Question 1

People with coal-worker’s pneumoconiosis are predisposed to developing which of the following diseases?

Explanation

Correct Answer: C- Progressive massive fibrosis Explanation Progressive massive fibrosis Simple coal-worker’s pneumoconiosis causes no symptoms or physical signs, nor any important

physiological abnormality. The danger associated with simple pneumoconiosis is that it predisposes to progressive massive fibrosis, a risk directly related to the degree of simple pneumoconiosis seen on the X-ray. Progressive massive fibrosis can occur during the coal- worker’s working life or it can appear clinically for the first time after (sometimes many years after) dust exposure ceases, even when there is no apparent simple pneumoconiosis on the X-ray. Progressive massive fibrosis usually causes a mixture of restriction of lung volumes and (due to associated emphysema) airflow obstruction. Ultimately, it can lead to cor pulmonale and death. However, the rate of progression is variable. In general, the earlier that progressive massive fibrosis develops in a person’s life, the more rapidly it is progressive. A patient with progressive massive fibrosis might complain of shortness of breath and symptoms of cor pulmonale. An unusual, but pathognomonic symptom is melanoptysis – the expectoration of the black contents of a cavitated lesion. Haemoptysis and finger clubbing suggest lung cancer and should not be attributed to pneumoconiosis. Abnormal signs in the chest, if present, relate to the presence of bullae, although sometimes lobar collapse can occur. Coal-worker’s pneumoconiosis is not associated with an increased risk of tuberculosis or of lung cancer, although obviously these diseases can be seen in coal miners and should be suspected if an unusual progression of radiological changes occurs. The association between pneumoconiosis and emphysema has been controversial, but there is now clear evidence of a parallel association between dust exposure and two effects – pneumoconiosis and airflow obstruction. The more dust that a miner has been exposed to, the greater are his risks of pneumoconiosis on the one hand, and productive cough, reduction in forced expiratory volume in 1 s (FEV1), and the presence of centri-acinar emphysema on the other. Of course, the latter risks are also related to cigarette smoking, and the effect of dust exposure is additive. Carcinoma of the lung Carcinoma of the lung is incorrect. Coal worker’s pneumoconiosis is not associated with an increased risk of lung cancer. Left-sided heart failure Left-sided heart failure is incorrect. Coal worker’s pneumoconiosis is not associated with an increased risk of heart failure. Silicosis Silicosis is incorrect. Coal worker’s pneumoconiosis is not associated with an increased risk of silicosis. Tuberculosis Tuberculosis is incorrect. Coal worker’s pneumoconiosis is not associated with an increased risk of tuberculosis.

Question 2

A 64-year-old mechanic and lifelong smoker noticed haemoptysis a few days after he had a cold. Clinical examination is unremarkable. His chest X-ray shows bilateral hilar enlargement and mediastinal widening. What is the next step in obtaining a diagnosis?

Explanation

Correct Answer: B- Computed tomography of the thorax Explanation Computed tomography of the thorax Where a chest X-ray has been requested in primary or secondary care and is incidentally suggestive of lung cancer, a second copy of the radiologist's report should be sent to a designated member of the lung cancer multidisciplinary team (MDT), usually the chest

physician. The MDT should have a mechanism in place to follow up these reports to enable the patient’s GP to have a management plan in place. Patients with known or suspected lung cancer should be offered a contrast-enhanced chest computed tomographic (CT) scan to further define the diagnosis and stage the disease. The scan should also include the liver and adrenals. Bronchoscopy Bronchoscopy is incorrect. Chest CT should be performed before an intended fibre-optic bronchoscopy or any other biopsy procedure. d-Dimer d- Dimer is incorrect. d-Dimer is an appropriate

investigation for pulmonary embolus. The history here is suggestive of lung carcinoma. Sputum sample Sputum sample is incorrect. Sputum sampling would not reveal the correct diagnosis here. This is not a history suggestive of respiratory infection. Ventilation/perfusion scan Ventilation/perfusion scan is incorrect. Ventilation/perfusion scans are used to investigate for pulmonary emboli in patients who cannot have CT pulmonary angiograms, eg owing to contrast allergy or severe renal impairment. This is not a history suggestive of pulmonary embolism.

Question 3

A 30-year-old asylum seeker has been complaining of cough, fever and weight loss. The chest X-ray shows a large upper-lobe lesion and the sputum shows acid-fast bacilli that are confirmed as Mycobacterium tuberculosis by polymerase chain reaction (PCR). Drug therapy with isoniazid, rifampicin, ethambutol and pyrazinamide has been started under directly observed therapy (DOT). Over the next 4 weeks the disease is found to be continuing to progress. What is the most likely reason?

Explanation

Correct Answer: C- Infection with multidrug-resistant tuberculosis Explanation Infection with multidrug-resistant tuberculosis Multidrug-resistant tuberculosis is defined as resistance to rifampicin and isoniazid, with or without resistance to other anti-TB drugs. Initial drug resistance is uncommon in previously untreated white patients born in the UK (< 2%). Higher levels of resistance occur in ethnic minority groups, particularly those of the Indian subcontinent and people of black African ethnic origin, with isoniazid resistance occurring in 4–6% of such patients. HIV- positivity, independent of ethnic group, is also a marker for increased drug resistance: a positive HIV result increases the chances of single- or multiple-drug resistance at least four-fold compared with an HIV- negative individual. Treatment is complex, time consuming and demanding for both the patient and the physician. Such treatment should only be carried out by physicians with substantial experience in managing complex resistant cases, and only in hospitals with appropriate isolation facilities. This might require transfer of the patient to an appropriate unit. Treatment of these patients has to be planned on an individual basis and needs to include reserve drugs. Such treatment must be closely monitored not only because of increased toxicity but, perhaps more importantly, full compliance is essential to prevent the emergence of further drug resistance. The treatment must therefore be directly observed throughout, both on an inpatient and an outpatient basis. Treatment should start with five or more drugs to which the organism is, or is likely to be susceptible, and should continue until sputum cultures become negative. Drug treatment then has to be continued with at least three drugs to which the organism is susceptible on in-vitro testing for a minimum of a further 9 months and perhaps up to or beyond 24 months, depending on the in-vitro drug-resistance profile, the available drugs and the patient’s HIV status. Consideration might also have to be given to resection of pulmonary lesions under drug cover. Aspiration pneumonia Aspiration pneumonia is incorrect. There is nothing in this history to suggest this gentleman would develop an aspiration pneumonia. In particular there is no history given of alcohol or drug excess, vomiting, reduced consciousness, swallowing difficulty or neuromuscular impairment; multidrug- resistant TB is far more likely. Carcinoma of the lung Carcinoma of the lung is incorrect. There is nothing in this history to suggest an underlying lung malignancy. In particular the patient is young and no smoking history is mentioned. Multidrug- resistant TB is more likely. Infection with an atypical mycobacterium Infection with an atypical mycobacterium is incorrect. Mycobacterium tuberculosis has already been identified in this case. Poor response to treatment due to multidrug- resistant M. tuberculosis is more likely than superadded infection. Underlying bacterial pneumonia Underlying bacterial pneumonia is incorrect. M. tuberculosis has already been identified in this case and it is more likely that this is a multidrug-resistant strain of M. tuberculosis, hence the poor response to treatment, rather than a superadded infection.

Question 4

An anxious, 25-year-old saleswoman presented with mild shortness of breath on exertion, which had come on gradually over several months. The symptom was intermittent and seemed to get worse in the evening. She had also been on treatment for depression over the previous 2 months. On examination, she has minimal weakness of shoulder abductors and slight weakness of eye closure bilaterally. Deep tendon reflexes are present and symmetrical throughout and plantars responses are flexor. You now have the results of the investigations – FBC, U&E, LFT, electrocardiography, chest X- ray and lung function tests were all normal. What is the most likely diagnosis?

