symptomatic three times a week or more, or waking one night a week. Ampicillin Ampicillin is incorrect. There is nothing to suggest an acute bacterial infection requiring antibiotic therapy. Oral steroids Oral steroids is incorrect. Oral steroids are used in acute exacerbations of asthma and in severe asthma as ‘step 5’ treatment. This woman does not have an acute exacerbation, she has poorly controlled chronic asthma and requires the addition of inhaled steroids (ie step 2 treatment). Salbutamol inhaler Salbutamol inhaler is incorrect. She already has a salbutamol inhaler and her symptoms are not controlled on this therapy alone. She requires additional medication. Theophylline Theophylline is incorrect. Theophylline can be given intravenously to treat acute exacerbations of asthma or orally as a long-term treatment as an add-on therapy forming part of ‘step 4’ treatment. This woman does not have an acute exacerbation, she has poorly controlled chronic asthma and requires the addition of inhaled steroids (ie step 2 treatment).

Question 9

A 60-year-old hairdresser complains that, after an attack of flu last year, she has been more breathless than usual when taking her evening walk. She has also felt short of breath when climbing the stairs. She has become concerned that she has a cardiac problem. She has lost about 6.4 kg (14 lbs) in weight during the last year. She has smoked 20 cigarettes per day for 45 years but does not drink alcohol. Other than an occasional paracetamol for headache, she is on no regular medication. On examination she was apyrexic and had bilateral clubbing. No lymphadenopathy was seen. Her jugular venous pressure was not raised and heart sounds were normal. Bibasal inspiratory crepitations were audible. No pedal oedema was seen. Bilateral reticular shadowing, mostly on the bases, was seen on the chest X-ray. Routine bloods were normal, except for an ESR of 35 mm in the 1st hour. Her high-resolution computed tomography scan showed probable fibrosis, most marked in the basal region. Respiratory function tests showed a restrictive ventilatory defect. Bronchoalveolar lavage showed an increased number of cells â€“ neutrophils and macrophages â€“ but no malignant cells. An open-lung biopsy showed an exudate of intra-alveolar macrophages with patchy interstitial fibrosis. What is the likely diagnosis?

Explanation

Correct Answer: C- Idiopathic pulmonary fibrosis Explanation Idiopathic pulmonary fibrosis Idiopathic pulmonary fibrosis (IPF), synonymous with cryptogenic fibrosing alveolitis (CFA), is a progressive and usually fatal disease of unknown cause characterised by sequential acute lung injury with subsequent scarring and end-stage lung disease. It may occur in any decade of life but is most commonly seen between the ages of 50 and 60 years; it is slightly more frequent in males than females. A history of progressive breathlessness on exertion in the absence of wheeze is typical. A dry cough may be present, but sputum production is unusual until the later stages of the disease. Haemoptysis is uncommon, but should suggest the development of lung malignancy that occurs with a 7- to 14-fold relative risk in patients with idiopathic pulmonary fibrosis. Chest pain is uncommon. Constitutional symptoms such as weight loss and lethargy are recognised. Lung function tests show a restrictive picture. Recent re-classification of the group of idiopathic interstitial pneumonias have allowed characterisation of seven different histological patterns based on lung biopsy analysis; the pattern in IPF is that of usual interstitial pneumonia (UIP). All other causes should be excluded before diagnosing idiopathic pulmonary fibrosis. The median survival time is approximately 5 years. Chronic left heart failure Chronic left heart failure is incorrect. Cardiovascular examination was normal and CT findings were of insterstital lung disease. There is no indication that this lady has heart failure. Extrinsic allergic alveolitis Extrinsic allergic alveolitis is incorrect. Extrinsic allergic alveolitis usually causes upper lobe disease. There is no history given re potential allergen exposure. Histologyclasically shows a triad of diffuse interstitial chronic inflammation, poorly formed interstitial granulomas, and tiny foci of organizing pneumonia. Of these, the most striking and consistent finding is a cellular chronic interstitial pneumonia characterized by thickening of alveolar septa (interstitium) by an inflammatory infiltrate composed mainly of lymphocytes and scattered plasma cells, along with an occasional multinucleated giant cell and/or a few aggregates of histiocytes (granulomas). Lymphangitis carcinomatosis Lymphangitis carcinomatosis is incorrect. Lymphangitis carcinomatosis is a metastatic lung disease characterised by the diffuse infiltration and obstruction of the pulmonary parenchymal lymphatic system by tumour cells. Chest radiograph classically shows a reticular or reticulonodular pattern of infiltrates. CT scans showinterlobular septal thickening, fissural thickening and preservation of the normal parenchymal architecture at the level of the secondary pulmonary lobule. Hilar lymphadenopathy is present in 50% cases. Sarcoidosis Sarcoidosis is incorrect. Sarcoidosis would classically be associated with bilateral hilar lymphadenopathy on chest radiograph. CT would classically show lymphadenopathy, nodules particularly in a peri bronchovascular distribution and bilateral fibrotic changes predominatly in thr middle and upper lobes.

Question 10

A 68-year-old man who has a long history of smoking presents to the Emergency Department with worsening shortness of breath. His general health has deteriorated over the past few months and recently he has been prescribed a salbutamol inhaler by his GP for cough and wheezing, particularly on exercise and at night. On examination he is lip pursing and has considerable wheeze on auscultation of the chest. He is pyrexial at 37.8 °C and has purulent sputum. He can only manage a peak flow of 150 l/min. Arterial blood gas sampling reveals a Pao2 of 7.2 kPa. He is allergic to penicillin. Which of the following would be the most appropriate choice for antibiotic therapy in this man?

Explanation

Correct Answer: B- Clarithromycin 500 mg bd IV Explanation Clarithromycin 500 mg bd IV This man has an exacerbation of chronic obstructive pulmonary disease (COPD). The most common causative pathogens are Haemophilus influenzae and Moraxella catarrhalis. The most appropriate antibiotic of the options listed would be a macrolide such as clarithromycin. It should be noted, however, that in patients taking theophyllines, concomitant use of macrolides can increase serum aminophylline levels. Other important acute treatments in this case would be repeated nebulisation with salbutamol and ipratropium 4- to 6-hourly, oxygen therapy and oral steroids. Non- invasive ventilation might be considered where the pH is 7.3 or less and the patient is not improving after 4 h of medical therapy. Ciprofloxacin 500 mg bd orally Ciprofloxacin 500 mg bd orally is incorrect. Ciprofloxacin will not adequately treat infection with Streptococcus pneumoniae, which is a common cause of respiratory infection in COPD. Co-amoxiclav 1.2 g tds intravenously Co-amoxiclav 1.2 g tds intravenously is incorrect. He is penicillin allergic, so this would not be an appropriate choice. Metronidazole 500 mg tds orally Metronidazole 500 mg tds orally is incorrect. Oral metronidazole is primarily used to treat Clostridium difficile infection. Absorption is poor in its oral form. Intravenous metronidazole is used to treat anaerobic infections, which are not a common cause of COPD exacerbations. Penicillin V 500 mg qds orally Penicillin V 500 mg qds orally is incorrect. He is penicillin allergic; this would not be an appropriate choice.

