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  • Question 1 - A mother brings her 3-year-old son to the GP worried about his motor...

    Incorrect

    • A mother brings her 3-year-old son to the GP worried about his motor development. Since he started walking 9 months ago, the child has been limping and avoiding weight bearing on the left leg. He has otherwise been healthy. He was born at term via a caesarean section, due to his breech position, and weighed 4.5kg. What is the probable reason for his limp?

      Your Answer: Slipped upper femoral epiphysis

      Correct Answer: Developmental dysplasia of the hip

      Explanation:

      The condition is developmental dysplasia of the hip, which is typically observed in individuals under the age of 4.

      Lower limb anatomy is an important topic that often appears in examinations. One aspect of this topic is the nerves that control motor and sensory functions in the lower limb. The femoral nerve controls knee extension and thigh flexion, and provides sensation to the anterior and medial aspect of the thigh and lower leg. It is commonly injured in cases of hip and pelvic fractures, as well as stab or gunshot wounds. The obturator nerve controls thigh adduction and provides sensation to the medial thigh. It can be injured in cases of anterior hip dislocation. The lateral cutaneous nerve of the thigh provides sensory function to the lateral and posterior surfaces of the thigh, and can be compressed near the ASIS, resulting in a condition called meralgia paraesthetica. The tibial nerve controls foot plantarflexion and inversion, and provides sensation to the sole of the foot. It is not commonly injured as it is deep and well protected, but can be affected by popliteral lacerations or posterior knee dislocation. The common peroneal nerve controls foot dorsiflexion and eversion, and can be injured at the neck of the fibula, resulting in foot drop. The superior gluteal nerve controls hip abduction and can be injured in cases of misplaced intramuscular injection, hip surgery, pelvic fracture, or posterior hip dislocation. Injury to this nerve can result in a positive Trendelenburg sign. The inferior gluteal nerve controls hip extension and lateral rotation, and is generally injured in association with the sciatic nerve. Injury to this nerve can result in difficulty rising from a seated position, as well as difficulty jumping or climbing stairs.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 2 - Which one of the following nerves innervates the long head of the biceps...

    Incorrect

    • Which one of the following nerves innervates the long head of the biceps femoris muscle?

      Your Answer: Common peroneal division of sciatic nerve

      Correct Answer: Tibial division of sciatic nerve

      Explanation:

      The common peroneal component of the sciatic nerve innervates the short head of biceps femoris, which may be absent at times. On the other hand, the tibial division of the sciatic nerve innervates the long head.

      The Biceps Femoris Muscle

      The biceps femoris is a muscle located in the posterior upper thigh and is part of the hamstring group of muscles. It consists of two heads: the long head and the short head. The long head originates from the ischial tuberosity and inserts into the fibular head. Its actions include knee flexion, lateral rotation of the tibia, and extension of the hip. It is innervated by the tibial division of the sciatic nerve and supplied by the profunda femoris artery, inferior gluteal artery, and the superior muscular branches of the popliteal artery.

      On the other hand, the short head originates from the lateral lip of the linea aspera and the lateral supracondylar ridge of the femur. It also inserts into the fibular head and is responsible for knee flexion and lateral rotation of the tibia. It is innervated by the common peroneal division of the sciatic nerve and supplied by the same arteries as the long head.

      Understanding the anatomy and function of the biceps femoris muscle is important in the diagnosis and treatment of injuries and conditions affecting the posterior thigh.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 3 - A 70-year-old retired delivery man visits his family physician with a complaint of...

    Incorrect

    • A 70-year-old retired delivery man visits his family physician with a complaint of knee pain. He reports that the pain is present in both knees and worsens towards the end of the day. The pain usually subsides after resting and in the morning. He has been experiencing knee pain for the past few years and used to take paracetamol, which provided relief. However, the pain has recently intensified, limiting his ability to work. The patient occasionally experiences right hip pain, but it does not bother him much. The patient has a medical history of well-controlled diabetes mellitus, hypertension, and lower back pain. He has a body mass index of 32 kg per m2 and takes metformin, insulin, and candesartan regularly. On examination, there is no redness, swelling, or tenderness over the knees. The physician recommends an X-ray of both knees. What is the most probable X-ray finding?

      Your Answer: Narrowed joint space, soft tissue swelling, subchondral sclerosis

      Correct Answer: Narrowed joint space, subchondral sclerosis, osteophytes

      Explanation:

      The patient’s symptoms are most consistent with osteoarthritis, with no signs of inflammation. Radiographic findings of narrowed joint space and osteophytes support this diagnosis. Other differential diagnoses include rheumatoid arthritis, gout, and pseudogout. The patient’s occupation as a delivery man may have contributed to the development of osteoarthritis. The presence of symptoms and limitations in daily activities should be considered in developing a management plan.

      Comparison of Osteoarthritis and Rheumatoid Arthritis

      Osteoarthritis and rheumatoid arthritis are two types of arthritis that affect the joints. Osteoarthritis is caused by mechanical wear and tear, resulting in the localized loss of cartilage, remodelling of adjacent bone, and associated inflammation. On the other hand, rheumatoid arthritis is an autoimmune disease that affects women more commonly than men and can occur in adults of all ages. It typically affects the MCP and PIP joints, causing bilateral symptoms and systemic upset, while osteoarthritis affects large weight-bearing joints such as the hip and knee, as well as the carpometacarpal joint and DIP and PIP joints, causing unilateral symptoms and no systemic upset.

      The typical history of osteoarthritis involves pain following use, which improves with rest, while rheumatoid arthritis involves morning stiffness that improves with use. X-ray findings for osteoarthritis include loss of joint space, subchondral sclerosis, subchondral cysts, and osteophytes forming at joint margins. For rheumatoid arthritis, X-ray findings include loss of joint space, juxta-articular osteoporosis, periarticular erosions, and subluxation.

      In summary, while both osteoarthritis and rheumatoid arthritis affect the joints, they have different causes, affected joints, symptoms, and X-ray findings. Understanding these differences can help with accurate diagnosis and appropriate treatment.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 4 - A 32-year-old female patient visits the GP with a concern about her middle...

    Correct

    • A 32-year-old female patient visits the GP with a concern about her middle finger's inability to flex at the end. During the examination, it is observed that she cannot bend the distal interphalangeal joint of her middle finger.

      Which muscle is accountable for this movement?

      Your Answer: Flexor digitorum profundus

      Explanation:

      The correct answer is that the flexor digitorum profundus muscle is responsible for flexing the distal interphalangeal joint. The other options, such as the flexor digitorum superficialis and flexor pollicis longus, are responsible for different movements and are therefore incorrect. The palmar interossei are also not responsible for flexion at the distal interphalangeal joint. Lastly, there is no such muscle as the flexor digiti medius.

      The forearm flexor muscles include the flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis, and flexor digitorum profundus. These muscles originate from the common flexor origin and surrounding fascia, and are innervated by the median and ulnar nerves. Their actions include flexion and abduction of the carpus, wrist flexion, adduction of the carpus, and flexion of the metacarpophalangeal and interphalangeal joints.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 5 - A 75-year-old man sustains a scaphoid bone fracture that is displaced. The medical...