Explanation

Correct Answer: C- Myasthenia gravis Explanation Myasthenia gravis This young woman has myasthenia gravis, an autoimmune condition. Muscle weakness might not be apparent on a single examination, so the examination should be repeated – most affected are the ocular and shoulder-girdle muscles Clinical features • Respiratory and proximal lower limb muscles can be involved early in the disease. • Breathlessness can develop early and cause sudden death. • Swallowing problems, slurred speech and difficulty in chewing can be caused by bulbar involvement. • Asymmetrical involvement of an external ocular muscle can mimic cranial nerve palsy but pupillary reflexes are normal. • Mild ptosis and weak facial muscles can make patients appear depressed. • Thymic enlargement is seen in only 15% of patients. Angina Angina is incorrect. Angina is very unlikely in a 25-year- old. Regardless, the symptoms described are not in keeping with angina. They are in keeping with muscular weakness. Eaton–Lambert syndrome Eaton-Lambert syndrome is incorrect. Eaton–Lambert syndrome is often associated with malignancy, often small cell lung cancer and of note this patient is young and has a normal chest radiograph. Ocular muscles are usually less affected than is seen with myasthenia gravis. Respiratory muscles are not usually affected in Eaton–Lambert syndrome. Overall, myasthenia gravis is a more likely diagnosis here. Somatisation disorder Somatisation disorder is incorrect. Somatisation disorder is a diagnosis of exclusion. This lady has clear symptoms and signs compatible with myasthenia gravis therefore it is more likely she has a pathological underlying diagnosis. Transient ischaemic attack Transient ischaemic attack is incorrect. The symptoms have had a gradual onset over several months, there are no risk factors mentioned for cerebrovascular disease and her symptoms are bilateral. This is not a history of transient iscahemic attacks.

Question 5

A 35-year-old woman who was previously fit and well presents with breathlessness that has been getting worse over 3–4 months. Her sister died a few years ago of a lung disease. On examination, her jugular venous pressure is raised and she has a palpable heave at the left sternal edge. Her BMI is 23, blood pressure is 135/72 mmHg and her pulse is 80 beats per min and regular. What would your provisional diagnosis be?

Explanation

Correct Answer: C- Familial primary pulmonary hypertension Explanation Familial primary pulmonary hypertension Primary pulmonary hypertension presents with breathlessness, fatigue, angina (due to right ventricular ischaemia) or presyncope/syncope. About 6% of all patients with primary pulmonary hypertension have a family history of the condition, which exhibits an autosomal dominant pattern of inheritance with incomplete penetrance. Physical signs include:

• Elevated JVP • Left parasternal heave • Pansystolic murmur (tricuspid regurgitation) • Right ventricular S4 • Peripheral oedema Chronic pulmonary thromboembolism Chronic pulmonary thromboembolism is incorrect. An important differential diagnosis of primary pulmonary hypertension is chronic pulmonary thromboembolism. However, given there is no history given of previous thromboembolism and a probable family history of a similar condition primary pulmonary hypertension is more likely in this case. Constrictive pericarditis Constrictive pericarditis is incorrect. Constrictive pericarditis would usually present with a more gradual history of symptoms over years rather than months. Also, you might expect a relevant history of a potential cause of constrictive pericarditis such as previous pericarditis, tuberculosis, cardiac surgery or radiotherapy. A history or clinical examination findings of peripheral oedema and ascites would be likely as would sinus tachycardia and there is no mention if these in this case. Pulmonary venous hypertension Pulmonary venous hypertension is incorrect. Pulmonary venous hypertension (an increase in pulmonary capillary wedge pressure over the normal 12-14 mmHg) is a consequence of chronic left sided heart failure e.g. due to mitral valve disease. This can increase pulmonary artery pressure but usually not severely. Symptoms expected would be more in keeping with left sided heart failure. Tricuspid regurgitation Tricuspid regurgitation is incorrect. Whilst this lady may well have tricuspid regurgitation as a consequence of her primary pulmonary hypertension it is not the primary problem leading to her current symptoms. The family history and lack of mention of a murmur make primary pulmonary hypertension the best unifying diagnosis for her symptoms.

Question 6

A 56-year-old woman with rheumatoid arthritis complains that she has had recurrent haemoptysis for over 5 years. She has never smoked and her only medication is a non-steroidal anti-inflammatory agent. She tells you that she coughs up phlegm every day and at times this contains streaks of fresh blood. She has no known respiratory disease, but tends to get frequent chest infections that are relieved by a course of antibiotics. What is the most likely diagnosis?

Explanation

Correct Answer: B- Bronchiectasis Explanation Bronchiectasis Some 3–4% of patients with rheumatoid arthritis develop bronchiectasis. This is characterised by recurrent haemoptysis. The history of expectorating phlegm on most days and frequent chest infections is suggestive of the diagnosis. A high-resolution computed tomography scan of her lungs will establish the diagnosis. Atypical pneumonia Atypical pneumonia is incorrect. This lady may indeed acquire infections with atypical organisms but the history suggests there is an underlying chronic respiratory disorder leaving her vulnerable to recurrent chest infections. Therefore, bronchiectasis is the most appropriate answer. Lung cancer Lung cancer is incorrect. Her lack of smoking history coupled with a history of rheumatoid arthritis and long (5-year) history of chronic productive cough with recurrent respiratory infections is more in keeping with bronchiectasis than malignancy. Pulmonary embolism Pulmonary embolism is incorrect. Although pulmonary emboli can be associated with haemoptysis, there are features in this history such as duration of symptoms, presence of daily sputum production and history of recurrent chest infections which make pulmonary embolism an unlikely cause of her haemoptysis. Tuberculosis Tuberculosis is incorrect. Tuberculosis can cause productive cough and haemoptysis. However, the duration of symptoms is too long to consider tuberculosis as a likely diagnosis. In addition, Mycobacterium tuberculosis would not respond to typical antibiotics used for respiratory tract infections.

Question 7

A 55-year-old woman attends the Chest Clinic complaining of a dry cough she has had for 6 months. It is worse when she has been walking and when she wakes up in the mornings. Examination and chest X-ray are both normal, as are her pulmonary function tests. Which of the following would be most helpful in making a diagnosis?

Explanation

Correct Answer: E- Trial of high-dose inhaled steroids Explanation Trial of high-dose inhaled steroids Cough-variant asthma represents one end of the asthma spectrum, with airway inflammation but minimal bronchoconstriction. Hence peak-flow measurement may not be as useful in establishing the diagnosis and potential benefit of steroids as a trial of steroids itself. There might not be a typical asthma history; the cough is typically worse in the mornings, in the cold air and after exercise. Methacholine challenge testing can be negative. Spirometry might be normal, with no evidence of bronchodilatation, and peak flows are often stable. Treatment is with high-dose inhaled steroids for at least 2 months, or a short course of oral steroids. Response to steroids is helpful when making the diagnosis of asthma. Bronchodilators often have little effect. Ambulatory oesophageal pH monitoring Ambulatory oesophageal pH monitoring is incorrect. pH monitoring is performed in people with suspected reflux who have not responded to empirical treatment with a proton-pump inhibitor, or if there is diagnostic uncertainty. Computed tomography scan of her chest Computed tomography scan of her chest is incorrect. Computed tomography is not usually required unless there is a suspicion of interstitial lung disease or cancer, or when all other investigations and treatments have failed. ENT examination with direct laryngoscopy ENT examination with direct laryngoscopy is incorrect. Ear, nose and throat (ENT) examination might be helpful if there is a suspicion of a postnasal drip – along with reflux and asthma, this is a common cause of chronic cough. Serial peak flows Serial peak flows is incorrect. This is a description of cough-variant asthma and therefore peak expiratory flows may well be normal and unhelpful in making the correct diagnosis.

Question 8

A 26-year-old woman arrives in the Arabic Gulf area from Australia. A few days later she presents to hospital with pleuritic chest pain and breathlessness. She is not on the oral contraceptive pill and has no family or personal history of deep vein thrombosis (DVT) or pulmonary embolism (PE). A pulmonary embolus is confirmed radiologically and she is started on warfarin. How long would you continue warfarin therapy in these circumstances?

