From the Guidelines
Clinical signs of a knee fracture include pain, swelling, bruising, deformity, inability to bear weight, limited range of motion, and audible sounds during the injury, and anyone experiencing these symptoms after knee trauma should seek immediate medical attention for proper diagnosis through physical examination and imaging studies. These signs occur because fractures disrupt the structural integrity of the bone, causing pain receptors to activate and triggering inflammatory responses 1.
Key Clinical Signs
- Pain, typically severe and worsening with movement or weight-bearing
- Swelling, developing rapidly due to bleeding and inflammation around the fracture site
- Bruising, appearing hours to days after the injury as blood from the fracture tracks through tissues
- Visible deformity, present if bone fragments are displaced
- Inability to walk or put weight on the affected leg
- Restricted and painful movement of the knee joint
- Audible sounds during the injury, such as a crack or pop
- Tenderness to touch over the fracture site
- Muscle spasms around the knee
- Signs of neurovascular compromise, such as numbness, tingling, or decreased pulses below the injury, in severe cases 1
Importance of Medical Attention
It is crucial to seek immediate medical attention if these symptoms are present, as prompt and accurate diagnosis facilitates adequate management and may prevent potential complications 1. Radiographs are usually the initial imaging modality in the evaluation of the acutely injured knee, and adequate clinical examination and appropriate application of established decision-making rules can reduce the number of radiographic studies, with a potential benefit of reducing healthcare costs and decreasing radiation exposure to the patient 1.
From the Research
Clinical Signs of a Knee Fracture
The clinical signs of a knee fracture can be determined through a detailed history of the mechanism of injury and symptoms, as well as a physical examination 2. Some key signs to look out for include:
- Pain and swelling around the knee
- Limited mobility or stiffness in the knee
- Instability or giving way of the knee
- Deformity or abnormal appearance of the knee
- Difficulty bearing weight on the affected leg
Diagnosis Without X-ray
While X-rays are often used to confirm a knee fracture, they are not always necessary for diagnosis. A physical examination can provide valuable information about the extent of the injury 2. Additionally, other imaging modalities such as arthroscopy or magnetic resonance imaging (MRI) may be used to evaluate the extent of displacement or confirm soft-tissue injuries 3, 4.
Commonly Missed Injuries
Some fractures and musculotendinous and ligamentous injuries around the knee can be subtle and difficult to detect, even with optimal imaging 3. These include:
- Tibial plateau fractures
- Segond fractures
- Stress fractures
- Fibular head fractures and dislocations
- Injuries to the patella and extensor mechanism
- Salter type fractures
Importance of Clinical Suspicion
Clinical suspicion is crucial in diagnosing knee fractures and other injuries, particularly those that may not be immediately apparent on imaging 3, 5. A high index of suspicion should be maintained, especially in cases of high-energy injuries or femoral shaft fractures, which are associated with a high incidence of serious ligamentous, meniscal, and chondral injury 5.