Answers for the April 2006 CME

These papers have been set on the review articles and aspects of current management papers from the January, February and March 2006 issues of the JBJS-Br.

1, Which of the following statements best describes what has been discovered through clinical study concerning the retention of information relevant to their treatment by orthopaedic patients ?

b, Less than half of the information will be retained for two weeks falling to about 10% retention at final follow-up.

2, In a study designed to determine the factors influencing the rate of medical malpractice claims, what was the only factor found to correlate positively at a significant level?

b, Density of lawyers in the geographical area.

3, Which of the following statements concerning the management of a patient with metastatic compression of the spinal cord treated by radiotherapy prior to excision best describes the appropriate management.

e, Radiation should be followed by surgical debridement after an interval of six to twelve weeks, excising all tissue of poor quality and repeating debridements until a perfectly healthy bed is obtained, regardless of the size of the resulting defect.

4, Which of the following flaps is not used to help cover a soft tissue defect at the level of L3?

e, Reverse Latissimus Dorsi flap.

5, Which of the following statements about Vacuum Assisted Closure of spinal wounds is not correct?

e, It has been shown to increase the perfusion pressure in local arteries.

6, What is the source of most osteoblasts found in callus around a fracture?

b, Endothelial and perithelial cells of invading capillaries.

7, Which of the following is the most significant contra indication to functional bracing of a fracture?

e, Significant axial instability.

8, After total hip or knee replacement in a patient with no medical condition that would itself cause elevated inflammatory markers, how long after normalisation of the CRP does ESR return to normal?

e, Approximately one year.

9, After successful treatment of a periprosthetic infection, which of the following tests will remain specifically positive?

c, Polymerase chain reaction.

10, Which test sets the highest standard in the diagnosis of infected total hip replacement?

d, Intra-operative tissue culture.

11, What is the recommended course of action if preoperative assessment of a loose prosthesis revealed no evidence of infection but cultures taken from peri-prosthetic tissues at the time of revision surgery are positive?

d, Continue appropriate intravenous antibiotics for six weeks after surgery.

12, A patient is found to have a methicillin sensitive staphylococcal infection of their hip replacement but there is significant bone loss on the pelvic side and they have developed life threatening comorbidities. A decision is therefore taken to simply suppress the infection with antibiotics, aiming to avoid surgery altogether. Assuming no contraindications to any of the antibiotics that follow, which agent or combination has the greatest chance of actually eradicating the infection?

c, Ciprofloxacin and rifampicin.

13, Which of the following was noted by the Lower Extremity Assessment Project (LEAP)?

d, If there is loss of sensation in the foot of a mangled extremity this will be due to neuropraxia of the posterior tibial nerve in a significant number of cases and will ultimately recover.

14, Which of the following organisms is a particular risk for infection of open fractures exposed to river or stream water?

c, Pseudomonas aeruginosa

15, An open fracture is swabbed in the emergency room and cultures from the swabs grow organisms. The fracture subsequently develops signs of overt infection. What is the chance that organisms cultured from the infected fracture will also have been cultured from the swabs taken in the emergency room?

d, About two in every three cases.

16, What is the appropriate antibiotic regime to accompany surgical treatment of a grade III open fracture exposed to soil contamination?

b, Penicillin G, a second generation cephalosporin and an aminoglycoside for three days.

17, What is the approximate risk of chronic osteomyelitis when open tibial fractures are managed by external fixation using non-circular frames?

b, 4%

18, What has been estimated as the proportion of infected open fractures in which the offending organism is acquired in hospital?

a, Almost half of all cases.

19, Which of the following is the strongest predictive factor for compartment syndrome in open tibial fracture?

e, The degree of bone comminution.

20, Which of the following variables is not assessed in calculating the Mangled Extremity Severity Score?

c, Nerve injury.

21, Which of the following was not a conclusion of the LEAP study?

a, Reconstruction and limb salvage improved the two year outcomes for Gustillo grade IIIB and IIIC injuries distal to the femur.

22, Which of the following is the commonest pattern of upper limb nerve involvement seen in leprosy?

c, Proximal or distal ulnar nerve.

23, Which of the following is not a prerequisite for elective hand reconstructive surgery in leprosy?

d, Recent steroid course to suppress neural inflammation.

24, Which of the following is the least suitable insertion site for a motor tendon transfer being used to correct a claw hand?

a, Central slip of the extensor tendon.

25, Which of the following motors is least suitable for use in opponensplasty?

b, Extensor digiti minimi.