Explanation

Correct Answer: B-3 months Explanation 3 months This young woman’s only risk factor is the long-haul flight, which is only a temporary risk factor. That being said, this would be considered a provoked PE, as such 3 months’ anti-coagulation is sufficient. 4–6 weeks 4–6 weeks is incorrect. Previous guidelines suggested that a duration of 4–6 weeks’ anticoagulation is adequate when a DVT has occurred post surgery. However, 2012 guidelines suggest a minimum of 3 months’ anticoagulation for all provoked DVTs. 6 months 6 months is incorrect. Patients with unprovoked PE should be treated initially for 3 months, with review at the 3 month stage for consideration of extension to 6 months, where there is thought to be increased risk of a recurrence. 6 months of anticoagulation is recommended for DVT or PE in the presence of active malignancy. The decision to stop or continue anticoagulation after 6 months in such patients should be made on an individual basis. 1 year 1 year is incorrect. Patients with unprovoked PE should be treated initially for 3 months, with review at the 3 month stage for consideration of extension to 6 months, where there is thought to be increased risk of a recurrence. 6 months of anticoagulation is recommended for DVT or PE in the presence of active malignancy. The decision to stop or continue anticoagulation after 6 months in such patients should be made on an individual basis. Lifelong Lifelong is incorrect. Lifelong anticoagulation is generally only recommended for a history or recurrent DVT/PE.

Question 9

In which of the following pulmonary diseases is the alveolar structure preserved?

Explanation

Correct Answer: B- Asthma Explanation Asthma Asthma is a chronic inflammatory disease of the bronchial airways that is characterised by a desquamative eosinophilic bronchitis. The defining clinical characteristics of asthma are reversible airway narrowing and increased airway responsiveness to non-specific provocative stimuli. The alveolar functional structure is preserved. Extrinsic allergic alveolitis Extrinsic allergic alveolitis is incorrect. Extrinsic allergic alveloitis is characterised histologically by alveolar destruction and interstitial inflammation. Non-caseating granulomas are also present and asteroid bodies may be found in or adjacent to the granulomas. Pneumonia Pneumonia is incorrect. Aveoli typically become fluid filled and distended in pneumonia. Idiopathic pulmonary fibrosis Idiopathic pulmonary fibrosis is incorrect. Marked architectural distortion and destruction are typically seen in idiopathic pulmonary fibrosis. Cryptogenic organising pneumonia Cryptogenic organising pneumonia is incorrect. In cryptogenic organising pneumonia there is excessive growth of granulation tissue causing chronic inflammation within the alveoli.

Question 10

A 29-year-old woman who is breastfeeding presents to the on-call GP with a cough productive of rust-coloured sputum. She has also had increasing fevers over the past few days. On examination, her temperature is 38.6 °C, blood pressure 110/70 mmHg and pulse 90 bpm. She has bronchial breathing at the right base on auscultation of her chest. She is allergic to penicillin.

Investigation:

Hb 12.5 g/dl

WCC 11.5 x 109/l

PLT 211 x 109/l

Sodium 139 mmol/l

Potassium 4.5 mmol/l

Creatinine 90 µmol/l A chest X-ray shows a right lower-lobe pneumonia. Which of the following would be the most appropriate antibiotic choice?

Explanation

Correct Answer: C- Clarithromycin Explanation Clarithromycin Clarithromycin is an appropriate choice in penicillin- allergic patients for the treatment of community- acquired pneumonia. Cefalexin Cefalexin is incorrect. Cefalexin would be a reasonable choice if there were no alternatives, but there is 10% crossover with penicillin allergy. Ciprofloxacin Ciprofloxacin is incorrect. Ciprofloxacin is associated with tendon rupture in juvenile animal models and is therefore not recommended during breastfeeding. Co-amoxiclav Co-amoxiclav is incorrect. This patient is allergic to penicillins, which immediately rules out co- amoxiclav, which is a combination of amoxicillin and clavulanic acid. Flucloxacillin Flucloxacillin is incorrect. This patient is allergic to penicillins, which immediately rules out flucloxacillin.

Question 11

You review a 35-year-old woman with progressively increased shortness of breath and lethargy after the birth of her first child. You send her for some pulmonary function tests, including measurement of gas transfer. Which of the following gases is usually used for measurement of gas transfer?

Explanation

Correct Answer: A- Carbon monoxide Explanation Carbon monoxide The Dlco (or diffusing capacity for carbon monoxide) is the standard method for measuring gas transfer from alveoli to red blood cells. Dlco is measured by looking at end-expiratory levels of carbon monoxide after inspiring a small amount and breath-holding. It is adjusted for haematocrit and alveolar volume. Conditions that affect the pulmonary vasculature and factors that lead to pulmonary fibrosis affect the Dlco. Carbon dioxide Carbon dioxide is incorrect. Dlco is measured by looking at end-expiratory levels of carbon monoxide after inspiring a small amount and breath-holding. Methane Methane is incorrect. Dlco is measured by looking at end-expiratory levels of carbon monoxide after inspiring a small amount and breath-holding. Nitrous oxide Nitrous oxide is incorrect. Dlco is measured by looking at end-expiratory levels of carbon monoxide after inspiring a small amount and breath-holding. Oxygen Oxygen is incorrect. Dlco is measured by looking at end- expiratory levels of carbon monoxide after inspiring a small amount and breath-holding.

Question 12

A 65-year-old man with severe rheumatoid arthritis (RA) is admitted with a right pleural effusion. He has been complaining of dyspnoea on exertion for the last 3 months. He has never smoked and has not worked for over 20 years, since his rheumatoid arthritis was first diagnosed. Which of the following is true?

Explanation

Correct Answer: A- A glucose level in pleural fluid of < 1.6 mmol/l is characteristic of a rheumatoid pleural effusion Explanation A glucose level in pleural fluid of < 1.6 mmol/l is characteristic of a rheumatoid pleural effusion These effusions are characterised by some or all of the following:

• Low glucose (< 1.6 mmol/l) (the correct answer) • High lactate dehydrogenase (> 700 IU/l) • Low pH (< 7.2) • A high rheumatoid factor titre (> 1:320) • High cholesterol levels Bilateral pleural effusions do not occur in RA Bilateral pleural effusions do not occur in RA is incorrect. About a quarter of patients experience bilateral effusions. Pleural effusions associated with RA show low levels of cholesterol Pleural effusions associated with RA show low levels of cholesterol is incorrect. As described pleural effusions are characterised by high levels of cholesterol. Pleural effusions occur in over 50% of patients with rheumatoid arthritis Pleural effusions occur in over 50% of patients with rheumatoid arthritis is incorrect. Around 5% of patients with RA develop pleural effusions. These mainly occur in older male patients who have subcutaneous nodules. The most appropriate treatment is chemical pleurodesis The most appropriate treatment is chemical pleurodesis is incorrect. The majority of these effusions resolve spontaneously within 3 months and require no intervention. Management is with treatment of RA in general. Occasionally they persist and massive pleural thickening develops. These patients might need decortication if they are symptomatic.

Question 13

A 17-year-girl who has cystic fibrosis presents with increasing cough productive of purulent sputum. She has had three previous admissions to hospital with exacerbations over the past 4 years. So far she is maintaining her weight and is able to continue her studies at school. On examination, she is pyrexial (37.8°C), her blood pressure is 120/72 mmHg and her pulse is 90 bpm and regular. She has bilateral crackles and wheeze; the crackles are particularly increased at the left base.

Investigation:

Hb 12.0 g/dl

WCC 13.1 x 109/l

PLT 181 x 109/l

Sodium 141 mmol/l

Potassium 4.9 mmol/l

Creatinine 110 µmol/l CRP 71 mg/l Previous sputum cultures show a growth of Pseudomonas aeruginosa. Which of the following is the most appropriate initial antimicrobial treatment?

