From the Guidelines
The management of an occult fracture of the knee should prioritize CT imaging as the next step after negative radiographs, given its superiority in detecting and characterizing fractures, as well as its ability to predict ligamentous and meniscal injuries 1. When managing an occult knee fracture, several key considerations must be taken into account to ensure the best possible outcome in terms of morbidity, mortality, and quality of life.
- Initially, patients should be advised to follow a regimen of rest, pain control, and appropriate weight-bearing restrictions, typically partial weight-bearing with crutches for 2-4 weeks.
- Pain management is crucial and can be achieved using NSAIDs such as ibuprofen (400-600mg three times daily) or naproxen (500mg twice daily) 1.
- The application of ice for 15-20 minutes every 2-3 hours during the first 48-72 hours can help reduce swelling and pain.
- A knee immobilizer or hinged brace may be used for stability and comfort, aiding in the healing process and reducing the risk of further injury.
- Follow-up imaging is critical, with CT recommended as the next imaging study after negative radiographs, due to its ability to detect occult fractures and predict ligamentous and meniscal injuries 1.
- If CT is not available or feasible, an MRI may be considered within 1-2 weeks if clinical suspicion remains high, as it is superior in evaluating bone marrow lesions, meniscal, and ligamentous injuries 1.
- Alternatively, a repeat X-ray in 10-14 days may reveal a previously invisible fracture as bone resorption occurs at the fracture site.
- Once pain allows, physical therapy should commence, focusing on gentle range of motion exercises and gradually progressing to strengthening, to prevent long-term joint problems and ensure optimal recovery. The choice of imaging and treatment approach should be guided by the most recent and highest quality evidence, prioritizing patient outcomes in terms of morbidity, mortality, and quality of life 1.
From the Research
Management of Occult Fracture of the Knee
The management of an occult fracture of the knee involves several steps, including diagnosis and treatment.
- Diagnosis: The diagnosis of an occult fracture of the knee can be made using various imaging modalities, including tomography 2, MRI 3, 4, and CT scan 3, 5, 6.
- Imaging modalities:
- Tomography: Tomography can be used to define the location and extent of the fracture 2.
- MRI: MRI has been shown to be highly sensitive and specific in diagnosing occult fractures of the knee, particularly those associated with meniscus and ligament injury 3, 4. It is also useful in detecting bone marrow edema and articular surface injury 3.
- CT scan: CT scan can be used to diagnose occult fractures, but it may not be as sensitive as MRI, particularly in the first 24 hours after injury 5, 6.
- Treatment: The treatment of an occult fracture of the knee depends on the severity of the fracture and the presence of associated injuries, such as meniscus and ligament tears.
- Associated injuries:
- Meniscus and ligament injury: The presence of meniscus and ligament injury can affect the treatment of the occult fracture, and MRI can be useful in detecting these injuries 3, 4.
- Bone marrow edema and articular surface injury: The presence of bone marrow edema and articular surface injury can also affect the treatment of the occult fracture, and MRI can be useful in detecting these injuries 3.