MF3 CRE Practice Questions
MSK
ANNE DANG, CCPA
ORTHOPAEDIC SURGERY PHYSICIAN ASSISTANT
MCMASTER UNIVERSITY
PHYSICIAN ASSISTANT EDUCATION PROGRAM CLASS OF 2011
ANNECCPA@GMAIL.COM
LAST UPDATED JUNE 24, 2013
SPECIAL THANKS TO:
DR. CLARK, PHYSIATRIST
OHOOD ELZIBAK., MCMASTER PAEP CLASS OF 2010
JACOB EAPPEN., MCMASTER PAEP CLASS OF 2014
Disclaimer
 All of these names and cases are fictitious but based on clinical
presentations that real patients may present with. Similarities to
anyone in real life is coincidental and unintended.
 The opinions expressed on this PowerPoint are those of the author,
and they do not reflect in any way those of the institutions to which
they are affiliated.
 This PowerPoint is for educational purposes only. It is not intended
as a substitute for the diagnosis, treatment and advice of a qualified
licensed professional. In no way should anyone consider that this
presentation represents the "practice of medicine." The author
assumes no responsibility for how this material is used. Also note
that the information is updated on occasion and due to a variety of
reasons, therefore, some information may be out of date.
Obligatory Preamble
 Written in the style of CRE (was called CAE back in 2010) based on case
studies that were given to the Class of 2011 in MF3 for the Orthopaedics
section
 MSK is an enormous topic, in addition to typical cases you’d see in
Orthopaedics, there is a lot of overlap with Rheumatology, Physiatry,
Neurology… you name it! With that being said, do not limit your
differential to just “Muscles and bones”, think metabolic, systemic,
inflammatory, neoplastic just like you would in a real clinical scenario.
 This in no way reflects the kind of questions you will receive on
the CRE, purpose is to have you practice answering the
question style and to review important topics in MSK.
 I am open to feedback about the cases, please contact me
(anneccpa@gmail.com) if you have any questions or concerns.
Study Tips
 Rather than memorizing a checklist of etiology,
symptoms & investigations - try to understand the
pathophysiology or why, the former then comes
more easily
 As JC puts it “Broad Brush Strokes”! Don’t get
bogged down by the nitty gritty details. Try to think
about what is will be relevant in understanding what
is going on with the patient, and how that affects
your choice of management
Outline
 Case 1: Shoulder Pain
 Case 2: Knee Pain
 Case 3: Joint Pain
 Case 4: Developmental abnormality
 Case 5: Back Pain
 Outline Review
Case 1: Shoulder Pain
REFERENCE CASE
MF3 : CASE 16C
MIKE CHIASSON
45 YEAR OLD MALE WITH SHOULDER PAIN
Case 1: Shoulder Pain
John, a 62-year-old male electrician presents to your
family doctor’s office with a 3 year history of right shoulder
pain. He cannot recall any specific injury or inciting event,
but notes the pain has been getting worse over time. He
says the pain is aggravated at work, especially when he is
lifting above the level of the shoulder or doing any work
overhead for a long period of time and is better with rest.
He localizes the pain to the anterolateral aspect of the
shoulder with no radiation. He has tried ice and heat with
no relief, and has not tried any other modalities of
treatment. He denies any numbness or tingling. Review of
systems is otherwise unremarkable. He is a non-smoker
and non-drinker.
Questions
Case 1:
Shoulder Pain
________________
John, a 62 year old male
electrician presents to your
family doctor office with a 3
year history of right shoulder
pain. He cannot recall any
specific injury or inciting event,
but notes the pain has been
getting worse with time. He says
the pain is aggravated at work,
especially when he is lifting
above the level of the shoulder
or doing any work overhead for
a long period of time and is
better with rest. He localizes the
pain to the anterolateral aspect
of the shoulder with no
radiation. He has tried ice and
heat with no relief, and has not
tried any other modalities of
treatment. Review of systems is
otherwise unremarkable. He is a
non-smoker and non-drinker
Based on this gentleman’s history,
name three differential diagnosis
and the reasoning for why you
included each on your differential
in the order of most likely to least
likely.
2. What findings on physical exam
would you expect to observe based
on what you think is the most
likely diagnosis?
3. What investigations would you
order? What would you expect to
find based on what you think is the
likely diagnosis?
4. Briefly explain what treatment
options are available to John.
1.
Answers to Case 1
QUESTION 1
At the top of your Differential:
 Rotator Cuff Pathology (tear or impingement)


Concepts to Review:
•
Rotator Cuff Tears
•
Shoulder Anatomy/ Rotator
Cuff Muscles


AC joint osteoarthritis


Helpful (Quick) Reads
•
•

American Family Physician:
Management of Shoulder
Impingement Syndrome &
Rotator Cuff Tears
Examples of Differential
Diagnosis for
Acute/traumatic
presentations of shoulder
pain: American Family
Physician
Diagnosing Rotator Cuff
Tears: American Family
Physician


Usually presents in elderly or after an injury (post-traumatic
OA)
Painful & stiff in the morning and gets better throughout the
day
Patients often describe “grinding” in the shoulder (this is a
result of ‘bone on bone’ arthritis)
Adhesive Capsulitis (“Frozen Shoulder”)



pain usually presents over the AC joint (superolateral aspect of
shoulder)
Shoulder Osteoarthritis (OA)

