|
| |
| * ortho 10, very good explanation to look for |
| | #531104 |
|
| |
| |
| |
An 18-year-old female gymnast lands her dismount
from the balance beam awkwardly. She reports the
knee buckling, hearing a pop and experiencing immediate
right knee pain. She presents to your office
45 minutes after the injury. She is able to bear some
weight on the leg but reports it is already swollen and
feels loose. On exam there is a knee effusion present.
The MOST likely isolated injury experienced by
this athlete is:
A) Medial meniscus tear.
B) Medial collateral ligament (MCL) sprain.
C) Distal quadriceps/patellar tendon rupture.
D) Anterior cruciate ligament (ACL) rupture.
E) None of the above.
The best test to confirm the diagnosis of the
above injury would be:
A) Plain film radiographs.
B) McMurray test.
C) Lachman test.
D) Anterior drawer test.
E) None of the above can confirm this diagnosis
independently. |
|
| Report Abuse |
|
| * Re:ortho 10, very good explanation to look for |
| #2187770 |
| |
| |
Discussion
The correct answer is D. Did the patient or someone
else hear a pop? If yes, suspect ACL tear (80%), meniscal
injury (15%), and rarely a fracture. When did you
notice swelling? If 0–12 hours after the injury, suspect
ACL tear or patellar dislocation/subluxation; if 12–24
hours, suspect meniscal injury. If there is hemarthrosis
on aspiration, suspect ACL injury (>75%), patellar subluxation,
or intraarticular fracture. A history of “My
knee gives way; buckles; feels loose; or comes apart”
may be secondary to patellar subluxation/dislocation,
ACL deficiency, or arthritis. Collateral ligament injuries,
MCL, or lateral collateral ligament (LCL) do not typically
present with significant effusion and typically feel
stable with forward ambulation but are painful with sideto-
side movements. Muscle or tendon rupture may
cause buckling, but will not typically cause effusion and
will generally have an obvious deformity and inability to
bear weight.
Discussion
The correct answer is C. In the hands of an experienced
clinician, the Lachman test is the most sensitive
test for ACL insufficiency (80%–95%). The anterior
drawer sign is negative in about 50% of acute ACL
tears, and often is negative subacutely. McMurray test is
used to evaluate for a meniscal tear. Plain films should
be obtained for all patients with acute knee injury with
effusion or suspected ACL tear. However, x-rays are
rarely positive for more than effusion or Segond fracture
(avulsion of the lateral joint capsule from the tibia).
Although an MRI may be considered a gold standard
test, its sensitivity has been reported as 97% when compared
with arthroscopy findings, and is positive in only
82% in cases of complete rupture. An orthopedic consult
is generally indicated if ACL injury is suspected,
and obtaining one is less expensive than MRI. |
|
| Report Abuse |
|
|
|
