Question 1

Which of the following is most likely to preclude curative lobectomy for lung carcinoma?

Explanation

Correct Answer: D- Malignant pleural effusions Explanation Malignant pleural effusions A malignant pleural effusion usually implies widely disseminated disease and any treatment is therefore often palliative. Forced expiratory volume in 1 s (FEV1) of 1.6 l Forced expiratory volume in 1 s (FEV1) of 1.6 l is incorrect. A forced expiratory volume in 1 s (FEV1) of over 1.5 l suggests that the patient has sufficient lung function to undergo an operation of this nature, but many of these patients will have considerable cardiorespiratory co-morbidity and a rigorous preoperative assessment is always required. Hypercalcaemia Hypercalcaemia is incorrect. Hypercalcaemia could be due to invasion of bone by the tumour, but this is not necessarily so; malignant cells in the lung tumour can produce humoral mediators which lead to an increase in the serum calcium level. Local invasion by primary tumour through the chest wall Local invasion by primary tumour through the chest wall is incorrect. Local invasion by the primary tumour through the chest wall is not in itself a reason why curative surgery should not be attempted, depending on the precise anatomy involved. Mediastinal lymph nodes enlarged on computed tomography (CT) Mediastinal lymph nodes enlarged on computed tomography is incorrect. The appearance of enlarged mediastinal lymph nodes on CT is suggestive of malignant spread but does not confirm it, thus this option is incorrect. A mediastinoscopy or biopsy guided by endobronchial ultrasound should be performed to confirm any enlarged nodes were malignant and if contralateral mediastinal nodes are confirmed malignant (ie N3 disease) then surgery would be contraindicated.

Question 2

A 32-year-old patient with asthma has been stable with inhaled salbutamol when required. Recently she has had to use her inhaler more frequently and also at night. What is the next step in her therapy?

Explanation

Correct Answer: E- Regular inhaled budesonide, inhaled salbutamol when required Explanation Regular inhaled budesonide, inhaled salbutamol when required This patient requires an escalation in her asthma management. At this stage with frequent use of salbutamol, a regular inhaled steroid for preventative therapy is required. With inhaled budesonide one appropriate option. Addition of oral corticosteroids Addition of oral corticosteroids is incorrect. Oral corticosteroids are reserved for step-5 managament of asthma that is not controlled with inhaled steroids, long- acting bronchodilators and additional oral therapies such as montelukast. Addition of oral leukotriene-receptor antagonist Addition of oral leukotriene-receptor antagonist is incorrect. Oral leukotriene-receptor antagonists are indicated as a trial after low dose inhaled corticosteroids. Addition of oral theophylline Addition of oral theophylline is incorrect. Oral theophylline is indicated after maximal inhaled corticosteroids and LABA if the asthma is still not controlled. Inhaled ß2-agonist at maximum dose Inhaled ß2-agonist at maximum dose is incorrect. The deterioration of symptoms on short-acting ß2- agonist monotherapy indicates inhaled steroids are required, ie step-2 asthma therapy.

Question 3

A 35-year-old woman presents with a 6-week history of malaise, with a dry cough, sweats and a stitch-like, right- sided chest pain. Apparently she had a heavy cold and cough at the beginning of the episode that improved initially. A past history of rheumatoid arthritis for which she takes weekly methotrexate is noted. On examination her BP is 125/80 mmHg, pulse is 75 bpm and regular. There are diminished breath sounds on the right-hand side of the chest and it is dull to percussion. There is no evidence of active synovitis. Investigations:

Hb 12.1 g/dl

WCC 11.2 × 109/l

PLT 303 × 109/l

ESR 72 mm/h

Na+ 137 mmol/l

K+ 4.3 mmol/l

Creatinine 110 μmol/l

CXR Right-sided pleural effusion Effusion pH 7.08 Effusion LDH 1556 U/l Effusion Glucose 2.0 mmol/l Effusion Protein 45 g/l Which of the following is the most likely diagnosis?

Explanation

Correct Answer: A- Empyema Explanation Empyema The pH, LDH and glucose all fit the criteria for diagnosis of empyema (rather than parapneumonic effusion) as defined in BTS guidelines. In all likelihood the empyema developed as a result of an acute pneumonia some 6 weeks earlier. Inflammatory pleural effusion Inflammatory pleural effusion is incorrect. The raised white count and ESR support the presence of continuing infection as no evidence is given of a flare of her rheumatoid. Mesothelioma Mesothelioma is incorrect. There is no history of asbestos exposure to support a diagnosis of mesothelioma. Parapneumonic effusion Parapneumonic effusion is incorrect. The pH, LDH and glucose all fit the criteria for diagnosis of empyema (raher than parapneumonic effusion) as defined in BTS guidelines. In all likelihood the empyema developed as a result of an acute pneumonia some 6 weeks earlier. Tuberculous effusion Tuberculous effusion is incorrect. With respect to tuberculosis we would expect a history of symptoms of greater than 6 weeks.

Question 4

A 71-year-old man who has a 40-pack-year smoking history presents to the GP with shortness of breath and bilateral ankle swelling. On examination he has a blood pressure of 145/90 mmHg, a plethoric face and bilateral coarse wheeze on auscultation of the chest. There is pitting oedema affecting both ankles. Which of the following has proved mortality benefit in this condition?

Explanation

Correct Answer: D- Long-term oxygen therapy Explanation Long-term oxygen therapy This patient has chronic obstructive pulmonary disease (COPD) with cor pulmonale, right ventricular failure. Both the National Heart Lung and Blood Institute (NHLB) and the Medical Research Council (MRC) trials showed a mortality benefit of long-term oxygen therapy (LTOT) in COPD. Although LTOT doubles the chances of survival, it must be used for over 15 h per day, but poor patient compliance often means this cannot be met. Bisoprolol Bisoprolol is incorrect. Bisoprolol offers benefit in left ventricular failure. Digoxin Digoxin is incorrect. Digoxin, although it offers relief of symptoms in severe heart failure, does not offer mortality benefit. Ipratropium Ipratropium is incorrect. Although useful for relief of COPD symptoms, ipratropium has no impact on survival. Ramipril Ramipril is incorrect. Ramipril offers benefit in left ventricular failure.

Question 5

A 60-year-old woman attends the clinic complaining of shortness of breath over the preceding 2 months. She has also had problems with nasal irritation, discharge and sinus pain. She is known to have asthma, which has recently been poorly controlled, despite inhaled steroids. Her full blood count has shown an eosinophilia of 13% and her chest X-ray shows peripheral pulmonary shadows. What is the most likely diagnosis?

Explanation

Correct Answer: C- Eosinophilic granulomatosis with polyangiitis Explanation Eosinophilic granulomatosis with polyangiitis Eosinophilicgranulomatosis with polyangiitis is an eosinophilic granulomatous inflammation of the respiratory tract with small- and medium-vessel necrotising vasculitis. It is diagnosed on finding four out of the following:

• Asthma • Blood eosinophilia > 10% • Vasculitic neuropathy • Pulmonary infiltrates • Sinus disease • Extravasculareosinophils on biopsy findings It is diagnosed clinically, although a biopsy should be sought for pathological confirmation. Allergic bronchopulmonaryaspergillosis Allergic bronchopulmonary aspergillosis (ABPA) is incorrect. ABPA is a condition in which people with asthma have a vigorous IgE response to Aspergillus, with associated eosinophilia, a positive skinprick test to Aspergillus and flitting consolidation on the chest X-ray. There is no associated sinus disease. Cryptogenic organising pneumonia Cryptogenic organising pneumonia (COP) is incorrect. COP is not typically associated with an eosinophilia. Granulomatosis with polyangiitis Granulomatosis with polyangiitis is incorrect. Granulomatosis with polyangiitis is not typically associated with an eosinophilia. Severe asthma Severe asthma is incorrect. This woman’s eosinophil count is high, higher than it would be with asthma alone, and the abnormal chest radiograph suggests an

alternative diagnosis. Causes of eosinophilia include:

• Allergic or hypersensitivity disease, including asthma with associated eczema • Allergic bronchopulmonary aspergillosis • Eosinophilic granulomatosis with polyangiitis • Loeffler syndrome • Tropical pulmonary eosinophilia • Chronic pulmonary eosinophilia • Hypereosinophilic syndrome • Acute eosinophilic pneumonia

Question 6

Which of the following investigations is most specific to allergic bronchopulmonary aspergillosis (ABPA)?

