Chapter 20 – Pathology I Structured SBA




Abstract




Pathology I Structured SBA Questions





Chapter 20 Pathology I Structured SBA


Rory Morrison and Rajesh Kakwani



Pathology I Structured SBA Questions





1. What type of afferent peripheral nerve fibre is responsible for transmitting vibration sense to the spinal cord?



A.

Aα (A alpha)


B.

Aβ (A beta)


C.

Aγ (A gamma)


D.

Aδ (A delta)


E.

C



2. Which of the following is not part of Kocher’s criteria for differentiating septic arthritis of the hip?



A.

C-reactive protein


B.

Erythrocyte sedimentation rate


C.

Fever


D.

Non-weight bearing


E.

White cell count



3. Septic arthritis may be caused by contiguous spread from osteomyelitis, typically due to an intra-articular metaphysis. Which of the following DOES NOT have an intra-articular metaphysis?



A.

Ankle


B.

Elbow


C.

Hip


D.

Knee


E.

Shoulder



4. Which of the following is a common causative organism of osteomyelitis in patients with sickle-cell disease?



A.

Enterococcus


B.

Haemophilus


C.

Propionibacterium acnes


D.

Salmonella


E.

Shigella



5. A 5-year old boy presents with a painful hip and unable to weight bear. His temperature is 38.8°C, his CRP is 120 and his ESR is 40. He is taken to theatre for an open arthrotomy due to concern about a septic hip.


Which is the best approach to the hip for this patient?



A.

Arthroscopic approach


B.

Hardinge approach


C.

Medial approach


D.

Posterior approach


E.

Smith-Petersen approach



6. A farmer slips and falls awkwardly, sustaining an open tibial shaft fracture. The paramedics manage to retrieve him from his farmyard and bring him to a major trauma centre hospital within an hour of injury.


Which of the following is the best management?



A.

IV co-amoxiclav, debridement and closure within 72 hours


B.

IV co-amoxiclav, debridement within 12 hours


C.

IV co-amoxiclav, debridement within 24 hours


D.

IV co-amoxiclav, debridement within 6 hours


E.

IV co-amoxiclav, immediate debridement



7. Concerning Brodie’s abscess, which of the following is true?



A.

A well-circumscribed cavity that is surrounded by a halo of sclerosis is typical for a Brodie’s abscess


B.

Brodie’s abscess typically occurs in the diaphysis of the bone


C.

Pseudomonas are typically found in a Brodie’s abscess


D.

Systemic reaction is proportional to the size of the abscess


E.

Treatment is with antibiotic therapy



8. A 4-year old girl presents with a 24-hour history of inability to weight bear with pain in the right hip. She is afebrile but looks flushed. Her leg is rotated out to the side on the bed, and she is hesitant to move it. Blood tests show a WCC of 13, CRP of 5 and ESR of 50.


What is the best form of management?



A.

Admit for observation


B.

Hip arthrotomy with debridement and washout


C.

MRI of the hip


D.

Start IV antibiotics and monitor response


E.

US of the hip



9. A microbiology report for a fluid sample obtained from a native joint aspiration concludes that ‘acid-fast bacilli are seen as bright red’.


Which of the following is the most likely organism?



A.

Aspergillus sp.


B.

Candida albicans


C.

Mycobacterium bovis


D.

Mycobacterium tuberculosis


E.

Staphylococcus aureus



10. Which of the following is INCORRECT?



A.

Mycobacteria are seen as bright red with Ziehl–Neelsen stain


B.

Mycobacterium tuberculosis are acid-fast bacilli


C.

Mycobacterium tuberculosis are obligate aerobes


D.

Short-duration chemotherapeutic treatment is required to minimise the risk of developing resistance


E.

The most likely cause of TB is Mycobacterium tuberculosis



11. A 60-year old patient with back pain has an MRI scan suggesting tuberculous spondylodiscitis. Routine microbiology culture tests are negative. There is no concern about malignancy.


Which of the following is correct?



A.

Mycobacterium TB appears as bright red colonies on Lowenstein–Jensen culture medium


B.

Obligate anaerobic, acid-fast bacilli would be seen in TB


C.

TB of the spine is the least common form of musculoskeletal TB


D.

The presence of skip lesions on the MRI suggests this is not TB


E.

Venous impregnation is the most likely route of spread



12. A 19-year old man is brought to fracture clinic with a 5th metacarpal neck fracture, associated swelling, no rotational deformity and a puncture wound over the 5th MCP joint where he punched someone.