Answers for the July 2006 CME

These papers have been set on the review articles and aspects of current management papers from the 2006 April, May and June issues of the JBJS-Br.

1, What is the volume of blood that has to be lost from the circulatory system of a healthy 75kg man before hypotension is usually first recordable?

d, 1500ml

2, What investigation is essential before applying a pelvic 'C' clamp to stabilise a pelvic fracture?

b, AP X Ray of the pelvis

3, Which of the following is a requirement before selective arterial embolisation can be considered to treat haemorrhage associated with pelvic fracture?

b, Restoration of circulatory status by initial fluid resuscitation

4, A patient has an unstable pelvic fracture with unilateral sacroiliac dislocation visible on plain X rays. An abdominal ultrasound reveals intraperitoneal fluid. The blood pressure normalised after 2 litres of intravenous crystalloid given quickly and the application of a 'C' clamp, but fell again 15 mins later when the rate of fluid administration was reduced to maintenance levels. What is the next appropriate step in management?

e, urgent laparotomy

5, Which of the following tissues yields the smallest proportion of mesenchymal stem cells when experimentally harvested for culture?

a, umbilical cord

6, According to experimental calculations, if a tibial nonunion could be treated by generating 6ml of new bone, what volume of bone marrow would have to be injected into the nonunion site to secure this effect?

d, 40ml

7, When large bone defects were experimentally treated by inserting a scaffold of polymeric microsperes and mesenchymal stem cells, what additional effect did BMP-7 confer?

c, Improved penetration of the scaffold by stem cells

8, Bony metastases from which of the following tumours is most likely to be sensitive to radiotherapy

a, breast

9, Which of the following is the commonest location for initial growth of a vertebral metastasis

c, Posterior elements

10, Which of the following is the commonest form of metastatic disease of the spine

e, Thoracic metastases in a patient with breast cancer

11, According to the classification system of Tomita, which of the following patients should be treated by marginal or intralesional excision for medium term local control of the tumour?

b, Slow growing tumour with treatable visceral metastases and multiple bone metastases

12, Although current evidence is weak, which of the following has been shown to provide lasting pain relief and improvements in motor power and walking capacity when used to treat spinal metastases

d, Vertebroplasty

13, From a synthesis of the available literature on tibial nailing, what is the approximate incidence of anterior knee pain at the end of follow up in patients who have undergone tibial intramedullary nailing.

d, 50%

14, Concerning retrograde femoral nailing, which of the following describes the reported effect of surgical approach on the incidence of knee pain

c, The incidence of knee pain is greatest when a paratendinous approach is used

15, To which super family of molecules do the Bone Morphogenetic Proteins belong?

b, TGF-beta

16, Which of the following is a potential advantage of gene therapy when used to deliver growth factors to a fracture site?

a, Prolonged expression of the protein

17, According to currently available randomised trials, what is the outcome when comparing autograft with BMP7 in a collagen carrier for tibial nonunions?

e, Union rates at 9 months were similar but morbidity differed, with 20% incidence of donor site pain in the autograft group

18, On EUA of a knee dislocation the anterior and posterior drawer tests, Lachmann and Dial tests are all positive. No fracture lines are apparent on plain films or CT scans. How would this injury be classified according to the system initially proposed by Schenk?

b, KD-III

19, What direction of knee dislocation is typically produced by knee hyperextension

a, anterior

20, In which of the following patterns of knee dislocation is common peroneal nerve injury most likely?

e, KD-V3L

21, Which of the following injuries is most commonly associated with knee dislocation

b, common peroneal nerve injury

22, If urgent vascular repair has been necessary to restore distal perfusion after a knee dislocation, which of the following is the appropriate next step.

d, Repair or reconstruct lateral ligaments then assess - if inadequate apply bridging external fixator

23, How long should definitive reconstruction be delayed after popliteal artery repair to allow the vascular anastamosis to mature sufficiently that a torniquet can be applied to the lower limb?

d, 6 to 12 months

24, Reconstruction of which ligamant is key to reducing the subluxed knee after dislocation without associated fracture?

d, PCL

25, What is the most appropriate remedial management for a patient found to have a 10cm deficit in the common peroneal nerve at exploration of a knee dislocation.

e, Tibialis posterior transfer

Answers for the October 2006 CME

These papers have been set on the review articles and aspects of current management papers from the July, August and September 2006 issues of the British Volume of the JBJS.

