I was taught—and still believe—that obtaining a thorough history can direct you to a good working diagnosis. About 20 years ago, while in the Navy, I had a patient who showed me that I should not be fooled by a history that does not fit the current presentation.
The patient was a 34-year-old sailor with right-side knee pain, occurring intermittently for a long time but worsening in recent months. The pain did not prevent him from running, performing in the Navy’s semi-annual fitness test, or participating in departmental physical fitness activities.
However, his pain worsened after he was assigned to a ship, which required him to ascend and descend the steep shipboard stairs or ladders. He also complained of some intermittent buckling or “giving out.” But he was quite clear when he stated that he had sustained no recent injury to explain his condition.
His history was notable for an injury he sustained six years earlier, while running. Although he could not remember the exact mechanism of injury, he recalled that his knee hurt and was swollen the next day. He was seen in medical, where he was given crutches, modified duty, and ibuprofen for a few days. After a relatively short time, his activity returned to normal.
I had seen a lot of knee pain on board ship, mostly of the patellar tendonitis or patellofemoral syndrome types, that could often be treated conservatively with temporary duty modification to avoid aggravating activity. More serious injuries—such as meniscal, collateral, or cruciate ligament tears—were associated with recent or acute injuries and a history including a suspicious mechanism of injury.
This patient’s complete knee exam was largely unremarkable, except his anterior drawer test seemed to have no distinct endpoint. When I compared the results with his asymptomatic left knee, I could not appreciate any difference.
So I relayed to him my thought process: If he had done something serious to his knee six years ago, it probably would have manifested sooner. As other clinicians did previously, I treated him conservatively with duty limitations and advised him that if he failed to improve soon, I would refer him to an orthopedist for a second opinion.
Well, he did not improve soon. Since he was still concerned, I provided the referral, without obtaining an MRI.
To perhaps everyone’s surprise—but most definitely mine—the patient was diagnosed with a complete ACL tear by the orthopedist (again, without MRI). He was scheduled for surgery at a later date.
What surprised me most was that someone could perform the way he was required to perform in the Navy for six years with a torn ACL. As a result of this case, I have not let a remote history of injury cloud my judgment since!