•
can be traumatic or atraumatic (chronic);
commonly aggravated by overhead activities;
pain typically localized to anterolateral aspect of shoulder;
Can present very similarly to rotator cuff tears, except patients
may explain “stiffness” is their most predominant complaint.
Risk factors including smoking and Diabetes, can be
idiopathic
Biceps Tendinopathy/Tendon Partial Tear
Based on a Diagnosis of Rotator Cuff Tear/Impingement
Answers to Case 1
QUESTION 2
Concepts to Review:
•
Shoulder Physical Exam
(inspection, palpation,
range of motion, power,
neurovascular assessment)
•
Shoulder Exam “Special
Tests”
•
•
•
•
Impingement
Biceps testing – biceps
pathology
Labral testing – rule out
SLAP/labral tears
Apprehension test – rule
out shoulder instability
(e.g. recurrent shoulder
dislocations)
Helpful Resource:
•
Physical exam of the
shoulder: AAFP
http://www.aafp.org/afp/2
000/0515/p3079.html
Inspection:
 You may or may not see rotator cuff muscle wasting, depending on
severity of the tear or chronicity of the problem
Palpation
 Tenderness over the superolateral aspect of shoulder
Active Range of Motion
 If its just impingement or rotator cuff tear alone, range of motion may
be full, but painful
 Forward flexion and abduction are either limited or painful above 90
degrees.
Power
 Should be at least 3+/4- on the Oxford power scale, and limited by
pain; you may be dealing with something else if power is less than this.
Neurovascular Status
 Rotator cuff tears/impingement does NOT cause numbness or tingling
on the affected extremity in most cases! If a patient presents with this,
you must adjust your differential diagnosis! (e.g. Thoracic Outlet
Syndrome, Brachial Plexus Neuropathies, etc.)
Special/Provocative Tests
 Positive Impingement Sign/Testing
Based on diagnosis of Rotator Cuff Tear/Impingement
Answers to Case 1
QUESTION 3

X-Ray: Rule out any bony abnormalities. X-rays in rotator cuff tears
may be normal or demonstrate narrowing of the subacromial
space.

Question 3: What investigations
would you order? What would you
expect to find based on what you
think is the likely diagnosis?
If the problem is chronic, there will be long term changes (extra details: superior
migration of the humeral head, narrowing of the subacromial space, spurring on
the undersurface of the acromion).

Ultrasound: Will often display tendinosis, partial or complete tearing of the
supraspinatus tendon or other rotator cuff muscles.

MRI: Usually a more definitive test to determine more precisely the size &
location of the rotator cuff tear/impingement/tendon inflammation. Useful if
you plan on referring to a specialist for a surgical opinion (i.e. orthopaedic
surgeon).
Quick Reference about Imaging
X-rays – evaluates bone
Ultrasounds – evaluates soft
tissue (e.g. muscles); but sound
radar is blocked by bone – so you
cannot see the entire anatomy of
the shoulder.
MRI – evaluates bone and muscle
– can appreciate entirety of
shoulder; used to evaluate muscle
pathology in greater detail in
Orthopaedics.
CT scan – for evaluating bony
anatomy in detail; usually ordered
by Orthopaedic Surgeons for
surgical planning for certain
fractures, or presentations of
arthritis.
In clinic: we usually order x-ray and ultrasound together first since they are the
fastest and cheapest, MRI waiting list in Hamilton is 2-3 months)
Other (extra knowledge)

CT Scan: If the x-ray comes back abnormal (e.g. bony lesions/depressions).
Usually ordered in a specialist setting.

Bone Scan: If you suspect a fracture (e.g. proximal humeral fracture) that did
not appear on x-ray

Blood work: If you are suspicious for a rheumatological cause of the pain
(e.g. Rheumatoid Arthritis), inflammatory or neoplastic cause, etc.
Based on a diagnosis of Rotator Cuff Tear/impingement
Answers to Case 1
QUESTION 4
Question 4: Briefly
explain what treatment
options are available to
John.
Non-Operative Management

Anti-inflammatories: for pain relief; John has no risk factors, but
we would advise him to take any NSAIDs with food, issues with
blood pressure, ensure he has no kidney disease or liver problems.

Physiotherapy (if you’re American – physical therapy): Specific
exercises will help strengthen muscles at the front & back of the
shoulder, to reduce impingement and offload the supraspinatus
muscle

Modified Activities: John may benefit from reducing his overhead
activities and work as an electrician. He may ask his employer to
switch to a more administrative role which does not require lifting
or overhead activities for several weeks.
Cortisone Injection: A steroid is injected into the subacromial
space to reduce inflammation and provide temporary pain relief.