1, Which of the following is an example of a multipotent stem cell?

d, mesenchymal stem cell

2, Concerning the risks of stem cell therapy, which specific tumour risk is much less when adult stem cell are used rather than embryonic stem cells

d, Teratoma

3, Which of the following is a contraindication to bone donation?

b, squamous cell carcinoma of the skin

4, Which of the following is not a mandatory serological test for bone donors ?

e, hepatitis E virus antibodies

5, Which of the following methods of sterilisation has the least adverse effect on the mechanical properties of donated bone ?

a, 25kGy irradiation of frozen bone

6, Which of the following will not improve the biomechanical properties of impacted graft prior to the insertion of a prosthesis ?

c, increasing the number of impactions from 30 to 50

7, According to Positron Emission Tomography studies, for how long does graft incorporation proceed after impaction grafting of the femur ?

b, one year

8, How do methods of preparation of tendon grafts affect the immunogenicity of the graft

d, by killing fibroblasts

9, After what time period after implantation is graft remodelling complete after implantation of autogenous tendon graft.

c, 12 months

10, For which of the following conditions potentially transmissible through allografting of tendons is there no donor screening test available.

a, Creutzfeld-Jakob disease

11, What is the approximate reduction in odds of obtaining an excellent or good result that occurs with the passage of each day after injury when internally fixing acetabular fractures.

d, 20%

12, What sort of molecule is Botulinum neurotoxin.

b, A polypeptide

13, How does botulinum toxin exert its effect

d, By blocking acetyl choline release

14, What is the approximate duration of chemodenervation with muscle relaxation that occurs after administration of botulinum toxin - A

d, 15 weeks

15, In which of the following muscles would a single injection of botulinum toxin A, accurately injected for maximum effect, be most likely to infiltrate the endplate zone

b, Biceps brachii

16, Consider the following list of observed measurements: 1,1,3,3,4,5,5,6,6,6,7,8,8,10,15,20 What is the interquartile range of these measurements?

e, 4 - 8

17, A series of observations are considered, some with positive values and some with negative. In order to study the variance of these observations the numerical value of each is subtracted from the arithmetic mean and the result is squared to eliminate negative values. The sum of the resultant for all values is then divided by the number of observations (minus one) to give a measure of variance. Since the values were squared, what statistic results if the square root of this measure of variance is calculated?

e, Confidence interval for the mean

18, What is the probability of finding a statistically significant difference between two parameters under statistical study when no difference actually exists

a, 'p'

19, Which of the following statements concerning the Pearson correlation coefficient is correct

a, the greater the sample size, the smaller the p value associated with any numerical value of correlation coefficient.

20, Which of the following statements is true for both the Perason correlation coefficient and the Spearman correlation coefficient

b, both can have values from -1 to +1

21, At least how many individuals should be included in a study of six covariates to be studied by multiple linear regression.

d, 60

22, The Cox proportional hazards regression analysis assesses the independent effect of multiple variables on the hazards ratio. What analysis is used to assess the effect of a single variable.

c, Kaplan Meier survival analysis

23, What represents the proportion of patients with a positive test result that actually have the disease or condition that the test was intended to detect.

d, the positive predictive value of the test

24, What statistic identifies the proportion of times that two observers agree on the classification of categorical data, modified to account for the number of times the agreement would occur by chance alone.

d, Kappa statistic

25, What action should be taken if an individual in one arm of a randomised controlled trial violates the protocol by switching treatment to that of the other arm of the trial.

a, Include the individual in the analysis as if they were still in their originally allocated group

Answers for the January 2007 CME

These papers have been set on the review articles and aspects of current management papers from the 2006 October, November and December issues of the JBJS-Br.

1, Which of the following sites is least frequently affected by osteoporotic fractures in women?

c, Pelvis

2, How is osteoporosis defined in the clinical setting?

d, Bone mass > 2.5 SDS below the mean for a young adult

3, Which of the following is not characteristic of osteoporotic bone:

b, increased cross sectional area of callus during healing

4, In the loaded taper model of femoral stem design, which of the following statements does not reflect the design philosophy:

b, Peak stresses are particularly reduced in Gruen zones 2 and 6 of the cement mantle

5, Which of the following is a consequence of selecting a highly polished stem rather than a roughened stem?

d, No effect is noted on the capacity of the stem/cement interface to transmit compressive stress

6, What is the main factor that makes movement between the stem and cement mantle inevitable?

a, Differences in elasticity comparing the stem material, cement and bone

7, Which of the following is an effect of adding a dorsal flange to a femoral stem design?

c, More cement-bone micromovement

8, Which of the following is not an effect of the collar, at least theoretically, when added to the design of a cemented femoral stem?

b, Prevents early resorbtion of the femoral neck

9, In which of the following situations is a collar a reasonable addition to the design of an implant ?

b, Composite beam stem undersized when compared to final broach

10, Which of the following statements concerning cement mantles around the femoral stem is correct?

a, Cement mantles less than 1mm thick where the implant contacts cortical bone promote earlier osteolysis.