Which of the following is the best management?



A.

Buddy-strapping little and ring fingers


B.

Complete short-arm cast


C.

Low threshold for operative exploration and washout


D.

Reduction of the fracture using Jahss technique


E.

Ulnar gutter splint for support



13. A patient presents to the minor injuries unit with a wound to the hand, sustained when she was trying to cut an avocado. It is a simple wound that can be closed directly and there is no tendon or neurovascular damage.


Which of the following is incorrect?



A.

If this woman had completed her primary immunisation, but boosters were incomplete, she requires a further booster dose.


B.

If this woman had not been immunised, then human tetanus immunoglobulin should be administered


C.

If this woman had not been immunised, then tetanus vaccine should be administered


D.

If this woman has been fully immunised, then she requires no further treatment for this wound.


E.

If this woman has been fully immunised, then she would only require further treatment if this was a high-risk tetanus-prone wound



14. A patient has a femoral fracture around the stem of a hip replacement. There is good bone stock, but the prosthesis looks loose.


How would you classify this fracture according to the Vancouver classification?



A.

A


B.

B1


C.

B2


D.

B3


E.

C



15. You are asked how you would manage a patient with a Vancouver type A periprosthetic hip fracture, with 1cm displacement of the fracture fragments.


Which of the following is the best response?



A.

Fixation with locking plate only


B.

Protected weight bearing


C.

Revision of the stem with additional cerclage wires


D.

Revision of the stem with no need for additional cerclage wires


E.

Revision of the stem with additional bone graft



16. A patient has previously undergone a total hip arthroplasty but falls and sustains a Vancouver B2 periprosthetic fracture. They are medically fit to undergo anaesthesia.


Which of the following is the best management option?



A.

Fixation with locking plate only


B.

Protected weight bearing


C.

Revision of the stem with fixation of the fracture


D.

Revision of the stem with no need for additional fixation


E.

Revision stem with additional bone graft



17. Concerning the management of periprosthetic fractures of the hip.


Which of the following is INCORRECT?



A.

Vancouver A fractures can be managed non-operatively


B.

Vancouver B1 fractures may be reclassified to B2 fractures intraoperatively


C.

Vancouver B1 fractures require a revision stem bypassing the fracture site, along with fixation of the fracture


D.

Vancouver B2 fractures require a revision stem bypassing the fracture site, along with fixation of the fracture


E.

Vancouver B3 fractures require revision of the femoral stem with allograft, or proximal femoral replacement



18. Which of the following is deemed to be the greatest cause of wear leading to aseptic loosening of an implant?



A.

Irregular particles <0.1µm in size


B.

Spherical particles 0.1–10µm in size


C.

Irregular particles >10µm in size


D.

Spherical particles <0.1µm in size


E.

Irregular particles 0.1–10µm in size



19. Stem-cement fretting is an example of which mode of wear?



A.

Mode 1


B.

Mode 2


C.

Mode 3


D.

Mode 4


E.

Mode 5



20. Which of the following best describes adhesive wear?



A.

Delamination secondary to repetitive stressing


B.

Formation of a junction between two surfaces leading to shearing


C.

The asperities in the harder surface cutting grooves into the softer


D.

The presence of galvanic currents between two materials


E.

The presence of polyethylene wear debris in between the normal articulation



21. A radiograph of a cemented hip stem shows sclerosis and thickening of the cortex medially and laterally at the level of the tip of the stem.


Which type of stem loosening is most likely to be the cause?



A.

Calcar pivot


B.

Cantilever bending


C.

Medial stem pivot


D.

Pistoning of the stem within the bone


E.

Pistoning of the stem within the cement



22. Which of the following is the typical cause of polyethylene wear in a total hip arthroplasty?



A.

Abrasive wear


B.

Crevice corrosion


C.

Fatigue delamination


D.

Galvanic corrosion


E.

Oxidative wear



23. Which is correct concerning cementing around a THA?



A.

Gruen zone 1 loosening occurs at the lesser trochanter


B.

Gruen zone 5 occurs at the tip of the stem


C.

DeLee and Charnley zone 3 is the most common area for osteolysis


D.

Barrack grade A indicates radiolucency >50% of the bone–cement interface


E.

DeLee and Charnley zone 1 is inferomedial



24. You are reviewing the MRI hip scan of one of your patients who has presented with hip pain, and the report mentions a ‘double-line sign’.


Which of the following is the most likely diagnosis?



A.

Avascular necrosis


B.

Osteoarthritis


C.