Explanation

Correct Answer: B- Ceftazidime and tobramycin Explanation Ceftazidime and tobramycin The combination of ceftazidime and tobramycin is the antibiotic regimen of choice for the treatment of cystic fibrosis exacerbations in patients with Pseudomonas aeruginosa. Both ceftazidime and tobramycin have good anti-pseudomonal activity and combination therapy is preferred to minimise development of resistant strains. Treatment should be continued for 10-14 days. Amoxicillin and clarithromycin Amoxicillin and clarithromycin is incorrect. This is an appropriate antibiotic regimen for a non-severe community-acquired pneumonia. It will not provide adequate anti-pseudomonal cover to treat an infective exacerbation of cystic fibrosis. Ciprofloxacin Ciprofloxacin is incorrect. Ciprofloxacin may be tried orally if an exacerbation is mild but intravenous combination therapy is preferable. Clindamycin Clindamycin is incorrect. Clindamycin does not provide adequate anti-pseudomonal cover. It is sometime used in cystic fibrosis to treat exacerbations secondary to Staphylococcus aureus. Piperacillin plus tazobactam (Tazocin®) Piperacillin plus tazobactam (Tazocin®) is incorrect. Tazobactam is not an antibiotic rather a beta- lactamase inhibitor, so Tazocin, which is a mixture of piperacillin (an antibiotic) and tazobactam (a drug which prevents bacteria from inactivating piperacillin) does not count as combination antibiotic therapy. Tazocin® is active against Pseudomonas aeruginosa. However, a combination of antibiotics is preferable to minimise the risk of antibiotic resistance which is why the correct choice here is ceftazidime and tobramycin.

Question 14

A 45-year-old man comes to the Respiratory Clinic for review. He has suffered a third episode of pneumonia over the course of the past year, and now has persistent right lower lobe changes on his X-ray. He is treated with regular Seretide and salbutamol for reversible airways obstruction and takes amlodipine for hypertension. On examination his BP is 132/82 mmHg, pulse is 70/min and regular. There are crackles at the right base consistent with consolidation. His temperature is 37.4 °C. His BMI is 24.

Investigations:

Hb 13.1 g/dl

WCC 9.2 × 109/l

PLT 201 × 109/l

Na+ 138 mmol/l

K+ 4.3 mmol/l

Creatinine 103 μmol/l CRP 32 mg/l

CXR Right lower lobe consolidation

HRCT Bronchial wall dilatation and thickening affecting the right lower lobe You suspect bronchiectasis. Which of the following is the most logical next step?

Explanation

Correct Answer: D- Serum immunoglobulins Explanation Serum immunoglobulins A number of the listed investigations are reasonable steps in elucidating the underlying cause of bronchiectasis, but serum immunoglobulins both to look for elevated IgE (consistent with possible allergic bronchopulmonary aspergillosis (ABPA)), and immunoglobulin deficiency (both IgA and IgG subclass deficiencies are possible) are a reasonable next step investigation. 24-h pH monitoring 24-h pH monitoring is incorrect. 24-h pH monitoring can be conducted if reflux is suspected. Bronchoscopy Bronchoscopy is incorrect. Bronchoscopy is not a standard investigation in bronchiectasis. It may be used to investigate localised bronchiectasis to rule out an obstructive cause. Ciliary function testing Ciliary function testing is incorrect. Ciliary function tests would be indicated if the history suggested underlying ciliary dysfunction (eg sinusitis, infertility) Sweat test Sweat test is incorrect. Late presentation with CF would be highly unusual, therefore a sweat test, if conducted, would occur much later in the investigation cascade.

Question 15

You are asked to look at a Heaf test performed 1 week ago on a man. His wife is on the ward with pulmonary tuberculosis. He is asymptomatic and has a normal chest X-ray. He has had a previous BCG vaccination. Looking at the test, the dots are joining up to make a faint red ring. What does this mean?

Explanation

Correct Answer: D- The man has previously had a BCG vaccination Explanation The man has previously had a BCG vaccination Heaf tests are graded as follows:

• 0 No reaction • 1 4–6 small dots • 2 Dots coalesce, normal skin in centre • 3 Dots coalesce, central skin filled in • 4 Solid induration > 10 mm, with or without vesiculation or ulceration This man has previously had a BCG vaccination is correct.Grade 2 is a normal response in the presence of a previous BCG vaccination. The man does not have tuberculosis and has not had a BCG vaccination The man does not have tuberculosis and has not had a BCG vaccination is incorrect. Without prior BCG vaccination in an HIV-negative patient with no previous exposure to TB a grade 0 reaction would be expected. The man has had a BCG vaccination and has tuberculosis The man has had a BCG vaccination and has tuberculosis is incorrect. A grade 3–4 reaction would indicate active disease in an HIV-negative patient. The man has HIV, but does not have tuberculosis The man has HIV, but does not have tuberculosis is incorrect. An HIV-positive patient without active tuberculosis would likely have a grade 0 reaction. The man has tuberculosis The man has tuberculosis is incorrect. A grade 3–4 reaction would indicate active disease in an HIV- negative patient.

Question 16

A 56-year-old man has a chest X-ray performed because he has become breathless on exertion and has inspiratory crackles. The chest X-ray reveals upper-lobe lung fibrosis. Which of the following is the most likely explanation?

Explanation

Correct Answer: E- Langerhans cell histiocytosis Explanation Langerhans cell histiocytosis Upper zone fibrosis typically occurs in:

• Tuberculosis • Extrinsic allergic alveolitis • Sarcoidosis • Ankylosing spondylitis • Allergic bronchopulmonary aspergillosis and farmer’s lung • Pneumoconiosis • Histiocytosis • Silicosis Asbestosis Asbestosis is incorrect. Asbestosis would usually result in lower-zone fibrosis and therefore Langerhan’s cell histiocytosis is more likely. However, many of these diseases can affect both the upper and lower zones as they progress. Connective tissue disease related interstitial lung disease Connective tissue disease related interstitial lung disease is incorrect. This would usually result in lower-zone fibrosis and is therefore less likely than Langerhan’s cell histiocytosis. However, many of these diseases can affect both the upper and lower zones as they progress. Drug-induced interstitial lung disease Drug-induced interstitial lung disease is incorrect. This would usually result in lower-zone fibrosis and is therefore less likely than Langerhan’s cell histiocytosis. However, many of these diseases can affect both the upper and lower zones as they progress. Idiopathic pulmonary fibrosis Idiopathic pulmonary fibrosis is incorrect. This would usually result in lower-zone fibrosis and therefore Langerhan’s cell histiocytosis is more likely. However, many of these diseases can affect both the upper and lower zones as they progress.

Question 17

A 50-year-old man has been referred by his GP because of a long-standing history of persistent cough productive of mucopurulent sputum. The patient was treated several times for recurrent chest infections. What is the most appropriate diagnostic step to confirm the diagnosis?

Explanation

Correct Answer: C- High-resolution computed tomography Explanation High-resolution computed tomography The gold standard for the diagnosis of bronchiectasis is thin-section high-resolution computed tomography (HRCT) of the chest, which has replaced the more invasive investigation of bronchography. The diagnostic criteria for bronchiectasis on HRCT depend on finding both dilatation and thickening of the affected bronchi, dilatation being present if the internal diameter of the bronchus is greater than the diameter of its accompanying pulmonary artery. The classic appearance of a cross-section of a thick-walled dilated bronchus next to the accompanying pulmonary artery is the ‘signet ring’ sign. Bronchial dilatation is also recognised when airways are seen in longitudinal section on CT and there is a failure of tapering as the bronchus courses towards the periphery. Bronchoscopy Bronchoscopy is incorrect. Bronchoscopy in bronchiectasis may demonstrate larger than expected bronchi with visible mucopurulent secretions, but it will not detect bronchiectasis affecting distal airways. Given the test is invasive and not always diagnostic, it is not routinely used in diagnosing bronchiectasis. Bronchoscopy is indicated in cases of localised bronchiectasis to rule out a foreign body or obstructing lesion, eg carcinoma. Chest X-ray Chest X-ray is incorrect. The chest radiograph can be normal in at least 50% of patients with computed tomographic or bronchographic evidence of bronchiectasis. If it is abnormal the findings reflect thickened and dilated bronchi, which produce tramline opacities and ring shadows. Retained mucus might be seen as tubular opacities, and there can be associated volume loss of the affected lobe. Spirometry Spirometry is incorrect. Spirometry is normal or obstructive in bronchiectasis, depending on the severity, but spirometry alone is not a sufficient diagnostic test for bronchiectasis. Ventilation/perfusion scan Ventilation/perfusion scan is incorrect. Ventilation/perfusion scans are used in the diagnosis of pulmonary embolism. They are not used to investigate for bronchiectasis.