Question 11

Which one of the following does not increase the risk of death in patients with severe pneumonia?

Explanation

Correct Answer: A- Age 49 years Explanation Age 49 years An age of 49 would not be associated with an increased risk of mortality from pneumonia. The risk factors for increased mortality in severe pneumonia are:

• Age over 60 years • Tachypnoea (respiratory rate > 30/min) • Underlying disease • Confusion • Multilobular involvement • Serum albumin < 35 g/l • Hypoxia (Pao2 < 8 kPa) • Leucocytosis > 20 × 109/l • Bacteraemia Leukopaenia is also associated with a higher rate of mortality in pneumonia. The CURB-65 severity scores for community-acquired pneumonia are:

• Confusion • BUN > 19 mg/dl (7 mmol/l) • Respiratory rate ≥ 30 • Systolic BP < 90 mmHg or Diastolic BP ≤ 60 mmHg • Age ≥ 65 Atrial fibrillation Atrial fibrillation is incorrect. This is associated with increased risk of mortality. Diastolic blood pressure < 60 mmHg Diastolic BP < 60 mmHg is incorrect. This is associated with increased risk of mortality. Urea > 7 mmol/l

Urea > 7 mmol/l is incorrect. This is associated with increased risk of mortality. White blood cell count < 4— 109/l White blood cell count < 4 × 109/l is incorrect. This is associated with increased risk of mortality.

Question 12

A 43-year-old patient with rheumatoid arthritis has been referred to you because of increasing shortness of breath and dry cough. Which medication is most likely to be responsible for her symptoms?

Explanation

Correct Answer: C- Methotrexate Explanation Methotrexate Methotrexate is an effective and moderately toxic disease-modifying anti-rheumatoid drug (DMARD). Pulmonary complications, in the form of pneumonitis (inflammation of the lung), are rare idiosyncratic reactions and are potentially lethal. The classical presentation is with rapid onset dyspnoea (shortness of breath), which may result in death after a few days. Therefore, patients should be advised to stop methotrexate if they experience dyspnoea or cough and to seek immediate medical attention. Gold Gold is incorrect. Gold has been superceded by newer and less toxic DMARDs. Side-effects from gold include dermatitis, stomatitis, haematuria, proteinuria including nephrotic syndrome and blood dyscrasias. Cases of pulmonary toxicity have been reported in the literature, but are relatively rare. Ibuprofen Ibuprofen is incorrect. Ibuprofen is not associated with pulmonary toxicity. Oral corticosteroids Oral corticosteroids is incorrect. Oral corticosteroids may increase risk of pulmonary infection but the description of respiratory symptoms in this case suggests a non- infective cause of pulmonary toxicity. Pulmonary toxicity due to a DMARD, in particular methotrexate is most likely. Sulfasalazine Sulfasalazine is incorrect. Sulfasalazine is associated with side-effects such as nausea and vomiting, rashes, arthralgia and hepatic dysfunction in up to 20% of patients. Sulphasalazine-induced pulmonary toxicity is rare.

Question 13

A patient who has had wheezy breathlessness for many years and who has previously been shown to have pulmonary infiltrates on chest X-ray and blood eosinophilia undergoes a high-resolution computed tomographic scan. This shows proximal bronchiectasis. Which of the following tests would be most useful in establishing the cause of her bronchiectasis?

Explanation

Correct Answer: A- Aspergillus skin-prick test Explanation Aspergillus skin-prick test Allergic bronchopulmonary aspergillosis is characterised by:

• Asthmatic symptoms • Peripheral blood eosinophilia • Positive skin tests or circulating precipitins to Aspergillus fumigatus • Abnormal chest X-ray • Raised total IgE A proportion of patients develop proximal bronchiectasis as a consequence of mucus plugging. Treatment during acute episodes is usually with oral corticosteroids. Of the options listed, aspergillus skin-prick test is the most specific investigation for allergic bronchopulmonary aspergillosis. Bronchoscopy and bronchoalveolar lavage Bronchoscopy and bronchoalveolar lavage is incorrect. Bronchoscopy and bronchoalveolar lavage are not diagnostic in allergic bronchopulmonary aspergillosis. Diagnosis is made on clinical, serological and radiological criteria. Histamine challenge test Histamine challenge test is incorrect. Histamine challenge test is a test used in the diagnosis of asthma and is partuclarly helpful in cough variant asthma. Measurement of total IgE Measurement of total IgE is incorrect. Total IgE is a helpful test in establishing the diagnosis of allergic bronchopulmonary aspergillosis, but in isolation is not specific enough to establish the diagnosis. Serum anti-neutrophil cytoplasmic antibody (ANCA) Serum anti-neutrophil cytoplasmic antibody (ANCA) is incorrect. ANCA testing is used to confirm a diagnosis of vasculitis.

Question 14

An obese 40-year-old woman with a history of asthma presents with progressive breathlessness. On examination she has a raised jugular venous pressure, ankle oedema, right parasternal heave and a murmur consistent with tricuspid regurgitation. Chest auscultation is clear. You understand from her husband that she has had progressively worsening symptoms over the past year. He has noticed that she has had particular problems with snoring and stopping breathing at night since he met her. Arterial blood gas results show: pH 7.39, Po2 7.3 kPa (normal range 11.3â€“12.6 kPa), Pco2 4.9 kPa (4.7â€“6.0 kPa). What is the most likely diagnosis?

Explanation

Correct Answer: E- Secondary pulmonary hypertension Explanation Secondary pulmonary hypertension The history of snoring is suggestive of sleep apnoea. Sleep apnoea is known to result in chronic nocturnal hypoxia, which in turn leads to pulmonary artery vasoconstriction. Eventually cor pulmonale develops, which is seen here.Treatment for this woman is likely to involve aggressive attempts to lose weight and nocturnal ventilatory support, probably using continuous positive airway pressure (CPAP) ventilation. Atrial septal defect Atrial septal defect is incorrect. Atrial septal defects can cause pulmonary hypertension, but patients would usually have a younger age at presentation. On auscultation split 1st and particularly 2nd heart sounds are often heard and an ejection systolic murmur is heard when moderate to large left to right shunts develop. Chronic asthma Chronic asthma is incorrect. There is nothing convincing in the history to suggest this lady has severe chronic asthma causing her cor pulmonale. The history is indicating a diagnosis of obstructive sleep apnoea and this is the most likely cause of her pulmonary hypertension. Primary pulmonary hypertension Primary pulmonary hypertension is incorrect. There is a clear aetiology for this lady’s pulmonary hypertension, i.e. she has secondary pulmonary hypertension. Pulmonary fibrosis Pulmonary fibrosis is incorrect. There is no occupational or drug exposure or comorbid connective tissue disease mentioned to suggest this patient is at risk of pulmonary fibrosis. There is no mention of clubbing or basal crackles that may suggest idiopathic pulmonary fibrosis. The history given is suggestive of secondary pulmonary hypertension as a consequence of untreated obstructive sleep apnoea.

