The gluteus medius is situated on the outer surface of the pelvis. It arises from the outer surface of the ilium between the iliac crest and posterior gluteal line above and the anterior gluteal line below. The gluteus medius is supplied by the fourth and fifth lumbar and first sacral nerves through the superior gluteal nerve

If a substance passes through the glomerular membrane with perfect ease, the glomerular filtrate contains virtually the same concentration of the substance as does the plasma and if the substance is neither secreted nor reabsorbed by the tubules, all of the filtered substance continues on into the urine. Glomerular filtration rate (GFR) describes the flow rate of filtered fluid through the kidney.

The prostate is situated in the pelvic cavity and is also located immediately below the internal urethral orifice at the commencement of the urethra. It is held in position by the puboprostatic ligaments, the superior fascia of the urogenital diaphragm and the anterior portions of the levatores ani. The base of the prostate is directed upward and is attached to the inferior surface of the urinary bladder while the apex is directed downward and is in contact with the superior fascia of the urogenital diaphragm.

Fractures of the distal radius account for up to 20% of all fractures treated in the emergency department. Initial assessment includes a history of the mechanism of injury, associated injury and appropriate radiological evaluation
Most of the fractures are caused by a fall on the outstretched hand with the wrist in dorsiflexion. The form and severity of fracture of distal radius as well as the concomitant injury of disco-ligamentary structures of the wrist also depend on the position of the wrist at the moment of hitting the ground. The width of this angle influences the localization of the fracture. Pronation, supination and abduction determine the direction of the force and the compression of the carpus and different appearances of ligament injuries.
The basic principle of fracture treatment is to obtain accurate fracture reduction and then to use a method of immobilization that will maintain and hold that reduction. While the goal of treatment in fracture distal end of the radius is the restoration of normal function, the precise methods to achieve that desired outcome are controversial. Intra-articular fractures of the distal end of the radius can be difficult to treat, at times, with a traditional conservative method. A number of options for treatment are available to prevent the loss of reduction in an unstable fracture of the distal end of the radius.
One of the recent advances in the treatment of distal radius fractures is the more frequent application of open reduction and internal fixation, especially for intra-articular fractures. There are two groups of fractures for which open reduction and internal fixation is advisable.
The first group includes the two-part shear fracture (Barton fracture), which actually is a radio-carpal fracture-dislocation. Although the anatomical reduction is possible by closed means in some cases, these fractures are very unstable and difficult to control in plaster. The second group includes complex intra-articular fractures in which the articular fragments are displaced, rotated or impacted and are not amenable to reduction through limited operative exposure.

The inferior pancreaticoduodenal artery is a branch of the superior mesenteric artery or from the first intestinal branch of the superior mesenteric artery. Once given off, it runs to the right between the pancreatic head and the duodenum and then ascends to form an anastomosis with the superior pancreaticoduodenal artery.

Penicillins and cephalosporins (e.g. cefuroxime, cefotaxime, ceftriaxone) inhibit bacterial cell wall synthesis through the inhibition of peptidoglycan cross-linking.
Macrolides (e.g. erythromycin), tetracyclines, aminoglycosides and chloramphenicol act by interfering with bacterial protein synthesis.
Sulphonamides (e.g. trimethoprim, co-trimoxazole) work by inhibiting the synthesis of nucleic acid

The maxillary sinuses usually develop symmetrically. The maxillary sinus ostium drains into the infundibulum which joins the hiatus semilunaris and drains into the middle meatus.

The U-wave, not always visible in ECGs, is thought to represent repolarisation of papillary muscles or Purkinje fibres. When seen, it is very small and occurs after the T-wave. Inverted U-waves indicate myocardial ischaemia or left ventricular volume overload. Prominent U-waves are most commonly seen in hypokalaemia. Other causes include hypercalcaemia, thyrotoxicosis, digitalis exposure, adrenaline and class 1A and 3 anti-arrhythmic agents. It can also be seen in congenital long-QT syndrome and in intracranial haemorrhage.

Latissimus dorsi is a triangular, flat muscle that covers the lumbar region and the lower half of the thoracic region. It is supplied by the sixth, seventh and eighth cervical nerves through the thoracodorsal (long subscapular) nerve.