Question 18

A 59-year-old man with a history of coronary artery disease is admitted for observation the evening after a house fire. He is thought to have inhaled a significant amount of smoke. The nurses put out a critical care call as he has deteriorated rapidly with increasing shortness of breath and hypoxia. He is intubated and ventilated by the ITU registrar. On examination his BP is 135/72 mmHg, and pulse is 88/min and regular. Which of the following favours a diagnosis of acute respiratory distress syndrome (ARDS)?

Explanation

Correct Answer: D- Increased elastic recoil Explanation ARDS is associated with increased elastic recoil. Fluid in the horizontal fissure on chest X-ray Fluid in the horizontal fissure on chest X-ray (Option A) is incorrect. Fluid in the horizontal fissure on chest X-ray implies fluid overload and an increased pulmonary artery wedge pressure. ARDS is associated with low pulmonary artery wedge pressure. High compliance High compliance (Option B) is incorrect. ARDS is associated with low compliance. Mechanical ventilation is a difficult balance between achieving adequate oxygenation and avoiding end organ damage relating to the high pressures required. High pulmonary artery wedge pressure High pulmonary artery wedge pressure (Option C) is incorrect. ARDS is associated with low pulmonary artery wedge pressure. Increased transfer factor Increased transfer factor (Option E) is incorrect. ARDS is associated with reduced gas exchange.

Question 19

A 74-year-old man with previously stable emphysema presents to A&E with right-sided pleuritic chest pain and sudden increase in shortness of breath. There are no other associated symptoms and no signs to suggest acute infection. There appears to be decreased vocal resonance over the upper right side of the chest. Which is the most likely diagnosis in this case?

Explanation

Correct Answer: C- A spontaneous pneumothorax Explanation A spontaneous pneumothorax Underlying COPD is the usual cause of pneumothorax in patients of this age group. Other, rarer causes of pneumothorax include asthma, underlying carcinoma, lung abscess and severe pulmonary fibrosis with cyst formation. Acute-onset pneumonia Acute-onset pneumonia is incorrect. The information provided states that there are no signs to suggest acute infection so an infectious cause of this man’s illness is unlikely. An exacerbation of COPD An exacerbation of COPD is incorrect. The sudden onset of shortness of breath associated with pleuritic chest pain with absence of infective symptoms in this case makes pneumothorax more likely than COPD exacerbation. Empyema Empyema is incorrect. The information provided states that there are no signs to suggest acute infection so an infectious cause of this man’s illness is unlikely. Furthermore, empyema would almost certainly have a more insidious onset of symptoms such as shortness of breath and chest pain. Pulmonary embolism Pulmonary embolism is incorrect. Pulmonary embolism can cause sudden onset shortness of breath and chest pain but the decreased vocal resonance detected points towards a diagnosis of pneumothorax.

Question 20

A 62-year-old heavy smoker comes to the Emergency Department with a persistent cough and severe shortness of breath meaning that he is unable to lay down flat in bed. He has a history of hypertension and chronic obstructive pulmonary disease (COPD) and a previous inferior myocardial infarction. On examination his BP is 155/72 mmHg, pulse is 80 bpm and regular. He has coarse crackles and wheeze consistent with his diagnosis of chronic obstructive pulmonary disease (COPD) on auscultation of the chest. You can feel supraclavicular lymphadenopathy.

Investigations:

Hb 12.0 g/dl

WCC 10.9 × 109/l

PLT 199 × 109/l

ESR 72 mm/1st hour

Na+ 138 mmol/l

K+ 4.0 mmol/l

Creatinine 120 μmol/l

ALT 230 U/l

Bilirubin 17 μmol/l

ALP 199 U/l Chest X-ray (CXR) Evidence of mediastinal mass, lymphadenopathy (previous X-ray did not show these changes some 3 months earlier) Which one of the following is the most likely diagnosis?

Explanation

Correct Answer: D- Small-cell lung carcinoma Explanation Small-cell lung carcinoma Of the options given, only small-cell lung cancer progresses rapidly enough to move from no changes on

CXR to significant changes within only 3 months. The abnormal liver function raises the possibility of hepatic metastases. The evidence of hepatic metastases should be further investigated with imaging, and the patient considered for platinum-based multi-drug regimen chemotherapy. Up to 70% of patients with small-cell lung cancer are recognised to have disseminated disease at the time of presentation. Adenocarcinoma of the lung Adenocarcinoma of the lung is incorrect. Adenocarcinoma of the lung would not progress rapidly enough to move from no changes on CXR to significant changes within only 3 months. Bronchoalveolar carcinoma Bronchoalveolar carcinoma is incorrect. Bronchoalveolar carcinoma would not progress rapidly enough to move from no changes on CXR to significant changes within only 3 months. Large-cell lung carcinoma Large-cell lung carcinoma is incorrect. Large-cell lung carcinoma would not progress rapidly enough to move from no changes on CXR to significant changes within only 3 months. Squamous-cell lung carcinoma Squamous-cell lung carcinoma is incorrect. Squamous- cell lung carcinoma would not progress rapidly enough to move from no changes on CXR to significant changes within only 3 months.

Question 21

A 45-year-old immigrant presents with chronic back pain, low-grade fevers, and an increasing kyphotic deformity of the thoracolumbar spine. Imaging reveals destruction of the T11 and T12 vertebral bodies with a paravertebral abscess. What is the most frequent route of spread for this pathogen to the spine in adults?

Explanation

Tuberculous spondylitis (Pott's disease) most commonly spreads to the spine hematogenously. In adults, Batson's valveless venous plexus is the primary route, leading to subchondral bone involvement and subsequent disc space narrowing.

Question 22

A 68-year-old female presents with progressive groin pain 12 years after a cementless total hip arthroplasty. Radiographs reveal significant eccentric wear of the polyethylene liner and periprosthetic osteolysis. What particle size of polyethylene wear debris is most biologically active in initiating this macrophage-mediated response?

Explanation

Polyethylene wear particles between 0.1 and 1.0 micrometers are the most biologically active. They are phagocytosed by macrophages, triggering the release of inflammatory cytokines (IL-1, IL-6, TNF-alpha) that stimulate osteoclast-mediated bone resorption.

Question 23

A 13-year-old obese male presents with a painful limp and obligatory external rotation of the hip during flexion. He is diagnosed with a slipped capital femoral epiphysis (SCFE). Which blood supply to the femoral head is most at risk in this condition?

Explanation

The lateral epiphyseal vessels, which are terminal branches of the medial femoral circumflex artery (MFCA), supply the majority of the femoral head. These vessels are highly vulnerable to stretching or kinking in SCFE, risking avascular necrosis.

Question 24

A 15-year-old boy presents with progressive knee pain and a palpable mass in the distal femur. Radiographs show a destructive metaphyseal lesion with a 'sunburst' periosteal reaction. Biopsy confirms classic high-grade intramedullary osteosarcoma. What is the defining histological hallmark of this tumor?

Explanation

The defining histological characteristic of osteosarcoma is the production of malignant osteoid by atypical, malignant spindle cells. Homer-Wright rosettes describe Ewing sarcoma, while a prominent chondroid matrix without osteoid points to chondrosarcoma.