Operative Management
Surgical Repair: if non-operative management fails, John may
consider surgical repair of the torn rotator cuff, with debridement
(cleanup) of the subacromial space. Surgery may be open or
arthroscopic.
Shoulder Case Study References
 Fongemie, A. Buss, D. Rolnick, S. Management of
Shoulder Syndrome and Rotator Cuff Tears. Am Fam
Physician. 1998 Feb 15; 57(4):667-674
 Hide, G. Ultrasonography for Rotator Cuff Injury.
Medscape. 2011 Jul 29 Accessed from
http://emedicine.medscape.com/article/401595overview#a22
 Miller, M. 2008. Review of Orthopaedics 5th ed.
Saunders Elseiver Philadelphia.
Case 2: Knee Pain
REFERENCE CASE
MF3 : CASE 17A
DANIEL GATTO
41-YEAR-OLD MALE WITH KNEE PAIN
Case 2: Knee Pain
Alex is a 26-year-old male who presents to a family medicine practice two
weeks after “twisting his knee” during a basketball game. He recalls the pain
was “sharp” and “hard to forget”. He is currently taking Naproxen for pain
and icing the knee. He feels the knee “gives way” sometimes while walking
and especially going down stairs. He reports occasional locking of the knee.
He has a history of Asthma and Tonsillectomy at age 5. He has no known drug
allergies. He works at a desk job.
On physical exam, you note he has antalgic gait. On inspection you notice
decreased quadriceps muscle bulk on the left compared to the right. The left
knee is slightly more swollen than the right but there is no redness. Range of
motion is full. He knee has neutral alignment. Testing of his MCL and LCL are
within normal limits. He has medial joint line tenderness to palpation.
Posterior sag sign is negative. He has a positive Lachman’s and Anterior
Drawer Test, and positive McMurray and Apley Test medially. He is distally
neurovascularly intact.
Questions
Case 2:
Knee Pain
________________
Alex is a 26-year-old male who presents to
a family medicine practice two weeks after
“twisting his knee” during a basketball
game. He recalls the pain was “sharp” and
“hard to forget”. He is currently taking
Naproxen for pain and icing the knee. He
feels the knee “gives way” sometimes while
walking and especially going down stairs.
He reports occasional locking of the knee.
He has a history of Asthma and
Tonsillectomy at age 5. He has no known
drug allergies. He works at a desk job.
On physical exam, you note he has antalgic
gait. On inspection you notice decreased
quadriceps muscle bulk on the left
compared to the right. The left knee is
slightly more swollen than the right but
there is no redness. Range of motion is full.
He knee has neutral alignment. Testing of
his MCL and LCL are within normal limits.
He has medial joint line tenderness to
palpation. Posterior sag sign is negative.
He has a positive Lachman’s and Anterior
Drawer Test, and positive McMurray and
Apley Test medially. He is distally
neurovascularly intact.
Based on the Alex’s initial
clinical presentation, what are
your top three on your
differential diagnosis? Give
evidence for each.
2. How would you explain the
decrease in quadriceps muscle
bulk on physical exam?
1.
Answers to Case 2
QUESTION 1
At the top of your Differential for Medial Knee Pain:
 ACL Tear: tear of the anterior cruciate ligament is
common in sudden deceleration or twisting injuries.
Evidence:

Question 1: Based on
the Alex’s initial clinical
presentation, what are
your top three on your
differential diagnosis?
Give evidence for each



Meniscal Tear: meniscal tears common in twisting
injuries, can happen in conjunction with ACL tears.

Concepts
•
Knee Anatomy
•
ACL tear vs. PCL
tear



Meniscal Tear
•
Osteoarthritis of the
knee
Locking of the knee is a common symptom, when tears of the
meniscus protrude and obstruct the knee from extending and
flexing
McMurray and Apley tests are positive for medial side.
Medial joint line pain
Medial Collateral Ligament (MCL) Tear or Strain