    Correct

    • A 75-year-old man sustains a scaphoid bone fracture that is displaced. The medical team decides to use a screw to fix the fracture. What structure is located directly medial to the scaphoid?

      Your Answer: Lunate

      Explanation:

      The lunate is positioned towards the middle in the anatomical plane. Injuries that involve high velocity and result in scaphoid fractures may also lead to dislocation of the lunate.

      The scaphoid bone has various articular surfaces for different bones in the wrist. It has a concave surface for the head of the capitate and a crescentic surface for the lunate. The proximal end has a wide convex surface for the radius, while the distal end has a tubercle that can be felt. The remaining articular surface faces laterally and is associated with the trapezium and trapezoid bones. The narrow strip between the radial and trapezial surfaces and the tubercle gives rise to the radial collateral carpal ligament. The tubercle also receives part of the flexor retinaculum and is the only part of the scaphoid bone that allows for the entry of blood vessels. However, this area is commonly fractured and can lead to avascular necrosis.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 6 - A 67-year-old postmenopausal woman visits the clinic to discuss her bone densitometry results....

    Incorrect

    • A 67-year-old postmenopausal woman visits the clinic to discuss her bone densitometry results. She has a history of hypertension and does not use tobacco, alcohol, or illicit drugs. Her BMI is 22.1 kg/m² and physical examination is unremarkable. Serum calcium, phosphorus concentrations, and serum alkaline phosphatase activity are within the reference ranges. The bone densitometry shows low bone density consistent with osteoporosis. What medication was most likely prescribed to inhibit osteoclast-mediated bone resorption, and resulted in no further loss of bone mineral density on repeat bone densitometry 1 year later?

      Your Answer: Teriparatide

      Correct Answer: Risedronate

      Explanation:

      Bisphosphonates, such as alendronate and risedronate, are used to treat osteoporosis by preventing bone resorption through the inhibition of osteoclasts. These drugs are taken up by the osteoclasts, preventing them from adhering to the bone surface and continuing the resorption process.

      Denosumab is a monoclonal antibody that works by binding to the receptor activator of nuclear factor kappa-B ligand (RANK-L), which blocks the interaction between RANK-L and RANK, ultimately reducing bone resorption.

      Raloxifene is a selective estrogen receptor modulator that has estrogen-like effects on bone, leading to decreased bone resorption and improved bone density.

      Romosozumab is a monoclonal antibody that inhibits the action of sclerostin, a regulatory factor in bone metabolism, ultimately leading to increased bone formation.

      Bisphosphonates: Uses, Adverse Effects, and Patient Counselling

      Bisphosphonates are drugs that mimic the action of pyrophosphate, a molecule that helps prevent bone demineralization. They work by inhibiting osteoclasts, the cells responsible for breaking down bone tissue. Bisphosphonates are commonly used to prevent and treat osteoporosis, hypercalcemia, Paget’s disease, and pain from bone metastases.

      However, bisphosphonates can cause adverse effects such as oesophageal reactions, osteonecrosis of the jaw, and an increased risk of atypical stress fractures of the proximal femoral shaft in patients taking alendronate. Patients may also experience an acute phase response, which includes fever, myalgia, and arthralgia following administration. Hypocalcemia may also occur due to reduced calcium efflux from bone, but this is usually clinically unimportant.

      To minimize the risk of adverse effects, patients taking oral bisphosphonates should swallow the tablets whole with plenty of water while sitting or standing. They should take the medication on an empty stomach at least 30 minutes before breakfast or another oral medication and remain upright for at least 30 minutes after taking the tablet. Hypocalcemia and vitamin D deficiency should be corrected before starting bisphosphonate treatment. However, calcium supplements should only be prescribed if dietary intake is inadequate when starting bisphosphonate treatment for osteoporosis. Vitamin D supplements are usually given.

      The duration of bisphosphonate treatment varies depending on the level of risk. Some experts recommend stopping bisphosphonates after five years if the patient is under 75 years old, has a femoral neck T-score of more than -2.5, and is at low risk according to FRAX/NOGG.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 7 - Sarah, a 67-year-old female, fell down some stairs and fractured her left calcaneus....

    Incorrect

    • Sarah, a 67-year-old female, fell down some stairs and fractured her left calcaneus. Before starting the management, the doctors conducted a neurovascular examination of Sarah's lower limb and foot. They found that Sarah has palpable pulses, but she has reduced sensation in her lateral left foot. The doctor suspects that the fracture may have caused nerve damage, leading to the reduced sensation.

      What nerve could be affected by the fracture, resulting in the reduced sensation in Sarah's lateral left foot?

      Your Answer: Lateral plantar nerve

      Correct Answer: Sural nerve

      Explanation:

      The lateral foot is innervated by the sural nerve, which is a branch of both the common fibular and tibial nerves. The medial aspect of the leg is innervated by the saphenous nerve, which arises from the femoral nerve. The sole of the foot is mainly innervated by branches of the tibial nerve, including the medial calcaneal, lateral, and medial plantar nerves. The dorsum of the foot is mainly innervated by the superficial fibular nerve, while the web space between the first and second toes is innervated by the deep fibular nerve.

      Anatomy of the Lateral Malleolus

      The lateral malleolus is a bony prominence on the outer side of the ankle joint. Posterior to the lateral malleolus and superficial to the superior peroneal retinaculum are the sural nerve and short saphenous vein. These structures are important for sensation and blood flow to the lower leg and foot.

      On the other hand, posterior to the lateral malleolus and deep to the superior peroneal retinaculum are the peroneus longus and peroneus brevis tendons. These tendons are responsible for ankle stability and movement.

      Additionally, the calcaneofibular ligament is attached at the lateral malleolus. This ligament is important for maintaining the stability of the ankle joint and preventing excessive lateral movement.

      Understanding the anatomy of the lateral malleolus is crucial for diagnosing and treating ankle injuries and conditions. Proper care and management of these structures can help prevent long-term complications and improve overall ankle function.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 8 - A 23-year-old individual presents to the emergency department with a gym-related injury. While...

    Incorrect

    • A 23-year-old individual presents to the emergency department with a gym-related injury. While lifting a heavy barbell off the floor, they experienced a hamstring pull. Upon examination, the doctor notes weak knee flexion facilitated by the biceps femoris muscle. The doctor suspects nerve damage to the nerves innervating the short and long head of biceps femoris. Which nerve specifically provides innervation to the short head of biceps femoris?

      Your Answer: Tibial branches of sciatic nerve

      Correct Answer: Common peroneal branch of sciatic nerve

      Explanation:

      The short head of biceps femoris receives innervation from the common peroneal division of the sciatic nerve. The superior gluteal nerve supplies the gluteus medius and minimus, while the inferior gluteal nerve supplies the gluteus maximus. The perineum is primarily supplied by the pudendal nerve.

      The Biceps Femoris Muscle

      The biceps femoris is a muscle located in the posterior upper thigh and is part of the hamstring group of muscles. It consists of two heads: the long head and the short head. The long head originates from the ischial tuberosity and inserts into the fibular head. Its actions include knee flexion, lateral rotation of the tibia, and extension of the hip. It is innervated by the tibial division of the sciatic nerve and supplied by the profunda femoris artery, inferior gluteal artery, and the superior muscular branches of the popliteal artery.