Question 25

A 25-year-old male sustains a comminuted midshaft tibial fracture. Twelve hours post-admission, he develops severe leg pain out of proportion to his injury that is worsened by passive stretch of his toes. When utilizing intracompartmental pressure monitoring, what delta pressure threshold strongly indicates the need for emergency fasciotomy?

Explanation

A delta pressure (Diastolic Blood Pressure minus Compartment Pressure) of 30 mmHg or less is widely accepted as an absolute indication for fasciotomy in acute compartment syndrome. Absolute compartment pressures are less reliable than delta pressure.

Question 26

During the repair of a complete Zone II flexor tendon laceration in the hand, the surgeon must preserve certain structures to prevent bowstringing of the tendon. Which of the following pulley combinations is most critical to preserve or reconstruct?

Explanation

The A2 and A4 pulleys are the most critical biomechanical pulleys in the finger flexor tendon sheath. Preserving or reconstructing them is essential to prevent bowstringing and maintain mechanical efficiency during finger flexion.

Question 27

A 22-year-old football player sustains a high-energy varus blow to his knee. Examination reveals significant posterolateral corner (PLC) instability. Which peripheral nerve is most commonly injured in association with this specific injury pattern?

Explanation

The common peroneal nerve is uniquely susceptible to traction injury during a varus and hyperextension force that disrupts the posterolateral corner (PLC) of the knee. Patients should be assessed for foot drop and numbness in the first web space.

Question 28

A 35-year-old male falls from a height and presents with severe midfoot pain and plantar ecchymosis. Radiographs reveal a diastasis between the first and second metatarsals. The Lisfranc ligament, critical for midfoot stability, primarily connects which two osseous structures?

Explanation

The Lisfranc ligament is a strong interosseous ligament that connects the lateral aspect of the medial cuneiform to the medial aspect of the base of the second metatarsal. Disruption leads to primary instability of the tarsometatarsal joint complex.

Question 29

During the process of secondary bone healing, a soft callus forms at the fracture site to bridge the gap before enchondral ossification occurs. What type of collagen is most predominant in this soft callus phase?

Explanation

The soft callus primarily consists of fibrocartilage, making Type II collagen the predominant type during this phase. As endochondral ossification progresses, it is gradually replaced by woven bone, which is predominantly Type I collagen.

Question 30

A 50-year-old male presents with severe lumbar back pain, saddle anesthesia, and bilateral lower extremity weakness. MRI reveals a massive L4-L5 disc herniation compressing the nerve roots. Which of the following factors is the most reliable early predictor of a favorable functional outcome following surgical decompression?

Explanation

In cauda equina syndrome, preoperative urinary continence status is the most significant predictor of postoperative bladder and bowel function recovery. Patients who are incontinent preoperatively have significantly poorer long-term outcomes.

Question 31

A 45-year-old male is brought to the trauma bay after a motorcycle crash. Pelvic radiographs show an anteroposterior compression type III (APC-III) pelvic ring injury. By definition, this injury pattern involves complete disruption of which posterior structures?

Explanation

An APC-III injury represents complete global instability of the hemipelvis. It is characterized by the complete disruption of both the anterior and posterior sacroiliac ligaments, as well as the sacrotuberous and sacrospinous ligaments.

Question 32

A 72-year-old male complains of a chronically painful knee 3 years after a primary total knee arthroplasty. According to the Musculoskeletal Infection Society (MSIS) criteria, what minimum synovial fluid white blood cell (WBC) count is highly suggestive of a chronic periprosthetic joint infection in a knee > 1 year post-op?

Explanation

For chronic periprosthetic joint infections (> 1 year post-op), a synovial fluid WBC count greater than 3,000 cells/uL (and > 80% polymorphonuclear cells) is a major threshold criterion according to standard MSIS guidelines.

Question 33

A 25-year-old male falls on an outstretched hand and sustains a non-displaced fracture of the proximal pole of the scaphoid. He is at a high risk for avascular necrosis and nonunion. What is the primary anatomical reason for this complication?

Explanation

The scaphoid relies on a retrograde blood supply, primarily from the dorsal carpal branch of the radial artery which enters at the distal pole. Fractures at the proximal pole effectively sever its blood supply, leading to high rates of avascular necrosis.

Question 34

In an 8-month-old female undergoing attempted closed reduction for developmental dysplasia of the hip (DDH), the surgeon encounters a block to concentric reduction. Which of the following is considered a primary intra-articular anatomic block to reduction in this condition?

Explanation

Common intra-articular obstacles to closed reduction in DDH include an inverted limbus (labrum), hypertrophied pulvinar, a tight/constricted transverse acetabular ligament, and a hypertrophied ligamentum teres.

Question 35

A 55-year-old patient with poorly controlled diabetes mellitus presents with a swollen, erythematous, and warm foot with a new 'rocker-bottom' deformity, but minimal pain. What is the proposed pathophysiology of the bone destruction in the active, acute phase of Charcot neuroarthropathy according to the neurovascular theory?

Explanation

The neurovascular theory posits that autonomic neuropathy results in loss of sympathetic tone, causing vasodilation, hyperemia, and increased active bone resorption by osteoclasts, which subsequently leads to mechanical failure and fractures.

Question 36

A 65-year-old female with severe osteoporosis is being treated with Denosumab to reduce her risk of pathologic fractures. What is the specific mechanism of action of this medication?

Explanation

Denosumab is a human monoclonal antibody that binds to Receptor Activator of Nuclear factor Kappa-B Ligand (RANKL), preventing its interaction with RANK on osteoclasts. This inhibits osteoclast formation, function, and survival.

Question 37

A 25-year-old male is admitted with bilateral femur fractures following a motor vehicle collision. Forty-eight hours later, he develops acute confusion, severe hypoxemia, and a petechial rash over his axillae and chest. What is the most likely diagnosis?

Explanation

Fat embolism syndrome classically presents with the clinical triad of hypoxemia, neurological abnormalities, and a petechial rash 24 to 72 hours after major long bone or pelvic fractures.

Question 38

A 40-year-old immigrant presents with chronic back pain, night sweats, and a new kyphotic deformity. MRI of the spine demonstrates marked destruction of two adjacent thoracic vertebral bodies and the intervening intervertebral disc. What is the most likely etiology?

Explanation

Spinal tuberculosis (Pott's disease) characteristically causes granulomatous destruction of adjacent vertebral bodies and the intervening disc, often leading to a sharp kyphotic deformity (gibbus).

Question 39

A 35-year-old male with a history of ankylosing spondylitis presents to the emergency department after a low-energy fall. He complains of severe lower neck pain. Plain radiographs show a highly rigid, osteopenic bamboo spine. What complication is he at the highest risk for in this scenario?

Explanation

Patients with ankylosing spondylitis have highly rigid, osteopenic spines. They are extremely susceptible to highly unstable spinal fractures (often through the ossified disc space) even from minor, low-energy trauma.

Question 40

A 65-year-old man with a history of lung cancer presents with progressively worsening right thigh pain. Radiographs reveal a large destructive lytic lesion in the proximal femur with a Mirels' score of 10. What is the most appropriate next step in management?

Explanation

A Mirels' score of 9 or greater indicates a high risk of impending pathological fracture. Prophylactic internal fixation is indicated prior to initiating localized radiation therapy.

Question 41

A 15-year-old boy presents with worsening knee pain and swelling. Radiographs of the distal femur show a mixed lytic and blastic lesion with a "sunburst" periosteal reaction and Codman's triangle. If distant metastasis is present, what is the most likely location?

Explanation

Osteosarcoma is the most common primary malignant bone tumor in youths. It metastasizes almost exclusively hematogenously, with the lungs being the most common site of distant spread.