Question 15

A 72-year-old woman is admitted with an infective exacerbation of chronic obstructive pulmonary disease. On admission, her blood gases taken while breathing 28% oxygen are: pH 7.31, Pao2 7.9 kPa, Paco2 7.5 kPa. Which of the following best describes the blood gas picture?

Explanation

Correct Answer: D- Decompensated type II respiratory failure Explanation Decompensated type II respiratory failure The patient’s blood gases show that she is hypoxic on oxygen – the Paco2 is elevated (Paco2> 6 kPa) and the

pH is low. These confirm a respiratory acidosis. There is hypoxia combined with CO2 retention. The blood gas picture is therefore one of decompensated type II respiratory failure. The prognosis is poor unless treated appropriately. The treatment in this case should be non- invasive positive-pressure ventilation (NIPPV). Data from good-quality randomised controlled trials indicate that NIPPV should be recommended as the first-line intervention, coupled with standard medical care, in all suitable patients with respiratory failure secondary to an acute exacerbation of chronic obstructive pulmonary disease. A trial of NIPPV should be considered early in the course of respiratory failure, before severe acidosis develops, as a means of avoiding endotracheal intubation and reducing treatment failure and mortality. Compensated type I respiratory failure Compensated type I respiratory failure is incorrect. The terms compensated/decompensated in respiratory failure refer to compensation for hypercapnoea. There is nothing to compensate for in type 1 respiratory failure ie the CO2 is low or normal so these options do not make sense. Regardless the gases show type II respiratory failure (low

pO2 and raised pCO2). Compensated type II respiratory failure Compensated type II respiratory failure is incorrect. The

pH would be normal in compensated type II respiratory failure (i.e. pH 7.35-7.45). Decompensated type I respiratory failure Decompensated type I respiratory failure is incorrect. The terms compensated/decompensated in respiratory failure refer to compensation for hypercapnoea. There is nothing to compensate for in type 1 respiratory failure ie the CO2 is low or normal so these options do not make sense. Regardless the gases show type II respiratory failure (low pO2 and raised pCO2). Partially compensated respiratory alkalosis Partially compensated respiratory alkalosis is incorrect. The pH is acidotic. Respiratory alkalosis would be represented by a high pH (>7.45) and a low pCO2 (<4kPa)

Question 16

A 50-year-old woman presents to the respiratory clinic with symptoms of increasing shortness of breath and a chronic cough. She was originally diagnosed by her GP as having asthma, but has had no significant response to a salbutamol inhaler. There has been slow weight loss over the past 6 months and problems with night sweats. On examination her BP is 155/72 mmHg, pulse is 70/min and regular. There are scattered crackles on auscultation of the chest. There is erythema nodosum and erythematous plaques resembling psoriasis.

Investigations:

Hb 12.2 g/dl

WCC 10.9 x 109/l

PLT 192 x 109/l

ESR 62 mm/1st hour

Na+ 138 mmol/l

K+ 4.3 mmol/l

Creatinine 120 μmol/l

CXR Bilateral hilar lymphadenopathy You suspect sarcoid. Which of the following is the best way to confirm the diagnosis?

Explanation

Correct Answer: E- Skin biopsy Explanation Skin biopsy Skin biopsy of one of the plaques is potentially very useful, and is likely to confirm the presence of non- caseating granulomas. An alternative diagnostic route could be via endobronchial and transbronchial biopsies. Bronchoalveolar lavage Bronchoalveolar lavage is incorrect. Bronchoalveolar lavage may show increased lymphocytes in the fluid in keeping with sarcoidosis, but this is non-specific. CT thorax CT thorax is incorrect. Although CT thorax is likely to confirm the presence of interstitial lung disease in a pattern suggestive of sarcoidosis, it is not definitive in establishing the diagnosis. Kveim test Kveim test is incorrect. Kveim testing is now obsolete because of the risk of transmission of new variant CJD and the time taken to obtain a result. Serum ACE Serum ACE is incorrect. Serum ACE is only raised in 60% of patients with sarcoidosis and is not specific for the condition.

Question 17

A 61-year-old man with a 40 pack-year smoking history presents with chronic cough, haemoptysis and weight loss. Unfortunately his chest X-ray reveals a large mass at the left hilum, suggestive of a bronchial carcinoma. A raised calcium is noted on routine blood work-up. What type of carcinoma would best fit this clinical picture?

Explanation

Correct Answer: E- Squamous-cell carcinoma of the bronchus Explanation Squamous-cell carcinoma of the bronchus Squamous-cell and small-cell bronchial carcinomas tend to occupy a central location. Squamous-cell carcinomas are more frequently associated with hypercalcaemia, so this is the correct answer in this case. In terms of frequency:

• 30% each are adenocarcinomas and squamous-cell carcinomas • 20% are small-cell carcinomas • 15–20% are large-cell carcinomas • 5% are bronchoalveolar-cell carcinomas. Adenocarcinoma of the bronchus Adenocarcinoma of the bronchus is incorrect. Lung cancers of this cell type tend to occur more frequently in the periphery of the lung. Bronchoalveolar-cell carcinoma Bronchoalveolar-cell carcinoma is incorrect. Bronchoalveolar-cell carcinoma has no correlation with cigarette smoking, making one of the other cell types more likely. Large-cell bronchial carcinoma Large-cell bronchial carcinoma is incorrect. Lung cancers of this cell type tend to occur more frequently in the periphery of the lung. Small-cell bronchial carcinoma Small-cell bronchial carcinoma is incorrect. As described, the hypercalcaemia makes squamous-cell carcinoma more likely.

Question 18

An 18-year-old man presents with a gradual onset of pallor, weakness, lethargy, dry cough and occasional haemoptysis. There are no extrapulmonary features. His chest X-ray shows diffuse pulmonary infiltrates. Lung biopsy shows no vasculitic changes and no evidence of immunoglobulin or complement deposition. His gas transfer factor (Tlco) is found to be elevated. Renal function is normal. What is the most likely diagnosis?

Explanation

Correct Answer: D- Idiopathic pulmonary haemosiderosis Explanation Idiopathic pulmonary haemosiderosis Idiopathic pulmonary haemosiderosis tends to occur in younger people and is characterised by pallor, weakness, lethargy, dry cough and occasional haemoptysis. There are no abnormal immunological features. Gas transfer is elevated as blood is already in the alveolar space. Behçet’s disease Behçet’s disease is incorrect. We are given no history of orogenital ulceration, which counts against a diagnosis of Behçet’s. Goodpasture syndrome Goodpasture syndrome is incorrect. There are no extrapulmonary features. There are no abnormal immunological features, which differentiates it from Goodpasture syndrome (where antibodies to basement membrane of lung and kidneys are seen). Granulomatosis with polyangiitis Granulomatosis with polyangiitis is incorrect. There are no signs of sinusitis or renal disease, making granulomatosis with polyangiitis less likely. Systemic lupus erythematosus Systemic lupus erythematosus (SLE) is incorrect. SLE is unlikely given the lack of extrapulmonary features.

