ORTHOPAEDICS
Questions&Answers
Q-1
A 26 year old primigravida pregnant woman at 34 weeks gestation presents with
tingling and numbness with occasional pain of her right hand in addition to
altered sensation over her right middle and index finger. Tinel test is negative.
What is the SINGLE most likely diagnosis?
A. Carpal Tunnel Syndrome
B. Radial nerve entrapment
C. Scaphoid fracture
D. Median nerve entrapment
E. Peripheral arterial disease
ANSWER:
Carpal Tunnel Syndrome
EXPLANATION:
Because the stem states that Tinel test is negative, you may be tricked into choosing a
different answer but remember that the Tinel test has a very low sensitivity for carpal
tunnel syndrome. If the patient has a high suspicion of having carpal tunnel syndrome
such as the classic tingling and numbness over the median distribution of the hand as
well as being pregnant (which is a high risk factor for carpal tunnel syndrome) then you
should always choose carpal tunnel syndrome as the answer.
Pregnancy is a known risk for carpal tunnel syndrome. In pregnancy, carpal tunnel is
due to fluid retention. The best thing to do is to advise the pregnant women to wear
wrist splints until delivery as after delivery, the carpal tunnel syndrome usually resolves.
Q-2
A 15 year old boy presents with fever and pain in the right lower thigh. The pain
has been ongoing for the past one month. On examination, there is a 2 cm by 2
cm mass at the lower third of his thigh which is red, warm and tender. An X-ray
shows bone destructionwith overlying onion-skin layers of periosteal bone
formation and a soft tissue mass. What is the SINGLE most likely diagnosis?
A. Tuberculous arthritis
B. Ewing’s sarcoma
C. Osteosarcoma
D. Osteomyelitis
E. Fibrosarcoma
,ANSWER:
Ewing’s sarcoma
EXPLANATION:
Ewing’s sarcoma
• A malignant round-cell tumour of long bones (typically grows in diaphysis of long
bones) and limb girdles, usually presents in adolescents (usually 5 to 15 years old)
Presentation
• As a mass or swelling commonly in long bones of arms and legs, pelvis or chest
• Pain at area of tumour
• Other signs and symptoms include: malaise, anorexia, weight loss, fever
Investigation
• A typical "onion skinning" type pattern is often seen on X-rays. This is due to bone
destruction with overlying concentric layers of new bone formation
Q-3
A 15 year old boy complains of pain in his leg which usually settles within an
hour of taking aspirin. The pain is described as a dull pain which is persistent
but is usually worse at night. What is the SINGLE most likely diagnosis?
A. Leiomyosarcoma
B. Liposarcoma
C. Chondrosarcoma
D. Exostosis
E. Osteoid osteoma
ANSWER:
Osteoid osteoma
EXPLANATION:
The key fact here is the aspirin. The fact that the bone pain responds to aspirin in such
a short time period is classic for osteoid osteoma.
Osteoid osteoma
• Benign bone tumor that develops in the long bones of the body such as the femur
and tibia
• Pain is unrelated to activity and is relieved quickly by NSAIDS
• Pain usually worse at night
• Frequently affects children and young adults
• Usually less than 1 cm in diameter
Important note to remember: Bone pain relieved well by NSAIDs is characteristic for
osteoid osteoma
Q-4
A 33 year old woman fell from playing volleyball and hit her right knee. Valgus
stress test is seen to be positive. What is the SINGLE most likely structure that is
injured?
, A. Anterior cruciate ligament
B. Posterior cruciate ligament
C. Lateral collateral ligament
D. Medial collateral ligament
E. Meniscus
ANSWER:
Medial collateral ligament
EXPLANATION:
Medial collateral ligament prevents the lateral movement of the tibia on the femur when
valgus (away from the midline) stress is placed on the knee.
The valgus stress test is performed with the hip abducted and the knee at 30° of flexion,
with one hand placed as a pivot on the knee. The other hand is placed on the foot with
an abducting force. The idea is to attempt to force the leg at the knee into valgus. The
fingers of the hand at the knee is used to feel the amount of joint-line opening that
occurs when valgus stress is applied. If the joint-line is seen to open up on the medial
side, this is indicative of a medial collateral ligament damage.
Test for knee ligament injuries
Medial collateral ligament → Valgus stress test
Lateral collateral ligament → Varus stress test
Anterior cruciate ligament → Anterior drawer test, Lachman test
Posterior cruciate ligament → Posterior drawer test
Q-5
A 2 year old girl preseents with a painless limp. On examination, there is unequal
skin folds and the left leg is shortner than the right leg. What is the SINGLE most
likely diagnosis?