Sodium nitroprusside is a potent peripheral vasodilator that affects both arterioles and venules. It is often administered intravenously to patients who are experiencing a hypertensive emergency. It reduces both total peripheral resistance as well as venous return, so decreasing both preload and afterload. For this reason it can be used in severe cardiogenic heart failure where this combination of effects can act to increase cardiac output. It is administered by intravenous infusion. Onset is typically immediate and effects last for up to ten minutes. The duration of treatment should not exceed 72 hours.

Metabolic alkalosis is a primary increase in bicarbonate (HCO3−) with or without compensatory increase in carbon dioxide partial pressure (Pco2); pH may be high or nearly normal. Metabolic alkalosis occurs as a consequence of a loss of H+ from the body or a gain in HCO3 -. In its pure form, it manifests as alkalemia (pH >7.40). As a compensatory mechanism, metabolic alkalosis leads to alveolar hypoventilation with a rise in arterial carbon dioxide tension p(CO2), which diminishes the change in pH that would otherwise occur. Normally, arterial p(CO2) increases by 0.5–0.7 mmHg for every 1 mmol/l increase in plasma bicarbonate concentration, a compensatory response that occurs very rapidly. If the change in p(CO2) is not within this range, then a mixed acid–base disturbance occurs. Likewise, if the increase in p(CO2) is less than the expected change, then a primary respiratory alkalosis is also present. However an elevated serum bicarbonate concentration can also occur due to a compensatory response to primary respiratory acidosis. A bicarbonate concentration greater than 35 mmol/l is almost always caused by metabolic alkalosis (as is the case in this clinical scenario). Calculation of the serum anion gap can also help to differentiate between primary metabolic alkalosis and the metabolic compensation for respiratory acidosis. The anion gap is frequently elevated to a modest degree in metabolic alkalosis because of the increase in the negative charge of albumin and the enhanced production of lactate. However, the only definitive way to diagnose metabolic alkalosis is by performing a simultaneous blood gases analysis, which reveals elevation of both pH and arterial p(CO2) and increased calculated bicarbonate.

This patient has an axillary vein thrombosis. It classically presents with pain and swelling of the affected limb. Venous duplex scan is needed to exclude a thrombus.

Primary proximal upper-extremity deep vein thrombosis (UEDVT) is less common than its secondary forms. The most common primary form is effort-related thrombosis, also called Paget-Schroetter syndrome. It usually occurs in, otherwise, healthy young men who report, before the onset of thrombosis, vigorous arm exercise such as lifting weights, playing badminton/tennis, pitching a baseball, or performing repetitive overhead activities, such as painting or car repair. Most patients with effort-related UEDVT have an underlying venous thoracic outlet syndrome (VTOS). Secondary causes of UEDVT include central line insertion, malignancy, or pacemakers.

Patients with UEDVT typically present with heaviness, discomfort, pain, paraesthesia, and swelling of the affected arm. Physical examination may reveal pitting oedema, redness, or cyanosis of the involved extremity; visible collateral veins at the shoulder or upper arm; and fever.

Diagnosis is made by:
1. FBC: platelet function
2. Coagulation profile
3. Liver function tests
4. Venous duplex scan: investigation of choice, provides information relating to flow and characteristics of the vessels.
5. D-dimer testing
6. CT scan: for VTOS

Treatment options for primary UEDVT are as follows:
1. Anticoagulation therapy should be undertaken with a once-daily regimen of LMWH or fondaparinux for at least five days, followed by vitamin K antagonists for at least three months. Unfractionated heparin instead of LMWH is recommended for patients with renal failure or for those treated with CDT.

2. Early thrombus removal and restoration of venous patency aim should be done immediately after starting the patient on heparin. Catheter-based therapy is recommended for patients with proximal UEDVT of recent onset and severe symptoms, low risk for bleeding complications, and good functional status.

The immediate treatment of hypercalcaemia involves intravenous fluid resuscitation. This may be complemented with the use of bisphosphonates and sometimes, diuretics. However, fluids are administered first. Normal saline is usually preferred for this over other solutions.

