Block 2 Practice Questions Flashcards
Which one of the following statements about septic (bacterial) arthritis is true?
The clinical features can be similar to gout
Which of the following risk factors is most likely to contribute to osteoporosis?
Inactivity
Which of the following is true regarding non-steroidal anti-inflammatory drugs?
They may cause renal impairment
With reference to the image of the leg and foot (anterior view) below, the tendon that is indicated by X belongs to which of the following?
Tibialis anterior
With reference to the image below of two articulated vertebrae (lateral view), which part of the vertebral column do these vertebrae belong?
Lumbar
A 75 year old woman with osteoarthritis is prescribed diclofenac.
Which one of the following statements about diclofenac sodium is correct?
It inhibits both Cox I and Cox II isoenzymes
Diclofenac is a non-specific COX inhibitor. The anti-inflammatory properties of these drugs relate to their ability to inhibit COX 2. Platelets contain the constitutively expressed COX1. COX1 in the kidney is responsible for the local production of prostaglandins which have vasodilator properties. COX1 in the stomach is responsible for the local production for prostaglandins (PGE1) which stimulate mucosal blood flow and bicarbonate mucus secretion.
The characteristic that is common to almost all forms of arthritis is which of the following?
Pain
A 69 year old man presents to his doctor with an acutely swollen painful right knee. He has had previous episodes of acute pain and swelling affecting his big toes and ankles over the last 10 years.
What is the most likely diagnosis?
Acute gout
With the past history of similar episodes in typical areas (podagra and knees), gout is the most likely explanation. Infection needs to be excluded in this clinical setting. Acute pseudogout, psoriatic and rheumatoid arthritis are possible but less likely.
A 28 year old man is involved in a head-on vehicle collision. He had allegedly been drinking at a pub with friends and left after a dispute. He was initially trapped in the car with the major impact on his right thigh. He is brought into the Emergency Department conscious, but pale with a pulse of 135bpm and blood pressure of 90/60mmHg. He has deformity of his mid thigh with visible bone protruding from an anterior wound.
Which of the following is the most likely early complication?
Femoral artery injury
Femoral fractures can shear the femoral artery, causing massive blood loss into the femoral compartment. S1 and L5 nerve roots are not located near the femur. A ruptured bladder can occur independently, but is not directly related to the fracture. A pulmonary embolus is a systemic complication, and occurs usually several days after the precipitating event.
Which of the following accelerates the natural process of fracture healing?
Restoring anatomical continuity of the bones
Many nerve fibres are coated with layers of condensed cell membrane (myelin).
What role does this play in the conduction of action potentials?
Increases the velocity of nerve conduction
Myelin lowers the capacitance of the axon where it covers it. This enables action potentials to jump from one internode (Node of Ranvier) to the next (saltatory conduction). This increases the velocity of conduction roughly 40 fold. It reduces the ion flows associated with action potential propagation.
With regard to the pathology of rheumatoid arthritis, which of the following statements is correct?
Pannus destroys articular cartilage and underlying bone
Rheumatoid arthritis involves synovial joints. The erosions are mainly articular. The nodules are associated with more severe disease, and consist of connective tissue with areas of fibrinoid necrosis with a mixed inflammatory infiltrate. It is associated with periarticular osteopenia.
A patient is found to have very low levels of Vitamin D.
Which of the following would you expect to find?
Muscle weakness
Which of the following does the median nerve innervate?
Opponens pollicis
The thumb muscles are also innervated by the radial and ulna nerves. The ulna nerve innervates adductor pollicis, the medial lumbricals, and the skin on the dorsum of the 5th digit.
Adenosine Tri-Phosphate (ATP) is the immediate source of energy within muscles.
With regard to ATP, which of the following statements is true?
One molecule of ATP is consumed per cross bridge cycle
A. Anaerobic ATP production can also occur
B. Correct
C. ATP is consumed rapidly but it is regenerated almost equally rapidly. Rigor only occurs on death.
D. ATP is synthesised in all cells by oxidative or anaerobic pathway and is not necessary in the diet.
E. The sodium pump does consume ATP but only a small fraction of the total. Crossbridge cycling consumes most ATP.
A 69 year old man presents to the doctor with an acutely swollen right knee. He has had previous episodes of acute pain and swelling in his big toes and ankles over the last 10 years.
What is the most appropriate initial investigation to determine the diagnosis?
