The Insall-Salvati Ratio is the ratio of the length of the patellar tendon to the length of the patella, when measured on an X-ray or MRI with the knees bent to 30 degrees.

 

Normal Insall-Salvati ratio

The normal ratio is 0.75 - 1.50. Higher ratios suggest that the patella is abnormally high.

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Dr Sheila Strover (Editor)
BSc (Hons), MB BCh, MBA

See biography...