Written from the perspective of an emergency physician who also runs a weekly minor fracture clinic, this column is intended to highlight a few key ED teaching points for commonly missed and commonly mismanaged ED orthopedic cases.
Most ED patients with a negative knee X-ray will have a soft tissue injury (STI). However, scattered among those STIs are many commonly missed diagnoses. There can be an operative STI (eg, a quadriceps or patellar tendon rupture), a septic knee, a limb-threatening spontaneously reduced knee dislocation (rarely), or an occult fracture. In this article, we focus on diagnostic strategies for occult fractures in the ED.
From a diagnostic point of view, we must appreciate that while X-rays are good tests, they are not perfect. It is well-recognized that 20 to 30 percent of scaphoid fractures are radiographically occult.1,2 For fractures around the knee, the sensitivity of knee X-rays is around 85 percent.3,4 Though not specifically studied, the sensitivity of plain radiographs for detecting fractures in ED patients with musculoskeletal injuries is estimated at 90 to 95 percent.
Here are four cases from our hospital. All four patients had an occult fracture.
A 12-year-old boy fell on his shoulder. The physical exam showed a tender, swollen mid-clavicle. X-rays were negative, and he was diagnosed with a probable STI of the clavicle. Treatment: a sling and follow-up in the minor fracture clinic.
A 13-year-old girl twisted her ankle. Her physical exam showed an antalgic gait and a sore and swollen ankle. X-rays were negative. She was diagnosed with a Salter-Harris I distal fibula versus ankle sprain. Treatment: a splint and follow-up in the minor fracture clinic.
A 69-year-old woman fell on her outstretched hand. Her physical exam revealed a tender, swollen distal radius. X-rays were negative, and she was diagnosed with a probable STI wrist. Treatment: a splint and follow-up in the minor fracture clinic.
A 72-year-old woman twisted her knee. Her physical exam revealed an antalgic gait and a tender, swollen knee. X-rays were negative, and she was diagnosed with a medial collateral ligament injury. Treatment: A splint and follow-up in the minor fracture clinic.
In the emergency department, X-rays are often used as diagnostic tools, but it’s better to think of X-rays as fracture management tools. In simple terms, a fracture can occur in one of two ways. Fractures can occur via abnormal force on normal bone. For example, a 25-year-old man falls off a roof and suffers a comminuted fracture of his distal radius.