Question 42

A 30-year-old female presents with knee pain. Radiographs show a distinct, eccentrically located lytic epiphyseal lesion in the proximal tibia. Biopsy confirms multinucleated giant cells resembling osteoclasts. Which targeted systemic therapy is most appropriate as an adjuvant?

Explanation

Denosumab is a monoclonal antibody against RANKL. It prevents the maturation of osteoclast-like giant cells, making it a highly effective treatment for Giant Cell Tumor of bone.

Question 43

A 45-year-old farmer sustains an open tibial shaft fracture with massive soft tissue loss and heavy soil contamination (Gustilo-Anderson Type IIIB). In addition to surgical debridement, what is the recommended empiric antibiotic regimen?

Explanation

Farm injuries are heavily contaminated and carry a significant risk for Clostridium infections. Guidelines recommend adding penicillin to a first-generation cephalosporin and an aminoglycoside for these specific injuries.

Question 44

A 22-year-old falls onto an outstretched hand and presents with tenderness in the anatomical snuffbox. Initial radiographs of the wrist are negative for fractures. What is the most appropriate management?

Explanation

Occult scaphoid fractures may not be visible on initial radiographs. Immobilization in a thumb spica splint with repeat radiographs in 10-14 days (or obtaining an immediate MRI) is standard of care to prevent nonunion.

Question 45

Six hours after intramedullary nailing of a tibial shaft fracture, a 30-year-old patient complains of agonizing leg pain that is unresponsive to escalating doses of intravenous opioids. The pain is severely exacerbated by passive extension of the toes. What is the most appropriate next step?

Explanation

Pain out of proportion to the injury and pain exacerbated by passive stretch of the involved muscles are classic hallmarks of acute compartment syndrome. Emergent four-compartment fasciotomy is required to prevent irreversible muscle necrosis.

Question 46

A 6-year-old falls from monkey bars and sustains a widely displaced Gartland Type III supracondylar humerus fracture. The hand is pink and warm, but the radial pulse is completely absent. What is the most appropriate next step in management?

Explanation

A "pulseless but pink" hand after a displaced supracondylar fracture usually indicates arterial kinking or spasm rather than complete transection. Urgent closed reduction and percutaneous pinning typically restores the pulse.

Question 47

A 45-year-old presents with acute, severe lower back pain radiating down both legs, associated with perianal numbness and new-onset urinary retention. What is the most appropriate next step?

Explanation

Cauda equina syndrome is an absolute orthopedic emergency characterized by saddle anesthesia, bilateral sciatica, and bowel or bladder dysfunction. Emergent MRI and surgical decompression are vital to prevent permanent neurological deficits.

Question 48

A 4-week-old female infant is found to have a positive Ortolani test during a routine pediatric examination. Ultrasound confirms developmental dysplasia of the hip (DDH). What is the preferred initial management?

Explanation

The Pavlik harness is the gold standard initial treatment for reducible developmental dysplasia of the hip in infants under 6 months of age. It holds the hips in flexion and abduction, allowing for dynamic acetabular remodeling.

Question 49

A 13-year-old overweight boy complains of a vague right groin and knee pain for 3 weeks and walks with a limp. On examination, there is obligatory external rotation of the right hip as it is flexed. What is the most appropriate treatment?

Explanation

The presentation is classic for Slipped Capital Femoral Epiphysis (SCFE). In situ fixation with a single percutaneous screw is the standard of care to stabilize the physis and prevent further slippage.

Question 50

A 12-year-old boy presents with localized thigh pain, low-grade fever, and an elevated ESR. Radiographs demonstrate a diaphyseal lytic lesion of the femur with an "onion-skin" periosteal reaction. Cytogenetic testing of the biopsy will most likely show which translocation?

Explanation

Ewing sarcoma often mimics osteomyelitis with systemic symptoms and an "onion-skin" lamellated periosteal reaction. It is driven by the t(11;22) chromosomal translocation, which forms the pathognomonic EWS-FLI1 fusion protein.

Question 51

A 40-year-old male with a history of chronic systemic corticosteroid use presents with progressive hip pain. MRI reveals a crescent sign in the anterosuperior aspect of the femoral head, without subchondral collapse (Ficat Stage II). What is the most appropriate joint-preserving surgical intervention?

Explanation

For pre-collapse (Ficat Stage I or II) avascular necrosis of the femoral head, core decompression is indicated. It aims to reduce intraosseous pressure, relieve pain, and stimulate revascularization.

Question 52

Six weeks after conservative cast management of a minimally displaced distal radius fracture, a 60-year-old patient suddenly loses the ability to actively extend the interphalangeal joint of the thumb. Which complication has most likely occurred?

Explanation

Extensor pollicis longus (EPL) tendon rupture is a well-recognized complication after nondisplaced or minimally displaced distal radius fractures. It occurs due to mechanical attrition over Lister's tubercle or local ischemia from hematoma.

Question 53

A 25-year-old male sustains an anterior shoulder dislocation during a rugby tackle. Following successful closed reduction, he notes persistent numbness over the lateral aspect of his deltoid muscle. Which nerve is most likely injured?

Explanation

The axillary nerve is the most frequently injured nerve during anterior shoulder dislocations. It supplies motor innervation to the deltoid and teres minor, and sensory innervation to the skin over the lateral shoulder.

Question 54

Two years after undergoing a total knee arthroplasty, a 65-year-old patient presents with a painful, swollen knee. Joint aspiration yields synovial fluid with a white blood cell count of 65,000/mcL (92% neutrophils). What is the gold-standard surgical management for this condition?

Explanation

This patient has a chronic periprosthetic joint infection (PJI). The standard of care in North America for a chronic PJI is a two-stage revision arthroplasty, involving implant removal, placement of an antibiotic spacer, and delayed reimplantation.

Question 55

A 70-year-old male complains of frequent clumsiness and dropping objects. Examination reveals a wide-based gait and generalized hyperreflexia. Flicking the distal phalanx of his middle finger results in an involuntary flexion of his thumb and index finger. What does this specific clinical sign indicate?

Explanation

The Hoffmann sign is elicited by flicking the middle finger nail; a reflexive flexion of the thumb and index finger is a positive result. It signifies upper motor neuron dysfunction, which is classically seen in cervical spondylotic myelopathy.

Question 56

A 30-year-old male arrives in the trauma bay following a high-speed motorcycle crash. His pelvis is mechanically unstable (anteroposterior compression type III), and he is hemodynamically unstable with a blood pressure of 75/40 mmHg despite 2 liters of crystalloids. What is the most appropriate immediate intervention?

Explanation

In a hemodynamically unstable patient with an open-book pelvic fracture, immediate application of a pelvic binder centered over the greater trochanters is essential. It effectively reduces pelvic volume, promoting the tamponade of life-threatening venous hemorrhage.

Question 57

A 32-year-old female presents with progressive knee pain. Radiographs reveal an eccentric, purely lytic lesion in the distal femoral epiphysis extending to the subchondral bone with no sclerotic border. What is the most appropriate definitive surgical management?

Explanation

Giant cell tumors of bone are benign but locally aggressive epiphyseal lesions. Standard treatment is extended intralesional curettage using a high-speed burr, local adjuvants (e.g., phenol or argon beam), and packing with polymethylmethacrylate (PMMA) bone cement to minimize recurrence.

Question 58

A 35-year-old male arrives at the trauma bay in hemorrhagic shock following a motorcycle accident. Radiographs reveal an Anteroposterior Compression (APC) Type III pelvic ring injury. To effectively reduce the pelvic volume and stabilize the fracture, where should the pelvic binder be centered?

Explanation

Pelvic binders must be centered directly over the greater trochanters to effectively compress the pelvic ring and close the symphysis pubis. Placement over the iliac crests can paradoxically worsen the deformity in APC injuries by acting as a fulcrum.

Question 59

A 45-year-old male is involved in a high-speed motor vehicle collision. Cervical radiographs demonstrate an anterior displacement of C5 on C6 by exactly 50% of the vertebral body width. What is the most likely mechanism of this specific injury?

