it is unlikely you will get any coverage for an existing condition. Whilst MPPI will usually offer cover on unrelated conditions (unless the condition is significant enough to affect other areas), you would expect the existing condition not to be covered.
A legacy condition (i.e. something that happened in the past but is no longer an issue) may get coverage depending on timescale. However, you would probably be better off with a PHI policy rather than a PPI policy.
I am an Independent Financial Adviser (IFA). Comments are for discussion purposes only. They are not financial advice. If you feel an area discussed may be relevant to you, then please seek advice from an Independent Financial Adviser local to you.