Explanation

Correct Answer: A- An early positive skinprick test for Aspergillus fumigatus Explanation An early positive skinprick test for Aspergillus fumigatus Positive skinprick tests reflect antigen-specific IgE. Computed tomographic (CT) evidence of proximal bronchiectasis Computed tomographic (CT) evidence of proximal bronchiectasis is incorrect. Proximal bronchiectasis is a feature of classical ABPA but it is not pathognomic and other causes of bronchiectasis should be considered. Positive history of exposure to Aspergillus Positive history of exposure to Aspergillus is incorrect. A specific exposure history is very difficult to elicit. Most people are exposed to small amounts of Aspergillus regularly and inhale spores in the air. However, only a minority become sensitised to Aspergillus and develop ABPA. Positive precipitins for Aspergillus Positive precipitins for Aspergillus is incorrect. Precipitins (IgG) are more usual with an aspergilloma, but may be positive in ABPA or in up to 10% of patients with asthma. Upper-zone fibrosis Upper-zone fibrosis is incorrect. Allergic bronchopulmonary aspergillosis is characterised by wheezy breathlessness, serum eosinophilia and pulmonary infiltrates on X-ray. Lobar collapse can also occur, due to mucus plugging. ABPA can cause apical fibrosis in its most severe form; however, there are many other causes of upper-lobe fibrosis, including tuberculosis, extrinsic allergic alveolitis, sarcoidosis and ankylosing spondylitis.

Question 7

A 58-year-old woman is admitted to the Emergency Department with suspected community- acquired pneumonia. She has a progressively worsening cough, productive of rusty sputum and shortness of breath over the past 3 days. She smokes five cigarettes per day, has hypertension treated with lisinopril, but no other significant past medical history. On examination her BP is 105/60 mmHg; pulse is 85/min and regular. There are signs of right lower lobe consolidation on auscultation. Respiratory rate is raised at 32, O2 sats on 40% O2 are 96%. Investigations:

Hb 13.1 g/dl

WCC 15.8 × 109/l

PLT 203 × 109/l CRP 230 mg/l

Na+ 138 mmol/l

K+ 4.5 mmol/l

Creatinine 122 μmol/l

Urea 6.9 mmol/l According to CURB-65 criteria, which of the following is a measure of increased severity?

Explanation

Correct Answer: C- Respiratory rate 32/min Explanation Respiratory rate 32/min CURB-65 criteria were drawn up to provide standardised assessment of the severity of pneumonia. They are listed below • confusion at onset (defined as an AMT of 8 or less) •

urea greater than 7 mmol/l (19 mg/dl) • respiratory rate of 30 breaths per minute or greater • blood pressure less than 90 mmHg systolic or diastolic blood pressure 60 mmHg or less • age 65 or older. The number of criteria correlate well with mortality at 30 days:

• 0 – 0.7% • 1 – 3.2% • 2 – 13.0% • 3 – 17.0% • 4 – 41.5% • 5 – 57.0% Any score of 2 or greater usually requires hospitalisation. Age 58 Age 58 is incorrect. Age ≥ 65 is a measure of increased severity. CRP 230 mg/l CRP 230 mg/l is incorrect. CRP is not classed as a measure of increased severity. Urea 6.9 mmol/l

Urea 6.9 mmol/l is incorrect. Urea greater than 7 mmol/l is a measure of increased severity. WCC 15.8 × 109/l

WCC 15.8 × 109/l is incorrect. WCC is not part of the CURB-65 score, which is the severity scoring system used in the UK. The pneumonia severity index, used in the USA, does include WCC with a WCC < 4 × 109/l or > 20 × 109/l indicating increased severity of pneumonia.

Question 8

A 65-year-old man known to have chronic obstructive pulmonary disease presented with progressive respiratory failure. He was treated in the Intensive Care Unit with mechanical ventilation and he improved. After extubation he was transferred to the ward. On the 2nd day on the ward his temperature spiked and he developed a productive cough with a yellow-green sputum. Blood results showed leucocytosis. A chest X-ray revealed a right-sided middle- and lower-lobe pneumonia. What is the most probable cause of his pneumonia?

Explanation

Correct Answer: D- Pseudomonal pneumonia Explanation Pseudomonal pneumonia Pseudomonas is a common pathogen in patients with bronchiectasis and cystic fibrosis. It also causes hospital- acquired infections, particularly in intensive care units or after surgery. Nosocomial or hospital-acquired infections should be suspected in patients with an onset of symptoms at least 48 hours after admission to the hospital. The sputum colour also gives a clue to the most likely diagnosis. Treatment is with anti-pseudomonal penicillin, ceftazidime, meropenem or ciprofloxacin. Aspiration pneumonia Aspiration pneumonia is incorrect. There is no history given to suggest this gentleman has aspirated. Haemophilus pneumonia Haemophilus pneumonia is incorrect. Haemophilus pneumoniae is more typically seen as a cause of community acquired pneumonia. Pneumococcal pneumonia Pneumococcal pneumonia is incorrect. Pneumcoccal pneumonias are usually community acquired. This man has a nosocomial pneumonia and is likely associated with being invasively ventilated. Pseudomonas aeruginosa is a common cause of ventilator associated pneumonia. Staphylococcal pneumonia Staphylococcal pneumonia is incorrect. Staphylococcal pneumonias are typically seen in immunosuppressed patients and intravenous drug abusers or following a viral respiratory tract infection. Staphylococcus aureus can be a cause of nosocomial pneumonia but ventilator associated pneumonias occurring late into an admission are typically due to gram negative bacteria and therefore Pseudomonal pneumonia is more likely in this case.

Question 9

A 32-year-old nurse who has had a positive tuberculin skin test comes to you for advice. She had been in contact with a patient who had pulmonary tuberculosis some 6 days earlier, and has not received a BCG vaccination in the past. She is well and her chest X-ray is normal. She has started a course of isoniazid and rifampicin. Which of the following is the most appropriate occupational health advice?

Explanation

Correct Answer: A- Continue isoniazid and rifampicin for at least 3 months Explanation Continue isoniazid and rifampicin for at least 3 months The National Institute for Health and Care Excellence (NICE) Guideline 33 suggests that healthcare workers with a positive tuberculin test after exposure to tuberculosis (TB) should be treated with a combination of isoniazid and rifampicin for 3 months or isoniazid alone for a period of 6 months. The positive tuberculin test raises the possibility of latent TB infection in this healthcare worker, which can be associated with a not inconsiderable risk of infection for patients if there is later development of pulmonary TB. Continue isoniazid and rifampicin for 1 month then isoniazid for a further 2 months Continue isoniazid and rifampicin for 1 month then isoniazid for a further 2 months is incorrect. The National Institute for Health and Care Excellence (NICE) Guideline 33 suggests that healthcare workers with a positive tuberculin test after exposure to TB should be treated with a combination of isoniazid and rifampicin for 3 months or isoniazid alone for a period of 6 months. The positive tuberculin test raises the possibility of latent TB infection in this healthcare worker, which can be associated with a not inconsiderable risk of infection for patients if there is later development of pulmonary TB. Stay off work and have a repeat chest X-ray in 6 weeks Stay off work and have a repeat chest X-ray in 6 weeks is incorrect. There is no evidence this lady has active TB. She has latent TB, which is not infectious, and therefore she need not stay off work if she is well. Stay off work for 2 weeks while she is on the initial prophylactic isoniazid course Stay off work for 2 weeks while she is on the initial prophylactic isoniazid course is incorrect. There is no evidence this lady has active TB. She has latent TB, which is not infectious, and therefore she need not stay off work if she is well. Stay off work for 6 weeks Stay off work for 6 weeks is incorrect. There is no evidence this lady has active TB. She has latent TB, which is not infectious, and therefore she need not stay off work if she is well.