Explanation

Anterior displacement of a cervical vertebra by 50% or more typically indicates bilateral facet dislocation. The classic mechanism of injury for a bilateral facet dislocation is severe hyperflexion combined with distraction.

Question 60

A 35-year-old immigrant presents with progressive back pain, night sweats, and lower extremity weakness. MRI reveals a destructive lesion of the T8-T9 vertebral bodies with relative sparing of the disc space and a large paraspinal abscess. What is the most appropriate next step in management?

Explanation

The clinical picture is classic for Pott's disease (spinal tuberculosis). A tissue biopsy with culture and PCR is required to confirm the diagnosis and guide appropriate multidrug antitubercular therapy.

Question 61

A 65-year-old male with a 40-pack-year smoking history presents with bilateral knee and ankle pain. Radiographs reveal symmetric, solid periosteal new bone formation along the diaphyses and metaphyses of the tibiae and fibulae. Which of the following is the most likely underlying diagnosis?

Explanation

Hypertrophic osteoarthropathy (HOA) is characterized by clubbing, polyarthritis, and symmetric periostitis of tubular bones. It is a paraneoplastic syndrome strongly associated with bronchogenic carcinoma.

Question 62

A 58-year-old female with known breast cancer presents with thigh pain. Radiographs show a 3.5 cm lytic lesion in the peritrochanteric region of the proximal femur. She complains of severe pain with weight-bearing. What does her Mirels' score dictate regarding management?

Explanation

Mirels' criteria assess pathologic fracture risk based on site (peritrochanteric = 3), pain (functional = 3), lesion type (lytic = 3), and size (>2/3 cortical diameter = 3). A score of 11 or 12 strongly indicates prophylactic internal fixation.

Question 63

A 7-year-old boy presents with a painful, solitary lytic lesion in the skull and a mild chronic cough. Biopsy of the skull lesion demonstrates cells with grooved nuclei expressing CD1a and S-100. Electron microscopy reveals Birbeck granules. Which of the following organs should also be carefully evaluated?

Explanation

Langerhans cell histiocytosis (eosinophilic granuloma) presents with lytic bone lesions and characteristic Birbeck granules. It can involve the lungs, particularly in systemic forms or older patients, necessitating pulmonary evaluation.

Question 64

A 40-year-old African American female presents with sausage-like swelling of her digits (dactylitis). Hand radiographs demonstrate multiple well-defined, cyst-like radiolucencies in the phalanges with a lace-like trabecular pattern. Chest X-ray shows bilateral hilar lymphadenopathy. What is the most likely diagnosis?

Explanation

Sarcoidosis can cause osseous involvement in 5-10% of patients, classically presenting as cyst-like lesions in the phalanges and dactylitis. This correlates strongly with the bilateral hilar lymphadenopathy seen on chest radiography.

Question 65

A 22-year-old male sustains a closed bilateral femoral shaft fracture in a motor vehicle accident. Thirty-six hours later, he develops tachypnea, confusion, and a petechial rash over his axillae and chest. Which of the following is the most effective initial management?

Explanation

Fat Embolism Syndrome presents with the triad of hypoxia, neurologic compromise, and petechial rash. The most effective prevention and management strategy involves early stabilization of long bone fractures and aggressive respiratory support.

Question 66

A 30-year-old female undergoes curettage and cementing of a giant cell tumor of the distal femur. Two years later, routine follow-up imaging reveals multiple asymptomatic, small, peripheral lung nodules. Biopsy of a lung nodule confirms histopathology identical to the primary tumor. What is the standard management for this pulmonary condition?

Explanation

"Benign" pulmonary metastases occur in 2-3% of giant cell tumors of bone. They are often indolent and can be managed with observation, denosumab therapy, or local surgical resection.

Question 67

A 15-year-old male is undergoing chemotherapy for conventional osteosarcoma of the proximal tibia. He presents to the emergency department with sudden onset pleuritic chest pain and shortness of breath. Chest radiograph shows a spontaneous pneumothorax. What is the most likely underlying cause?

Explanation

Spontaneous pneumothorax in a pediatric patient with osteosarcoma is highly suspicious for the rupture of a cavitating subpleural pulmonary metastasis. Osteosarcoma frequently metastasizes to the lungs.

Question 68

A 45-year-old male with a long history of ankylosing spondylitis and severe restrictive lung disease presents after a minor mechanical fall. He complains of severe neck pain but denies neurological deficits. Initial cervical radiographs appear unremarkable. What is the most appropriate next step?

Explanation

Patients with ankylosing spondylitis have highly rigid, brittle spines and are at severe risk for unstable fractures even from low-energy trauma. A CT or MRI is mandatory as conventional radiographs easily miss these potentially devastating fractures.

Question 69

A 72-year-old male presents with increasing pain in his right thigh and increasing hat size. Radiographs of the femur show cortical thickening, coarse trabeculation, and a bowing deformity. Laboratory studies show a significantly elevated alkaline phosphatase with normal calcium and phosphorus. Which of the following is the primary cellular defect?

Explanation

Paget's disease of bone is characterized by an initial phase of furious osteoclastic bone resorption followed by a disorganized, chaotic phase of osteoblastic bone formation. This results in structurally weak, woven bone.

Question 70

An 11-year-old boy presents with a 2-month history of thigh pain and low-grade fever. Radiographs show a permeative diaphyseal lesion in the femur with a prominent "onion-skin" periosteal reaction. Which of the following cytogenetic abnormalities is most diagnostic for this tumor?

Explanation

Ewing sarcoma is classically characterized by the t(11;22)(q24;q12) translocation, which results in the EWS-FLI1 fusion protein. It typically presents with a permeative diaphyseal lesion and a multi-lamellated periosteal reaction.

Question 71

A 65-year-old man presents with severe mid-back pain. Laboratory tests reveal anemia, hypercalcemia, and elevated serum creatinine. Serum protein electrophoresis shows a monoclonal spike. Which test is most appropriate to evaluate the full extent of skeletal involvement?

Explanation

Multiple myeloma lesions are purely lytic and often lack osteoblastic activity, leading to false-negative results on standard Technetium-99m bone scans. A whole-body low-dose CT or conventional skeletal survey is the standard for detecting these lesions.

Question 72

A 35-year-old female with severe, persistent asthma managed with long-term oral prednisone presents with insidious onset of groin pain with weight-bearing. Radiographs of the hip are normal. MRI shows a focal subchondral band of low signal intensity in the anterosuperior femoral head on T1-weighted images. What is the most likely diagnosis?

Explanation

Long-term corticosteroid use is a major risk factor for avascular necrosis of the femoral head. MRI is the most sensitive imaging modality, typically showing a well-demarcated subchondral band of low T1 signal.

Question 73

A 50-year-old male with end-stage renal disease on hemodialysis presents with diffuse bone pain. Radiographs reveal subperiosteal bone resorption in the phalanges and a "rugger jersey" spine. Which of the following laboratory profiles is expected?

Explanation

Renal osteodystrophy (secondary hyperparathyroidism) results from phosphate retention and failure of the kidneys to convert Vitamin D to its active form. This leads to hypocalcemia, hyperphosphatemia, and a compensatory significant rise in parathyroid hormone (PTH).

Question 74

A 14-year-old girl is evaluated for recurrent fractures following minor trauma. She also has a history of severe anemia and cranial nerve palsies. Radiographs reveal generalized dense, sclerotic bones with absent medullary canals and an "Erlenmeyer flask" deformity of the distal femurs. The pathogenesis involves a defect in which of the following?

Explanation

Osteopetrosis (marble bone disease) is caused by defective osteoclastic bone resorption, often due to a failure to form the ruffled border. This results in dense, brittle bones that obliterate the marrow space, leading to cytopenias.

Orthopedic Prometric MCQs - Chapter 4 Part 1

Orthopedic Prometric MCQs - Chapter 4 Part 5

Orthopedic Prometric MCQs - Chapter 4 Part 5

Chapter Index