      On the other hand, the short head originates from the lateral lip of the linea aspera and the lateral supracondylar ridge of the femur. It also inserts into the fibular head and is responsible for knee flexion and lateral rotation of the tibia. It is innervated by the common peroneal division of the sciatic nerve and supplied by the same arteries as the long head.

      Understanding the anatomy and function of the biceps femoris muscle is important in the diagnosis and treatment of injuries and conditions affecting the posterior thigh.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 9 - A 50-year-old man presents to the emergency department with a 24-hour history of...

    Incorrect

    • A 50-year-old man presents to the emergency department with a 24-hour history of left knee pain and swelling. He has difficulty bearing weight on the left leg and reports no recent trauma, fevers, or chills. The patient has also been experiencing constipation, excessive urination, and fatigue for several months. He has a history of passing a kidney stone with hydration. He does not take prescription medications or use tobacco, alcohol, or illicit drugs.

      During examination, the patient's temperature is 37.2 ºC (98.9ºF) and blood pressure is 130/76 mmHg. The right knee is tender, erythematous, and swollen. Arthrocentesis reveals a white blood cell count of 30,000/mm3, with a predominance of neutrophils and numerous rhomboid-shaped crystals.

      What substance is most likely the composition of the crystals?

      Your Answer:

      Correct Answer: Calcium pyrophosphate

      Explanation:

      The patient is experiencing acute inflammatory arthritis, which is likely caused by pseudogout. This condition occurs when calcium pyrophosphate dihydrate crystals are deposited in the synovial fluid, and it is often associated with chronic hypercalcemia resulting from primary hyperparathyroidism. Pseudogout typically affects the knee joint, and the presence of rhomboid-shaped calcium pyrophosphate crystals in the synovial fluid is diagnostic. Calcium hydroxyapatite crystals are typically found in tendons, while calcium oxalate is the most common component of renal calculi. Xanthomas refer to the deposition of cholesterol and other lipids in soft tissues, while gout is characterized by the deposition of monosodium urate in joints and soft tissues.

      Understanding Pseudogout

      Pseudogout, also known as acute calcium pyrophosphate crystal deposition disease, is a type of microcrystal synovitis that occurs when calcium pyrophosphate dihydrate crystals are deposited in the synovium. This condition is commonly associated with increasing age, but younger patients who develop pseudogout usually have an underlying risk factor such as haemochromatosis, hyperparathyroidism, low magnesium or phosphate levels, acromegaly, or Wilson’s disease.

      The knee, wrist, and shoulders are the most commonly affected joints in pseudogout. Diagnosis is made through joint aspiration, which reveals weakly-positively birefringent rhomboid-shaped crystals, and x-rays, which show chondrocalcinosis. In the knee, linear calcifications of the meniscus and articular cartilage can be seen.

      Management of pseudogout involves joint fluid aspiration to rule out septic arthritis, followed by treatment with NSAIDs or intra-articular, intra-muscular, or oral steroids, similar to the treatment for gout. Understanding the risk factors and symptoms of pseudogout can help with early diagnosis and effective management of this condition.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 10 - A 65-year-old woman is recuperating from a tibia fracture and has been wearing...

    Incorrect

    • A 65-year-old woman is recuperating from a tibia fracture and has been wearing a snug cast over the proximal knee for three weeks. She reports numbness over the lateral two-thirds of the outer leg. During a lower limb neurological examination, the junior doctor suspects injury to the common fibular nerve. Which muscle is expected to be unaffected in this patient?

      Your Answer:

      Correct Answer: Biceps femoris

      Explanation:

      The short head of the biceps femoris muscle is supplied by the common peroneal division of the sciatic nerve, while the long head is innervated by the tibial branch of the sciatic nerve. Despite this, the biceps femoris can still perform knee flexion. The extensor digitorum longus, extensor hallucis longus, and fibularis tertius muscles are all innervated by the deep fibular nerve, which is a branch of the common fibular nerve. Weakness in toe extension and big-toe extension may occur due to damage to these muscles, while the fibularis tertius muscle is important for eversion of the foot during walking.

      The Biceps Femoris Muscle

      The biceps femoris is a muscle located in the posterior upper thigh and is part of the hamstring group of muscles. It consists of two heads: the long head and the short head. The long head originates from the ischial tuberosity and inserts into the fibular head. Its actions include knee flexion, lateral rotation of the tibia, and extension of the hip. It is innervated by the tibial division of the sciatic nerve and supplied by the profunda femoris artery, inferior gluteal artery, and the superior muscular branches of the popliteal artery.

      On the other hand, the short head originates from the lateral lip of the linea aspera and the lateral supracondylar ridge of the femur. It also inserts into the fibular head and is responsible for knee flexion and lateral rotation of the tibia. It is innervated by the common peroneal division of the sciatic nerve and supplied by the same arteries as the long head.

      Understanding the anatomy and function of the biceps femoris muscle is important in the diagnosis and treatment of injuries and conditions affecting the posterior thigh.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 11 - A 26-year-old male presents to his primary care physician complaining of anterior hip...

    Incorrect

    • A 26-year-old male presents to his primary care physician complaining of anterior hip pain that exacerbates when he lifts his thigh towards his chest. Upon further inquiry, the physician discovers that the patient is an avid runner and runs more than 60 km per week. The physician suspects that the pain may be a result of the patient overusing his hip flexor muscles.

      Based on the physician's suspicion, which muscle is the most probable to be impacted?

      Your Answer:

      Correct Answer: Iliopsoas

      Explanation:

      Although Pectineus is a hip flexor, it is not as significant as iliopsoas in this function. Its origin is the pubic bone, and it inserts into the femur. Additionally, it assists in adducting and internally rotating the thigh.

      The Psoas Muscle: Origin, Insertion, Innervation, and Action

      The psoas muscle is a deep-seated muscle that originates from the transverse processes of the five lumbar vertebrae and the superficial part originates from T12 and the first four lumbar vertebrae. It inserts into the lesser trochanter of the femur and is innervated by the anterior rami of L1 to L3.

      The main action of the psoas muscle is flexion and external rotation of the hip. When both sides of the muscle contract, it can raise the trunk from the supine position. The psoas muscle is an important muscle for maintaining proper posture and movement, and it is often targeted in exercises such as lunges and leg lifts.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 12 - A 67-year-old man with peripheral vascular disease is scheduled for a below knee...

    Incorrect

    • A 67-year-old man with peripheral vascular disease is scheduled for a below knee amputation. Can you identify the compartment in the lower leg where peroneus brevis is located?

      Your Answer:

      Correct Answer: Lateral compartment

      Explanation:

      The deep transverse fascia divides the leg into anterior and posterior compartments, while the interosseous membrane separates them. The lateral compartment includes the peroneus brevis muscle.