Septic arthritis with underlying osteomyelitis


D.

TB affecting the hip


E.

Undisplaced subcapital fracture



25. A 60-year-old man presents with progressive painful pes planus. Radiographs show the deformity is due to collapse of the navicular.


Which of the following is the most likely diagnosis?



A.

Freiberg’s disease


B.

Kienbock’s disease


C.

Kohler’s disease


D.

Mueller–Weiss syndrome


E.

Sever’s disease



26. A 58-year-old woman presents with fairly acute-onset knee pain but denies any history of trauma or previous knee problems. There are no concerning features of infection. She has plain radiographs and an MRI of the knee. T2-weighted images show bone oedema, particularly in the medial femoral condyle.


Which is the most likely diagnosis?



A.

Osteoarthritis flare


B.

Lateral meniscal tear


C.

Spontaneous osteonecrosis of the knee


D.

Osteochondral defect


E.

Traumatic fracture



27. A 75-year-old female with a history of polymyalgia rheumatica presents with a short history of acute hip pain. She denies any trauma. Radiographs show Steinberg stage V osteonecrosis, and a Kerboul angle of >200 degrees.


Which of the following is the best form of management?



A.

Cemented total hip arthroplasty


B.

Decompression and fibula bone graft


C.

Non-operative management


D.

Rotational osteotomy


E.

Uncemented total hip arthroplasty



28. Concerning the management of osteonecrosis of the hip, which of the following is the best option?



A.

A Kerboul angle of >200 degrees is associated with a favourable outcome with joint-sparing procedures


B.

Femoral head decompression is the mainstay of treatment for Ficat stage IV cases


C.

Rotational transtrochanteric osteotomy (Sugioka) moves the affected part of the femoral head laterally, inferiorly and posteriorly


D.

Steroid-induced osteonecrosis should be managed by osteotomy


E.

Total hip arthroplasty is best for younger patients with stage IV disease



29. A patient presents to your clinic with an acute history of hip pain, and radiographs show osteopaenia and sclerosis of the femoral head, which remains spherical.


What stage of osteonecrosis is present according to the Ficat classification?



A.

0


B.

I


C.

II


D.

III


E.

IV



30. Which of the following is the most common cause of osteonecrosis of the hip?



A.

Alcohol


B.

Caisson’s disease


C.

Gaucher’s disease


D.

Idiopathic primary


E.

Steroid-induced



31. Which of the following is the most common organism causing prosthetic joint infection?



A.

E. coli


B.

Group B streptococci


C.

Propionibacterium acnes


D.

Pseudomonas spp.


E.

S. epidermidis



32. Which of the following is not of use in the diagnosis of prosthetic joint infection?



A.

CRP


B.

ESR


C.

IL-6


D.

Intraoperative Gram stain


E.

Intraoperative histopathology



33. Which of the following facultative, anaerobic gram-positive rod is an organism commonly isolated from an infected shoulder arthroplasty?



A.

Group B Streptococcus


B.

Propionibacterium acnes


C.

Staphylococcus aureus


D.

Staphylococcus epidermidis


E.

Streptococcus pneumoniae



34. A patient presents to hospital with a 1-week history of a painful knee, with associated swelling, erythema and warmth. They had a TKR 2 years ago, with no postoperative complications. Radiographs show well-fixed implants. An aspiration performed on admission to hospital is growing S. epidermidis.


Which of the following is the best form of management?



A.

Arthroscopic washout


B.

Debridement, antibiotics and implant retention


C.

Intravenous antibiotics


D.

Single-stage revision


E.

Two-stage revision



35. Teicoplanin is commonly used as antibiotic prophylaxis for arthroplasty cases.


How does teicoplanin work?



A.

Inhibits beta-lactam


B.

Inhibits DNA gyrase


C.

Inhibits peptidoglycan polymerisation


D.

Inhibits ribosomal protein synthesis


E.

Inhibits RNA polymerase



36. With regard to trying to reduce infections following arthroplasty surgery, which of the following is INCORRECT?



A.

HEPA can help reduce colony-forming units to <10/m3 in theatre


B.

Intravenous glycopeptides are the treatment of choice for MRSA infection


C.

Iodophors are inactivated by blood, faeces and pus


D.

Screening for MRSA has no benefit on infection rate


E.

The skin preparations chlorhexidine and povidone-iodine reduced bacterial counts by 99% and 97%, respectively, following use


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Jan 14, 2021 | Posted by in ORTHOPEDIC | Comments Off on Chapter 20 – Pathology I Structured SBA

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