By Dr Chris Milne, Sports Physician\t<\/p>\n
What is it? <\/strong> What causes it?<\/strong> Symptoms \u2013 what you notice<\/strong><\/p>\n Signs \u2013 what the doctor finds<\/strong><\/p>\n Investigations<\/strong> Treatment<\/strong><\/p>\n
\nIt occurs when the patella moves out of its usual groove in front of the knee.<\/p>\n
\nIt is caused by a variety of factors including muscle imbalance, a small or high riding patella, a shallow groove for it to track in, plus excess joint mobility and flat feet.<\/p>\n\n
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\nX-rays can show an associated fracture of the inner border of the patella. A \u2018skyline\u2019 view is most useful for this. X-rays can also show a small or high riding patella, plus a shallow groove for the patella to track in. MRI scans are rarely needed but may show bone bruising, which is an additional clue in tricky cases; patellar instability is often quite subtle and may be overlooked by less experienced doctors. CT scans are usually only ordered if surgical stabilisation is being considered.<\/p>\n\n
\nPerform quadriceps exercises to strengthen the muscles in front of the thigh.<\/li>\n
\nIn severe cases of recurrent patellar instability, surgery to stabilise the patella may be required.<\/li>\n