      Fascial Compartments of the Leg

      The leg is divided into compartments by fascial septae, which are thin layers of connective tissue. In the thigh, there are three compartments: the anterior, medial, and posterior compartments. The anterior compartment contains the femoral nerve and artery, as well as the quadriceps femoris muscle group. The medial compartment contains the obturator nerve and artery, as well as the adductor muscles and gracilis muscle. The posterior compartment contains the sciatic nerve and branches of the profunda femoris artery, as well as the hamstrings muscle group.

      In the lower leg, there are four compartments: the anterior, posterior (divided into deep and superficial compartments), lateral, and deep posterior compartments. The anterior compartment contains the deep peroneal nerve and anterior tibial artery, as well as the tibialis anterior, extensor digitorum longus, extensor hallucis longus, and peroneus tertius muscles. The posterior compartment contains the tibial nerve and posterior tibial artery, as well as the deep and superficial muscles. The lateral compartment contains the superficial peroneal nerve and peroneal artery, as well as the peroneus longus and brevis muscles. The deep posterior compartment contains the tibial nerve and posterior tibial artery, as well as the flexor hallucis longus, flexor digitorum longus, tibialis posterior, and popliteus muscles.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 13 - Which one of the following is not a pathological response to extensive burns...

    Incorrect

    • Which one of the following is not a pathological response to extensive burns in elderly patients?

      Your Answer:

      Correct Answer: Absolute polycythaemia

      Explanation:

      The primary pathological response is haemolysis.

      Pathology of Burns

      Extensive burns can cause various pathological changes in the body. The heat and microangiopathy can damage erythrocytes, leading to haemolysis. The loss of capillary membrane integrity can cause plasma leakage into the interstitial space, resulting in hypovolaemic shock. This shock can occur up to 48 hours after the injury and can cause a decrease in blood volume and an increase in haematocrit. Additionally, protein loss and secondary infections, such as Staphylococcus aureus, can occur. There is also a risk of acute peptic stress ulcers, known as Curling’s ulcers. Furthermore, full-thickness circumferential burns in an extremity can lead to compartment syndrome.

      The healing process of burns depends on the severity of the burn. Superficial burns can heal through the migration of keratinocytes to form a new layer over the burn site. However, full-thickness burns can result in dermal scarring, which may require skin grafts to provide optimal coverage. It is important to understand the pathology of burns to provide appropriate treatment and prevent further complications.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 14 - A 33-year-old female visits her doctor complaining of a red rash on her...

    Incorrect

    • A 33-year-old female visits her doctor complaining of a red rash on her hands. She first noticed the rash a few weeks ago after moving into her new apartment with her partner. However, in the past few days, the rash has become extremely itchy and is keeping her up at night. Despite using her regular moisturizer cream, the rash has not improved. Upon examination, the doctor observes a bilateral erythematous rash on both hands that extends into the interdigital spaces, with multiple excoriation marks. The rash is not present anywhere else, and there are no other significant findings.

      What is the likely diagnosis, and what is the underlying mechanism behind this patient's presentation?

      Your Answer:

      Correct Answer: Delayed-type IV hypersensitivity reaction

      Explanation:

      The severe itching caused by scabies is a result of a delayed-type IV hypersensitivity reaction to the mites and their eggs, which occurs around 30 days after infestation. This type of reaction involves T-cells and antigen-presenting cells, leading to an inflammatory response. Scabies is typically spread through close skin-to-skin contact with an infected person. An allergic reaction to the patient’s regular moisturizer would be a type I hypersensitivity reaction, which causes acute itching. Antigen-antibody complex deposition in the epidermis would be a type III hypersensitivity reaction, while psoriasis is caused by hyperproliferation of epidermal keratinocytes and presents with red, scaly patches on extensor surfaces. Bacterial skin infections like cellulitis cause warm, swollen, and red skin with systemic symptoms like fever.

      Scabies: Causes, Symptoms, and Treatment

      Scabies is a skin condition caused by the mite Sarcoptes scabiei, which is spread through prolonged skin contact. It is most commonly seen in children and young adults. The mite burrows into the skin, laying its eggs in the outermost layer. The resulting intense itching is due to a delayed hypersensitivity reaction to the mites and eggs, which occurs about a month after infection. Symptoms include widespread itching, linear burrows on the fingers and wrists, and secondary features such as excoriation and infection.

      The first-line treatment for scabies is permethrin 5%, followed by malathion 0.5% if necessary. Patients should be advised to avoid close physical contact until treatment is complete and to treat all household and close contacts, even if asymptomatic. Clothing, bedding, and towels should be laundered, ironed, or tumble-dried on the first day of treatment to kill off mites. The insecticide should be applied to all areas, including the face and scalp, and left on for 8-12 hours for permethrin or 24 hours for malathion before washing off. Treatment should be repeated after 7 days.

      Crusted scabies, also known as Norwegian scabies, is a severe form of the condition seen in patients with suppressed immunity, particularly those with HIV. The skin is covered in hundreds of thousands of mites, and isolation is essential. Ivermectin is the treatment of choice.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 15 - As a medical student on placement with a surgical team, you come across...

    Incorrect

    • As a medical student on placement with a surgical team, you come across a patient who has developed foot drop in their right leg after surgery. You notice that the patient is dragging their right foot and experiencing weakness in dorsiflexion and eversion of their foot, as well as an inability to extend their toes. Which nerve is most likely to have been affected during the operation?

      Your Answer:

      Correct Answer: Common fibular nerve

      Explanation:

      The common fibular nerve starts at the top of the popliteal fossa, passing medial to the biceps femoris and then crossing over the head of the gastrocnemius. It provides an articular branch to the knee before winding around the neck and passing under the Fibularis longus. At this point, it divides into superficial and deep branches. In the popliteal fossa, it also divides to give the lateral sural cutaneous nerve, which joins with a branch from the tibial nerve to form the sural nerve. If the nerve is damaged, it can result in foot drop, which can occur due to prolonged pressure on the nerve during an operation or other causes. Motor loss of other nerves, such as the tibial, sciatic, inferior gluteal, or femoral nerves, can result in weakness in other muscles.

      Lower limb anatomy is an important topic that often appears in examinations. One aspect of this topic is the nerves that control motor and sensory functions in the lower limb. The femoral nerve controls knee extension and thigh flexion, and provides sensation to the anterior and medial aspect of the thigh and lower leg. It is commonly injured in cases of hip and pelvic fractures, as well as stab or gunshot wounds. The obturator nerve controls thigh adduction and provides sensation to the medial thigh. It can be injured in cases of anterior hip dislocation. The lateral cutaneous nerve of the thigh provides sensory function to the lateral and posterior surfaces of the thigh, and can be compressed near the ASIS, resulting in a condition called meralgia paraesthetica. The tibial nerve controls foot plantarflexion and inversion, and provides sensation to the sole of the foot. It is not commonly injured as it is deep and well protected, but can be affected by popliteral lacerations or posterior knee dislocation. The common peroneal nerve controls foot dorsiflexion and eversion, and can be injured at the neck of the fibula, resulting in foot drop. The superior gluteal nerve controls hip abduction and can be injured in cases of misplaced intramuscular injection, hip surgery, pelvic fracture, or posterior hip dislocation. Injury to this nerve can result in a positive Trendelenburg sign. The inferior gluteal nerve controls hip extension and lateral rotation, and is generally injured in association with the sciatic nerve. Injury to this nerve can result in difficulty rising from a seated position, as well as difficulty jumping or climbing stairs.

