A 22-year-old athlete experienced the sudden onset of right knee pain 2 weeks ago, when his right heel was planted while the rest of his body twisted to the left. The patient heard a loud pop and fell to the ground. The pain was excruciating and localized to the posterolateral aspect of the proximal tibia. The patient was initially unable to stand without assistance. The patient had no past history of knee pain or problems and his past medical and surgical history was unremarkable.
Even given this brief history, could you make a working hypothesis at this stage?
The history would indicate some form of ligamentous damage to the knee, most likely the anterior cruciate ligament at the very least.
What is your differential diagnosis?
Given the mechanism of injury the differential diagnoses could include a muscle tear, a tear of the meniscus, or an avulsion fracture.
What tests and measures do you plan to use during the physical examination?
The most useful tests in this instance would be the stability tests of the knee to assess the integrity of the ligaments.
The physical examination revealed the following findings at the right knee:
- Positive Lachman test.
- Positive pivot-shift test.
- Positive anterior drawer test.
- Negative reverse pivot-shift, McMurray, Apley, and Slocum tests.
- Negative varus and valgus stress tests.
- The strength examination revealed overall strength of involved knee to be at 3+/5, although results may have been affected by pain.
- ROM of the involved knee was grossly limited to the flexed open-packed position for the knee. The patient was unable to achieve terminal extension. Muscle lengths were not assessed secondary to pain.
Following the physical examination, has your working hypothesis changed?
Using the information from the history and the tests and measures, it is very likely that this patient has sustained a tear of the anterior cruciate ligament of the right knee.
What is your planned course of action?
Because the patient is an athlete, it is likely that he will choose to undergo a surgical reconstruction of the anterior crucial ligament and will therefore need a referral to an orthopedic surgeon.
Describe the intrinsic and extrinsic factors that can make an individual more vulnerable to an ACL tear.
In which age group you ACL injuries more commonly occur?
Are male or female athletes more prone to ACL tears?
Describe the typical mechanism of injury that results in an ACL ...