•
Alex had a twisting injury
He has the sensation of “giving way” and swelling in the area
Positive anterior drawer and Lachman Test on physical exam
MCL injuries occur when there is a valgus force to the knee. You would
have experienced laxity of the medial side when applying a valgus force
on physical exam – this exam was normal on Alex’s exam.
Muscle wasting can be caused by various factors
Answers to Case 2
QUESTION 2
Question 2: How would
you explain the
decrease in quadriceps
muscle bulk on physical
exam?
In Alex’s case, most likely:
 Deconditioning/disuse of the muscle due to
pain and guarding of the knee. This may happen
even if he is neurovascularly intact.
 Decrease in quadriceps muscle strength following
his ACL injury may contribute to sensation of
functional instability of the knee (i.e. “giving way”).
Knee Case Study References
Calmbach, W. Hutchens, M. Evaluation of Patients
Presenting with Knee Pain: Part I. History, Physical
Examination, Radiographs, and Laboratory Tests. Am
Fam Physician. 2003 Sept 1; 68(5): 907-912
Calmback, W. Hutchens, M. Evaluation of Patients
Presenting with Knee Pain: Part II. Differential
Diagnosis. Am Fam Physician. 2003 Sep 1;68(5):917922.
Case 3: Joint Pain
REFERENCE CASE:
ANN GREEN
Case 3: Joint Pain
Janice, a 52-year-old female comes to your office with bilateral shoulder pain
worse on the right than the left for the past several months. She also notes the
knees and hands have been bothering her recently. She notes stiffness in her
joints in the morning, and trying to get up or move after driving or sitting for
prolonged periods of time. She also reports a long-standing history of
difficulty with opening jars, writing and computer work. She has not had any
investigations or treatments done. Review of systems otherwise negative.
Upon further questioning, Janice smokes 1 pack per day for the past 20 years.
She used work as a project manager for an IT company but has had to
discontinue due to her progressive joint pain, blaming it on “old age”. She is
allergic to Penicillin.
On physical exam, you note she has swelling on bilateral wrists which are soft
and warm to touch, metacarpophalangeal (MCP) and proximal
interphalangeal (PIP) joints. You also note swan neck deformities in several
finger PIP, ulnar deviation of the MCP, and Boutonniere deformity of thumb.
Questions
Case 3:
Joint Pain
________________
Janice, a 52-year-old female comes to your
office with bilateral shoulder pain worse on
the right than the left for the past several
months. She also notes the knees and
hands have been bothering her recently.
She notes stiffness in her joints in the
morning, and trying to get up or move after
driving or sitting for prolonged periods of
time. She also reports a long-standing
history of difficulty with opening jars,
writing and computer work. She has not
had any investigations or treatments done.
Review of systems otherwise negative.
Upon further questioning, Janice smokes 1
pack per day for the past 20 years. She
works as a project manager for an IT
company. She is allergic to Penicillin.
On physical exam, you note she has
swelling on bilateral wrists,
metacarpophalangeal (MCP) and proximal
interphalangeal (PIP) joints. You also note
swan neck deformities in several finger
PIP, ulnar deviation of the MCP, and
Boutonniere deformity of thumb.
What two diagnoses are on the
top of your differential after
reviewing Janice’s History and
Physical Exam?
2. What investigations would you
order? What parameters are you
looking for to confirm the most
likely diagnosis?
3. What treatment options are
available to Janice?
4. Why is Janice’s presentation
unlikely to be osteoarthritis?
1.
Most likely diagnosis:
Answers to Case 3
QUESTION 1
Question 1: What two diagnoses
are on the top of your differential
after reviewing Janice’s History
and Physical Exam?
References:
American College of Rheumatology
1987 revised classification material
for rheumatoid arthritis
 Rheumatoid Arthritis (RA):
Based on Janice’s presentation, the clinical presentation
that is consistent with rheumatoid arthritis include:
 Bilateral presentation
 Ulnar deviation at the MCPs, Boutonniere deformity
and swan neck deformities are classic findings of RA.
 Insidious onset / no history
of trauma
 Morning and startup stiffness
 Multiple joints affected
 Seronegative Polyarthritis
 Reactive Arthritis (Reiter’s Syndrome)
 Systemic Lupus Erythematous
 Pseudogout
Based on the most likely diagnosis being Rheumatoid Arthritis:
Answers to Case 3
QUESTION 2
Question 2: What investigations
would you order? What parameters
are you looking to confirm the
most likely diagnosis?
Blood work:
Elevated
ESR and C-reactive protein
Positive Rheumatoid Factor (RF)
Positive anti-CCP antibody
To rule out other rheumatologic disorders: Uric Acid (rule out
pseudogout/CPPD)
Investigations:
X-ray:
Bone erosions; ulnar deviation of MTPs, absence of Heberden’s
Nodes, Swan Neck Deformity of PIPs.
MRI: may show synovitis of affected joints
Joint aspiration: rule out presence of CPPD crystals (pseudogout)
Image 1: UptoDate
Image 2: http://ra-ss.blogspot.ca/p/30-years-of-ra.html
Referral to Rheumatologist
Answers to Case 3
QUESTION 3
Question 3: What
treatment options are
available to Janice?
Early use of DMARD (Disease Modifying Antirheumatic
Drug) e.g. Methotrexate; may take four to six weeks to take
effect
Or use of Biologics if she does not respond to use of
DMARDs include Etanercept, Adalimumab, infliximab,
golimumab (TNF inhibitors); effects are more rapid than
DMARD
NSAIDs (nonsteroidal anti-inflammatory drugs) as an
adjunct for initiating DMARD therapy or controlling
Janice’s flares.
Short term use of Glucocorticosteroid Prednisone, with
caution against the risks of chronic use e.g. GI bleeding, risk
for osteoporosis and fractures, diabetes mellitus, infections,
cataracts and impaired HPA axis response,
Smoking cessation counseling for Janice
Answers to Case 3
QUESTION 4
Osteoarthritis may present very similarly to Rheumatoid Arthritis,
however, there are important distinctions:
Question 4: What reasons
is this unlikely
osteoarthritis?
Feature
Rheumatoid arthritis
Osteoarthritis
Heberden’s Nodes
Absent
Present
Stiffness
Worse after resting (e.g. morning
stiffness)
Evening stiffness or worse after
activity
Positive Lab Findings
Positive Rheumatoid Factor
Positive anti-CCP Antibody
Increased ESR and CRP
Negative Rheumatoid Factor
Anti-CCP Antibody negative
Normal ESR and CRP
Joints
Soft, warm and tender (synovitis)
Hard and bony
Joints in hands affected
MCP and PIP
DIP and CMC
Extra-articular manifestations
Present
Absent
Image 1: http://www.bio.davidson.edu/courses/immunology/students/spring2006/dresser/ra.html
Image 2: http://www.cedars-sinai.edu/Patients/Health-Conditions/Osteoarthritis.aspx
Table from UptoDate
Case 3 References

Lipsky P. Algorithms for the diagnosis and management of musculoskeletal complaints: A new
tool for the primary-care provider. (See
www.swmed.edu/home_pages/cme/endurmat/lipsky/index.html.)

O’Dell, J. Use of glucocorticoids in the treatment of rheumatoid arthritis. UptoDate. 2012 Dec
17. Accessed April 12, 2013 from http://www.uptodate.com/contents/use-of-glucocorticoids-inthe-treatment-of-rheumatoid-arthritis?source=see_link

Schur, P & Moreland, L. General Principles of management of rheumatoid arthritis in adults.
UptoDate. 2013 Feb 4. Accessed April 12, 2013 from
http://www.uptodate.com/contents/general-principles-of-management-of-rheumatoidarthritis-in-adults?source=related_link

Venables, P. Maini, R. Clinical features of rheumatoid arthritis. UptoDate. 2012 Oct 6. Accessed
April 12, 2013 from http://www.uptodate.com/contents/clinical-features-of-rheumatoidarthritis?source=see_link

