7 improvements of minimally invasive total knee surface arthroplasty: 1. shorten the surgical incision while protecting the soft tissues; 2. use the flexion and extension of the knee to help intraoperative exposure; 3. use the movement of the skin incision to help surgical exposure; 4. choose a surgical approach that protects the quadriceps; 5. avoid turning the patella; 6. avoid joint dislocation during osteotomy; 7. minimally invasive surgical instruments.