Question 10

A 30-year-old asthmatic patient has the following drug regimen: regular inhaled corticosteroids, regular inhaled long-acting•ß2-agonists (salmeterol), oral leukotriene- receptor antagonists and inhaled short-acting ß2-agonists when required. Although her compliance is good, her symptoms are still not satisfactorily controlled. What is the next step in her therapy?

Explanation

Correct Answer: D- Oral theophylline Explanation Oral theophylline Theophylline is indicated in the treatment of chronic asthma when symptoms are still not controlled despite inhaled corticosteroids, long-acting ß-agonists and leukotriene receptor antagonists. Theophylline improves lung function and symptoms, but side-effects occur more commonly. Antibiotics Antibiotics is incorrect. Antibiotics are only indicated if there is evidence of a (non-viral) infective exacerbation, which is not the case here. Oral cromoglicate Oral cromoglicate is incorrect. Inhaled, not oral, cromoglicate is used in the treatment of asthma. Oral steroids Oral steroids is incorrect. Oral steroids are appropriate in acute exacerbations of asthma. Their long- term use is reserved as ‘step 5’ treatment. This lady requires ‘step 4’ treatment. Switch to nebuliser Switch to nebuliser is incorrect. Salbutamol nebulisers are usually reserved for the management of acute asthma exacerbations. They are occasionally used at home by very severe asthmatics on otherwise maximal therapy.

Question 11

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

Explanation

Correct Answer: B- Lobar pneumonia Explanation Lobar pneumonia The classic presentation of pneumonia is of a cough and fever with the variable presence of sputum production, dyspnoea and pleurisy. Most patients have constitutional symptoms such as malaise, fatigue and asthenia, and many also have gastrointestinal symptoms. Examination of the lung might reveal decreased vesicular breath sounds, localised foci of crepitations, dullness to percussion and sometimes bronchial wheeze. The chest X-ray is a pivotal test for the confirmation of pneumonia. Atelectasis due to carcinoma of the lung Atelectasis due to carcinoma of the lung is incorrect. The acute history associated with signs of infection and the relatively young age of this patient make a diagnosis of pneumonia more likely than lung cancer with atelectasis. Mesothelioma Mesothelioma is incorrect. There is no history suggestive of asbestos exposure here. The acute nature of this gentleman’s symptoms combined with evidence of infection make pneumonia a more likely diagnosis. Mesothelioma would typically have a more gradual onset of symptoms and present with progressive dyspnoea and/or chest pain. Pneumothorax Pneumothorax is incorrect. The history is compatible with infection and the signs are not compatible with pneumothorax. In pneumothorax clinical examination would reveal decreased air entry and hyper resonance to percussion. Tuberculosis Tuberculosis is incorrect. The history given is of respiratory infection, so tuberculosis is a possibility; however, nothing in the history suggests an increased risk of tuberculosis (eg previous TB, contact with patients known to have TB, immunosuppression, alcoholism). Therefore a bacterial pneumonia is more likely.

Question 12

Which lung disease is associated with the descriptions of ‘pink puffer’ and ‘blue bloater’?

Explanation

Correct Answer: A- Chronic obstructive pulmonary disease Explanation Chronic obstructive pulmonary disease Pink puffers have a good respiratory drive. Clinical features:

• Pursed-lip breathing with intense dyspnoea • Often thin and elderly • Sparce production of sputum • Oedema and overt heart failure (rare complications)

Investigations:

• Blood gases are near-normal until pre-terminally there is very severe airways obstruction • Total lung capacity increased • Reduction in transfer factor Blue bloaters have a poor respiratory drive. Clinical features:

• Quite mild dyspnoea • Often obese • Production of large volumes of sputum • Infective exacerbations • Often oedematous • Can develop cor pulmonale Investigations:

• Blood gases show hypercapnia, hypoxaemia, elevated plasma bicarbonate • Severe nocturnal hypoxaemia • Airways obstruction might only be moderate • Transfer factor approximately normal Cystic fibrosis Cystic fibrosis is incorrect. Cystic fibrosis is not associated with the descriptions in the question. Pulmonary fibrosis Pulmonary fibrosis is incorrect. Pulmonary fibrosis is not associated with the descriptions in the question. Small-cell lung cancer Small-cell lung cancer is incorrect. Small-cell lung cancer is not associated with the descriptions in the question. Tuberculosis Tuberculosis is incorrect. Tuberculosis is not associated with the descriptions in the question.

Question 13

A 30-year-old woman presents with shortness of breath. This began gradually, around 2 years ago, but now she is breathless on climbing a flight of stairs. There is no past history of note. On examination, the jugular venous pulse is raised, carotid pulse volume is reduced and there is evidence of right ventricular hypertrophy. There are right-sided murmurs on cardiac auscultation. Her chest X-ray shows pulmonary artery enlargement; the electrocardiogram shows right axis deviation and right ventricular hypertrophy. Arterial blood gases reveal hypoxia and hypercapnia; a lung perfusion scan is normal. Cardiac catheterisation reveals that right-sided pressures are markedly raised. Which diagnosis best fits with this clinical picture?

Explanation

Correct Answer: D- Primary pulmonary hypertension Explanation Primary pulmonary hypertension Primary pulmonary hypertension is characterised by the development of significantly raised pulmonary artery pressure with no apparent cause (normal VQ scan, no evidence of left heart failure). Plexogenic pulmonary arteriopathy is found in 30–60% of people with this condition and is characterised by medial hypertrophy and concentric laminar intimal fibrosis. The gene for primary pulmonary hypertension has now been mapped to chromosome 2, and mutations in the bone morphogenic protein receptor have been identified in some patients. Intravenous epoprostenol (prostacyclin) and oxygen therapy have been shown to improve quality of life in sufferers.

Phosphodiesterase-5 (PDE-5) inhibitors and endothelin receptor antagonists have also been shown to have some therapeutic effect. Unfortunately, several studies report a mean survival of only 2.5 years from diagnosis, with right ventricular failure and sudden death the main causes of death. Asthma Asthma is incorrect. This lady has evidence of significant right heart failure and her main respiratory symptom is dyspnoea rather than wheeze or cough. The symptoms and investigations described are not in keeping with a diagnosis of asthma. Chronic thromboembolic disease Chronic thromboembolic disease is incorrect. The perfusion scan is not suggestive of chronic thromboembolic disease, which makes primary pulmonary hypertension the most likely diagnosis. Idiopathic pulmonary fibrosis Idiopathic pulmonary fibrosis is incorrect. Idiopathic pulmonary fibrosis (IPF) typically occurs in the sixth decade of life. If IPF is advanced enough to cause right ventricular hypertrophy (as is described in this case) then it is likely that the chest radiograph would show significantly abnormal lung fields with reticulonodular shadowing +/- honeycombing. Right ventricular failure Right ventricular failure is incorrect. This case does indeed describe right ventricular hypertrophy and failure, but given the dyspnoea and degree of hypoxia with a normal chest X-ray other than pulmonary artery hypertrophy and the patient’s age then primary pulmonary hypertension is the diagnosis that best fits the clinical picture in its entirety.