Venables, P. Maini, R. Diagnosis and differential diagnosis of rheumatoid arthritis. UptoDate.
2012 Mar 28. Accessed April 12, 2013 from http://www.uptodate.com/contents/diagnosis-anddifferential-diagnosis-of-rheumatoidarthritis?source=search_result&search=rheumatoid+arthritis&selectedTitle=1%7E150
Case 4: Developmental
Abnormality
REFERENCE CASE:
ANN GREEN
Case 4: Joint Pain
You are in your second year PA clerkship and have decided to do a
rotation overseas with a supervisor who is looking to bring health care
to underserviced areas. While doing home visits to administer
vaccinations in one of the local villages, you meet Jane, a lovely 8year-old female accompanied by her mother.
Starvation and poverty are endemic in Jane’s village. Jane’s mother
has explained food has been difficulty to come by, and Jane has had
trouble growing as fast as some of her classmates. Upon further
questioning, you learn that Jane is sick frequently with infections.
On physical examination you note that Jane is small in stature for her
age. You notice significant varus alignment of the knees, as well as
bowing of the tibia and fibula.
Questions
Case 4:
Developmenta
l Abnormality
1.
2.
________________
You are in your second year PA clerkship
and have decided to do a rotation overseas
with a supervisor who is looking to bring
health care to underserviced areas. While
doing home visits to administer
vaccinations in one of the local villages,
you meet Jane, a lovely 8-year-old female
accompanied by her mother.
Starvation and poverty are endemic in
Jane’s village. Jane’s mother has explained
food has been difficulty to come by, and
Jane has had trouble growing as fast as
some of her classmates. Upon further
questioning, you learn that Jane is sick
frequently with infections.
On physical examination you note that
Jane is small in stature for her age. You
notice significant varus alignment of the
knees, as well as bowing of the tibia and
fibula.
3.
4.
5.
What is the likely diagnosis? What
other questions would you ask to
clarify this diagnosis?
Explain the pathophysiology
behind the disease.
How would the disease process
present differently if Jane was an
adult at the time of onset? When
Jane was a neonate?
What investigations would you
order to confirm the diagnosis and
what specific findings would you
expect?
What treatment options and
education would you recommend
for Jane and her mother?
Answers to Case 4
QUESTION 1

Most likely diagnosis is Rickets as a result of Vitamin D
Deficiency (Calcipenic Rickets)

Rule out causes of Vitamin D Deficiency:
Decreased nutritional intake: Ask about diet, e.g. what a
typical breakfast, lunch, and dinner consists of to
understand over time what Jane’s nutritional picture looks
like
Decreased synthesis: i.e. those with darker pigmented skin
in low sunlight times of the year or clothing coverage
Constitutional symptoms to rule out neoplasms that may
be causing hormonal imbalances
Maternal Factors: (1) Maternal Vitamin D deficiency; (2)
Prematurity; (3) Exclusive breast feeding
Ask about family history (rule out inherited Vitamin D
resistance)
Medications: Anticonvulsants, antiretroviral drug use for
HIV, glucocorticosteroids, Antifungal agents such as
Ketoconazole
Do a thorough review of systems to rule out kidney
disorders, liver disorders parathyroid hormone problems
Rule out causes of malabsorption (e.g. Celiac’s Disease,
inflammatory bowel disease, pancreatic insufficiency,
cholesstasis, post-gut resection or bariatric surgery)

Question 1: What is the
likely diagnosis? What
other questions would you
ask to clarify this
diagnosis?







Answers to Case 4
QUESTION 2
Question 2: Explain the
pathophysiology behind
the disease.
 Vitamin D Metabolism Overview:
 Vitamin D3 (dietary and synthesized in skin
from sunlight exposure) and Vitamin D2
 Carried to the liver by D-binding protein to
the liver where it is converted into 25(OH)-D
a storage form of Vitamin D
 In the kidney, 25(OH)-D is converted to125(OH)2D regulated by PTH, serum Calcium
& Phosphate.
 Vitamin D increases calcium absorption from
gut & reasborption from kidney.
 Pathophysiology: For Jane, there is
likely a significant dietary role for her
disease process. There are two subtypes
of rickets:


Calcipneic Rickets: due to low intestinal
absorption of calcium but not necessarily to
hypocalcemia
Phosphophenic
Image from http://www.uptodate.com/contents/image?imageKey=ENDO/65360&topicKey=ENDO%2F2021&source=outline_link&utdPopup=true
Answers to Case 4
QUESTION 1
Question 3: How would
the disease process
present differently if
Jane was an adult at the
time of onset? When
Jane was a neonate?
Vitamin D Deficiency in a:
 Neonate – delayed closure of the
fontanelles
 Adult –Presents as Osteomalacia

Presentation is difference since growth
plates are closed including “bone pain”,
and joint pain muscle weakness,
difficult walking

Answers to Case 4
QUESTION 4
Question 4: What
investigations would
you order to confirm
the diagnosis?


