Comprehensive Clinical Case Study in
Musculoskeletal Medicine- Evaluation and
Management of Acute K Newest Exam Preparation
With Complete Questions And Correct Answers With
Rationales Already Graded A+Brand New Version!!
1. What is the most likely diagnosis based on the patient's history and
physical examination findings?
A) Medial collateral ligament sprain
B) Lateral meniscus tear
C) Anterior cruciate ligament tear
D) Patellar dislocation
Answer: C) Anterior cruciate ligament tear
Explanation: The patient's history of a non-contact pivot injury with an
audible "pop," immediate pain, significant swelling (hemarthrosis), and
the sensation of instability are classic for an ACL tear. The positive
Lachman and anterior drawer tests are highly specific for ACL
insufficiency.
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2. The Lachman test is considered the most sensitive and specific test
for ACL integrity. A "soft endpoint" on the Lachman test indicates
what?
A) The ACL is intact and taut
B) The ACL is completely ruptured
C) The posterior cruciate ligament is injured
D) There is a meniscal tear
Answer: B) The ACL is completely ruptured
Explanation: A firm endpoint indicates the ligament is intact and stops
the translation of the tibia on the femur. A soft or absent endpoint,
where the tibia translates forward without a distinct stop, indicates a
complete tear of the ACL.
3. The anterior drawer test is performed with the patient's knee flexed
to what approximate angle?
A) 30 degrees
B) 45 degrees
C) 90 degrees
D) 120 degrees
Answer: C) 90 degrees
Explanation: The anterior drawer test is performed with the knee flexed
to approximately 90 degrees. This position relaxes the hamstrings and
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allows the examiner to assess anterior translation of the tibia relative to
the femur.
4. What is the most common mechanism of injury for an ACL tear?
A) A direct blow to the lateral knee
B) A non-contact deceleration or pivot maneuver
C) A hyperextension injury with a direct blow to the anterior tibia
D) A forced varus stress to the knee
Answer: B) A non-contact deceleration or pivot maneuver
Explanation: Most ACL injuries are non-contact and occur during sudden
deceleration, pivoting, or landing from a jump with the knee near full
extension. This mechanism places significant stress on the ACL, leading
to rupture.
5. The presence of a large knee effusion within a few hours of the injury
is highly suggestive of:
A) A simple muscle strain
B) A chronic degenerative condition
C) A ligamentous or intra-articular injury causing hemarthrosis
D) A patellofemoral tracking disorder
Answer: C) A ligamentous or intra-articular injury causing hemarthrosis
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Explanation: Rapid onset of a large effusion (hemarthrosis) within 2-4
hours of injury indicates bleeding into the joint, which is typical of an
ACL tear or other intra-articular injuries such as an osteochondral
fracture.
6. Which of the following physical examination tests is used to assess
the integrity of the posterior cruciate ligament?
A) Lachman test
B) Anterior drawer test
C) Posterior drawer test
D) McMurray's test
Answer: C) Posterior drawer test
Explanation: The posterior drawer test assesses the PCL by evaluating
posterior translation of the tibia relative to the femur at 90 degrees of
flexion. A positive test indicates PCL insufficiency.
7. In the setting of an acute ACL tear, which associated injury is most
commonly found?
A) Medial collateral ligament sprain
B) Lateral collateral ligament sprain
C) Meniscal tear
D) Patellar tendon rupture