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      • Musculoskeletal System And Skin
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  • Question 16 - A 33-year-old man presents to the emergency department with lateral knee pain. He...

    Incorrect

    • A 33-year-old man presents to the emergency department with lateral knee pain. He reports that the pain began two hours ago while playing hockey, and he was struck on the anteromedial aspect of his extended knee by a hockey stick. An x-ray of the knee reveals an avulsion fracture of the fibular head. Which muscle is the probable culprit for this patient's avulsion fracture?

      Your Answer:

      Correct Answer: Biceps femoris

      Explanation:

      The fibular head serves as the insertion point for both the long and short head of the biceps femoris muscle. However, sudden contractions of the biceps femoris can lead to an avulsion fracture of the fibular head, where the fracture fragment may be attached to the lateral collateral ligament or biceps femoris tendon.

      The fibularis brevis muscle originates from the distal two-thirds of the fibular bone. If the ankle joint suddenly inverts, it can pull on the fibularis tendon and cause an avulsion of the tuberosity at the base of the fifth metatarsal.

      The flexor hallucis longus muscle originates from the distal two-thirds of the posterior surface of the fibular bone. This muscle not only allows for flexion of the big toe but also contributes to plantarflexion and inversion of the foot.

      The soleus muscle originates from the proximal one-third of the posterior surface of the fibular bone. It is a large muscle covered in thick fascia, which aids in its secondary function of pumping venous blood back into the heart through the skeletal muscle pump.

      The Biceps Femoris Muscle

      The biceps femoris is a muscle located in the posterior upper thigh and is part of the hamstring group of muscles. It consists of two heads: the long head and the short head. The long head originates from the ischial tuberosity and inserts into the fibular head. Its actions include knee flexion, lateral rotation of the tibia, and extension of the hip. It is innervated by the tibial division of the sciatic nerve and supplied by the profunda femoris artery, inferior gluteal artery, and the superior muscular branches of the popliteal artery.

      On the other hand, the short head originates from the lateral lip of the linea aspera and the lateral supracondylar ridge of the femur. It also inserts into the fibular head and is responsible for knee flexion and lateral rotation of the tibia. It is innervated by the common peroneal division of the sciatic nerve and supplied by the same arteries as the long head.

      Understanding the anatomy and function of the biceps femoris muscle is important in the diagnosis and treatment of injuries and conditions affecting the posterior thigh.

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  • Question 17 - A 55-year-old male was diagnosed with gout six months ago. Since then, he...

    Incorrect

    • A 55-year-old male was diagnosed with gout six months ago. Since then, he has had two episodes. The last episode was three weeks back. He was treated with indomethacin during each episode. Today, he has no symptoms. Hypertension was diagnosed four years ago, which is well-controlled with a thiazide. He also takes pantoprazole occasionally for acid reflux.

      What should be taken into consideration for this patient?

      Your Answer:

      Correct Answer: Stop thiazide

      Explanation:

      Patients with gout should be evaluated for the discontinuation of precipitating drugs, such as thiazides. In cases where hypertension is also present, losartan may be a suitable alternative due to its uricosuric action. During acute management of gout, medications such as colchicine, indomethacin, and steroids may be prescribed. However, since this patient has been symptom-free for three weeks, these medications are not currently necessary. The occasional use of pantoprazole does not require cessation.

      Gout is caused by chronic hyperuricaemia and is managed acutely with NSAIDs or colchicine. Urate-lowering therapy (ULT) is recommended for patients with >= 2 attacks in 12 months, tophi, renal disease, uric acid renal stones, or prophylaxis if on cytotoxics or diuretics. Allopurinol is first-line ULT, with a delayed start recommended until inflammation has settled. Lifestyle modifications include reducing alcohol intake, losing weight if obese, and avoiding high-purine foods. Other options for refractory cases include febuxostat, uricase, and pegloticase.

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  • Question 18 - Rachel is a 26-year-old female who arrives at the emergency department with an...

    Incorrect

    • Rachel is a 26-year-old female who arrives at the emergency department with an anteriorly dislocated shoulder and fracture of the surgical neck of the humerus.

      What signs are most likely to be elicited due to the probable nerve damage?

      Your Answer:

      Correct Answer: Loss of sensation over the deltoid muscle on the outer-upper arm

      Explanation:

      If a patient is experiencing difficulty abducting their arm after a humeral neck fracture, it may be due to damage to the axillary nerve. This nerve is commonly affected by anterior shoulder dislocations and surgical neck fractures of the humerus. The axillary nerve provides sensation to the area over the deltoid muscle, known as the regimental area. It is important to note that the skin over the olecranon is supplied by the radial nerve, while the intercostobrachial nerve supplies the skin over the axilla. The musculocutaneous nerve is responsible for supplying sensation to the skin over the palmar surface of the lateral forearm. Damage to the axillary nerve would not specifically affect the C6 dermatome.

      Upper limb anatomy is a common topic in examinations, and it is important to know certain facts about the nerves and muscles involved. The musculocutaneous nerve is responsible for elbow flexion and supination, and typically only injured as part of a brachial plexus injury. The axillary nerve controls shoulder abduction and can be damaged in cases of humeral neck fracture or dislocation, resulting in a flattened deltoid. The radial nerve is responsible for extension in the forearm, wrist, fingers, and thumb, and can be damaged in cases of humeral midshaft fracture, resulting in wrist drop. The median nerve controls the LOAF muscles and can be damaged in cases of carpal tunnel syndrome or elbow injury. The ulnar nerve controls wrist flexion and can be damaged in cases of medial epicondyle fracture, resulting in a claw hand. The long thoracic nerve controls the serratus anterior and can be damaged during sports or as a complication of mastectomy, resulting in a winged scapula. The brachial plexus can also be damaged, resulting in Erb-Duchenne palsy or Klumpke injury, which can cause the arm to hang by the side and be internally rotated or associated with Horner’s syndrome, respectively.

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  • Question 19 - Which one of the following muscles does not attach to the radius? ...

    Incorrect

    • Which one of the following muscles does not attach to the radius?

      Your Answer:

      Correct Answer: Brachialis

      Explanation:

      The ulna serves as the insertion point for the brachialis muscle, while the remaining muscles are inserted onto the radius.

      Anatomy of the Radius Bone

      The radius bone is one of the two long bones in the forearm that extends from the lateral side of the elbow to the thumb side of the wrist. It has two expanded ends, with the distal end being the larger one. The upper end of the radius bone has articular cartilage that covers the medial to lateral side and articulates with the radial notch of the ulna by the annular ligament. The biceps brachii muscle attaches to the tuberosity of the upper end.

      The shaft of the radius bone has several muscle attachments. The upper third of the body has the supinator, flexor digitorum superficialis, and flexor pollicis longus muscles. The middle third of the body has the pronator teres muscle, while the lower quarter of the body has the pronator quadratus muscle and the tendon of supinator longus.