Urgent management in hypercalcaemia is indicated if:
1. Serum calcium level >3.5 mmol/L
2. Reduced consciousness
3. Severe abdominal pain
4. Pre-renal failure

Management options include:
1. Intravenous fluid resuscitation with 3–6 litres of 0.9% normal saline in 24 hours
2. Concurrent administration of calcitonin to help lower calcium levels
3. Medical therapy (usually if corrected calcium >3.0mmol/L)

The Gustilo open fracture classification system is the most commonly used classification system for open fractures.
This system uses the amount of energy, the extent of soft-tissue injury and the extent of contamination for determination of fracture severity. Progression from grade 1 to 3C implies a higher degree of energy involved in the injury, higher soft tissue and bone damage and higher potential for complications.
Grade Injury
1 Low energy wound <1cm
2 Greater than 1cm wound with moderate soft tissue damage
3 High energy wound > 1cm with extensive soft tissue damage
3 A (sub group of 3) Adequate soft tissue coverage
3 B (sub group of 3) Inadequate soft tissue coverage
3 C (sub group of 3) Associated arterial injury

It is important to recognize that a Gustilo score of grade 3C implies vascular injury as well as bone and connective-tissue damage. Grade 3C is defined as an open fracture associated with an arterial injury requiring repair, irrespective of degree of soft-tissue injury. The lack of peripheral pulses indicate arterial injury.
A less morbid damage control approach (compared with ligation) for patients with extremity vascular injury is vascular shunting, a technique that has been available for over 50 years. A vascular shunt is a synthetic tube that is inserted into the vessel and secured proximally and distally. Shunts were placed in the context of damage control to allow stabilization of Gustilo 3C fractures or limb replantation. Vascular shunts are typically used for larger, more proximal arteries and veins such as the femoral and popliteal arteries. Shunts can remain in place up to six hours, but definitive vascular reconstruction should be performed as soon as the patient is sufficiently stable to undergo the procedure. Once a fracture is identified, it is reduced as much as possible and splinted. If an open fracture is suspected, the patient should be taken to the operating room to debride and stabilize the fracture (usually with external fixation) either after life-threatening injuries have been managed or concurrently while less emergency chest, abdominal, or head injuries are being addressed. Revascularization — Ischemia due to vascular injury is a major risk factor for amputation, and, ideally, the injury will be identified and treated within six hours to minimize ischemic nerve and muscle damage.

An anal fistula is an abnormal tract between the anal canal and the skin around the anus.
Anal fistulas can be classified according to their relationship with the external sphincter. A fistula may be complex, with several openings onto the perianal skin. Intersphincteric fistulas are the most common type and cross only the internal anal sphincter. Trans-sphincteric fistulas pass through both the internal and external sphincters.

The aim is to drain the infected material and encourage healing.
For simple intersphincteric and low trans-sphincteric anal fistulas, the most common treatment is a fistulotomy or laying open of the fistula tract.
For high and complex (deeper) fistulas that involve more muscle, with a high risk of faecal incontinence or recurrence, surgery aims to treat the fistula and preserve sphincter-muscle function. Techniques include a 1‑stage or 2‑stage seton (suture material or rubber sling) either alone or in combination with fistulotomy, ligation of an intersphincteric fistula tract, creating a mucosal advancement flap, injecting glue or paste, or inserting a fistula plug .

The cricothyroid muscle is the only tensor muscle of the larynx aiding with phonation. It attaches to the anterolateral aspect of the cricoid and the inferior cornu and lower lamina of the thyroid cartilage. Its action tilts the thyroid forward to help tense the vocal cords.

All of the listed options are true regarding radioiodine therapy, except for the first option. Treatment with radioiodine does not increase the risk of parathyroid carcinoma.

Recurrence of Graves’ disease is treated similar to normal Graves’ disease. However, some patients may need definitive treatment with radioiodine or thyroidectomy. These patients are usually hypothyroid post treatment and are treated with L-thyroxine until their TSH values are within normal parameters.

The rhomboid major arises from the second, third, fourth and fifth thoracic vertebrae. It is inserted into a narrow tendinous arch attached to the root of the spine of the scapula and the inferior angle. By its insertion in the inferior angle of the scapula, it acts on this angle and produces a slight rotation of the scapula on the side of the chest. It also retracts the scapula by working with the trapezius muscle.