11, Which of the following is more common in obese than in non-obese patients undergoing hip replacement?

a, Bleeding problems in peri-operative period

12, Which of the following structures can be disrupted but will not defunction the superior shoulder suspensory complex, even in combination with a second injury of the complex?

c, Coracoacromial ligament

13, Which of the following is the most significant risk factor for nonunion of fractures of the middle third of the clavicle?

d, Shortening of > 2 cm

14, In which position of the hip is impingement pain most apparent on clinical examination?

e, Flexion, adduction and internal rotation

15, Which of the following statements concerning labral tears in the hip is incorrect?

d, They are most common in relation to the posterior rim

16, What results does the current literature on the management of labral tears reveal?

c, After tear resection 80% of those with no arthritic change on X ray had a good result compared with 50% of those with arthritic changes present

17, What is the most common complication of labral repair, as described in the largest published series to date?

a, Capsule-labral adhesions

18, Approximately what proportion of patients undergoing arthroscopic removal of loose bodies from the hip develop recurrent symptoms sufficiently severe to warrant a further arthroscopy?

e, One in three

19, In which of the following pathological conditions of the hip is there the weakest consensus of opinion favouring arthroscopic management?

c, Osteonecrosis

20, In which position of the hip does cam type impingement occur?

d, Deep flexion and internal rotation

21, Which of the following is not an absolute contra-indication to hip arthroscopy?

d, Morbid obesity

22, Which of the following complications is least frequent after hip arthroscopy?

c, Infection

23, Which of the following is not part of the minimum dataset to be collected by a joint replacement register, as recommended by the International Society of Arthroplasty registries?

e, Whether or not cement is used

24, If 4000 patients are admitted to a randomised controlled trial comparing two knee replacements, what is the chance that a 30% difference in revision rate at 10 years (true difference 6.6% vs 5%) will be missed even if all patients are followed up for the full 10 year period?

c, 20%

25, Which of the following is not a benefit of a national arthroplasty register?

c, Promotes evolution of surgical technique

Answers for the April 2007 CME

1, Which of the following tests will detect the changes of heterotopic ossification after joint replacement earliest?

D, Venous CTX-1

2, Which of the following is not a risk factor for the development of heterotopic ossification around the hip after surgery ?

A, Cemented implant

3, On a plain AP X Ray taken 6 months after hip replacement, heterotopic bone is seen, with bony spurs forming only from the region of the acetabulum, with none apparent on the greater trochanter. The gap between the spurs and the outline of the greater trochanter is measured as 9mm. What Brooker grade would you assign?

D, Grade 3

4, Which cell is implicated in the genesis of heterotopic ossification

D, Pluripotential mesenchymal stem cell

5, Which movement improves most after excision of symptomatic heterotopic bone following hip replacement

D, Flexion

6, Which of the following statement correctly summarises the action of bisphosphonates when used as prophylaxis for heterotopic ossification after total hip replacement

C, They delay the appearance of heterotopic bone until treatment is stopped

7, Which of the following is the most effective form of prophylaxis against heterotopic ossification after hip replacement?

D, Radiotherapy 7Gy 24hrs post-op

8, Internalisation of which of the following is not facilitated by the transferrin receptor?

C, CrIV

9, Which of the following does not occur in response to circulation metal ions from orthopaedic implants?

C, Increased circulating CD8+ T cells

10, Which of the following statements is incorrect?

B, Chromosomal aberrations in circulating lymphocytes result in a higher incidence of haematological malignancies

11, Which of the following metals, used in orthopaedic alloys and implants, does not generate reactive oxygen species in vivo

A, Aluminium

12, What is the characteristic pattern of inflammation in the tissues around a loose metal-on-metal prosthesis

D, Perivascular lymphocyte infiltration with accumulation of plasma cells

13, Which of the following bone grafting materials is osteogenic

A, Autogenous cancellous bone

14, Application of which technology allows a reduction in the time between harvesting of a femoral head and its safe use as fresh frozen graft

C, Nucleic acid amplification

15, Which of the following infective agents has not, so far, been documented to transmit from human to human via bone grafts