Blood work:
 Serum Calcium, Vitamin D levels of 25(OH)D, Parathyroid
Hormone (PTH), ALP, Phosphorus, Kidney Function Tests
X-rays to rule out pathologic fractures in areas of pain
Blood work Findings: Expected findings highlighted in red with
Vitamin D deficiency with child who has normal kidney and liver
function
Image from http://www.uptodate.com/contents/image?imageKey=PEDS/56687&topicKey=PEDS%2F14590&source=outline_link&search=rickets&utdPopup=true
Case 4 – Question 4: Supplementary Slide
Image from: http://www.uptodate.com/contents/image?imageKey=PEDS/81032&topicKey=PEDS%2F5856&source=outline_link&search=search+rickets&utdPopup=true
Answers to Case 4
QUESTION 5
Question 5: What
treatment options and
education would you
recommend for Jane
and her mother?
 Treatment:
 Vitamin D Replacement (D3): for
Jane’s age, it would be 2000 IU/day for
six weeks, followed by maintenance of
600 to 1000 IU/day
 Since Jane is also presenting with
clinical manifestations of rickets, she
should have Calcium along side her
Vitamin D supplementation (10-20
mg/kg/day)
Resources
 Carpenter, T. Overview of rickets in children. UptoDate.
2013, Mar 28. Accessed April 19, 2013 from
http://www.uptodate.com/contents/overview-of-ricketsinchildren?source=search_result&search=vitamin+d+defi
ciency+neonate&selectedTitle=3%7E150
 Menkes, CJ. Clinical Manifestations, diagnosis and
treatment of osteomalacia. UptoDate. 2013, Apr 3.
Accessed April 19, 2013 from
http://www.uptodate.com/contents/clinicalmanifestations-diagnosis-and-treatment-ofosteomalacia?source=search_result&search=osteomalaci
a&selectedTitle=1%7E117
Case 5: Back Pain
REFERENCE: MF3 MSK JACK GAMBLE
CASE STUDY
REVIEWED BY DR. CLARK, MD, FRSCS(C)
PHYSICAL MEDICINE AND REHABILITATION /
PHYSIATRY MD
Case 5: Back Pain
50 year old male Donald presents to the Emergency room with an acute on chronic episode of low
back pain. He has worked in construction for 30 years and despite “strains” in the past, has
never sought treatment for his low back pain. He has had longstanding intermittent numbness
and tingling down the lateral lower leg made worse with walking, and better with rest, sitting or
lying in a supine position which you identify as “neurogenic claudication”. He does not take any
medications, and has an otherwise benign past medical history.
Inspection of spine curvature is normal. He has pain with forward flexion of the lower back. He is
tender to palpation of his lumbar paraspinals and midline structures at the level of L5/S1. He
can walk on his heels and perform a full squat. However, he was unable to stand up on his toes
on the left side (weak plantarflexion).
His hip, knee, and ankle exam is unremarkable. He reports decreased pinprick and light touch
over the posterior calf and lateral foot, but also reports he has decreased sensation near the
groin area bilaterally. Straight raise leg reproduces his symptoms at 30 degrees of elevation.
Romberg testing is negative. Upper extremity testing was unremarkable. Muscle strength is 2+
at the hips, knees and ankles, with normal muscle stretch reflexes at the knees. Absent ankle
reflex on the left. Peripheral pulses are palpable.
Upon further questioning, he has noted urinary retention and difficulty with bowel movement in
the past week. He also notes new onset erectile dysfunction within the past 24 hours. He denies
any constitutional symptoms, hearing or vision changes.
1.
Questions
Case 5:
Back Pain
2.
3.
4.
a) What red flags appeared in Donald’s clinical
presentation that would have you worried about a
potential medical emergency?
b)What other urgent conditions would you want to
rule on your differential diagnosis in an ER setting?
What investigations would you order to rule out
serious conditions?
a) What are the potential differential diagnosis if
Donald presented without the red flags, in a
primary care setting with chronic low back pain?
b) What investigations would you order in that
circumstance?
If the most likely serious condition is confirmed
from your investigations, what treatment options
are available to Donald?
BONUS: Explain the various findings on Donald’s
physical exam, and the rationale for performing
those tests.
BONUS 2: Explain a diagnostic approach to
presentations of non-specific low back pain
Answers to Case 5
QUESTION 1 a)
Question 1: a) What red
flags appeared in
Donald’s clinical
presentation that
would have you
worried about a
potential medical
emergency?
B) What would you want to
rule out first on your
differential diagnosis?
American College of Radiology: “Red Flags” for potentially
serious underlying cause for low back pain:

Trauma (cumulative)

Underlying Systemic Diagnosis: (1) Age > 50 years;
(2) Unexplained weight loss; (3) Duration longer
than 6 weeks; (4) Night Pain; (5) History of Cancer

Unexplained fever, history of urinary or other
infections

Immunosuppression/Diabetes Mellitus

IV Drug Use

Prolonged use of corticosteroids, osteoporosis

Focal neurologic deficits with progressive or
disabling symptoms, cauda equina syndrome
(bowel or bladder dysfunction)




New onset “bilateral groin pain” could represent saddle
anesthesia
Prior Surgery
RULE OUT CAUDA EQUINA SYNDROME OR
SPINAL CORD COMPRESSION
DDx: Spinal Cord Neoplasma, Diabetic Neuropathy,
ALS, Traumatic Peripheral Nerve Lesions,
Osteomyelitis, Perineural Cysts

Answers to Case 5
QUESTION 1b)
Question 1: a) What red
flags appeared in Donald’s
clinical presentation that
would have you worried
about a potential medical
emergency?
B) What would you
want to rule out first on
your differential
diagnosis?
RULE OUT CAUDA EQUINA SYNDROME
Other Urgent Differential Diagnosis for Low Back Pain:

Spinal Cord Neoplasma

Perineural Cysts

Aortic Aneurysm

Costochondritis

GI Disease: Pancreatitis, Cholecystitis, Penetrating
Ulcer

Infection: Osteomyelitis, septic discitis, epidural
abscess, bacterial endocarditis

Pelvis Organs: Prostatitis, Endometriosis,

*Renal Disease: Neophrolithiasis, Pyelonephritis
Answers to Case 5
QUESTION 2


Question 2: What
investigations would you
order to rule out serious
conditions.
Investigations in a ER setting
Blood work: CBC, chemistries, fasting blood sugar (rule
out anemia, infection, and kidney dysfunction) + ESR
(rule out inflammatory pathology such as infection)
Catheterize bladder and measure post-void residual (> 50100cc is abnormal): rule out urinary retention from other
causes (e.g. atonic bladder from certain meds)
Imaging:

Urgent MRI and/or CT scan

Lumbar spine x-ray to rule out trauma, fracture, disc space
narrowing and spondylolysis