Fine-needle aspiration (FNA) cytology of axillary lymph nodes is a simple, minimally invasive technique that can be used to improve preoperative determination of the status of the axillary lymph nodes in patients with breast cancer, thereby serving as a tool with which to triage patients for sentinel versus full lymph node dissection procedures. FNA of axillary lymph nodes is a sensitive and very specific method with which to detect metastasis in breast cancer patients. Because of its excellent positive predictive value, full axillary lymph node dissection can be planned safely instead of a sentinel lymph node dissection when a preoperative positive FNA result is rendered.

The deep inguinal ring is near the midpoint of the inguinal ligament, below the anterior superior iliac spine. It is lateral to the inferior epigastric artery. The superficial ring, however, is found above the pubic tubercle. The supravesical fossa is the space between the median and medial umbilical folds.

Answer: Rupture of the aorta distal to the left subclavian artery

Aortic rupture is typically the result of a blunt aortic injury in the context of rapid deceleration. After traumatic brain injury, blunt aortic rupture is the second leading cause of death following blunt trauma. Thus, this condition is commonly fatal as blood in the aorta is under great pressure and can quickly escape the vessel through a tear, resulting in rapid haemorrhagic shock, exsanguination, and death.
Traumatic aortic transection or rupture is associated with a sudden and rapid deceleration of the heart and the aorta within the thoracic cavity. Anatomically, the heart and great vessels (superior vena cava, inferior vena cava, pulmonary arteries, pulmonary veins, and aorta) are mobile within the thoracic cavity and not fixed to the chest wall, unlike the descending abdominal aorta. Injury to the aorta during a sudden deceleration commonly originates near the terminal section of the aortic arch, also known as the isthmus. This portion lies just distal to the take-off of the left subclavian artery at the intersection of the mobile and fixed portions of the aorta.

Acute pancreatitis is an inflammatory condition of the pancreas most commonly caused by biliary tract disease or alcohol abuse. Damage to the pancreas causes local release of digestive proteolytic enzymes that autodigest pancreatic tissue. Acute pancreatitis usually presents with epigastric pain radiating to the back, nausea and vomiting, and epigastric tenderness on palpation. The diagnosis is made based on the clinical presentation, elevated serum pancreatic enzymes, and findings on imaging (CT, MRI, ultrasound) that suggest acute pancreatitis. Treatment is mostly supportive and includes bowel rest, fluid resuscitation, and pain medication. Enteral feeding is usually quickly resumed once the pain and inflammatory markers begin to subside. Interventional procedures may be indicated for the treatment of underlying conditions, such as ERCP or cholecystectomy in gallstone pancreatitis. Localized complications of pancreatitis include necrosis, pancreatic pseudocysts, and abscesses. Systemic complications involve sepsis, ARDS, organ failure, and shock and are associated with a considerable rise in mortality.

The Ranson score is used to predict the severity of acute pancreatitis:
At admission
age in years > 55 years
white blood cell count > 16000 cells/mm3
blood glucose > 11.1 mmol/L (> 200 mg/dL)
serum AST > 250 IU/L
serum LDH > 350 IU/L

At 48 hours
Calcium (serum calcium < 2.0 mmol/L (< 8.0 mg/dL)
Haematocrit fall >10%
Oxygen (hypoxemia PO2 < 60 mmHg)
BUN increased by 1.8 or more mmol/L (5 or more mg/dL) after IV fluid hydration
Base deficit (negative base excess) > 4 mEq/L
Sequestration of fluids > 6 L

Interpretation If the score ≥ 3, severe pancreatitis likely. If the score < 3, severe pancreatitis is unlikely Or Score 0 to 2 : 2% mortality Score 3 to 4 : 15% mortality Score 5 to 6 : 40% mortality Score 7 to 8 : 100% mortality

A calculus in the ureter, if less than 5mm in diameter is likely to pass spontaneously. However, a larger calculus irritates the ureter and may become lodged, leading to hydroureter and/or hydronephrosis. Likely sites where the calculus might get lodged, include pelviureteric junction, distal ureter at the level of iliac vessels and the vesicoureteric junction. An obstruction can result in reduced glomerular filtration. There can be deterioration in renal function due to hydronephrosis and a raised glomerular pressure, leading to poor renal blood flow. Permanent renal dysfunction usually takes about 4 weeks to occur. Secondary infection can also occur in chronic obstruction.