      The lower end of the radius bone is quadrilateral in shape. The anterior surface is covered by the capsule of the wrist joint, while the medial surface has the head of the ulna. The lateral surface ends in the styloid process, and the posterior surface has three grooves that contain the tendons of extensor carpi radialis longus and brevis, extensor pollicis longus, and extensor indicis. Understanding the anatomy of the radius bone is crucial in diagnosing and treating injuries and conditions that affect this bone.

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  • Question 20 - A 36-year-old woman visits her GP complaining of a severe, itchy, red rash...

    Incorrect

    • A 36-year-old woman visits her GP complaining of a severe, itchy, red rash on her hands and arms that started a few days ago. The itching is so intense that it is affecting her sleep. She denies any family history of asthma, eczema, or hay fever and is otherwise healthy. During the consultation, she mentions that a colleague had a similar issue last week.

      Upon examination, the GP observes a widespread erythematous rash on both hands, particularly in the interdigital web spaces and the flexor aspect of the wrists, with excoriation marks. There is no crusting, and the rash is not present anywhere else.

      What is the recommended first-line treatment for this likely diagnosis?

      Your Answer:

      Correct Answer: Permethrin 5% cream

      Explanation:

      A cream containing steroids may be applied to address eczema.

      As a second option for scabies, an insecticide lotion called Malathion is used.

      For hyperkeratotic (‘Norwegian’) scabies, which is prevalent in immunosuppressed patients, oral ivermectin is the recommended treatment. However, this patient does not have crusted scabies and is in good health.

      To alleviate dry skin in conditions such as eczema and psoriasis, a topical emollient can be utilized.

      Scabies: Causes, Symptoms, and Treatment

      Scabies is a skin condition caused by the mite Sarcoptes scabiei, which is spread through prolonged skin contact. It is most commonly seen in children and young adults. The mite burrows into the skin, laying its eggs in the outermost layer. The resulting intense itching is due to a delayed hypersensitivity reaction to the mites and eggs, which occurs about a month after infection. Symptoms include widespread itching, linear burrows on the fingers and wrists, and secondary features such as excoriation and infection.

      The first-line treatment for scabies is permethrin 5%, followed by malathion 0.5% if necessary. Patients should be advised to avoid close physical contact until treatment is complete and to treat all household and close contacts, even if asymptomatic. Clothing, bedding, and towels should be laundered, ironed, or tumble-dried on the first day of treatment to kill off mites. The insecticide should be applied to all areas, including the face and scalp, and left on for 8-12 hours for permethrin or 24 hours for malathion before washing off. Treatment should be repeated after 7 days.

      Crusted scabies, also known as Norwegian scabies, is a severe form of the condition seen in patients with suppressed immunity, particularly those with HIV. The skin is covered in hundreds of thousands of mites, and isolation is essential. Ivermectin is the treatment of choice.

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  • Question 21 - A patient in his 50s has undergone a muscle biopsy for progressive muscle...

    Incorrect

    • A patient in his 50s has undergone a muscle biopsy for progressive muscle weakness. During his clinic visit, the doctor presents a histological specimen and indicates the sarcomere. What is the doctor referring to?

      Your Answer:

      Correct Answer: The region between two Z-lines on the myofibril

      Explanation:

      The area between Z lines is known as the sarcomere. The skeletal muscle is composed of the following elements, as shown in the diagram.

      The Process of Muscle Contraction

      Muscle contraction is a complex process that involves several steps. It begins with an action potential reaching the neuromuscular junction, which causes a calcium ion influx through voltage-gated calcium channels. This influx leads to the release of acetylcholine into the extracellular space, which activates nicotinic acetylcholine receptors, triggering an action potential. The action potential then spreads through the T-tubules, activating L-type voltage-dependent calcium channels in the T-tubule membrane, which are close to calcium-release channels in the adjacent sarcoplasmic reticulum. This causes the sarcoplasmic reticulum to release calcium, which binds to troponin C, causing a conformational change that allows tropomyosin to move, unblocking the binding sites. Myosin then binds to the newly released binding site, releasing ADP and pulling the Z bands towards each other. ATP binds to myosin, releasing actin.

      The components involved in muscle contraction include the sarcomere, which is the basic unit of muscles that gives skeletal and cardiac muscles their striated appearance. The I-band is the zone of thin filaments that is not superimposed by thick filaments, while the A-band contains the entire length of a single thick filament. The H-zone is the zone of the thick filaments that is not superimposed by the thin filaments, and the M-line is in the middle of the sarcomere, cross-linking myosin. The sarcoplasmic reticulum releases calcium ion in response to depolarization, while actin is the thin filaments that transmit the forces generated by myosin to the ends of the muscle. Myosin is the thick filaments that bind to the thin filament, while titin connects the Z-line to the thick filament, altering the structure of tropomyosin. Tropomyosin covers the myosin-binding sites on actin, while troponin-C binds with calcium ions. The T-tubule is an invagination of the sarcoplasmic reticulum that helps co-ordinate muscular contraction.

      There are two types of skeletal muscle fibres: type I and type II. Type I fibres have a slow contraction time, are red in colour due to the presence of myoglobin, and are used for sustained force. They have a high mitochondrial density and use triglycerides as

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  • Question 22 - A 76-year-old man is experiencing symptoms suggestive of intermittent claudication. You plan to...

    Incorrect

    • A 76-year-old man is experiencing symptoms suggestive of intermittent claudication. You plan to evaluate the extent of his condition by measuring his ankle brachial pressure index. In order to do so, you need to locate the dorsalis pedis artery. Which of the following statements regarding this artery is incorrect?

      Your Answer:

      Correct Answer: It originates from the peroneal artery

      Explanation:

      The anterior tibial artery continues directly into the dorsalis pedis artery.

      The foot has two arches: the longitudinal arch and the transverse arch. The longitudinal arch is higher on the medial side and is supported by the posterior pillar of the calcaneum and the anterior pillar composed of the navicular bone, three cuneiforms, and the medial three metatarsal bones. The transverse arch is located on the anterior part of the tarsus and the posterior part of the metatarsus. The foot has several intertarsal joints, including the sub talar joint, talocalcaneonavicular joint, calcaneocuboid joint, transverse tarsal joint, cuneonavicular joint, intercuneiform joints, and cuneocuboid joint. The foot also has various ligaments, including those of the ankle joint and foot. The foot is innervated by the lateral plantar nerve and medial plantar nerve, and it receives blood supply from the plantar arteries and dorsalis pedis artery. The foot has several muscles, including the abductor hallucis, flexor digitorum brevis, abductor digit minimi, flexor hallucis brevis, adductor hallucis, and extensor digitorum brevis.

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  • Question 23 - A 16-year-old soccer player injures her ankle while playing a game. She reports...

    Incorrect

    • A 16-year-old soccer player injures her ankle while playing a game. She reports that her ankle turned inward, causing her foot to roll inward, and she experienced immediate pain and swelling.

      What ligament is the most probable to have been sprained in this scenario?

