How to design The Objective Structured Clinical Examination (OSCE) in hand surgery
Examinations
are formidable even to the best prepared, for the greatest fool may ask more
than the wisest man can answer. (Charles Colton, 1780-1832)
The OSCE has been in place since 1970 and used in Dundee and now widely employed in medical education as a cost effective tool for competence assessment. The literature’s view on this is well summarised as follows (Walther N.K.A. van Mook, 2009) :-
- The ‘magic bullet’ regarding
professionalism assessment does not exist.
•
Current ‘state-of-the-art’ in the assessment of
professional behaviour is combining multiple methods (triangulation) in varied
contexts with multiple observers over a longitudinal trajectory.
•
Current state of the art in education of
professional behaviour is assessment with adequate follow-up and with the
provision of opportunities for remediation; only assessment without remediation
loses ground.
OSCE
for fixation in an oblique fracture of the 3rd metacarpus in a
plastic bone model
Aim:
To assess the candidates ability to perform
inter fragmentary compression of a fracture of a metacarpus with a 2 mm screw
using the lag screw principle.
This OSCE station will test a candidate in the
following domains:-
Knowledge: The principles of lag screw fixation
Skills: The ability to accurately and
effectively place a lag screw to produce adequate compression across a
standardised oblique fracture in a plastic bone model.
Attitude: Attention to detail and methodical planning
process.
The Station layout - on a standard student desk
Scenario
A standardise oblique fracture created with a
saw in the 3 metacarpus of a plastic hand model
Instructions
for candidate
- Stably
fix the fracture that has been reproduced in this model using the implants
provided.
- Chose
your implant and place it accurately to obtain stable fixation.
- Use
the equipments provided to assist you.
- Plan
you procedure on the paper provided.
- Use
all protective equipment provided.
- Ensure
that you fixation is safe, stable and appropriate.
Instruction
to examiner
The
time for this station is 15 minutes.
Ensure
the candidate chooses his fixation choice and plans it first on paper before
proceeding.
- Choose
lag screw technique using a single 2 mm screw
- Reduces
accurately the fracture and holds it with a reduction clamp
- Chooses
the site for placement of the lag screw – right angle to fracture and at
least 4 mm from the fracture edges
- Uses
a 2mm drill guide to drill the pilot hole with a 2 mm drill ensuring only
the near cortex is drilled
- Uses
the 1.5mm drill sleeve in the pilot hole to drill a 1.5mm hole in the far
cortex with a 1.5 mm drill
- Measures
accurately the length of the required screw
- Countersinks
the entry hole to ensure the head of screw will be flushed with the bone
- Chooses
the appropriate screw and confirms the length on the measuring scale
- Inserts
the screws and
- Confirm
compression at fracture site.
The
resources required
- Plastic
Bones hand model
- Cork
board with rubber bands to anchor model
- 2
mm Hand Compact Hand Set including instruments and implants (Synthes)
- Power
drill cordless
Mark
sheet
A checklist marking has been used here as it
allows for quantification of results and provides objectivity and by adding a
heavy weight age to the choice of fixation it shows the importance of choosing
the best options for fixation of an oblique fracture.
A global rating was not used as it did not
allow for specific areas of assessment and the checklist allows for more
accurate feedback for the candidates in areas of weakness for remedial
learning.
Max Actual
Ensure the candidate chooses the right
fixation technique – a lag screw technique using a single 2 mm screw
|
4
|
|
Reduces accurately the fracture and holds it
with a reduction clamp
|
1/2
|
|
Chooses the site for placement of the lag
screw – right angle to fracture and at least
4 mm from the fracture edges
|
1/2
|
|
Uses a 2mm drill guide to drill the pilot
hole with a 2 mm drill ensuring only the near cortex is drilled
|
1/2
|
|
Uses the 1.5mm drill sleeve in the pilot hole
to drill a 1.5mm hole in the far cortex with a 1.5 mm drill
|
1/2
|
|
Measures accurately the length of the
required screw
|
1/2
|
|
Countersinks the entry hole to ensure the
head of screw will be flushed with the bone
|
1/2
|
|
Chooses the appropriate screw and confirms
the length on the measuring scale
|
1/2
|
|
Inserts the screws in line with drill hole
|
1/2
|
|
Confirm compression at fracture site.
|
2
|
|
Max 10
Advantages of this OSCE
• Each candidate undergoes the same assessment
material and scoring system under identical conditions
• Versatile format to assess any part of
curriculum in hand surgery
• Potentially provides both candidate and
trainer with detailed analysis of performance
• Potential for objective feedback
Disadvantages of this OSCE
• Resource intensive needing planning and
resources like equipment, personnel and time
• Not a holistic assessment tool as this only
test for psychomotor skills
• Examiners need to be trained to assess
objectively
References
Walther N.K.A. van
Mook et al
General
considerations regarding assessment of professional behaviour, European Journal
of Internal Medicine, Volume 20, Issue 4, July 2009, Pages e90-e9