My knee still aches weeks after a fall, but the X-ray was normal. Why?

What the X-ray can and cannot show

X-rays are good for detecting fractures, alignment problems and arthritis. They do not show soft tissues such as the meniscus, ligaments or cartilage, and they cannot see bleeding and swelling inside the bone. A bone bruise from landing hard on the knee, for example on a tiled floor, pavement or a padel court, can therefore be painful while the X-ray looks normal.

Occasionally a small fracture is not visible on the first X-ray and shows up later or on MRI or CT.

Likely causes of a lingering ache

• Bone bruise: deep ache, worse on standing, kneeling or stairs, sometimes at night
• Cartilage injury: aching with swelling after activity, sometimes catching
• Meniscus tear: pain on one side of the joint, worse with twisting or squatting
• Kneecap or tendon bruising: pain at the front, worse when kneeling
• Bursitis: a soft swelling over the kneecap after a direct blow

What to do in the meantime

Reduce activities that clearly provoke the pain, such as running, jumping and kneeling on hard floors. Keep the knee moving with gentle bending and straightening, and maintain strength with straight-leg raises and a stationary bike if comfortable. A cushion or chair can help if kneeling at prayer is painful; questions about praying seated can be discussed with a scholar.

When an MRI and review make sense

Book an assessment if the ache has not clearly improved after three to four weeks, if the knee swells, locks or gives way, if you cannot fully straighten it, or if pain wakes you at night. At Aman Hospital in Doha, Dr. Gelber examines the knee, decides whether an MRI is needed, and explains the findings and a plan to get you moving normally again.