Question 19

A 62-year-old smoker with a 2-day history of cough and fever is admitted with a diagnosis of left- sided pneumonia and left-sided pleural effusion up to the 6th intercostal space. Pleural fluid is aspirated and sent for tests. Which one of the following is an indication for inserting a chest drain?

Explanation

Correct Answer: D- Pleural fluid pH < 7.2 Explanation Pleural fluid pH < 7.2 Pleural effusions should be drained:

• When the fluid is infected • When the pH is < 7.2 • When a Gram stain shows the presence of organisms • When the fluid is frankly purulent • When clinical improvement is slow despite antibiotic therapy Bloodstained pleural fluid Bloodstained pleural fluid is incorrect. This is not an indication for insertion of a chest drain. Pleural fluid glucose > 2 mmol/l Pleural fluid glucose > 2 mmol/l is incorrect. This is not an indication for insertion of a chest drain. Pleural fluid lactate dehydrogenase > 200 IU/l Pleural fluid lactate dehydrogenase > 200 IU/l is incorrect. This is not an indication for insertion of a chest drain. Serous pleural fluid Serous pleural fluid is incorrect. This is not an indication for insertion of a chest drain.

Question 20

A 47-year-old woman presents with a chronic cough, weight loss and haemoptysis. She is a lifelong non- smoker and has previously been completely well, on no regular medication. On examination she looks thin and her body mass index (BMI) is 20 kg/m2. Her blood pressure is 132/70 mmHg and her pulse is 80 bpm and regular. General respiratory and abdominal examination is unremarkable.

Investigation:

Hb 12.4 g/dl

WCC 7.8 x 109/l

PLT 211 x 109/l

Sodium 139 mmol/l

Potassium 4.4 mmol/l

Creatinine 110 µmol/l Albumin 31 g/l (normal range 37-49 g/l) Alanine aminotransferase (ALT) 231 U/l (5-35 U/l) A chest X-ray shows a right upper-lobe tumour with hilar extension. Bronchoscopy was performed but no biopsies were obtained (washings negative so far). Which of the following is the most likely diagnosis?

Explanation

Correct Answer: A- Adenocarcinoma Explanation Adenocarcinoma The peripheral nature of this tumour and the fact that the patient is a lifelong non-smoker make adenocarcinoma the most likely diagnosis. Because the primary tumour is peripheral it is quite possible that an initial bronchoscopy might be negative. It would be worth repeating the bronchoscopy in this case, although thoracoscopy or computed tomography-guided biopsy are other methods that could be used to obtain tumour material. Given the hilar lymphadenopathy, it is unlikely that this patient will be a candidate for surgery Bronchial carcinoid Bronchial carcinoid is incorrect. The weight loss is suggestive of an underlying malignancy. There are no symptoms to suggest metastatic carcinoid, therefore adenocarcinoma is more likely. Large-cell carcinoma Large-cell carcinoma is incorrect. Large-cell carcinoma is typically peripherally located, as in this case, but one would expect a history of smoking. Small-cell carcinoma Small-cell carcinoma is incorrect. A history of smoking would be expected in small-cell carcinoma. Squamous-cell carcinoma Squamous-cell carcinoma is incorrect. A history of smoking would be expected in squamous-cell carcinoma.

Question 21

A 6-year-old boy presents with a completely displaced, extension-type supracondylar humerus fracture. He has an absent radial pulse but the hand is warm and pink. What is the most appropriate next step in management?

Explanation

A "pink, pulseless" hand in the setting of a supracondylar humerus fracture is generally managed with urgent closed reduction and percutaneous pinning. Vascular exploration is indicated if the hand remains dysvascular (white and pulseless) after anatomical reduction is achieved.

Question 22

A 45-year-old man presents with acute onset of bilateral sciatica, saddle anesthesia, and urinary retention. MRI reveals a massive L4-L5 central disc herniation. Within what time frame is surgical decompression generally recommended to optimize bladder function recovery?

Explanation

Cauda equina syndrome is an absolute surgical emergency. Decompression within 48 hours has been shown to significantly improve the chances of recovering bladder, bowel, and sexual function compared to later decompression.

Question 23

A 32-year-old woman sustains a displaced, Pauwels type III femoral neck fracture after a motor vehicle collision. Which of the following fixation constructs provides the most biomechanically stable construct for this specific fracture pattern?

Explanation

Pauwels type III fractures have a vertical shear pattern, making them highly unstable. A sliding hip screw (dynamic hip screw) with a derotation screw provides superior biomechanical stability against vertical shear forces compared to multiple cancellous screws.

Question 24

A 24-year-old man falls onto his outstretched hand and presents with anatomic snuffbox tenderness. Initial radiographs are negative for a fracture. What is the most appropriate next step in management?

Explanation

A clinically suspected scaphoid fracture with negative initial radiographs should be treated with thumb spica immobilization and re-evaluated in 10-14 days. Alternatively, acute MRI can be performed to definitively rule out the fracture and avoid prolonged immobilization.

Question 25

A 65-year-old woman complains of a painful catch and audible "clunk" when extending her knee from a flexed position, 1 year after a posterior-stabilized total knee arthroplasty. What is the pathophysiologic cause of this complication?

Explanation

Patellar clunk syndrome occurs in posterior-stabilized total knee arthroplasty when a fibrous nodule forms on the undersurface of the quadriceps tendon. This nodule catches in the femoral intercondylar box during extension, typically requiring arthroscopic debridement.

Question 26

A 15-year-old boy presents with progressive knee pain and a palpable mass over the distal femur. Radiographs demonstrate a mixed lytic/sclerotic lesion with periosteal elevation (Codman triangle). Biopsy confirms conventional high-grade osteosarcoma. What is the standard treatment sequence?

Explanation

The standard of care for conventional high-grade osteosarcoma involves neoadjuvant chemotherapy, followed by wide surgical resection (favoring limb salvage), and subsequently adjuvant chemotherapy. Osteosarcoma is generally considered radioresistant.

Question 27

A 13-year-old obese boy presents with an atraumatic limp and right groin pain for 3 weeks. On examination, he has obligate external rotation of the right hip with passive flexion. What is the most appropriate initial treatment?

Explanation

The clinical presentation is classic for a slipped capital femoral epiphysis (SCFE). The standard initial treatment is in situ percutaneous fixation with a single partially threaded cannulated screw to stabilize the physis and prevent further slippage.

Question 28

A 6-week-old female infant is noted to have an asymmetric thigh crease and a positive Ortolani test on the left side. Ultrasound confirms an unstable left hip. What is the first-line treatment?

Explanation

The Pavlik harness is the gold standard first-line treatment for reducible developmental dysplasia of the hip (DDH) in infants younger than 6 months. It dynamically maintains the hip in flexion and abduction, promoting normal acetabular development.

Question 29

A 55-year-old manual laborer presents with right shoulder pain and weakness, particularly with external rotation. MRI reveals a massive, retracted tear of the supraspinatus and infraspinatus tendons with severe fatty infiltration (Goutallier stage 4). He has intact deltoid function. What is the most appropriate surgical option?