      Your Answer:

      Correct Answer: Anterior talofibular ligament

      Explanation:

      The most frequently sprained ligament in ankle inversion injuries is the anterior talofibular ligament, which runs from the talus to the fibula and restricts inversion in plantar flexion. The calcaneonavicular ligament, located between the calcaneus and navicular bones, stabilizes the medial longitudinal arch and is not involved in resisting inversion or eversion, making it unlikely to be injured. The deltoid ligament, found on the medial side of the ankle, resists eversion and is therefore not typically affected in inversion injuries. The interosseous ligament, located between the tibia and fibula above the ankle joint, is only impacted if there is trauma to the lower leg. The Lisfranc ligament, which connects the second metatarsal to the medial cuneiform, is more commonly disrupted by direct blows or axial loads on a plantarflexed foot with rotation, whereas a simple sprain to the anterior talofibular ligament is more common in inversion injuries.

      Ankle Sprains: Types, Presentation, Investigation, and Treatment

      Ankle sprains occur when ligaments in the ankle are stretched or torn. The ankle joint is composed of the distal tibia and fibula and the superior aspect of the talus, which form a mortise secured by ligamentous structures. Low ankle sprains involve the lateral collateral ligaments, with the anterior inferior tibiofibular ligament being the most commonly injured. Inversion injury is the most common mechanism, causing pain, swelling, tenderness, and sometimes bruising. Low ankle sprains are classified into three grades based on the extent of ligament disruption, bruising and swelling, and pain on weight-bearing. Radiographs should be done to rule out associated fractures, and MRI may be useful for evaluating perineal tendons. Treatment for low ankle sprains involves rest, ice, compression, and elevation, with occasional use of a removable orthosis, cast, or crutches. Surgical intervention is rare.

      High ankle sprains involve the syndesmosis, which is rare and severe. The mechanism of injury is usually external rotation of the foot, causing the talus to push the fibula laterally. Patients experience more pain when weight-bearing than with low ankle sprains. Radiographs may show widening of the tibiofibular joint or ankle mortise, and MRI may be necessary for high suspicion of syndesmotic injury. Treatment for high ankle sprains involves non-weight-bearing orthosis or cast until pain subsides, or operative fixation if there is diastasis or failed non-operative management.

      Isolated injuries to the deltoid ligament are rare and frequently associated with a fracture, such as Maisonneuve fracture of the proximal fibula. Treatment for deltoid ligament injuries is similar to that for low ankle sprains, provided the ankle mortise is anatomically reduced. If not, reduction and fixation may be necessary.

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  • Question 24 - Which of the following bones is associated with the distal articular surface of...

    Incorrect

    • Which of the following bones is associated with the distal articular surface of the cuboid?

      Your Answer:

      Correct Answer: 5th metatarsal

      Explanation:

      The cuboid bone is situated on the outer side of the foot, positioned between the heel bone at the back and the fourth and fifth toe bones towards the front.

      The foot has two arches: the longitudinal arch and the transverse arch. The longitudinal arch is higher on the medial side and is supported by the posterior pillar of the calcaneum and the anterior pillar composed of the navicular bone, three cuneiforms, and the medial three metatarsal bones. The transverse arch is located on the anterior part of the tarsus and the posterior part of the metatarsus. The foot has several intertarsal joints, including the sub talar joint, talocalcaneonavicular joint, calcaneocuboid joint, transverse tarsal joint, cuneonavicular joint, intercuneiform joints, and cuneocuboid joint. The foot also has various ligaments, including those of the ankle joint and foot. The foot is innervated by the lateral plantar nerve and medial plantar nerve, and it receives blood supply from the plantar arteries and dorsalis pedis artery. The foot has several muscles, including the abductor hallucis, flexor digitorum brevis, abductor digit minimi, flexor hallucis brevis, adductor hallucis, and extensor digitorum brevis.

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  • Question 25 - A 26-year-old patient with a past medical history of Crohn's disease is initiated...

    Incorrect

    • A 26-year-old patient with a past medical history of Crohn's disease is initiated on azathioprine. What is the mode of action of azathioprine?

      Your Answer:

      Correct Answer: Inhibits purine synthesis

      Explanation:

      The active compound mercaptopurine, which inhibits purine synthesis, is produced through the metabolism of azathioprine, a purine analogue.

      Azathioprine is a medication that is converted into mercaptopurine, which is an active compound that inhibits the production of purine. To determine if someone is at risk for azathioprine toxicity, a test for thiopurine methyltransferase (TPMT) may be necessary. Adverse effects of this medication include bone marrow depression, nausea and vomiting, pancreatitis, and an increased risk of non-melanoma skin cancer. If infection or bleeding occurs, a full blood count should be considered. It is important to note that there may be a significant interaction between azathioprine and allopurinol, so lower doses of azathioprine should be used. However, azathioprine is generally considered safe to use during pregnancy.

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  • Question 26 - A 57-year-old patient arrives at the emergency department by ambulance following a car...

    Incorrect

    • A 57-year-old patient arrives at the emergency department by ambulance following a car accident. Upon examination, it is observed that his hip is in flexion, abduction, and external rotation. An X-ray reveals that the right femoral head is larger than the left and is positioned medially to the acetabulum. No fractures or skin lesions are detected. The patient undergoes closed reduction with traction while under sedation. Later, during a physiotherapy evaluation, it is discovered that he is unable to adduct his thigh. What nerve is most likely to have been damaged?

      Your Answer:

      Correct Answer: Obturator nerve

      Explanation:

      If a patient is unable to adduct their thigh after an anterior hip dislocation, it is likely due to damage to the obturator nerve. This nerve supplies the hip adductor muscles and sensation to the medial thigh. In contrast, damage to the femoral nerve would result in an inability to flex the hip or extend the knee, making it an unlikely cause for this specific symptom. Compression of the inferior gluteal nerve can cause piriformis syndrome, while compression of the lateral femoral cutaneous nerve can lead to meralgia paresthetica, but neither of these would affect the patient’s ability to adduct their leg. Damage to the superior gluteal nerve would result in a positive Trendelenburg’s sign.

      Lower limb anatomy is an important topic that often appears in examinations. One aspect of this topic is the nerves that control motor and sensory functions in the lower limb. The femoral nerve controls knee extension and thigh flexion, and provides sensation to the anterior and medial aspect of the thigh and lower leg. It is commonly injured in cases of hip and pelvic fractures, as well as stab or gunshot wounds. The obturator nerve controls thigh adduction and provides sensation to the medial thigh. It can be injured in cases of anterior hip dislocation. The lateral cutaneous nerve of the thigh provides sensory function to the lateral and posterior surfaces of the thigh, and can be compressed near the ASIS, resulting in a condition called meralgia paraesthetica. The tibial nerve controls foot plantarflexion and inversion, and provides sensation to the sole of the foot. It is not commonly injured as it is deep and well protected, but can be affected by popliteal lacerations or posterior knee dislocation. The common peroneal nerve controls foot dorsiflexion and eversion, and can be injured at the neck of the fibula, resulting in foot drop. The superior gluteal nerve controls hip abduction and can be injured in cases of misplaced intramuscular injection, hip surgery, pelvic fracture, or posterior hip dislocation. Injury to this nerve can result in a positive Trendelenburg sign. The inferior gluteal nerve controls hip extension and lateral rotation, and is generally injured in association with the sciatic nerve. Injury to this nerve can result in difficulty rising from a seated position, as well as difficulty jumping or climbing stairs.

