Study Design: Resident’s case problem.
Background: A 21-year-old healthy athletic male military cadet with complaint of worsening diffuse left knee pain was evaluated 4 days after onset. The knee pain began 2 hours after completing a long car trip, worsened over the subsequent 3 days, and became almost unbearable during the return trip. The patient reported constant pain, limited knee motion, and difficulty ambulating. In addition, he was unable to perform physical military training or attend academic classes due to the severe left knee pain. Past medical history revealed a mild left lateral calf strain 21⁄2 weeks prior, which completely resolved within 24 hours of onset.
Diagnosis: Our physical examination led us to either monoarticular arthritis, pseudothrombophlebitis (ruptured Baker’s cyst), or a lower leg deep vein thrombosis (DVT) as the cause of knee pain. Diagnostic imaging of this patient revealed a left superficial femoral vein thrombosis and popliteal DVT, with bilateral pulmonary emboli (PE).
Discussion: A systematic differential diagnosis was undertaken to rule out a potentially fatal DVT diagnosis as the cause of knee pain, despite minimal DVT risk factors. The physical therapist in a direct-access setting must ensure timely evaluation and referral of a suspected DVT, even when patient demographics cause the practitioner to question the likelihood of this diagnosis. The physical examination findings, clinical suspicion, and established clinical prediction rules can accurately dictate the appropriate referral action necessary.
J Orthop Sports Phys Ther. 2006;36(9):686-697. doi:10.2519/jospt.2006.2251
Key Words: blood, pulmonary embolism, screening