Question 14

You are called to see a 50-year-old woman who is having difficulty breathing after undergoing a laparoscopic cholecystectomy. She is making a lot of noisy inspiratory effort with stridor. You notice that she is on long-term warfarin for thromboembolic disease, salbutamol and inhaled steroids for asthma and penicillamine for severe rheumatoid arthritis. Which of the following tests would be the most helpful in diagnosing her current problem?

Explanation

Correct Answer: D- Spirometry with flow–volume loop Explanation Spirometry with flow–volume loop This woman has stridor due to cricoarytenoid arthritis. This is seen in studies in up to 75% of patients with rheumatoid arthritis. It can cause sore throat, hoarse voice and stridor, but is often asymptomatic. However, symptoms can rapidly worsen in the post-operative period. It is unrelated to any lung fibrosis. The flow– volume loop can be abnormal, as can direct laryngoscopy and high- resolution computed tomography of the larynx. Patients can need urgent tracheostomy and steroids, both orally and via joint injection. Chest X-ray Chest X-ray is incorrect. Chest X-ray may well be normal and therefore unhelpful here. Computed tomography scan of the chest Computed tomography (CT) scan of the chest is incorrect. CT chest would not show the cricoarytenoid arthritis. CT imaging of the larynx would be required. Peak flow Peak flow is incorrect. Peak flow measurement is useful in assessing the severity of an exacerbation of asthma.The presence of stridor makes an acute exacerbation of this lady’s asthma unlikely. Spirometry with transfer factor measurement Spirometry with transfer factor measurement is incorrect. This lady has stridor due to cricoarytenoid arthritis; this will not affect her transfer factor. The most appropriate and helpful combination of pulmonary function tests is spirometry with flow–volume loop.

Question 15

A 49-year-old woman has been admitted with haemoptysis and epistaxis. Her chest X-ray shows multiple rounded lesions with alveolar shadowing. Her serum is positive for cytoplasmic anti- neutrophil cytoplasmic antibody (c-ANCA). What is the most likely diagnosis?

Explanation

Correct Answer: C- Granulomatosis with polyangiitis Explanation Granulomatosis with polyangiitis Almost all patients will have evidence of granulomatous lung disease at presentation, which is often accompanied by alveolar capillaritis. The bronchi can also be affected and bronchial stenoses occur as late manifestations. Symptoms include:

• Cough • Dyspnoea • Haemoptysis • Chest pain (which can be pleuritic) Signs on chest examination depend on the nature of the pulmonary lesions and include:

• Fine crepitations • Bronchial breathing • Pleural rubs and signs of pleural effusion (less common) Radiology – pulmonary granulomas are usually diagnosed on the basis of chest X-ray and computed tomography, which show single or multiple rounded lesions, which can cavitate. Bronchoscopy – often reveals granulomatous inflammation and the diagnosis can sometimes be made from bronchial biopsies. Carcinoma of the lung Carcinoma of the lung is incorrect. The chest radiograph appearances, epistaxis and positive c-ANCA are far more in keeping with granulomatosis with polyangiitis than lung cancer. Echinococcosis Echinococcosis is incorrect. Echinococcosis is caused by a larval infection with initial infection occurring in the liver; it behaves like a slow-growing tumour and can spread to other organs like metastases. Presentation is typically with right upper quandrant pain and jaundice. Pulmonary disease can occur but is not classical and the

investigations described in this scenario are far more in keeping with vasculitis. Systemic lupus erythematosus Systemic lupus erythematosus (SLE) is incorrect. Pulmonary manifestations of SLE are variable and include pleurisy, pleural effusion, pneumonitis, pulmonary hypertension, interstitial lung disease and, rarely, diffuse alveolar haemorrhage. Cavitating lesions such as described in this case are not typical of SLE. Positive c-ANCA, as in this case, is associated with granulomatosis with angiitis. SLE is associated with positive antinuclear antibodies, double-stranded DNA antibodies and extractable nuclear antigens such as Sm, SSA, SSB and RNP antibodies. Tuberculosis Tuberculosis is incorrect. The chest radiograph appearances, epistaxis and positive c-ANCA are far more in keeping with granulomatosis with polyangiitis than tuberculosis.

Question 16

A 65-year-old patient with new-onset chronic obstructive pulmonary disease (COPD) asks you about his prognosis. Which of the following single tests is the most important predictor of survival in patients with COPD?

Explanation

Correct Answer: E- FEV1 (forced expiratory volume in 1 s) Explanation

FEV1 (forced expiratory volume in 1 s) The strongest predictors of survival in patients with COPD are:

• Age • Baseline FEV1 (forced expiratory volume in 1 s) Fewer than 50% of patients whose FEV1 has fallen to 30% of predicted are alive 5 years later. There is an even stronger relationship between survival and the post- bronchodilator FEV1, rather than the pre-bronchodilator

FEV1. Other unfavourable prognostic factors which become apparent in patients with severe disease include:

• Severe hypoxaemia • Raised pulmonary arterial pressure • Low carbon monoxide transfer Factors favouring improved survival are stopping smoking and a marked bronchodilator response. A reduced FEV1 is also an important additional risk factor for lung cancer, independent of age or cigarette smoking. Blood gases Blood gases is incorrect. Severe hypoxaemia or type 2 respiratory failure indicate an adverse prognosis in COPD, but are not as predictive as FEV1. Chest X-ray Chest X-ray is incorrect. A chest radiograph showing severe bullous emphysema suggests an adverse prognosis in COPD, but is not as predictive as FEV1. Electrocardiogram Electrocardiogram is incorrect. An electrocardiogram showing evidence of right ventricular hypertrophy and strain in COPD is suggestive of cor pulonale, which indicates an adverse prognosis in COPD, but this is not as predictive as FEV1. Exercise tolerance Exercise tolerance is incorrect. Poor exercise tolerance is an indicator of poorer prognosis in COPD, and exercise tolerance is taken into account when calculating the prognosis of an individual with COPD using the BODE index. The BODE index uses a patient with COPD’s

FEV1, 6 min walk distance, MRC breathlessness score and body mass index to calculate a score which can be used to predict long-term outcome. The higher an individual’s BODE index score, the poorer the prognosis. Thus exercise tolerance is a prognostic indicator; however, in isolation, it is not as predictive as FEV1.

Question 17

A 50-year-old woman is admitted with a dry cough, shortness of breath and a 2-week history of intermittent fevers. She had flu-like symptoms at the beginning of her illness. On examination she has right-sided crepitations and a chest X-ray shows patchy shadowing at her right lower lobe, with an air bronchogram. Her white cell count and C-reactive protein (CRP) are raised. She is started on antibiotics for community-acquired pneumonia, improves clinically and is discharged after 2 days. You see her in clinic 3 months later, when she tells you that she is no better. Her chest X-ray shows left upper-lobe consolidation. What is the most likely cause of this?

