Finding the right tests…
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Emergency services available 24 x 7
Finding the right tests…
CT Scan
CT of the knee is built around bone, not the ligaments and cartilage that an MRI shows best - it's the scan doctors reach for when a knee fracture is complex, such as one involving the joint surface itself, and the exact pattern of broken bone needs to be mapped before surgery. It's also used to plan knee replacement, where precise bone measurements guide implant sizing. The scan takes X-ray images from multiple angles around the knee and reconstructs them into detailed cross-sections, and often a 3D model of the bone. Unlike MRI, it won't show a torn ligament or meniscus clearly, so your doctor picks CT specifically when bone detail, not soft tissue, is the priority.
This scan focuses on the bones of your knee - the femur, tibia, and patella - and how a fracture runs through them. It's used to map complex breaks and to plan knee surgery. Your doctor combines these images with your exam findings, and may add an MRI separately if soft tissue also needs checking.
CT builds high-resolution 3D images of bone by taking advantage of how strongly bone absorbs X-rays compared with surrounding tissue. That makes it the more reliable choice for mapping a complex knee fracture, particularly one involving the joint surface, like a tibial plateau fracture, where the exact pattern of broken bone changes how a surgeon operates.
CT has limited ability to show ligaments, tendons, or cartilage. If your doctor needs to check the ACL, meniscus, or cartilage surfaces, an MRI is the better test - the two are often used together in complex knee trauma, one for bone and one for soft tissue.
- A fracture where the joint surface itself may be involved - Planning before knee replacement or complex fracture surgery - A fracture already seen on X-ray that needs more detail - Checking bone healing after surgery
Ask your doctor whether this scan alone is enough for your situation, or whether an MRI is needed alongside it.
CT is built for bone detail, so it's the better choice for mapping a complex fracture. MRI shows ligaments, cartilage, and the meniscus far more clearly, so your doctor picks whichever - or both - fits what's being checked.
Not reliably. CT has limited ability to show soft tissue like ligaments and cartilage, so an MRI is the test used for those injuries.
Detailed bone measurements from CT help a surgeon size and position the implant accurately, which matters more in complex or unusual knee anatomy.
Yes, it uses X-rays. Your doctor weighs the radiation against how much detail is needed for your fracture or surgical planning.
This page is general information about the test, not medical advice. Your own report's reference ranges apply — please discuss your results with your doctor.
The scan itself is quick, usually just a few minutes on the table. Ask the centre for a more exact estimate for your appointment.
Not usually for a fracture or bone-planning scan. Contrast is only added if your doctor has a specific reason to request it.
Preparation is generally minimal, mainly removing metal jewelry near the knee. Ask your doctor or the centre about anything specific to your case.
No, X-ray usually comes first. CT is used when more bone detail is needed than a plain X-ray provides, such as for a complex fracture.