Microscopy of synovial fluid
Although the most likely diagnosis is gout, this patient needs a knee aspiration and microscopy to exclude septic arthritis, and to diagnose gout. The other tests may aid the diagnosis, but they do not make the diagnosis.
Which of the following is true regarding gouty arthritis?
It is caused by precipitation of urate crystals in joints
What is the most important direct action of the vitamin D hormone, 1,25 dihydroxyvitamin D?
Increase gut calcium absorption
A 46 year old woman presents with a three-month history of pain and stiffness in multiple joints. It takes her two hours in the morning before her joints “loosen up”.
What distribution of involvement would suggest that this is due to rheumatoid arthritis?
Proximal interphalangeal and metacarpophalangeal joints
A 75 year old woman presents with a 6 month history of pain in her right knee, which is worse with prolonged walking. She has no relevant past history. Physical examination reveals a small effusion and crepitus on movement. Her BMI is 32kg/m2.
Which statement is true regarding the diagnostic workup of this patient?
Aspiration of the fluid is likely to reveal a white cell count < 200 x 106/L
This lady’s history, which contains the typical features of osteoarthritis of the knee, is the most important diagnostic tool. CRP is not usually elevated in osteoarthritis. XRay can be normal in osteoarthritis. The effussion associated with osteoarthritis is typically low in white cells and clear in appearance. Rheumatoid factor is present in 10% of the normal population.
A 46 year old woman presents with a 12 month history of pain and stiffness in multiple joints. She is most troubled in the morning and it takes her two hours in the morning before her joints “loosen up”. She is investigated and found to have antibodies to cyclic citrullinated peptide.
Which of the following pathological features would you most likely see?
Synovial hyperplasia
Various phases of joint destruction are seen in RA: early RA, erosion formation, pseudocyst formation, and advanced RA.
In early RA, inflammation leads to synovial hyperemia and swelling (pannus formation). Synovial processes adhere to cartilage surfaces at joint periphery.
In the stage of erosion formation, marginal destruction of cartilage, granulation tissue formation, and osteoclastic resorption of nearby bone leads to tissue loss, which is radiologically depicted as erosion.
With pseudocyst formation, granulation tissue formed in continuity with the inflamed synovial membrane continues to replace bone and cartilage at circumference of articular surfaces. This tissue extends through the surfaces to form radiolucent zones called pseudocysts.
In advanced RA, the extent of synovitis and fasciitis, tendonitis, and cellulitis becomes greater than before. Adhesions between joint surfaces cause ligament and capsule laxity. This, in addition to muscle atrophy and tendonitis, allows joint subluxation to occur. Little normal articular cartilage remains. Secondary osteoarthritis develops with osteoporosis. Fibrous ankylosis is likely with joint shortening and destruction.
A 53 year old man has had frequent attacks of gout. He has developed nodules over his elbows one of which breaks down to ooze white paste.
What is the principle component of this paste?
Sodium urate
Gout is caused by the saturation, and deposition of insoluble monosodium urate crystals within joints. It is characterised by elevated levels of uric acid in body fluids.
A 17 year old student fell off his skateboard 2 days ago. He presents to the Emergency Department with pain over the base of his thumb and tenderness over the region of the anatomical snuffbox. There is also a small amount of swelling over the same region with no other deformity.
What is the most likely diagnosis?
Scaphoid fracture
A patient undergoing halothane anaesthesia develops muscular rigidity, rapidly increasing body temperature and cyanosis.
What mechanism underlies this reaction?
Release of calcium from the sarcoplasmic reticulum
A. A distractor
B. This is wrong, the problem is within the muscle.
C. Correct
D. Neuromuscular blocking drugs do not stop the contractures.
E. Mutations in the Na channel can cause depolarisation at the end of long tetani leading to slower relaxation (myotonia).
A 75 year old woman presents with a six-month history of pain in her right knee, which is worse with prolonged walking. She has no relevant past history. Physical examination reveals a small effusion and crepitus on movement. Her body mass index is 32. You make a diagnosis of osteoarthritis
Which of the following is the most important initial aspect of treatment?
Weight loss
The symptoms and function of patients with early osteoarthritis are best improved by lifestyle measures. This includes weight loss, activity modification, physiotherapy exercises, mobility aids. Paracetamol is the pharmacological agent of first choice for pain relief. NSAIDs commonly cause peptic ulcer disease in the elderly. Surgical options are best reserve for late, debilitating osteoarthritis.