Explanation

Correct Answer: A- Cryptogenic organising pneumonia Explanation Cryptogenic organising pneumonia Cryptogenic organising pneumonia is a non-specific inflammatory pulmonary process, with buds of granulation tissue forming in the distal air spaces. Organising pneumonia can have a number of causes, including connective tissue disease, infection and drugs, but if there is no obvious cause it is called ‘cryptogenic’. It causes non-specific symptoms of fever, dry cough, malaise, anorexia and weight loss. Treatment is with steroids. Relapse is common, with further consolidation, and patients might need treatment with increased steroid doses. It is associated with raised a white cell count and C-reactive protein (CRP) levels. The chest X-ray can show consolidation, nodules or thickened septal lines. The consolidation typically occurs in different places at different times. Computed tomography (CT) findings are characteristic, with multiple patchy alveolar opacities, which often spontaneously migrate. The diagnosis might be made on the basis of CT alone, or on transbronchial or open lung biopsy. Eosinophilic pneumonia Eosinophilic pneumonia is incorrect. Acute eosinophilic pneumonia can present with cough, dyspnea, myalgia, fever and chest pain. Chest radiograph shows flitting peripheral infiltrates. Peripheral eosinophilia would likely be seen in acute eosinophilic pneumonia, which is not mentioned here. Lymphangioleiomyomatosis Lymphangioleiomyomatosis is incorrect. Lymphangioleiomyomatosis is a rare disease affecting women of childbearing age, who have abnormal proliferation of atypical smooth muscle cells throughout their lungs and airways – CT shows multiple small cysts. Cystic destruction of the lungs occurs and respiratory failure eventually develops. The condition is associated with the presence of abdominal tumours (eg angiomyolipomas and lymphangioleiomyomas). Pulmonary alveolar proteinosis Pulmonary alveolar proteinosis is incorrect. Pulmonary alveolar proteinosis is a rare defect in which the alveoli become filled with proteinaceous material that cannot be cleared. It usually presents between 30 and 50 years of age (unless congenital, which accounts for 10% of cases). Onset is often insidious, over several months to years. Patients typically present with a dry cough and breathlessness. Chest radiograh typically shows symmetrical perihilar and lower lobe consolidation. CT shows air-space shadowing, classically with a ‘crazy paving’ appearance due to interlobular septal thickening. Recurrent bacterial pneumonia Recurrent bacterial pneumonia is incorrect. Recurrent lobar bacterial infection is unusual in an immunocompetent adult.

Question 18

An anxious 22-year-old woman presented with mild shortness of breath on exertion that had come on gradually over several months. Her symptoms are intermittent, but worse in the evening, and her speech becomes slurred during the episodes. She has recently started treatment for anxiety. On examination, she looked depressed but there were no other positive clinical findings. Other than an ESR of 26 mm in the 1st hour, her routine blood results were normal. Chest X-ray, lung function tests and electrocardiography were all normal. What is the most likely diagnosis?

Explanation

Correct Answer: B- 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. 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 ischemic attacks. Unstable angina Unstable 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.

Question 19

A 38-year-old man presents to the GP complaining of shortness of breath. He has a history of smoking 10 cigarettes per day and is obese. Other history of note includes hypertension, for which he is treated with atenolol 50 mg daily. Pulmonary function shows:

• Peak expiratory flow rate (PEFR) 540 l/min (predicted is 600 l/min) • Ratio of the forced expiratory volume in 1 s to the forced vital capacity (FEV1/FVC) is 90% predicted • The FVC falls when measured supine versus standing up Which of the following is the most likely diagnosis?

Explanation

Correct Answer: E- Obesity-related changes in pulmonary function tests Explanation Obesity-related changes in pulmonary function tests This man has small reductions in the peak expiratory flow rate (PEFR) and in the ratio of forced expiratory volume in 1 s to the forced vital capacity (FEV1/FVC), and the FVC falls when measured in the supine position. The most likely explanation here is increased abdominal fat, leading to a functional reduction in FVC. Treatment of choice is aggressive weight reduction, and he should also be encouraged to stop smoking. Finally, atenolol might not be the most appropriate choice of antihypertensive treatment in a young man. If there is a suggestion of erectile dysfunction, a switch to an

alternative agent such as an angiotensin-converting enzyme (ACE) inhibitor should be considered. Asthma Asthma is incorrect. Asthma would be associated with an obstructive pattern of spirometry and PEFR would likely be lower. Atenolol-related obstructive lung picture Atenolol-related obstructive lung picture is incorrect. The spirometry pattern described here is restrictive not obstructive. Chronic obstructive pulmonary disease (COPD) Chronic obstructive pulmonary disease (COPD) is incorrect. COPD is associated with an obstructive pattern of spirometry and given this man’s age and likely less than 30-pack-year smoking history, COPD is unlikely. Early fibrotic lung disease Early fibrotic lung disease is incorrect. Fibrotic lung disease does cause a restrictive pattern on spirometry but the change in FVC on changing position coupled with the mention of his obesity makes obesity a more likely cause for his symptoms.

Question 20

A breathless 70-year-old smoker presents with the following lung function tests Forced expiratory volume in 1 second (FEV1) 1.5 l (60%) Forced vital capacity (FVC) 1.8 l (55%)

FEV1/FVC ratio 84% Total lung capacity (TLC) 66% predicted Residual volume (RV) 57% predicted Carbon monoxide transfer factor (Tlco) 55% predicted Transfer coefficient (Kco) 60% predicted What is the most likely diagnosis in this case?

Explanation

Correct Answer: D- Interstitial lung disease Explanation Interstitial lung disease The lung function tests show a significant restrictive defect. Only interstitial lung disease or obesity can fit this picture. But given the decrease in Kco (ie after correcting for alveolar volumes), the most likely answer is interstitial lung disease. Anaemia Anaemia is incorrect. Anaemia can cause reduced transfer factor but would not cause/explain the other abnormaities seen on these pulmonary function tests. Asthma Asthma is incorrect. Asthma is associated with airflow obstruction, not restriction. Emphysema Emphysema is incorrect. Emphysema would be associated with airflow obstruction, not restriction (i.e normal FVC, and reduced FEV1/FVC ratio. TLC and RV would also be high, not low as is seen here. Obesity Obesity is incorrect. Obesity can cause a restrictive pattern of lung function but obesity alone would not affect the Kco. In the case of obesity, the gas exchange after correcting for the alveolar volume would in fact be high.

Question 21

According to Perren's strain theory of fracture healing, what is the maximum tissue strain tolerated by lamellar bone formation?

Explanation

Lamellar bone can only form in a low-strain environment of less than 2%. Cartilage tolerates up to 10% strain, while granulation tissue can tolerate up to 100% strain during secondary bone healing.

Question 22

A 65-year-old man presents with progressive groin pain 5 years after an uncomplicated primary total hip arthroplasty utilizing a metal-on-polyethylene bearing. Serum cobalt levels are significantly elevated, while chromium levels are normal. Radiographs are unremarkable. What is the most likely cause of his symptoms?

Explanation

Elevated serum cobalt with normal or mildly elevated chromium in a metal-on-polyethylene total hip arthroplasty suggests mechanically assisted crevice corrosion, also known as trunnionosis, at the head-neck junction.

Question 23

During an ilioinguinal approach to the acetabulum, brisk arterial bleeding is encountered near the posterior aspect of the superior pubic ramus. This vessel is most likely an anastomosis between which two arteries?

Explanation

The corona mortis is a vascular anastomosis between the external iliac system (inferior epigastric artery/vein) and the internal iliac system (obturator artery/vein). It is located on the posterior aspect of the superior pubic ramus.

Question 24

In a 12-year-old boy presenting with a unilateral slipped capital femoral epiphysis (SCFE), which of the following is considered an absolute indication for prophylactic pinning of the contralateral hip?

Explanation

Endocrine disorders, such as hypothyroidism or renal osteodystrophy, are strong indications for prophylactic pinning of the contralateral asymptomatic hip due to a very high risk of bilateral SCFE involvement.

Question 25

Which of the following is the most common complication associated with the use of a bone-patellar tendon-bone (BPTB) autograft for anterior cruciate ligament reconstruction?

Explanation

Anterior knee pain, especially pain associated with kneeling, is the most frequently reported complication following BPTB autograft harvest. Patellar fracture or tendon rupture are much more severe but rare.