Explanation

In older or relatively low-demand patients with a massive, irreparable rotator cuff tear and severe fatty infiltration, a reverse total shoulder arthroplasty is indicated. It provides excellent pain relief and restores active elevation by utilizing the intact deltoid muscle.

Question 30

A 40-year-old man feels a "pop" in his posterior ankle while playing basketball. He has a positive Thompson test. Which of the following functional outcomes is most consistently improved with surgical repair of this injury compared to conservative management?

Explanation

Surgical repair of an acute Achilles tendon rupture significantly decreases the re-rupture rate compared to traditional nonoperative management. However, patients must be counseled that surgery carries higher risks of complications such as infection and sural nerve injury.

Question 31

A 28-year-old man sustained a closed midshaft tibia fracture treated with an intramedullary nail. Six hours postoperatively, he complains of severe leg pain out of proportion to the injury, not relieved by opioids. Passive stretch of his toes causes excruciating pain. What is the most sensitive early clinical sign of this condition?

Explanation

Pain out of proportion to the injury and pain exacerbated by passive stretch of the ischemic muscles are the earliest and most sensitive clinical signs of acute compartment syndrome. Pulselessness and paralysis are very late, often irreversible signs.

Question 32

A 20-year-old female soccer player undergoes an anterior cruciate ligament reconstruction using a bone-patellar tendon-bone autograft. Which of the following complications is most specifically associated with this graft choice compared to hamstring autograft?

Explanation

Bone-patellar tendon-bone (BTB) autografts are highly associated with donor site morbidity, specifically anterior knee pain and pain with kneeling. Hamstring autografts have a lower incidence of anterior knee pain but may lead to mild hamstring weakness.

Question 33

A 50-year-old man with poorly controlled diabetes presents with a chronic, non-healing ulcer on the plantar aspect of his foot. Probe-to-bone testing is positive. Which imaging modality is the most specific for confirming osteomyelitis in this setting?

Explanation

MRI is highly sensitive and specific for detecting osteomyelitis, particularly in the diabetic foot. It provides superior anatomical detail and can clearly differentiate between bone infection, marrow edema, and surrounding soft tissue infection.

Question 34

A 45-year-old pregnant woman presents with numbness and tingling in her thumb, index, and middle fingers, especially at night. Examination reveals a positive Phalen test. What is the most appropriate initial management?

Explanation

Carpal tunnel syndrome during pregnancy is common due to fluid retention and typically resolves postpartum. Initial management should always be conservative, prioritizing night-time volar wrist splinting to maintain a neutral wrist position and alleviate symptoms.

Question 35

A 65-year-old woman falls on her outstretched hand and sustains a dorsally displaced distal radius fracture. Which eponym correctly describes this specific fracture pattern?

Explanation

A Colles fracture is an extra-articular fracture of the distal radius with dorsal comminution and dorsal displacement. A Smith fracture is its reverse counterpart, characterized by volar angulation and displacement.

Question 36

A 30-year-old man sustains a Gustilo-Anderson Type IIIB open tibia fracture following a motorcycle accident. The wound is 12 cm long with extensive soft tissue stripping and exposed bone. Which of the following intravenous antibiotic regimens is most appropriate initially?

Explanation

For Gustilo-Anderson Type III open fractures, broad-spectrum antibiotic coverage is required to mitigate infection risk. Standard initial therapy includes a first-generation cephalosporin for Gram-positive coverage combined with an aminoglycoside for Gram-negative coverage.

Question 37

A 7-year-old boy presents with a painless limp that has worsened over the past few months. He has limited internal rotation and abduction of his left hip. Radiographs reveal fragmentation and sclerosis of the proximal femoral epiphysis. What is the most likely diagnosis?

Explanation

Legg-Calve-Perthes disease is an idiopathic avascular necrosis of the proximal femoral epiphysis, typically occurring in boys aged 4-8 years. Radiographic progression follows stages of initial sclerosis, fragmentation, reossification, and finally healing or remodeling.

Question 38

A 25-year-old man sustains an anteroposterior compression (APC) type III pelvic ring injury in a crush accident. He remains hemodynamically unstable despite initial fluid resuscitation and the application of a pelvic binder. What is the most appropriate next step to control the hemorrhage?

Explanation

In a hemodynamically unstable patient with a pelvic ring injury where mechanical volume reduction (pelvic binder) has failed, pelvic angiography with embolization is indicated. This helps identify and occlude arterial bleeding, which is frequently from branches of the internal iliac artery.

Question 39

A 55-year-old woman with longstanding rheumatoid arthritis presents with neck pain and paresthesias in her hands. Flexion-extension radiographs of the cervical spine demonstrate an atlanto-dens interval (ADI) of 8 mm. What does this finding indicate?

Explanation

In adults, an atlanto-dens interval (ADI) greater than 3 mm on flexion-extension lateral radiographs is indicative of atlantoaxial instability (subluxation). This is a frequent and potentially devastating complication in patients with advanced rheumatoid arthritis.

Question 40

A 10-year-old boy presents with a 2-month history of pain and swelling in his left mid-thigh. Radiographs reveal a permeative lytic lesion in the diaphysis of the femur with an "onion skin" periosteal reaction. Histology shows small round blue cells. Which chromosomal translocation is commonly associated with this tumor?

Explanation

The clinical presentation and histology are classic for Ewing sarcoma, which typically affects the diaphysis of long bones. It is highly associated with the t(11;22) translocation, which results in the EWS-FLI1 fusion gene.

Question 41

A 65-year-old man with a 20-year history of severe Rheumatoid Arthritis presents for an elective total hip arthroplasty. Which of the following is the most critical preoperative assessment required before proceeding with general anesthesia and intubation?

Explanation

Patients with long-standing rheumatoid arthritis are at high risk for cervical instability, specifically atlantoaxial subluxation. Flexion-extension cervical spine radiographs are essential preoperatively to evaluate for instability that could cause fatal neurologic injury during intubation.

Question 42

A 72-year-old woman with a recent distal radius fracture has a DEXA T-score of -3.1 at the lumbar spine. She is started on teriparatide therapy. What is the primary mechanism of action of this medication?

Explanation

Teriparatide is a recombinant human parathyroid hormone (PTH 1-34) analog. When administered intermittently, it acts as an anabolic agent by directly stimulating osteoblast activity and increasing new bone formation.

Question 43

A 45-year-old man presents with a swollen, painful knee and "sausage-like" swelling of his second and third toes. Radiographs of his hands show classic "pencil-in-cup" deformities of the distal phalanges. What is the most likely diagnosis?

Explanation

Psoriatic arthritis classically presents with dactylitis (sausage digits) and asymmetric oligoarthritis. Radiographic findings include the pathognomonic "pencil-in-cup" deformity caused by severe periarticular erosions and bone resorption.