Bone Scan – may detect malignant tumor or metastases,
infection and occult fractures
Other Tests

Meningitis (causing spinal cord compression) workup
unlikely necessary unless patients present with neck
symptoms

Syphilis/Lyme serologies (rule out meningovascular
syphilis)

Lumbar puncture to rule out meningitis (CSF Exam)
Answers to Case 5
QUESTION 3 a)_
Question 3: a) What are
the potential
differential diagnosis if
Donald presented
without the red flags,
in a primary care
setting with chronic
low back pain?
b) What investigations
would you order in that
circumstance?
Mechanical Back Pain

Lumbar Strain

Herniated Disc

Osteoporosis

Fractures

Sciatica: numbness and tingling of sciatic nerve to foot or
ankle

Piriformis Syndrome: the piriformis muscle
compresses/irritates the sciatic nerve

S1 radiculopathy: impairment of a nerve root

Spondylosis (arthritis of spine)

Spondylolisthesis (anterior displacement of vertebra  90%
degenerative)

Spondylolysis: fracture usually at L5 of the pars interarticularis

Spinal Stenosis: narrowing of the central spinal canal by bone
or soft tissues

Congenital: Lordosis, kyphosis, scoliosis
Neoplasia: multiple myeloma, metastatic carcinoma,
lymphoma/leukemia, spinal cord tumors, retroperitoneal tumors.
Inflammatory Arthritis: IBD, Ankylosing Spondylitis, Reiter’s
Syndrome.
Paget’s Disease
Answers to Case 5
QUESTION 3 b)
Question 3: a) What are
the potential
differential diagnosis if
Donald presented
without the red flags,
in a primary care
setting with chronic low
back pain?
b) What
investigations would
you order in that
circumstance?
Investigations (outpatient):

MRI of lumbar spine – r/o fracture, tumor,
infection, structural abnormality of the spinal cord

X-ray of lumbar spine

Blood work (if systemic disease is suspected) with
or without rheumatologic markers
Outpatient setting:
 EMG and nerve conduction studies:
 not appropriate in an emergency setting, any nerve damage in
arms takes 5-10 days before showing up on EMG, and 2 weeks
for peripheral legs.
 Any same day acute pain you are trying to investigate may
appear normal on EMG and nerve conduction studies.

Answers to Case 5
QUESTION 4
Question 4: If the serious
condition is confirmed
from your investigations,
what treatment options are
available to Donald?

Determine underlying cause of cauda
equina syndrome
If Urgent Surgery Required: Admit
patient to appropriate service from
Emergency within 24 hours (Orthopaedic
Surgery or Neurosurgery)
Answers to Case 5
BONUS
QUESTION
BONUS: Explain the
various findings on
Donald’s physical exam,
and the rationale for
performing those tests
Assessing lumbar spine range of motion
Romberg Testing rule out dorsal column
abnormalities
Lumbar Nerve Root Irritation tests





Straight Leg Raise: rule out sciatica
Femoral stretch test
Nerve Root Conduction Tests



L5 – hip abduction (Trendelenburg test), ankle
dorsiflexion, great toe extension
S1 – hip extension, great toe flexion, ankle reflex
Upper Motor Neuron Test (absent
Babinski is normal)
Lower sacral nerve root tests



Saddle sensation
 Muscle strength testing
 Muscle stretch reflexes
Image from:
http://www.uptodate.com/contents/image?imageKey=PC%2F68791&topicKey=PC%2F7782&rank=1%7E132&source=see_l
ink&search=low+back+pain&utdPopup=true
 Back Predominant: more likely
Answers to Case 5
BONUS Q 2
Approach to
Non-Specific
Back Pain
mechanical




Back
Buttock
Trochanteric (hip)
Groin (SI joint)
 Leg Predominant: anywhere
below gluteal fold



radicular pain
peripheral neuropathy
entrapment neuropathy
References
 Dawodu, S. Cauda Equina and Conus Medullaris Syndromes Treatment &
Management. MedScape Reference: Drugs, Diseases and Procedures. 2013,
Mar 6. Accessed April 19, 2013 from
http://emedicine.medscape.com/article/1148690-overview
 Hall, H. Rampersaud, R. The Practical Management of Low Back Pain.
Family Medicine Forum. Accessed April 23, 2013 from
http://www.spinecanada.ca/assessing_tlb_web2011.pdf
 Wheeler, S. Wipf, J. Staiger, T. Deyo, R. Approach to the diagnosis and
evaluation of low back in adults. UptoDate. 2012, Apr 5. Accessed April 19,
2013 from http://www.uptodate.com/contents/approach-to-the-diagnosisand-evaluation-of-low-back-pain-inadults?source=search_result&search=approach+to+low+back+pain&select
edTitle=1%7E150
Resources
 Larsen, Betty. The diagnosis and pharmacologic
management of low back pain. JAAPA 2012 [PDF
available] http://www.jaapa.com/the-diagnosisand-pharmacologic-management-of-low-backpain/article/229325/
Case 6: Red, Swollen Joint
Case 6: Red, Swollen Joint
 64 year-old-male David presents to a walk-in clinic complaining of
14 hour history of sudden redness and swelling after “bumping his
foot” on a concrete ledge the night before. Past medical history
includes Type II Diabetes, which is well-controlled and he is
currently taking Metformin and ASA 81. He works as an executive
and has a history of alcohol abuse.
He has no known drug allergies. His speech is slightly slurred, and
upon further questioning, you learn that David had come straight
from a family outing and had some “meat, potatoes, and a few
drinks”.
On physical examination, Davis afebrile, there is significant
swelling, warmth and erythema over the first MTP with decreased
range of motion and pain with ambulation. You determine this is
monoarticular and no other joints are affected. There are no
lacerations or open wounds on inspection around the joint.
Questions
Case 6:
Red, swollen
joint
Based on David’s presentation,
list the top three diagnoses on
your differential and rationale
for each.
2. What is the pathophysiology for
the most likely diagnosis?
3. What investigations would you
order and why?
4. What treatment options are
available to David and what
management should be initiated
to prevent recurrence?
1.

