''I am writing this to show my appreciation for all that you have done for me, when I think back to the excruciating pain I was in 3 months ago''.
''The pain has greatly eased and my movement has improved''.
''My general wellbeing has also improved since I started treatment''.
''I express my profound gratitude to you for the treatment I have received and the interest you took in researching my condition''.
Best wishes and kind regards