A. Transient synovitis
B. Developmental dysplasia of the hip
C. Perthes’ disease
D. Juvenile idiopathic arthritis
E. Slipped capital femoral epiphysis
ANSWER:
Developmental dysplasia of the hip
EXPLANATION:
Developmental dysplasia of the hip (DDH)
• Formerly referred to as congenital dislocation of the hip (CDH). DDH is now the
preferred term to reflect that DDH is an ongoing developmental process.
• Defined simply as abnormal growth of the hip
• More common in the left hip
Risk factors
• An important risk factor to remember is vaginal delivery of babies with breech.
• 80% of cases occur in girls
, Barlow test: attempts to dislocate an articulated femoral head
Ortolani test: attempts to relocate a dislocated femoral head.
Ultrasound is used to confirm the diagnosis if clinically suspected. This is used up to
4.5 months of age because the hips remain cartilaginous up to this time. After 4.5
months, an anteroposterior pelvic radiography is more useful.
Management
• Pavlik harness in children younger than 4-6 months
• Surgery is reserved for older children
COMPARING LIMPS IN CHILDREN
The table below gives good keywords and hints that the examiners would include to
point you towards a specific diagnosis.
Developmental Perthes’ disease Slipped Upper
dysplasia of the Femoral Epiphysis
hip (DDH) (SUFE)
Age 0 to 5 years old 5 to 10 years old 10 to 15 years old
Pain Painless Chronic pain (slowly Painful
developing pain)
Risk factors Breech delivery Obese
On examination Unequal skin folds Stiffness and The affected limb
One leg shorter reduced range of will be shorter and
hip movement lies in external
rotation
Abduction is limited.
When the hip is
flexed, it will rotate
externally
Transient Juvenile idiopathic Septic arthritis
synovitis arthritis
Description Acute hip pain Arthritis occuring in Acute hip pain
associated with viral someone who is associated with
infection (most less than 16 years systemic upset
commonly an upper old that lasts for
respiratory tract more than three
infection) months
Fever Present (usually Present if systemic- Present (continuous
mild) onset JIA (fever can fever)
occur at the same
time every day with
a spontaneous rapid
return to baseline)
Features usually Pain on weight- Blanching rash Very unwell child
given in exam bearing but not at (salmon pink rash)
rest
Questions&Answers
Q-1
A 26 year old primigravida pregnant woman at 34 weeks gestation presents with
tingling and numbness with occasional pain of her right hand in addition to
altered sensation over her right middle and index finger. Tinel test is negative.
What is the SINGLE most likely diagnosis?
A. Carpal Tunnel Syndrome
B. Radial nerve entrapment
C. Scaphoid fracture
D. Median nerve entrapment
E. Peripheral arterial disease
ANSWER:
Carpal Tunnel Syndrome
EXPLANATION:
Because the stem states that Tinel test is negative, you may be tricked into choosing a
different answer but remember that the Tinel test has a very low sensitivity for carpal
tunnel syndrome. If the patient has a high suspicion of having carpal tunnel syndrome
such as the classic tingling and numbness over the median distribution of the hand as
well as being pregnant (which is a high risk factor for carpal tunnel syndrome) then you
should always choose carpal tunnel syndrome as the answer.
Pregnancy is a known risk for carpal tunnel syndrome. In pregnancy, carpal tunnel is
due to fluid retention. The best thing to do is to advise the pregnant women to wear
wrist splints until delivery as after delivery, the carpal tunnel syndrome usually resolves.
Q-2
A 15 year old boy presents with fever and pain in the right lower thigh. The pain
has been ongoing for the past one month. On examination, there is a 2 cm by 2
cm mass at the lower third of his thigh which is red, warm and tender. An X-ray
shows bone destructionwith overlying onion-skin layers of periosteal bone
formation and a soft tissue mass. What is the SINGLE most likely diagnosis?
A. Tuberculous arthritis
B. Ewing’s sarcoma
C. Osteosarcoma
D. Osteomyelitis
E. Fibrosarcoma
,ANSWER:
Ewing’s sarcoma
EXPLANATION:
Ewing’s sarcoma
• A malignant round-cell tumour of long bones (typically grows in diaphysis of long
bones) and limb girdles, usually presents in adolescents (usually 5 to 15 years old)
Presentation
• As a mass or swelling commonly in long bones of arms and legs, pelvis or chest
• Pain at area of tumour
• Other signs and symptoms include: malaise, anorexia, weight loss, fever
Investigation
• A typical "onion skinning" type pattern is often seen on X-rays. This is due to bone
destruction with overlying concentric layers of new bone formation
Q-3
A 15 year old boy complains of pain in his leg which usually settles within an
hour of taking aspirin. The pain is described as a dull pain which is persistent
but is usually worse at night. What is the SINGLE most likely diagnosis?
