The Emergency Room (ER) manages knee pain by addressing acute injuries or conditions that threaten the limb or the patient’s overall health. This setting is designed for rapid diagnosis and stabilization, not for the ongoing management of chronic knee issues like long-standing arthritis. Patients are typically directed to the ER for severe symptoms such as a visible deformity, the inability to bear any weight on the leg, sudden and significant swelling, or intense pain that is unmanageable at home. The goal of the ER visit is to quickly identify and treat fractures, dislocations, or potential infections, ensuring the patient is stable before arranging long-term specialized care.
Initial Assessment and Triage
The patient’s journey begins with triage, a swift evaluation to determine the urgency of the condition and prioritize care. Nurses and physicians assess vital signs and the chief complaint to screen for immediate threats, such as septic arthritis, which presents with fever and a warm, severely painful joint. A detailed patient history is taken, focusing on the mechanism of injury, such as the direction of force or a reported “pop” sound, which can point toward ligament damage.
A physical examination is performed to localize the injury and assess the integrity of the knee’s structures. This includes careful palpation to find areas of bony tenderness, a check of the active and passive range of motion, and a thorough neurovascular assessment. The provider checks for intact distal pulses and sensation in the foot and lower leg to rule out compromise to blood vessels or nerves. The examination also involves applying specific clinical decision rules, such as the Ottawa Knee Rules, to determine whether imaging is necessary.
Diagnostic Imaging and Testing
The primary tool for diagnosing acute knee trauma is the plain film X-ray, which provides immediate images of the bone structure. X-rays are used to identify fractures of the femur, tibia, or patella, as well as joint dislocations. While effective for bony injury, X-rays do not visualize soft tissues like ligaments, tendons, or menisci, which require other methods.
If infection is suspected, the physician may order blood tests, including a complete blood count and inflammatory markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). In some cases, a joint aspiration (arthrocentesis) is performed to collect synovial fluid directly from the knee joint. This fluid is then analyzed for white blood cell count, glucose, and culture to confirm or rule out an infection or crystalline arthropathy, such as gout.
Advanced imaging like Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scans are rarely performed during the initial ER visit. The MRI, which offers detailed views of soft tissues, is typically reserved for outpatient follow-up with an orthopedist to diagnose ligament or meniscus tears. A CT scan may be used to better define complex fractures involving the joint surface, particularly tibial plateau fractures, when planning for immediate surgical intervention.
Immediate Pain Management and Stabilization
Providing immediate relief and preventing further injury is a core component of the ER visit. Pain management typically begins with non-steroidal anti-inflammatory drugs (NSAIDs), which reduce both pain and inflammation. For severe pain, short-acting opioid medications may be administered, using the lowest effective dose necessary to manage acute discomfort.
Stabilization is achieved through immobilization of the joint, often using a knee immobilizer or a splint to hold the leg straight. This prevents movement that could exacerbate a fracture or ligament tear. Patients are provided with crutches and instructed on non-weight bearing or protected weight bearing to minimize stress on the injured joint.
For specific injuries, the ER may perform an active procedure, such as a closed reduction. This involves manually guiding a dislocated joint, like a kneecap or the entire knee joint, back into alignment. Following a reduction, the neurovascular status is immediately re-checked, and the limb is immobilized to maintain stability.
Discharge Instructions and Next Steps
The ER visit concludes with comprehensive discharge instructions guiding the patient’s recovery until they can see a specialist. Patients are given prescriptions, which may include pain medication or antibiotics if an infection was treated or suspected. The standard home care advice often includes the R.I.C.E. protocol to help reduce swelling and pain:
- Rest
- Ice
- Compression
- Elevation
Specific instructions detail weight-bearing limits, advising the patient on how to use crutches and how long to keep the knee immobilized. A follow-up plan is provided, emphasizing the need to schedule an appointment with an orthopedic specialist or a primary care physician for definitive diagnosis and treatment. Patients are also educated on specific “red flags” that require an immediate return to the emergency department, such as a high fever, loss of sensation or inability to move the foot, or uncontrolled pain despite medication.