Many patients will require imaging of their knee to help in diagnosis and surgical planning. Every patient attending outpatient clinic will have radiographs (Xrays) taken of their knee when standing. This allows for diagnosis of arthritis and some other conditions and helps to exclude rare causes of knee pain such as cancer. If the history of the problem together with the clinical examination give a clear picture of the diagnosis and clinical condition you may be offered treatment (surgery, physiotherapy, orthotics) without a scan.
However if there is a need for more information then a MRI scan will be requested. This test is performed on a separate day at the hospital and involves lying in a machine for approximately 45 minutes. The scan can be a bit claustrophobic but it is important to lie still so that a clear image can be obtained.
The scans are reported on by an expert radiologist (xray doctor) and this may lead to a delay in being seen for follow up after a scan while the radiology report is done and typed up. In the private sector this will usually be no more than a fortnight but in the NHS this can be 6-8 weeks.