Question 26

A 55-year-old man presents with bilateral hand clumsiness and frequent tripping. On physical examination, flicking the nail of his middle finger results in involuntary flexion of the thumb and index finger. This clinical sign indicates compression or dysfunction of which neural pathway?

Explanation

The Hoffmann sign indicates an upper motor neuron lesion, specifically identifying dysfunction of the corticospinal tract. It is frequently positive in patients with cervical spondylotic myelopathy.

Question 27

A 32-year-old manual laborer presents with chronic dorsal wrist pain. Radiographs reveal sclerosis of the lunate without collapse. MRI confirms avascular necrosis of the lunate. Ulnar variance is negative 3 mm. What is the most appropriate surgical intervention?

Explanation

In Lichtman Stage II (sclerosis without collapse) or Stage IIIa with ulnar minus variance, joint-leveling procedures such as a radial shortening osteotomy are indicated. This offloads the lunate and halts disease progression.

Question 28

Which of the following is the most important prognostic factor for long-term survival in a patient with a high-grade intramedullary osteosarcoma following neoadjuvant chemotherapy and wide surgical resection?

Explanation

The percentage of tumor necrosis, or histologic response, following neoadjuvant chemotherapy is the single most important prognostic factor for overall survival in osteosarcoma. Greater than 90% necrosis indicates a favorable prognosis.

Question 29

A 45-year-old man sustains a Schatzker IV tibial plateau fracture featuring a displaced posteromedial fragment. Which surgical approach provides the most direct access for the application of a buttress plate to this specific fragment?

Explanation

A posteromedial approach utilizing the interval between the medial head of the gastrocnemius and the pes anserinus allows for direct visualization and the application of an anti-glide buttress plate to the posteromedial fragment.

Question 30

What is the primary biomechanical function of the proteoglycan aggrecan within the articular cartilage matrix?

Explanation

Aggrecan is the predominant proteoglycan in articular cartilage. Its highly negatively charged glycosaminoglycan (GAG) side chains create an osmotic gradient that draws water into the matrix, providing compressive resistance.

Question 31

A 60-year-old diabetic patient presents with a warm, swollen, erythematous foot without ulceration. Radiographs show periarticular fragmentation, subluxation, and bony debris at the tarsometatarsal joints. According to the Eichenholtz classification, what is the appropriate initial management?

Explanation

The patient is in the acute fragmentation phase (Eichenholtz Stage 1) of Charcot arthropathy. The mainstay of treatment is immobilization and offloading, typically utilizing a total contact cast, until the acute inflammation resolves.

Question 32

A 72-year-old man presents with bilateral leg pain exacerbated by walking. Which of the following historical findings most reliably differentiates neurogenic claudication from vascular claudication?

Explanation

Neurogenic claudication caused by spinal stenosis improves with lumbar flexion, such as when riding a bicycle, because it increases the spinal canal diameter. Vascular claudication is exacerbated by any leg exercise regardless of posture.

Question 33

A 4-month-old girl with developmental dysplasia of the hip (DDH) has been treated in a Pavlik harness for 3 weeks. Examination reveals an inability to actively extend her knee on the affected side. What is the most likely cause of this complication?

Explanation

Femoral nerve palsy is a recognized complication of the Pavlik harness if the hip is positioned in excessive hyperflexion. The harness must be adjusted or removed to resolve the compression and allow nerve recovery.

Question 34

A 22-year-old rugby player sustains a flexor digitorum profundus (FDP) avulsion from the distal phalanx. The tendon has retracted into the palm (Leddy-Packer Type I). Within what timeframe must surgical repair ideally be performed to prevent irreversible tendon necrosis and severe myostatic contracture?

Explanation

Leddy-Packer Type I FDP avulsions retract into the palm, completely disrupting the vincular blood supply. Early surgical repair within 7 to 10 days is critical before the tendon undergoes necrosis or severe contracture.

Question 35

A 24-year-old baseball pitcher presents with a painful clunk in his shoulder during the late cocking phase of throwing. An MRI arthrogram reveals a superior labral tear extending into the long head of the biceps tendon anchor, causing instability of the biceps-labral complex. This represents which type of SLAP lesion?

Explanation

A Type II SLAP lesion involves detachment of the superior labrum and the origin of the long head of the biceps tendon from the supraglenoid tubercle. This leads to distinct instability of the biceps-labral complex.

Question 36

Six weeks following a minimally displaced Colles' fracture treated in a short arm cast, a 65-year-old woman presents unable to actively extend the interphalangeal joint of her thumb. She recalls a sudden painless pop the previous day. What is the most appropriate surgical treatment?

Explanation

Delayed rupture of the EPL following a distal radius fracture leaves degenerated and retracted tendon ends, rendering direct repair impossible. An EIP to EPL tendon transfer is the gold standard treatment for restoration of function.

Question 37

During a primary total knee arthroplasty, trial components are inserted, and the surgeon notes the knee is tight in flexion but balanced and symmetric in extension. Which of the following adjustments is the most appropriate step to achieve balanced gaps?

Explanation

Downsizing the femoral component reduces the anterior-posterior dimension of the femur, thereby increasing the flexion gap without altering the extension gap. Resecting more distal femur would only increase the extension gap.

Question 38

A 60-year-old woman with metastatic breast cancer presents with a lytic lesion in the mid-diaphysis of her femur. The lesion occupies 50% of the cortical diameter. She reports moderate pain with weight-bearing. What is her Mirels' score, and what does it recommend?

Explanation

Site: Lower extremity (2), Pain: Moderate (3), Lesion: Lytic (3), Size: 1/3-2/3 cortex (2). Total score = 10. A Mirels' score of 9 or greater is a strong indication for prophylactic internal fixation to prevent impending pathologic fracture.

Question 39

Which endogenous molecule functions by binding to RANKL (Receptor Activator of Nuclear Factor Kappa-B Ligand) to inhibit osteoclast differentiation and prevent excessive bone resorption?

Explanation

Osteoprotegerin (OPG) acts as a critical decoy receptor. By binding to RANKL, it prevents RANKL from interacting with its receptor (RANK) on osteoclast precursors, thereby halting osteoclastogenesis and reducing bone resorption.

Question 40

A 6-year-old boy presents with a completely displaced extension-type supracondylar humerus fracture. On arrival, his hand is pink, but the radial pulse is absent. After a satisfactory closed reduction and percutaneous pinning, the hand remains pink and warm with a capillary refill of less than 2 seconds, but the pulse remains absent on Doppler ultrasound. What is the most appropriate next step in management?

Explanation

A pink, pulseless hand after adequate reduction and stabilization of a supracondylar humerus fracture is generally managed with close clinical observation. Emergent exploration is indicated only if the hand is poorly perfused (white and pulseless) after reduction.

Question 41

A 25-year-old man sustains a high-energy Pauwels type III femoral neck fracture. Biomechanically, which of the following internal fixation constructs provides the most stability against the high shear forces inherent to this specific fracture pattern?

Explanation

Pauwels III fractures have a vertically oriented fracture line, generating extremely high shear forces across the fracture site. A fixed-angle device such as a dynamic hip screw (often combined with a derotation screw) provides superior biomechanical stability compared to multiple independent cancellous screws.

Question 42

A 45-year-old manual laborer presents with chronic wrist pain and is diagnosed with Scaphoid Nonunion Advanced Collapse (SNAC) Stage II. Radiographs show arthritis limited to the radioscaphoid joint, with preservation of the midcarpal articulation. Which of the following is the most appropriate surgical intervention?

Explanation

SNAC Stage II is characterized by radioscaphoid arthritis, making scaphoid reconstruction alone inadequate due to the pre-existing joint damage. Proximal row carpectomy or scaphoid excision with a four-corner fusion are highly effective salvage procedures when the radiolunate and midcarpal joints are completely spared.