Question 44

A 55-year-old man develops acute monoarticular knee pain and profound swelling on postoperative day 3 following a lumbar fusion. Joint aspirate reveals a WBC count of 45,000 cells/mm3 and negatively birefringent needle-shaped crystals. Which medication is most appropriate for the immediate acute management of this joint?

Explanation

The aspirate findings are diagnostic of an acute gout flare caused by monosodium urate crystals. NSAIDs like indomethacin, or alternatively colchicine or intra-articular steroids, are first-line treatments for acute flares, whereas allopurinol is reserved for chronic prevention.

Question 45

A 60-year-old man with Ankylosing Spondylitis presents to the emergency department after a low-energy fall from a standing height. He reports new-onset severe lower back pain but is neurologically intact. Standard AP and lateral radiographs of the lumbar spine are unremarkable. What is the next most appropriate step in management?

Explanation

Patients with ankylosing spondylitis have rigid, osteoporotic spines making them highly susceptible to unstable "chalk-stick" fractures, even from minor trauma. An occult fracture must be ruled out with advanced imaging (CT or MRI) when plain films are negative.

Question 46

An 82-year-old woman falls and sustains a displaced femoral neck fracture. She takes warfarin for atrial fibrillation, and her admission INR is 3.5. Which of the following is the most appropriate agent to reverse her coagulopathy for urgent surgical intervention?

Explanation

Prothrombin complex concentrate (PCC) provides the most rapid and effective reversal of warfarin-induced coagulopathy. It contains factors II, VII, IX, and X, allowing for prompt normalization of the INR prior to urgent orthopedic surgery.

Question 47

A 65-year-old man is prescribed rivaroxaban for deep vein thrombosis (DVT) prophylaxis following a total hip arthroplasty. What is the mechanism of action of this medication?

Explanation

Rivaroxaban is an oral anticoagulant that directly inhibits Factor Xa. Unlike low molecular weight heparins, it does not require antithrombin III for its anticoagulant activity.

Question 48

An 8-year-old boy presents with diffuse bone pain, poor wound healing, and bleeding gums. Radiographs show a thickened metaphyseal band (Frankel line) and an adjacent radiolucent zone (Trummerfeld zone). A deficiency in which of the following biochemical processes is most likely responsible?

Explanation

The patient has scurvy due to Vitamin C deficiency. Vitamin C is a crucial cofactor for prolyl and lysyl hydroxylases, which are required for the cross-linking and stabilization of the collagen triple helix.

Question 49

A 45-year-old woman presents with diffuse bone pain and proximal muscle weakness. Laboratory studies show low normal serum calcium, low phosphorus, elevated alkaline phosphatase, and elevated parathyroid hormone. Radiographs reveal radiolucent bands perpendicular to the bone cortex. What is the most likely diagnosis?

Explanation

The clinical and laboratory profile (indicating secondary hyperparathyroidism due to Vitamin D deficiency) combined with radiolucent bands (Looser zones or pseudofractures) is classic for osteomalacia. Osteomalacia is characterized by the defective mineralization of newly formed osteoid.

Question 50

A 68-year-old man presents with progressive bowing of his right tibia and an increasing hat size. Radiographs of the skull show "cotton wool" exudates, and the tibia shows pronounced cortical thickening. Which of the following best describes the classic histologic appearance of his bone?

Explanation

The patient has Paget's disease of bone, which is characterized by chaotic and excessive bone remodeling. Histologically, this is represented by prominent, disorganized cement lines creating a classic "mosaic" or "jigsaw puzzle" pattern of woven and lamellar bone.

Question 51

A 12-year-old boy with sickle cell disease presents with fever, severe left thigh pain, and a limp. An MRI shows diffuse bone marrow edema with a subperiosteal fluid collection. Blood cultures are drawn. While Staphylococcus aureus is the most common overall cause, which organism is characteristically associated with this specific patient population?

Explanation

Patients with sickle cell disease are particularly susceptible to Salmonella osteomyelitis due to autosplenectomy and impaired macrophage function. However, Staphylococcus aureus still remains the most common overall infecting organism.

Question 52

A 14-year-old boy with Hemophilia A presents with recurrent severe hemarthroses of the right knee. Which of the following describes the primary mechanism of joint destruction in hemophilic arthropathy?

Explanation

Recurrent bleeding into the joint leads to pronounced synovial hypertrophy and deposition of iron (hemosiderin). This iron accumulation induces oxidative stress and stimulates enzymes that cause direct chondrocyte apoptosis and progressive cartilage destruction.

Question 53

A 6-year-old boy diagnosed with Duchenne Muscular Dystrophy requires an urgent closed reduction and percutaneous pinning of a displaced supracondylar humerus fracture. Which of the following anesthetic agents is absolutely contraindicated in this patient?

Explanation

Succinylcholine, a depolarizing neuromuscular blocker, is absolutely contraindicated in patients with Duchenne Muscular Dystrophy. Its use can cause massive potassium efflux from fragile, unstable muscle cells, leading to life-threatening hyperkalemia and cardiac arrest.

Question 54

During an intramedullary nailing of a femur fracture, an otherwise healthy 20-year-old man develops sudden tachycardia, muscle rigidity, and a rapid rise in end-tidal CO2. His core temperature spikes to 39.5 degrees Celsius. What is the immediate drug of choice for this condition?

Explanation

The patient is experiencing malignant hyperthermia, an acute hypermetabolic crisis triggered by volatile anesthetics or succinylcholine. Dantrolene, a ryanodine receptor antagonist, must be administered immediately to halt the uncontrolled release of calcium from the sarcoplasmic reticulum.

Question 55

A 3-year-old girl is brought to the clinic due to noticeable anterolateral bowing of her left tibia. On physical exam, you note multiple cafe-au-lait spots and axillary freckling. What genetic mutation is most likely responsible for her condition?

Explanation

Anterolateral bowing of the tibia (often progressing to pseudoarthrosis) and cafe-au-lait spots are classic signs of Neurofibromatosis Type 1. NF1 is caused by an autosomal dominant mutation in the neurofibromin 1 gene located on chromosome 17.

Question 56

A 4-year-old boy with a history of multiple low-energy fractures presents with a new diaphyseal femur fracture. On examination, he has blue sclerae and mild hearing loss. Radiographs show generalized osteopenia and severe bowing of the long bones. Which class of medication is commonly used to decrease fracture incidence in this condition?

Explanation

The patient has Osteogenesis Imperfecta, typically caused by an autosomal dominant defect in Type 1 collagen. Intravenous bisphosphonates (e.g., pamidronate) are the mainstay of medical therapy to increase bone mineral density and reduce the frequency of fractures in these children.

Question 57

A 65-year-old active male is undergoing a total hip arthroplasty. Which of the following bearing surfaces has the lowest volumetric wear rate but the highest risk of catastrophic failure via fracture?

Explanation

Ceramic-on-ceramic bearings exhibit the lowest volumetric wear of all bearing surfaces. However, they carry a unique risk of catastrophic brittle fracture and postoperative squeaking.