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  • Question 27 - Which of the following anatomical structures is located in the spiral groove of...

    Incorrect

    • Which of the following anatomical structures is located in the spiral groove of the humerus?

      Your Answer:

      Correct Answer: Radial nerve

      Explanation:

      Fractures involving the shaft can compromise the radial nerve, which is located in this groove.

      The humerus is a long bone that runs from the shoulder blade to the elbow joint. It is mostly covered by muscle but can be felt throughout its length. The head of the humerus is a smooth, rounded surface that connects to the body of the bone through the anatomical neck. The surgical neck, located below the head and tubercles, is the most common site of fracture. The greater and lesser tubercles are prominences on the upper end of the bone, with the supraspinatus and infraspinatus tendons inserted into the greater tubercle. The intertubercular groove runs between the two tubercles and holds the biceps tendon. The posterior surface of the body has a spiral groove for the radial nerve and brachial vessels. The lower end of the humerus is wide and flattened, with the trochlea, coronoid fossa, and olecranon fossa located on the distal edge. The medial epicondyle is prominent and has a sulcus for the ulnar nerve and collateral vessels.

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  • Question 28 - A 56-year-old man presents to his GP complaining of numbness and tingling in...

    Incorrect

    • A 56-year-old man presents to his GP complaining of numbness and tingling in his thumb, middle, and index fingers for the past 8 months. This is beginning to interfere with his work as a financial analyst. He has a history of hypothyroidism for which he takes 100 micrograms of thyroxine daily.

      Which nerves are involved in this condition?

      Your Answer:

      Correct Answer: Median nerve

      Explanation:

      To identify the affected nerve, it is crucial to accurately diagnose the underlying condition. The patient’s symptoms, such as numbness and tingling in the thumb and middle finger (and possibly the radial half of the ring finger), suggest carpal tunnel syndrome. Additionally, the patient’s occupation involving computer use and hypothyroidism are risk factors for this condition.

      Carpal tunnel syndrome occurs when the median nerve is compressed at the carpal tunnel as it passes through the wrist.

      Carpal tunnel syndrome is a condition that occurs when the median nerve in the carpal tunnel is compressed. This can cause pain and pins and needles sensations in the thumb, index, and middle fingers. In some cases, the symptoms may even travel up the arm. Patients may shake their hand to alleviate the discomfort, especially at night. During an examination, weakness in thumb abduction and wasting of the thenar eminence may be observed. Tapping on the affected area may also cause paraesthesia, and flexing the wrist can trigger symptoms.

      There are several potential causes of carpal tunnel syndrome, including idiopathic factors, pregnancy, oedema, lunate fractures, and rheumatoid arthritis. Electrophysiology tests may reveal prolongation of the action potential in both motor and sensory nerves. Treatment options may include a six-week trial of conservative measures such as wrist splints at night or corticosteroid injections. If symptoms persist or are severe, surgical decompression may be necessary, which involves dividing the flexor retinaculum.

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  • Question 29 - Which of the following is not found in the deep posterior compartment of...

    Incorrect

    • Which of the following is not found in the deep posterior compartment of the lower leg?

      Your Answer:

      Correct Answer: Sural nerve

      Explanation:

      The deep posterior compartment is located in front of the soleus muscle, and the sural nerve is not enclosed within it due to its superficial position.

      Muscular Compartments of the Lower Limb

      The lower limb is composed of different muscular compartments that perform various actions. The anterior compartment includes the tibialis anterior, extensor digitorum longus, peroneus tertius, and extensor hallucis longus muscles. These muscles are innervated by the deep peroneal nerve and are responsible for dorsiflexing the ankle joint, inverting and evert the foot, and extending the toes.

      The peroneal compartment, on the other hand, consists of the peroneus longus and peroneus brevis muscles, which are innervated by the superficial peroneal nerve. These muscles are responsible for eversion of the foot and plantar flexion of the ankle joint.

      The superficial posterior compartment includes the gastrocnemius and soleus muscles, which are innervated by the tibial nerve. These muscles are responsible for plantar flexion of the foot and may also flex the knee.

      Lastly, the deep posterior compartment includes the flexor digitorum longus, flexor hallucis longus, and tibialis posterior muscles, which are innervated by the tibial nerve. These muscles are responsible for flexing the toes, flexing the great toe, and plantar flexion and inversion of the foot, respectively.

      Understanding the muscular compartments of the lower limb is important in diagnosing and treating injuries and conditions that affect these muscles. Proper identification and management of these conditions can help improve mobility and function of the lower limb.

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  • Question 30 - A 26-year-old gardener presents to her GP with a two week history of...

    Incorrect

    • A 26-year-old gardener presents to her GP with a two week history of elbow swelling. She reports a gradual onset of the swelling, with no apparent triggers, and experiences pain and warmth upon touch. She denies any swelling in other areas and is generally in good health.

      The patient has a medical history of well-managed rheumatoid arthritis and is currently taking methotrexate. There are no other known medical conditions.

      During the physical examination, a tender, soft, fluctuant mass is palpated on the posterior aspect of the patient's elbow.

      Based on the above information, what is the most probable diagnosis?

      Your Answer:

      Correct Answer: Olecranon bursitis

      Explanation:

      Understanding Olecranon Bursitis

      Olecranon bursitis is a condition that occurs when the olecranon bursa, a fluid-filled sac located over the olecranon process at the proximal end of the ulna, becomes inflamed. This bursa serves to reduce friction between the elbow joint and the surrounding soft tissues. The inflammation can be caused by trauma, infection, or systemic conditions such as rheumatoid arthritis or gout. It is also commonly known as student’s elbow due to the repetitive mild trauma of leaning on a desk using the elbows.

      The condition is more common in men and typically presents between the ages of 30 and 60. Causes of olecranon bursitis include repetitive trauma, direct trauma, infection, gout, rheumatoid arthritis, and idiopathic reasons. Patients with non-septic olecranon bursitis typically present with swelling over the olecranon process, which is often the only symptom. Some patients may also experience tenderness and erythema over the bursa. On the other hand, patients with septic bursitis are more likely to have pain and fever.

      Signs of olecranon bursitis include swelling over the posterior aspect of the elbow, tenderness on palpation of the swollen area, redness and warmth of the overlying skin, fever, skin abrasion overlying the bursa, effusions in other joints if associated with rheumatoid arthritis, and tophi if associated with gout. Movement at the elbow joint should be painless until the swollen bursa is compressed in full flexion.

      Investigations are not always needed if a clinical diagnosis can be made and there is no concern about septic arthritis. However, if septic bursitis is suspected, aspiration of bursal fluid for microscopy and culture is essential. Purulent fluid suggests infection, while straw-coloured bursal fluid favours a non-infective cause. Understanding the causes, symptoms, and signs of olecranon bursitis can help in its diagnosis and management.

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