Answers to Case 6
QUESTION 1
Question 1: Based on
David’s presentation, list
the top three diagnoses on
your differential and
rationale for each.


Septic Arthritis: Infection of the MTP joint
may be less likely due to lack of open wound
that results in bacteria seeding into the joint.
However, this is not a prerequisite for septic
arthritis. Assume it is septic arthritis until
otherwise proven, which would result in
rapid destruction of joint if not treated.
Acute gouty attack: caused by
hyperuricemia in blood and other bodily
fluids (synovial fluid) resulting in
precipitation in connective tissue throughout
the body. His risk factors include high urate
intake – including meat, alcohol, as well as
Diabetes.
Cellulitis: A cellulitis infection may be
coincidentally located over the MTP joint and
may mimic an acute gouty attack or cellulitis.
Answers to Case 6
QUESTION 2
Question 2: What is the
pathophysiology for the
most likely diagnosis?
For Pathophysiology of Acute Gouty Attack
Hyperuricemia caused by:
 Excessive production of uric acid (alcohol,
tumor lysis, obesity)
 Excessive consumption of uric acid results
in excessive nucleid acid turnover
(glutamine  hypoxanthine  xanthine 
uric acid)
 Impaired renal excretion of uric acid
(intrinsic: dehydration, renal disease;
secondary to drugs: thiazides, alcohol)
Hyperuricemia results in formation of
monosodium urate crystals.
Answers to
Case 6
QUESTION 3
What investigations
would you order and
why?
 Arthrocentesis: aspiration of joint fluid
for fluid analysis (cell count and
differential, gram stain, culture
sensitivity & microscopic analysis for
crystals – under polarized light to
differentiate crystal type
 Blood Work: CBC (elevated ESR), WBC
(left shift); renal, liver function tests
(before initiating anti-gout therapy)
 Serum uric acid is often misused to
diagnose gout: attacks triggered by
crystal formation are not related to
serum levels of uric acid. 10% of
patients who have gout do not have
hyperuricemia. Elevated Uric acid
levels in blood do not predict gout.
Answers to Case
6 QUESTION 3
What investigations
would you order and
why?
IMAGING STUDIES
Imaging Studies:
 X-ray & CT scans are adjuncts but not
necessary for diagnosing gout
 X-ray: plain radiographs may show
some soft tissue swelling, tophi
development but may be negative in
first year of disease

You may see erosions with overhanging
edges
Image from http://emedicine.medscape.com/article/329958-workup
Answers to
Case 6
QUESTION 4
What treatment options
are available to David
and what management
should be initiated to
prevent recurrence?
 Treatment
 Acute gouty attacks  treat with
pharmacologic therapy within 24 hours
of attack onset.
 For severe pain (polyarticular/large
joints) :
1) Colchicine and NSAIDs or
 2) Oral corticosteroids & colchicine or
3) intra-articular steroid


Mild to moderate pain (few small
joints, 1 joint). Monotherapy with
topical ice as needed:
1) NSAID (or COX2 inhibitor)
 2) Systemic corticosteroids
 3) Colchicine

Khanna, D. et al ACR: Guidelines for Management of Gout. Vol. 64, No. 10, October 2012, pp 1447–1461
Answers to Case
6 QUESTION 4
What treatment options
are available to David
and what management
should be initiated to
prevent recurrence?
 Prophylaxis
 Initiate urate lowering therapy (see table
below, if presence of gout, frequent attacks,
CKD stage 2, previous urolithiasis)
 Pharmacologic choices:


First line: Low dose colchicine or low dose
NSAIDs
Second line: Low dose prednisone or
prednisolone
Avoid
Limit
Encourage
Organ meats high in
purine content
(liver, kidney)
Serving sizes of:
Beef, lamb, seafood
(e.g. sardines,
shellfish)
Low fat or non-fat
dairy products
High fructose corn
syrup
Alcohol
Sweet fruit juices,
table sugar, table
salt
Vegetables
Alcohol
Khanna, D. et al ACR: Guidelines for Management of Gout. Vol. 64, No. 10, October 2012, pp 1447–1461
Case 6 References
 Rothschild, B. 2013 June 17. Gout and Pseudogout.
Accessed June 24, 2013 from
http://emedicine.medscape.com/article/329958workup#aw2aab6b5b8
 Khanna, D. et al ACR: Guidelines for Management
of Gout. Vol. 64, No. 10, October 2012, pp 1447–
1461
Outline Review
 Case 1: Shoulder Pain [Rotator Cuff Disease]
 Case 2: Knee Pain [ACL tear/meniscus tear]
 Case 3: Joint Pain [Rheumatoid Arthritis]
 Case 4: Developmental abnormality [Rickets /
Vitamin D Deficiency and Metabolism]
 Case 5: Low Back Pain [Cauda Equina/L5/S1
radiculopathy]
 Case 6: Red Swollen Joint [Acute Gouty Attack]
Other Resources
 I’ve written a resource on Rotator Cuff Pathology
based on experience from working in Orthopaedic
Surgery outpatient clinic, you can view it here:
http://anneccpa.wordpress.com/2013/02/11/should
er-impingement-syndrome/