Question 58

A 32-year-old male presents with a hemodynamically unstable APC III pelvic ring injury following a motorcycle crash. A pelvic binder is applied, but he remains hypotensive despite initial fluid resuscitation. What is the most appropriate next step in management?

Explanation

Hemodynamically unstable pelvic fractures requiring massive transfusion should undergo emergent pelvic packing or angioembolization. External fixation alone is insufficient for controlling ongoing major retroperitoneal venous or arterial hemorrhage.

Question 59

In the surgical management of an unstable slipped capital femoral epiphysis (SCFE) using a single cannulated screw, which complication is most directly related to unrecognized intra-articular hardware penetration?

Explanation

Chondrolysis (rapid cartilage destruction) is strongly associated with unrecognized intra-articular hardware penetration during SCFE pinning. Careful fluoroscopic evaluation using the approach-withdraw technique helps prevent this.

Question 60

Which of the following bundles of the anterior cruciate ligament (ACL) is tightest in full knee extension and provides the primary restraint to anterior tibial translation at 0 to 20 degrees of flexion?

Explanation

The posterolateral (PL) bundle of the ACL is tight in extension and provides the primary restraint to anterior translation in early flexion. The anteromedial (AM) bundle becomes tight in flexion.

Question 61

A 65-year-old male presents with progressive hand clumsiness, gait instability, and hyperreflexia in both lower extremities. MRI shows severe cervical stenosis at C4-C5. Which of the following physical examination findings is most specific for cervical myelopathy?

Explanation

The inverted supinator reflex (finger flexion when testing the brachioradialis reflex) is a highly specific upper motor neuron sign for cervical myelopathy. Spurling sign tests for cervical radiculopathy, not myelopathy.

Question 62

A 15-year-old boy presents with a painful mass near his right knee. Radiographs reveal a poorly defined, destructive lesion in the distal femoral metaphysis with a "sunburst" periosteal reaction. Biopsy confirms osteosarcoma. What is the most significant prognostic factor for overall survival?

Explanation

The most important prognostic factor in high-grade extremity osteosarcoma is the histological response to neoadjuvant chemotherapy. Achieving greater than 90% tumor necrosis correlates with significantly improved survival.

Question 63

A 28-year-old carpenter sustains a volar laceration to his index finger over the middle phalanx. Both the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons are transected. Into which flexor tendon zone does this injury fall?

Explanation

Zone II extends from the A1 pulley to the insertion of the FDS on the middle phalanx. It contains both the FDS and FDP tendons within a narrow fibro-osseous sheath, making repairs here notoriously prone to adhesions.

Question 64

Which of the following mechanical factors provides the primary stimulus for secondary bone healing characterized by robust callus formation?

Explanation

Secondary bone healing (via callus formation and endochondral ossification) requires relative stability with interfragmentary micro-motion. Absolute stability, such as that provided by compression plating, leads to primary bone healing without callus.

Question 65

A 30-year-old male sustains a closed tibial shaft fracture. Twelve hours post-injury, he complains of severe leg pain out of proportion to the injury. Which of the following clinical findings is the most sensitive early indicator of acute compartment syndrome?

Explanation

Pain with passive muscle stretch is the most sensitive and earliest clinical sign of acute compartment syndrome. Pulselessness, paralysis, and pallor are late signs indicating irreversible ischemia.

Question 66

Following a total knee arthroplasty, a patient presents with early postoperative knee stiffness. Which surgical error during the procedure is most likely to result in severely restricted knee flexion?

Explanation

Oversizing the femoral component in the anteroposterior dimension excessively tightens the flexion gap, mechanically limiting postoperative knee flexion. Undersizing would lead to a loose flexion gap and potential instability.

Question 67

A 4-month-old female infant is evaluated for asymmetric thigh folds. Ultrasound reveals a dysplastic left hip with an alpha angle of 50 degrees and a beta angle of 80 degrees. What is the most appropriate initial management?

Explanation

For developmental dysplasia of the hip (DDH) in an infant under 6 months of age, the Pavlik harness is the gold standard initial treatment. It maintains the hip in flexion and abduction to safely promote acetabular remodeling.

Question 68

A 45-year-old male feels a sudden pop in his posterior heel while playing tennis. On examination, the Thompson test is positive. Which vascular territory is most prone to degeneration and rupture in the Achilles tendon?

Explanation

The "watershed" zone of the Achilles tendon has the most tenuous blood supply and is the most common site for rupture. It is located approximately 2 to 6 cm proximal to its insertion on the calcaneus.

Question 69

A 22-year-old rugby player has recurrent anterior shoulder instability. An MRI arthrogram reveals a bony Bankart lesion with 25% glenoid bone loss. Which surgical procedure is most appropriate to restore stability?

Explanation

In patients with recurrent anterior instability and significant glenoid bone loss (typically greater than 20-25%), a coracoid transfer (Latarjet procedure) is indicated. Soft tissue arthroscopic Bankart repair alone carries an unacceptably high failure rate in this setting.

Question 70

A 40-year-old typist complains of numbness in the small and ring fingers of her right hand, along with weakness in pinch strength. Froment's sign is positive. Which nerve is most likely compressed, and at what anatomical site?

Explanation

Numbness in the ulnar digits and weak pinch (a positive Froment's sign due to adductor pollicis weakness) strongly indicate ulnar neuropathy. The cubital tunnel at the elbow is the most common site of ulnar nerve compression.

Question 71

Which biomechanical property of titanium makes it highly advantageous for use in uncemented orthopedic implants compared to stainless steel or cobalt-chrome alloys?

Explanation

Titanium has a lower modulus of elasticity compared to cobalt-chrome or stainless steel, making it closer to the stiffness of cortical bone. This reduces stress shielding and promotes better load sharing and osseointegration.

Question 72

A 25-year-old male sustains a burst fracture of L1 after a fall. He has no neurologic deficits. Which radiographic finding is the strongest indication for operative stabilization rather than non-operative management?

Explanation

Disruption of the posterior ligamentous complex (PLC) makes a thoracolumbar burst fracture highly mechanically unstable. According to the TLICS system, PLC disruption is a strong indication for surgical stabilization.

Question 73

A 9-year-old girl presents with fever, weight loss, and severe mid-shaft thigh pain. Radiographs show a permeative diaphyseal lesion of the femur with an "onion skin" periosteal reaction. What specific chromosomal translocation is diagnostic for this malignancy?

Explanation

Ewing sarcoma is classically associated with the t(11;22)(q24;q12) chromosomal translocation, resulting in the EWS-FLI1 fusion protein. It typically presents in the diaphysis of long bones with an "onion skin" appearance.

Question 74

A 35-year-old manual laborer complains of chronic dorsal wrist pain. Radiographs reveal sclerosis and fragmentation of the lunate bone, and ulnar minus variance. What is the most appropriate initial surgical intervention for stage IIIA Kienböck's disease in this patient?

Explanation

In patients with early-stage Kienböck's disease and ulnar negative variance, a radial shortening osteotomy is indicated. This joint-leveling procedure unloads the radiolunate joint, allowing potential revascularization of the lunate.

