Do I need an MRI before knee arthroscopy, or can the scope find the problem?

From diagnostic scope to targeted treatment

Before MRI was widely available, surgeons sometimes scoped a painful knee to find out what was wrong. Modern MRI shows the menisci, ligaments, cartilage and bone in detail without an operation, so arthroscopy has become a treatment for a problem already identified rather than a way of searching for one.

Operating without a clear diagnosis carries the risks of surgery with an uncertain chance of benefit. If the source of pain is outside the joint, such as a tendon, the kneecap tracking, the hip or the back, a scope will not help.

How the decision is made

• History: how the problem started, whether there was a twist or a pop, and whether the knee locks, catches, gives way or swells
• Examination: tenderness along the joint line, specific meniscus and ligament tests, kneecap movement, and checking the hip and alignment
• X-rays: often taken standing, to show arthritis, alignment and bony fragments, which MRI can understate
• MRI: to confirm tears, cartilage injury or loose bodies and to plan the procedure

The most important step is matching the scan to the symptoms. Many MRIs show findings, such as a degenerate meniscus, that are common in people without pain. Dr. Gelber operates when the examination and the imaging tell the same story.

When the MRI looks normal but the knee still hurts

A normal MRI is reassuring, and most knees with a normal scan improve with targeted physiotherapy and time. Occasionally a small problem, such as an unstable flap of meniscus or a cartilage lesion, is hard to see. In that case Dr. Gelber may repeat the examination after a period of rehabilitation, review the images again, or request a different scan before arthroscopy is considered.

If you already have an MRI from another centre in Qatar, bring the images on a disc or a download link as well as the written report.