A. Leiomyosarcoma
B. Liposarcoma
C. Chondrosarcoma
D. Exostosis
E. Osteoid osteoma
ANSWER:
Osteoid osteoma
EXPLANATION:
The key fact here is the aspirin. The fact that the bone pain responds to aspirin in such
a short time period is classic for osteoid osteoma.
Osteoid osteoma
• Benign bone tumor that develops in the long bones of the body such as the femur
and tibia
• Pain is unrelated to activity and is relieved quickly by NSAIDS
• Pain usually worse at night
• Frequently affects children and young adults
• Usually less than 1 cm in diameter
Important note to remember: Bone pain relieved well by NSAIDs is characteristic for
osteoid osteoma
Q-4
A 33 year old woman fell from playing volleyball and hit her right knee. Valgus
stress test is seen to be positive. What is the SINGLE most likely structure that is
injured?
, A. Anterior cruciate ligament
B. Posterior cruciate ligament
C. Lateral collateral ligament
D. Medial collateral ligament
E. Meniscus
ANSWER:
Medial collateral ligament
EXPLANATION:
Medial collateral ligament prevents the lateral movement of the tibia on the femur when
valgus (away from the midline) stress is placed on the knee.
The valgus stress test is performed with the hip abducted and the knee at 30° of flexion,
with one hand placed as a pivot on the knee. The other hand is placed on the foot with
an abducting force. The idea is to attempt to force the leg at the knee into valgus. The
fingers of the hand at the knee is used to feel the amount of joint-line opening that
occurs when valgus stress is applied. If the joint-line is seen to open up on the medial
side, this is indicative of a medial collateral ligament damage.
Test for knee ligament injuries
Medial collateral ligament → Valgus stress test
Lateral collateral ligament → Varus stress test
Anterior cruciate ligament → Anterior drawer test, Lachman test
Posterior cruciate ligament → Posterior drawer test
Q-5
A 2 year old girl preseents with a painless limp. On examination, there is unequal
skin folds and the left leg is shortner than the right leg. What is the SINGLE most
likely diagnosis?
A. Transient synovitis
B. Developmental dysplasia of the hip
C. Perthes’ disease
D. Juvenile idiopathic arthritis
E. Slipped capital femoral epiphysis
ANSWER:
Developmental dysplasia of the hip
EXPLANATION:
Developmental dysplasia of the hip (DDH)
• Formerly referred to as congenital dislocation of the hip (CDH). DDH is now the
preferred term to reflect that DDH is an ongoing developmental process.
• Defined simply as abnormal growth of the hip
• More common in the left hip
Risk factors
• An important risk factor to remember is vaginal delivery of babies with breech.
• 80% of cases occur in girls
, Barlow test: attempts to dislocate an articulated femoral head
Ortolani test: attempts to relocate a dislocated femoral head.
Ultrasound is used to confirm the diagnosis if clinically suspected. This is used up to
4.5 months of age because the hips remain cartilaginous up to this time. After 4.5
months, an anteroposterior pelvic radiography is more useful.
Management
• Pavlik harness in children younger than 4-6 months
• Surgery is reserved for older children
COMPARING LIMPS IN CHILDREN
The table below gives good keywords and hints that the examiners would include to
point you towards a specific diagnosis.
Developmental Perthes’ disease Slipped Upper
dysplasia of the Femoral Epiphysis
hip (DDH) (SUFE)
Age 0 to 5 years old 5 to 10 years old 10 to 15 years old
Pain Painless Chronic pain (slowly Painful
developing pain)
Risk factors Breech delivery Obese
On examination Unequal skin folds Stiffness and The affected limb
One leg shorter reduced range of will be shorter and
hip movement lies in external
rotation
Abduction is limited.
When the hip is
flexed, it will rotate
externally
Transient Juvenile idiopathic Septic arthritis
synovitis arthritis
Description Acute hip pain Arthritis occuring in Acute hip pain
associated with viral someone who is associated with
infection (most less than 16 years systemic upset
commonly an upper old that lasts for
respiratory tract more than three
infection) months
Fever Present (usually Present if systemic- Present (continuous
mild) onset JIA (fever can fever)
occur at the same
time every day with
a spontaneous rapid
return to baseline)
Features usually Pain on weight- Blanching rash Very unwell child
given in exam bearing but not at (salmon pink rash)
rest