Question 75

A 6-year-old boy presents with a painless limp. Radiographs show sclerosis and flattening of the capital femoral epiphysis. According to the Herring lateral pillar classification, greater than 50% loss of lateral pillar height categorizes the hip into which group?

Explanation

In the Herring classification for Legg-Calvé-Perthes disease, a loss of more than 50% of the lateral pillar height defines Group C. This group carries the poorest prognosis regarding long-term hip joint congruity and function.

Question 76

Which zone of normal articular cartilage contains the highest concentration of water and has collagen fibers oriented parallel to the joint surface to resist shear forces?

Explanation

The superficial (tangential) zone of articular cartilage has the highest water content and lowest proteoglycan concentration. Its densely packed collagen fibers run parallel to the surface to provide vital resistance against shear stress.

Question 77

A 15-year-old boy presents with a painful mass around his right knee. Radiographs reveal a lytic, destructive lesion in the distal femur metaphysis with a sunburst periosteal reaction. Biopsy confirms high-grade conventional osteosarcoma. Which of the following genetic alterations is most frequently associated with the pathogenesis of this tumor?

Explanation

Conventional osteosarcoma is highly associated with mutations in tumor suppressor genes, particularly TP53 (Li-Fraumeni syndrome) and RB1 (hereditary retinoblastoma). t(11;22) is characteristic of Ewing sarcoma, while GNAS mutations are seen in fibrous dysplasia.

Question 78

A 9-year-old girl presents with a permeative diaphyseal lesion in her left tibia with an associated large soft tissue mass. Biopsy reveals small round blue cells expressing CD99. The most likely cytogenetic abnormality involves a translocation that creates which of the following fusion proteins?

Explanation

Ewing sarcoma is characterized by the t(11;22)(q24;q12) translocation in 85% of cases, resulting in the EWS-FLI1 fusion protein. CD99 is a highly sensitive but non-specific cell surface marker for this tumor.

Question 79

A 32-year-old woman presents with a radiolucent, eccentric, epiphyseal-metaphyseal lesion in her proximal tibia. Biopsy shows multinucleated giant cells admixed with mononuclear stromal cells. If systemic therapy is indicated, which of the following mechanisms best describes the targeted biologic agent commonly used?

Explanation

Denosumab is a monoclonal antibody that binds to RANKL, preventing it from activating RANK on the surface of osteoclasts and their precursors. In giant cell tumors of bone, the neoplastic mononuclear stromal cells express RANKL, which recruits the reactive multinucleated giant cells.

Question 80

A neonate is evaluated for multiple fractures and cranial nerve palsies. Radiographs show diffusely dense, 'bone-within-bone' appearance in the vertebrae and long bones. A defect in which of the following enzymes or proteins is most likely responsible for this condition?

Explanation

Osteopetrosis results from defective osteoclast resorption, often due to a deficiency in carbonic anhydrase II or TCIRG1 mutations. This leads to an inability to acidify Howship's lacuna, preventing the breakdown of bone matrix and resulting in dense, brittle bones.

Question 81

A 65-year-old man presents with progressive bowing of his right femur and increasing head size. Laboratory studies show markedly elevated alkaline phosphatase with normal calcium and phosphorus. Histological examination of the affected bone is most likely to show which of the following?

Explanation

Paget disease of bone is characterized by chaotic bone remodeling. The classic histologic hallmark is a mosaic pattern of lamellar bone with prominent cement lines due to irregular, rapid episodes of bone resorption and formation.

Question 82

A 55-year-old patient with end-stage renal disease on hemodialysis presents with bone pain. Radiographs reveal subperiosteal bone resorption of the radial aspect of the middle phalanges and a 'rugger-jersey' spine. Which of the following pathophysiologic sequences best explains these findings?

Explanation

In renal osteodystrophy, failing kidneys retain phosphate and fail to convert 25-hydroxyvitamin D to its active form, 1,25-dihydroxyvitamin D. This leads to hypocalcemia, which stimulates the parathyroid glands to overproduce PTH, causing secondary hyperparathyroidism and subperiosteal resorption.

Question 83

A 45-year-old man presents with severe generalized bone pain and muscle weakness. Labs reveal severe hypophosphatemia, normal serum calcium, and elevated alkaline phosphatase. A small benign mesenchymal tumor is discovered in his thigh. Secretion of which of the following substances by the tumor is responsible for his metabolic bone disease?

Explanation

Tumor-induced osteomalacia (oncogenic osteomalacia) is a paraneoplastic syndrome caused by tumors that secrete FGF23. FGF23 inhibits renal phosphate reabsorption and decreases 1-alpha-hydroxylase activity, leading to hypophosphatemia and osteomalacia.

Question 84

A 7-year-old boy with a highly restricted diet presents with gingival bleeding, petechiae, and bone pain. Radiographs of his knees show a dense zone of provisional calcification (Frankel line) and a radiolucent zone adjacent to it (Trummerfeld zone). The underlying biochemical defect involves impaired:

Explanation

The clinical picture describes scurvy, caused by Vitamin C (ascorbic acid) deficiency. Vitamin C is an essential cofactor for prolyl and lysyl hydroxylases, which are required for the stable triple-helix formation of collagen.

Question 85

A 6-year-old child presents with short stature, corneal clouding, and severe genu valgum. Radiographs of the cervical spine reveal hypoplasia of the odontoid process. Urinalysis demonstrates high levels of keratan sulfate. What is the most likely diagnosis?

Explanation

Morquio syndrome (MPS Type IV) is an autosomal recessive disorder caused by a deficiency in enzymes degrading keratan sulfate. Odontoid hypoplasia is a hallmark skeletal feature that poses a high risk for atlantoaxial instability and myelopathy.

Question 86

A 12-year-old boy of Ashkenazi Jewish descent presents with hepatosplenomegaly, anemia, and bone pain. Radiographs of his distal femora demonstrate an 'Erlenmeyer flask' deformity. Bone marrow aspirate reveals large macrophages with a 'wrinkled tissue paper' appearance. What is the deficient enzyme?

Explanation

Gaucher disease is a lysosomal storage disorder caused by a deficiency of glucocerebrosidase. The accumulation of glucocerebroside in macrophages leads to bone marrow expansion, causing osteopenia, bone crises, and the classic Erlenmeyer flask deformity of the distal femur.

Question 87

A newborn is noted to have rhizomelic shortening of the limbs, frontal bossing, and midface hypoplasia. Genetic testing reveals a gain-of-function mutation in the FGFR3 gene. Which of the following best describes the fundamental defect in bone formation in this condition?

Explanation

Achondroplasia is caused by an activating mutation in FGFR3, which paradoxically inhibits chondrocyte proliferation and hypertrophy in the growth plate. This selectively impairs enchondral ossification, leading to short long bones, while intramembranous ossification (cranial vault) remains relatively unaffected.

Orthopedic Prometric MCQs - Chapter 4 Part 1

Orthopedic Prometric MCQs - Chapter 4 Part 10

Orthopedic Prometric MCQs - Chapter 4 Part 10

Chapter Index