Question 43

A 70-year-old woman presents with recurrent posterior dislocations following a primary total hip arthroplasty performed via a posterior approach. Radiographic evaluation demonstrates an acetabular component in 5 degrees of retroversion and 45 degrees of abduction. The femoral stem is stable and placed in 15 degrees of anteversion. What is the most definitive surgical management?

Explanation

The normal target for acetabular component positioning is 15-20 degrees of anteversion and 40-45 degrees of abduction. Revising the malpositioned, retroverted acetabular shell to achieve proper anteversion addresses the primary biomechanical cause of her posterior instability.

Question 44

A 15-year-old boy presents with a destructive lesion of the distal femur highly suspicious for osteosarcoma. When performing an incisional biopsy of this lesion, which of the following oncologic principles is most critical to follow?

Explanation

Biopsy incisions for suspected musculoskeletal sarcomas must be longitudinal and placed directly within the planned surgical approach for definitive resection. This ensures that the entire biopsy tract, which is considered contaminated with tumor cells, can be excised en bloc.

Question 45

A 32-year-old man undergoes intramedullary nailing of a closed, highly comminuted tibial shaft fracture. In the recovery room, he complains of unrelenting pain out of proportion to the injury. Which of the following pressure measurement profiles unequivocally confirms the diagnosis of acute compartment syndrome?

Explanation

The Delta P (diastolic blood pressure minus absolute compartment pressure) is the most reliable and validated indicator of acute compartment syndrome. A Delta P of less than 30 mmHg indicates critically inadequate tissue perfusion and is a strict clinical indication for emergent, four-compartment fasciotomy.

Question 46

A 45-year-old male presents following a high-speed motorcycle accident. Radiographs reveal an Antero-Posterior Compression (APC) Type II pelvic ring injury. In this specific injury pattern, which of the following structures remains intact, thereby preserving vertical stability?

Explanation

In an APC II injury, the anterior sacroiliac, sacrotuberous, and sacrospinous ligaments are ruptured alongside a symphyseal diastasis. The strong posterior sacroiliac ligaments remain intact, which preserves vertical stability despite the rotational instability.

Question 47

A 22-year-old female sustains a displaced basicervical femoral neck fracture. Which of the following fixation constructs provides the most biomechanical stability for this specific fracture pattern?

Explanation

Basicervical fractures behave biomechanically like intertrochanteric fractures. A sliding hip screw (SHS), often combined with a derotation screw, provides superior biomechanical stability compared to multiple cancellous screws for this pattern.

Question 48

A 6-year-old boy falls from monkey bars and sustains a heavily displaced extension-type supracondylar humerus fracture. On examination, he is unable to flex the interphalangeal joint of his thumb and the distal interphalangeal joint of his index finger. Which nerve is most likely injured?

Explanation

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

Question 49

A 13-year-old obese male presents with right groin pain and a limp. Radiographs confirm a stable slipped capital femoral epiphysis (SCFE). During in situ pinning with a single cannulated screw, which complication is most likely if the screw is placed in the anterosuperior quadrant of the femoral head?

Explanation

Placement of the screw in the anterosuperior quadrant of the femoral head risks penetration of the joint space and injury to the lateral epiphyseal vessels, leading to avascular necrosis. Screws should ideally be placed in the center-center position.

Question 50

An infant is being treated with a Pavlik harness for Developmental Dysplasia of the Hip (DDH). At the two-week follow-up, the mother notes the child is no longer actively extending the knee on the treated side. What is the most appropriate next step in management?

Explanation

Loss of active knee extension indicates a femoral nerve palsy, the most common nerve injury associated with Pavlik harness use due to hyperflexion. The harness must be temporarily discontinued to allow the nerve to recover.

Question 51

A 65-year-old male is undergoing a Total Knee Arthroplasty (TKA). Intraoperatively, after making the standard bone cuts, the knee is tight in flexion but well-balanced in extension. Which of the following is the most appropriate next step to balance the knee?

Explanation

A tight flexion gap with a balanced extension gap requires isolated augmentation of the flexion gap. Releasing the PCL, downsizing the femoral component, or increasing the posterior tibial slope will selectively increase the flexion gap.

Question 52

A 40-year-old male sustains a traumatic anterior shoulder dislocation. After closed reduction, an MRI shows an avulsion of the anterior labrum along with the anterior band of the inferior glenohumeral ligament (IGHL). What is the specific name of this lesion?

Explanation

A classic Bankart lesion is defined as an avulsion of the anterior-inferior labrum and the attached inferior glenohumeral ligament complex from the anterior glenoid rim. It is the primary essential lesion in anterior shoulder instability.

Question 53

A 28-year-old carpenter amputates his index finger at the level of the proximal phalanx base. Replantation is attempted. What is the standard correct sequence of structural repair in digit replantation?

Explanation

The standard sequence for digit replantation is: Bone (osteosynthesis), Extensor tendons, Flexor tendons, Arteries, Nerves, and finally Veins. This sequence establishes skeletal stability before vascular repair and ensures the volar structures are repaired before closing.

Question 54

A 15-year-old male presents with severe right thigh pain. Radiographs reveal a permeative diaphyseal lesion with an "onion-skin" periosteal reaction. A biopsy shows small round blue cells. What genetic translocation is most commonly associated with this diagnosis?

Explanation

Ewing sarcoma is characterized by small round blue cells and an "onion-skin" periosteal reaction. The t(11;22) translocation, resulting in the EWS-FLI1 fusion protein, is found in approximately 85% of these cases.

Question 55

A 55-year-old woman is evaluated for right hand numbness and tingling. Physical exam reveals a positive Phalen's test and atrophy of the abductor pollicis brevis. Carpal tunnel release is planned. Which anatomical structure forms the ulnar border of the carpal tunnel?

Explanation

The carpal tunnel is bordered ulnarly by the pisiform and the hook of the hamate. The radial border consists of the scaphoid tubercle and the ridge of the trapezium.

Question 56

A 24-year-old athlete feels a "pop" in his knee while pivoting. MRI confirms an isolated anterior cruciate ligament (ACL) rupture. He opts for a bone-patellar tendon-bone (BPTB) autograft reconstruction. Which of the following is the most common complication specific to this graft choice?

Explanation

Anterior knee pain (patellofemoral pain) is the most common complication following ACL reconstruction using a BPTB autograft. While patellar fracture or tendon rupture can occur, they are much less common.

Question 57

A 35-year-old female sustains a closed midshaft humeral fracture and presents with a radial nerve palsy (wrist drop). The fracture is managed non-operatively in a functional brace. At 12 weeks, there is no clinical or EMG evidence of nerve recovery. What is the most appropriate next step in management?

Explanation

Failure of radial nerve recovery by 3 months (12 weeks) post-injury, confirmed by lack of clinical and EMG evidence of reinnervation, is an indication for surgical exploration of the nerve. Tendon transfers are typically reserved for permanent, unrecoverable injuries.

Question 58

A 75-year-old male with a history of prostate cancer presents with progressively worsening back pain and bilateral leg weakness. MRI of the thoracic spine shows a large epidural metastatic mass causing severe spinal cord compression at T8. He has been non-ambulatory for 24 hours. What is the best initial definitive treatment?

Explanation

For acute malignant spinal cord compression causing an active neurologic deficit, high-dose IV dexamethasone should be started immediately. Emergent surgical decompression followed by radiation is the standard of care for solid tumors causing cord compression with acute decline.

Question 59

A 65-year-old active male is undergoing a total hip arthroplasty. The surgeon chooses highly cross-linked polyethylene (HXLPE) instead of conventional polyethylene. Which of the following trade-offs is most directly associated with increasing the irradiation dose to create HXLPE?

