Chennai,May 29: A 'high flex' total knee replacement was done recently on a 69-year old Osteo-arthritis afflicted British woman through a 'minimally invasive operation', at a city hospital here, the doctor, who performed the surgery, said today. "The woman, Mary Carmichael was able to walk with a frame, bend and touch the floor with her hands and get more than 90 degrees in bending in less than a week and left for London yesterday," Dr A K Venkatachalam, a well-known Orthopaedic surgeon said. She arrived here for the operation on May 16. Though she had the National Health Service cover, she did not inquire with the insurance agency, as she decided to have the surgery done in India. She located the doctor through internet and after a quick exchange of e-mails she came down here from Edinburgh. Venkatachalam said the minimally invasive operation "involves making a cut in the skin about 4-5 inches long as opposed to 8 to 10 inches in a traditional knee joint replacement." "Minimally invasive knee replacement spares tissue dissection, reducing post-operative pain, avoids blood transfusion and accelerates recovery. High flexion prosthesis permits the patient to regain normal bending of 155 degrees," he said. (Our Correspondent)