A, Creutzfeldt-Jakob disease

16, Which of the folowing processes improves the osteoconductive properties of corticocancellous bone graft

A, Delipidation

17, Which of the following is not virucidal when used during the preparation of bone for grafting

E, Radiation at 25kGy

18, Which of the following is absent from demineralised bone matrix

B, Calcium sulphate

19, Which of the following is not observed when using a step cut technique at the junction between host bone and a massive allograft, followed by internal fixation

C, Improved probability of union

20, Which structure is thought to act in concert with the vastus medialis obliquus muscle as a combined dynamic unit, stabilising the patella during knee flexion

B, Medial patellofemoral ligament

21, Which of the following procedures would be most appropriate for symptomatic patellofemoral instability with degenerative disease affecting both surfaces of the patellofemoral joint on arthroscopy

C, Lateral release with tibial tubercle elevation

22, For which of the following is there least evidence for a beneficial effect when used to irrigate open fractures

D, Pulse lavage at 75psi

23, Which of the following is not a normal step in the process of longitudinal growth at an epiphyseal plate

A, Hypertrophic chondrocytes mineralise the transverse septae

24, Which of the following is an anti-catabolic treatment in securing fracture union

E, Nitrogen containing bisphosphonates

25, Which of the following is an anabolic agent in the context of experimental fracture healing

E, OP-1

A CME test paper was not published in July 2007

Answers for the October 2007 CME

1, What is the material structure of the deep surface of the long head of the biceps tendon in its groove adjacent to the lesser tuberosity.

b, Fibrocartilage

2, What are the clinical signs of an ‘hourglass’ biceps tendon

e, Loss of the last 10-20 degrees of both active and passive shoulder abduction and elevation

3, What loss of elbow strength occurs as a result of tenotomy of the long head of the biceps tendon in patients who already have a massive, irreparable rotator cuff tear.

e, 40% loss of both flexion and supination

4, Which of the following is not a usual constituent of either the powder or liquid components of a bone cement pack

a, Acryllic acid

5, Which of the following pairs of materials has, numerically, the greatest mis-match in stiffness.

a, Bone cement – Cobalt Chrome

6, According to Charnley, what is the approximate area of the bone/cement interface of a cemented femoral stem

c, 80cm²

7, Which of the following statements concerning bone cement is true

a, It becomes saturated with water in vivo, which has a plasticisng effect

8, For how long does the polymerisation process continue after mixing powder and liquid constituents of a bone cement pack

d, 6 weeks

9, What is the main adverse effect when Rifampicin is added to bone cement

a, It delays cement setting for several days

10, Approximately what proportion of the antibiotic added to cement is ever released

b, 7.5%

11, Which of the following preparation techniques for antibiotic loaded cement should be avoided

e, Add 2g liquid gentamicin to liquid component of cement before mixing with powder

12, Which of the following properties of bone cement is not governed by International standards

c, Fatigue resistance

13, Which of the following has the greatest risk of congenital talipes equinovarus (CTEV)

e, The monozygotic twin of a child with CTEV

14, Which of the following is most commonly associated with CTEV

d, Spina Bifida

15, Which of the following structures contributes to the biceps pulley’

d, Middle glenohumeral ligament

16, In what position of the arm can the long head of the biceps dislocate into the empty footprint of supraspinatus in the presence of a supraspinatus tear?

b, Abduction and internal rotation

17, What are the clinical signs of an entrapped hourglass biceps tendon

b, Loss of the last 20 degrees of active and passive elevation with normal rotation

18, In which of the following structures have nerve fibres from the sinuvertebral nerves not been observed

c, Outer region of the nucleus pulposus

19, Which part of the intervertebral disc has been shown to have a primarily, if not wholly, sympathetic nerve supply

a, Anterior disc

20, In the degenerate disc, which of the following is true

b, Nerve fibres penetrate further towards the central region than in healthy discs

21, For what purpose were the Oxford hip and knee scores designed

d, As outcome measures in randmised controlled trials

22, What range of scores do the originators of the Oxford hip and knee scores recommend to be used

a, 0 to 48

23, If the Oxford knee score is used in an intervention such as osteotomy, which of the following is an example of the sort of parameter that should be measured to confirm that appropriate measurement properties have been maintained

b, Cronbachs Alpha

24, In patient reported outcome measures, which of the following can be used to estimate the minimal clinically important different between pre and post intervention scores

b, Half the standard deviation of the change observed

25, What does an accurate estimation of the minimal clinically important change most usefully feed into when setting up a trial

d, Power calculation