Explanation

Increasing irradiation decreases the wear rate of polyethylene but reduces its mechanical properties, such as ultimate tensile strength and fatigue crack propagation resistance. To prevent oxidation, HXLPE is often remelted or annealed.

Question 60

In anteroposterior compression (APC) type III pelvic ring injuries, massive hemorrhage is most commonly associated with disruption of which of the following structures?

Explanation

While arterial bleeding (e.g., internal pudendal or obturator) can occur in APC injuries, the most common source of massive hemorrhage in pelvic ring disruptions is the presacral venous plexus and cancellous bone.

Question 61

A 34-year-old male presents after a motor vehicle collision with a Levine-Edwards Type II traumatic spondylolisthesis of the axis (Hangman's fracture). Imaging shows 4 mm of translation and significant angulation. What is the most appropriate definitive management?

Explanation

Type II Hangman fractures typically have >3mm translation and significant angulation due to disruption of the C2-C3 disc. They are traditionally treated with halo vest immobilization after gentle reduction, though surgery may be indicated if reduction cannot be maintained.

Question 62

A 22-year-old female soccer player undergoes anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BTB) autograft. Six months postoperatively, she reports anterior knee pain with kneeling. Compared to hamstring autograft, BTB autograft has a higher risk of which of the following?

Explanation

BTB autografts are associated with a higher incidence of donor site morbidity, specifically anterior knee pain and pain with kneeling, compared to hamstring autografts. Rates of graft failure and return to sport are generally comparable.

Question 63

A 13-year-old obese male presents with a 4-week history of left knee pain and an antalgic gait. Examination reveals obligatory external rotation of the left hip upon flexion. Radiographs confirm a stable slipped capital femoral epiphysis (SCFE). What is the primary reason to perform single-screw in situ fixation over multiple-screw fixation?

Explanation

Single-screw fixation is the standard of care for a stable SCFE. Compared to multiple screws, a single screw provides adequate stability while significantly decreasing the risk of inadvertent joint penetration and subsequent chondrolysis.

Question 64

Bone morphogenetic proteins (BMPs) are osteoinductive factors belonging to the TGF-beta superfamily. Which BMP is most heavily implicated in the standard FDA-approved formulation for open tibial shaft fractures (rhBMP-2)?

Explanation

Recombinant human BMP-2 (rhBMP-2) is FDA-approved for use in acute, open tibial shaft fractures treated with an intramedullary nail. BMP-7 (OP-1) was previously approved for recalcitrant tibial nonunions under a humanitarian device exemption.

Question 65

A 45-year-old cyclist presents with numbness and tingling in his small and ring fingers. He has weakness of finger abduction but normal sensation over the dorso-ulnar aspect of his hand. Where is the most likely site of nerve compression?

Explanation

Normal dorso-ulnar sensation indicates the compression is distal to the dorsal ulnar cutaneous nerve branch (sparing the cubital tunnel). Involvement of both volar sensation (ring/small fingers) and intrinsic motor function localizes the lesion to Zone 1 of Guyon's canal.

Question 66

A 15-year-old boy presents with knee pain. Radiographs show a sunburst periosteal reaction in the distal femur. Biopsy confirms high-grade osteosarcoma. Which of the following is the most significant prognostic factor for survival in this patient?

Explanation

The histologic response to neoadjuvant chemotherapy, defined as the percentage of tumor necrosis at the time of definitive resection, is the single most important prognostic factor for long-term survival in high-grade osteosarcoma.

Question 67

During open reduction and internal fixation of a supination-external rotation type IV ankle fracture, the surgeon assesses the syndesmosis. Which intraoperative fluoroscopic finding best indicates a reduced syndesmosis?

Explanation

A reduced syndesmosis and restored fibular length are indicated by a medial clear space that is equal to the superior clear space on the mortise view. The tibiofibular clear space should be < 5 mm, and overlap should be > 10 mm on the AP view.

Question 68

A 24-year-old overhead athlete undergoes an arthroscopic Bankart repair for recurrent anterior shoulder instability. Which of the following structural lesions must be addressed to minimize the risk of recurrent instability postoperatively?

Explanation

An engaging Hill-Sachs lesion can lever the humeral head out of the glenoid when the shoulder is in abduction and external rotation. If not addressed (e.g., via a remplissage procedure or bone block), it significantly increases the risk of recurrent instability.

Question 69

Which of the following biomechanical terms best describes the progressive deformation of a viscoelastic material, such as articular cartilage, when subjected to a constant load over time?

Explanation

Creep is defined as the time-dependent, progressive deformation of a material under a constant load. Stress relaxation is the decrease in stress over time when a material is held at a constant strain.

Question 70

During a total knee arthroplasty, trial components are placed. The knee is balanced in flexion, but is tight medially in extension. Which of the following releases is most appropriate to achieve a balanced gap?

Explanation

A knee that is tight medially only in extension requires release of structures that are tense in extension. The posteromedial capsule and the posterior oblique ligament should be released first to correct this asymmetric extension tightness.

Question 71

A 13-year-old girl with adolescent idiopathic scoliosis (AIS) has a right thoracic curve of 35 degrees. She is Risser stage 1 and premenarchal. What is the most appropriate management?

Explanation

In a skeletally immature patient (Risser 0-2, premenarchal) with an AIS curve between 25 and 40 degrees, full-time bracing (e.g., Thoracolumbosacral orthosis) is the gold standard to prevent curve progression to surgical magnitude.

Question 72

A 30-year-old carpenter sustains a laceration to the volar aspect of his index finger at the level of the proximal phalanx. Both the FDS and FDP tendons are completely severed. This injury is classified as occurring in which flexor tendon zone?

Explanation

Zone II ('no man\'s land') extends from the A1 pulley (distal palmar crease) to the FDS insertion at the middle phalanx. Injuries here involve both the FDS and FDP within the tight fibro-osseous sheath, complicating surgical repair.

Question 73

When treating congenital talipes equinovarus (clubfoot) using the Ponseti method, what is the correct order of deformity correction?

Explanation

The mnemonic CAVE dictates the sequence of correction in the Ponseti method: Cavus (first ray elevated), Adductus (forefoot adduction), Varus (hindfoot varus), and finally Equinus (hindfoot equinus, often requiring a percutaneous Achilles tenotomy).

Question 74

A 40-year-old male sustains a closed transverse fracture of the middle third of the humerus. On examination, he is unable to extend his wrist or digits. What is the most appropriate initial management of the nerve palsy?

Explanation

Primary radial nerve palsy in the setting of a closed humeral shaft fracture has a high rate of spontaneous recovery (>70%). The standard initial management is observation and conservative fracture care (e.g., functional brace or coaptation splint).

Question 75

A 68-year-old male presents with increasing leg bowing and deep bone pain. Radiographs reveal cortical thickening and coarsened trabeculae of the tibia. Serum alkaline phosphatase is markedly elevated, but calcium and phosphate are normal. Which medication is considered the first-line treatment for his symptomatic disease?

Explanation

Intravenous nitrogen-containing bisphosphonates (like zoledronic acid) are the treatment of choice for symptomatic Paget's disease of bone due to their high efficacy and prolonged remission rates compared to older therapies.

Question 76

A 55-year-old female presents with stage II adult acquired flatfoot deformity (posterior tibial tendon dysfunction). Which of the following physical examination findings differentiates stage II from stage III disease?

Explanation

Stage II posterior tibial tendon dysfunction is characterized by a flexible hindfoot valgus deformity. Progression to stage III is marked by the development of a fixed, rigid hindfoot deformity and subtalar arthritis.

Orthopedic Prometric MCQs - Chapter 4 Part 1

Orthopedic Prometric MCQs - Chapter 4 Part 3

Orthopedic Prometric MCQs - Chapter 4 Part 3

Chapter Index