Wrist pain after a fall – this is what an MRI scan can show

After a fall, it is common for the wrist to be X-rayed immediately when seeking care. Many times, the information may be that no fracture is visible but the pain experienced persists, for example when you lean on something, open a lid or carry a grocery bag. Then the next question is: if the X-ray is normal, what is actually hurting?

Wrist pain after a fall - what can be seen with an MRI when the X-ray was normal?

A regular X-ray is good for detecting many skeletal injuries, but it does not catch everything. Especially early after a fall, small fractures, bone damage without a clear crack and soft tissue injuries can be difficult to see. When the doctor still suspects an injury despite normal or unclear X-rays, further investigation is recommended with MRI of the wrist or sometimes even CT.

MRI, or magnetic resonance imaging, is particularly valuable because it can show both the skeleton and soft tissues. The examination can also detect occult fractures – fractures that are not visible on regular X-rays – but also damage to ligaments, cartilage, tendon sheaths and bone marrow.

When a normal X-ray is not enough

The fact that the X-rays are normal does not automatically mean that the wrist is uninjured. If pain persists, further investigation is needed to determine the underlying cause. Here are some examples:

• If you have clear tenderness in the so-called anatomical snuffbox at the base of the thumb, swelling and pain when straining, suspicion of a navicular fracture is often raised even when the X-ray does not show any definite findings.
• If tenderness over the distal radius, i.e. the radius of the forearm near the wrist, this may also be due to a navicular fracture. It may be that the fracture was hidden on the initial X-ray. MRI can then show both an actual fracture and bone marrow edema, i.e. swelling inside the bone that indicates a fresh injury.

An MRI is often performed to determine whether there is an injury that requires other treatment than just rest and time. This may involve the need for a cast, orthosis, referral to a hand surgeon or clearer activity restrictions.

MRI can find hidden fractures in the small bones of the wrist

The classic example of fractures in the small bones of the wrist is a fracture of the scaphoid, or navicular bone. It is a small bone on the thumb side of the wrist that is often injured when reaching with an outstretched hand in a fall, for example. It is important not to miss such a fracture, since the blood supply to parts of the bone is relatively sensitive and a delayed diagnosis can increase the risk of non-healing and later osteoarthritis.

MRI can show more than just the navicular bone. Other carpal bones, such as the triquetrum, capitate or hamate, can also be damaged without these appearing clearly on X-ray. In addition, an MRI examination can reveal an occult fracture in the distal radius. If the pain remains in the same clear location, especially on the thumb or little finger side, there is good reason to continue with an investigation.

MRI can show damage to the ligaments and cartilage in the wrist

After a fall, the ligaments and cartilage of the wrist can also be damaged. This can cause pain, swelling, clicking sounds or the feeling that the wrist is unstable, even though a regular X-ray looks normal.

A ligament that is often damaged is located in the middle of the wrist, between two small bones on the thumb side. It is called the scapholunate ligament and helps to hold the bones in place. An injury can hurt when you grab something, lean on your hand or, for example, do a push-up.

TFCC, Triangular FibroCartilage Complex, is an area of ​​cartilage and ligaments on the little finger side of the wrist. It works somewhat like a shock absorber and helps to stabilize the wrist. A TFCC injury can hurt when you twist your forearm, carry something heavy, or stand up with the support of your hand.

MRI can then help detect such injuries and also show problems with tendons or other signs of a more severe sprain. Sometimes more tests are needed to determine the injury.

What do findings such as bone marrow edema, bone bruise, and partial injury mean?

It is common for questions to arise when reading the radiologist's report on the MRI scan, which is often filled with difficult words and concepts that you have not previously learned. Here are two explanations:

• Bone marrow edema:It means that there is fluid-rich swelling inside the bone, often as a sign of a recent strain or impact injury. It can be equivalent to a skeletal contusion, sometimes called a bone bruise, and does not necessarily mean that the bone is broken completely.
• Partial ligament injury: This means that some of the ligament fibers are damaged, but not the entire structure. Such injuries can hurt for a long time and sometimes require relief, orthosis and targeted rehabilitation, but they do not always require surgery. How serious the finding is depends on which fibers are damaged, whether the joint has become unstable and what your symptoms look like.

Sometimes an MRI shows no fracture and no clearly torn ligament, but instead swelling in the soft tissues. This can still explain the pain and provide support for continued recovery with gradual loading. A normal or near-normal MRI response can also be valuable, as it reduces the suspicion of an injury that is at risk of worsening if you start using your hand again.

When should you proceed with an MRI for wrist pain after a fall?

MRI of the wrist is not necessary for everyone who has pain after a fall. Many sprains and minor soft tissue injuries heal with time, rest, and gradual return to activity. But some patterns indicate that further investigation is needed, especially if the first X-ray was normal.

This applies, for example, if you have:

• clear pinpoint tenderness at the base of the thumb or over a small area of ​​the wrist
• persistent pain after a few days despite relief
• swelling and pain when you put weight on your hand
• reduced grip strength or a feeling that the wrist is "giving way"
• pain on the little finger side when twisting or lifting

If a navicular fracture is suspected, guidelines recommend early MRI, as the examination can both confirm and rule out the injury better than just waiting to do another X-ray. In some cases, CT is used instead, especially if the question mainly concerns exact bone anatomy or assessment of healing, but MRI is strong when you also want to see soft tissues and early bone changes.

A wrist injury can therefore be more than a "sprain", even when the X-ray result initially looks reassuring. If you suspect that something is wrong with your wrist despite having had normal X-rays, a next step may be to have an MRI scan.