Orthopedic Teaching Cases 2023, Jan, 17 | 12:00 am

2 Sports Medicine CASES

CASE                                2                               

An 18-year-old soccer player injures her knee during competition. She reports her knee buckled when stepping to kick the ball. She fell to the ground after hearing a pop and was unable to stand on her right leg. Since then, she has been able to bear some weight, but she does not trust her leg.

On examination, she has a large swollen knee.

 

The MOST likely isolated injury experienced by this athlete is:

  1. Anterior cruciate ligament (ACL) rupture

  2. Medial meniscus tear

  3. Medial collateral ligament (MCL) sprain

  4. Quadriceps tendon rupture

 

Discussion

The correct answer is (A). Following this noncontact soccer injury, the athlete has a sense of instability and a large swollen knee which is most consistent with an ACL rupture. Although acute meniscal tears can result in large effusions, typically they present as mechanical symptoms such as catching and locking. Collateral ligament injuries do not typically present with swelling. Commonly, these injuries feel stable when moving straight ahead but are painful with side-to-side movements. A quadriceps rupture is uncommon in a young, healthy athlete and would result in an inability to stand or extend the knee.

In the acutely injured knee, the best test to confirm the diagnosis would be:

  1. X-rays

  2. McMurray test

  3. Lachman test

  4. Pivot shift test

  5. Grind test

 

Discussion

The correct answer is (C). The most useful diagnostic test for an acute ACL rupture is the Lachman test. It is the most sensitive test for ACL insufficiency (80–95%). Radiographs can be helpful in affirming that there is no bony injury. The McMurray test is an assessment of meniscal pathology. The pivot shift test is pathognomonic for ACL tears but is best suited for a chronic injury. The grind test is a measure of

patellofemoral pain.

 

The primary blood supply to the ACL is the:

  1. Lateral superior geniculate artery

  2. Descending geniculate artery

  3. Middle geniculate artery

  4. Recurrent anterior tibial artery

 

Discussion

The correct answer is (C). The middle geniculate artery provides the primary blood to the ACL.

Which of the following vessels is a branch of the femoral artery?

  1. The descending geniculate artery

  2. The superior geniculate arteries

  3. The inferior geniculate arteries

  4. The middle geniculate artery

 

Discussion

The correct answer is (A). The descending geniculate artery is a branch of the femoral artery.

An MRI of the injured knee shows a characteristic pattern of bony edema following this injury. Where would you typically see the bone bruising in this athlete?

  1. Anterior lateral femoral condyle and anterior medial tibial plateau

  2. Posterior lateral femoral condyle and anterior lateral tibial plateau

  3. Anterior medial femoral condyle and posterior lateral tibial plateau

  4. Anterior medial femoral condyle and posterior medial tibial plateau

  5. Anterior lateral femoral condyle and posterior lateral tibial plateau

 

Discussion

The correct answer is (E). MRI of an ACL tear is shown in Figure 9–2A. The ACL rupture results in a sudden translation of the tibia anterior relative to the femur, resulting in a transchondral fracture (bone bruise) of the anterior lateral femoral condyle and the posterior lateral tibial plateau (Fig. 9–2B).

 

 

Figure 9–2 A–B

 

Initial treatment of this athlete should include all of the following EXCEPT:

  1. Quadriceps strengthening

  2. Hamstring strengthening

  3. Proprioceptive training

  4. Lateral movement drills

  5. Effusion control

 

Discussion

The correct answer is (D). Lateral movements, like planting, cutting, and pivoting are contraindicated in patients with ACL ruptures and can result in recurrent instability and/or additional injury.

If she elects to treat her injury without surgery, which activities are appropriate?

  1. Running

  2. Biking

  3. Rowing

  4. Swimming

  5. All of the above

 

Discussion

The correct answer is (E). Individuals with ACL- deficient knees have very good outcomes with nonsurgical treatment if they can avoid cutting and pivoting movements. Activity modification should include any sport that does not put them at risk.

 

Objectives: Did you learn...?

 

The diagnosis of an acute knee injury?

 

 

To understand the presentation of an ACL rupture? To anticipate the relevant findings on MRI?

 

The role of nonoperative treatment in ACL injuries?