Iron deficiency anaemia is the most common type of anaemia. It can occur due to deficiency of iron from decreased intake, increased loss or inadequate absorption. An MCV less than 80 will indicated iron deficiency anaemia. On the smear the RBCs will be microcytic hypochromic and will also show poikilocytosis. Iron profile tests are important to make a diagnosis. Clinically the patient will be pale and lethargic.

Carbon tetrachloride (CCl4) is a common agent used in the dry cleaning industry and is thought to cause the formation of free radicals. It causes rapid breakdown of the endoplasmic reticulum due to decomposition of lipids and severe liver cell injury. Within less than 30 mins, hepatic protein synthesis declines, lipid export is reduced due to lack of apoprotein and there is an influx of calcium and cell death.

Answer: Sickle cell disease

An anal fissure is a painful linear tear or crack in the distal anal canal, which, in the short term, usually involves only the epithelium and, in the long term, involves the full thickness of the anal mucosa. Anal fissures develop with equal frequency in both sexes; they tend to occur in younger and middle-aged persons.

The exact aetiology of anal fissures is unknown, but the initiating factor is thought to be trauma from the passage of a particularly hard or painful bowel movement. Low-fibre diets (e.g., those lacking in raw fruits and vegetables) are associated with the development of anal fissures. No occupations are associated with a higher risk for the development of anal fissures. Prior anal surgery is a predisposing factor because scarring from the surgery may cause either stenosis or tethering of the anal canal, which makes it more susceptible to trauma from hard stool.

In rare cases, an anal fissure may develop due to:
-anal cancer
-HIV
-tuberculosis
-syphilis
-herpes

A study showed that a patient may exhibit severe, disabling, anorectal symptoms which are disproportionate to physical findings. Rarely leukaemia may be the cause, and the first signs of blood dyscrasia may appear in the anorectum. The diagnosis may not be suggested by the history, physical examination or routine laboratory data.

Crohn’s disease can also cause problems around the anus. These may include tiny but painful cracks in the skin known as anal fissures. Tunnelling sores called fistulas cause abnormal connections between the bowel and the skin; or an abscess, a pocket of inflamed or dead tissue that is usually very painful.

Cirrhosis is disease of the liver that is characterized by fibrosis leading to disorganization of the hepatic architecture. It shows the development of regenerative nodules surrounded by dense fibrotic tissue. Cirrhosis shows non-specific symptoms initially, which include fatigue, anorexia and weight loss. It can later progress to portal hypertension, ascites and liver failure.
Micronodular cirrhosis is named so, due to the uniformly small nodules (<3 mm in diameter) and thick regular bands of connective tissue. These nodules lack lobular organization with distortion of central hepatic venules and portal triads. Over a period of time, macronodular cirrhosis develops, with bigger nodules (3 mm to 5 cm in diameter) surrounded by broad fibrous bands, and some amount of lobular organization. Mixed cirrhosis combines features of both micronodular and macronodular cirrhosis.

The long thoracic nerve innervates the serratus anterior muscle which holds the scapula forward and balances the rhomboids and the trapezius muscles which retract the scapula. Injury to this nerve results in a ‘winged scapula’ with a posterior protrusion.

U waves are prominent if it is >1-2mm or 25% of the height of the T wave. Abnormally prominent U waves are characteristically seen in severe hypokalaemia.

Answer: Surveillance annual flexible sigmoidoscopy from age 13 years until age 30 years.

Familial adenomatous polyposis (FAP) is the most common adenomatous polyposis syndrome. It is an autosomal dominant inherited disorder characterized by the early onset of hundreds to thousands of adenomatous polyps throughout the colon. If left untreated, all patients with this syndrome will develop colon cancer by age 35-40 years. In addition, an increased risk exists for the development of other malignancies.
Most patients with FAP are asymptomatic until they develop cancer. As a result, diagnosing presymptomatic patients is essential.

Of patients with FAP, 75%-80% have a family history of polyps and/or colorectal cancer at age 40 years or younger.

Nonspecific symptoms, such as unexplained rectal bleeding (haematochezia), diarrhoea, or abdominal pain, in young patients may be suggestive of FAP.

In a minority of FAP families a mutation cannot be identified and so annual flexible sigmoidoscopy should be offered to at risk family members from age 13–15 years until age 30, and at three to five year intervals thereafter until age 60 years.